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1.
Cancer ; 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38881266

RESUMO

BACKGROUND: Androgen deprivation therapy (ADT) in prostate cancer (PCa) has been associated with development of insulin resistance. However, the predominant site of insulin resistance remains unclear. METHODS: The ADT & Metabolism Study was a single-center, 24-week, prospective observational study that enrolled ADT-naive men without diabetes who were starting ADT for at least 24 weeks (ADT group, n = 42). The control group comprised men without diabetes with prior history of PCa who were in remission after prostatectomy (non-ADT group, n = 23). Prevalent diabetes mellitus was excluded in both groups using all three laboratory criteria defined in the American Diabetes Association guidelines. All participants were eugonadal at enrollment. The primary outcome was to elucidate the predominant site of insulin resistance (liver or skeletal muscle). Secondary outcomes included assessments of body composition, and hepatic and intramyocellular fat. Outcomes were assessed at baseline, 12, and 24 weeks. RESULTS: At 24 weeks, there was no change in hepatic (1.2; 95% confidence interval [CI], -2.10 to 4.43; p = .47) or skeletal muscle (-3.2; 95% CI, -7.07 to 0.66; p = .10) insulin resistance in the ADT group. No increase in hepatic or intramyocellular fat deposition or worsening of glucose was seen. These changes were mirrored by those observed in the non-ADT group. Men undergoing ADT gained 3.7 kg of fat mass. CONCLUSIONS: In men with PCa and no diabetes, 24 weeks of ADT did not change insulin resistance despite adverse body composition changes. These findings should be reassuring for treating physicians and for patients who are being considered for short-term ADT.

2.
Eur J Neurosci ; 59(1): 82-100, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38056827

RESUMO

Cardiorespiratory fitness has a potent effect on neurocognitive health, especially regarding the hippocampal memory system. However, less is known about the impact of cardiorespiratory fitness on medial temporal lobe extrahippocampal neocortical regions. Specifically, it is unclear how cardiorespiratory fitness modulates these brain regions in young adulthood and if these regions are differentially related to cardiorespiratory fitness in young versus older adults. The primary goal of this study was to investigate if cardiorespiratory fitness predicted medial temporal lobe cortical thickness which, with the hippocampus, are critical for spatial learning and memory. Additionally, given the established role of these cortices in spatial navigation, we sought to determine if cardiorespiratory fitness and medial temporal lobe cortical thickness would predict greater subjective sense of direction in both young and older adults. Cross-sectional data from 56 young adults (20-35 years) and 44 older adults (55-85 years) were included. FreeSurfer 6.0 was used to automatically segment participants' 3T T1-weighted images. Using hierarchical multiple regression analyses, we confirmed significant associations between greater cardiorespiratory fitness and greater left entorhinal, left parahippocampal, and left perirhinal cortical thickness in young, but not older, adults. Left parahippocampal cortical thickness interacted with age group to differentially predict subjective sense of direction in young and older adults. Young adults displayed a positive, and older adults a negative, correlation between left parahippocampal cortical thickness and sense of direction. Our findings extend previous work on the association between cardiorespiratory fitness and hippocampal subfield structure in young adults to left medial temporal lobe neocortical regions.


Assuntos
Aptidão Cardiorrespiratória , Adulto Jovem , Humanos , Adulto , Idoso , Estudos Transversais , Lobo Temporal/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Cognição , Imageamento por Ressonância Magnética
3.
N Engl J Med ; 383(2): 129-140, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32640131

RESUMO

BACKGROUND: Injuries from falls are major contributors to complications and death in older adults. Despite evidence from efficacy trials that many falls can be prevented, rates of falls resulting in injury have not declined. METHODS: We conducted a pragmatic, cluster-randomized trial to evaluate the effectiveness of a multifactorial intervention that included risk assessment and individualized plans, administered by specially trained nurses, to prevent fall injuries. A total of 86 primary care practices across 10 health care systems were randomly assigned to the intervention or to enhanced usual care (the control) (43 practices each). The participants were community-dwelling adults, 70 years of age or older, who were at increased risk for fall injuries. The primary outcome, assessed in a time-to-event analysis, was the first serious fall injury, adjudicated with the use of participant report, electronic health records, and claims data. We hypothesized that the event rate would be lower by 20% in the intervention group than in the control group. RESULTS: The demographic and baseline characteristics of the participants were similar in the intervention group (2802 participants) and the control group (2649 participants); the mean age was 80 years, and 62.0% of the participants were women. The rate of a first adjudicated serious fall injury did not differ significantly between the groups, as assessed in a time-to-first-event analysis (events per 100 person-years of follow-up, 4.9 in the intervention group and 5.3 in the control group; hazard ratio, 0.92; 95% confidence interval [CI], 0.80 to 1.06; P = 0.25). The rate of a first participant-reported fall injury was 25.6 events per 100 person-years of follow-up in the intervention group and 28.6 events per 100 person-years of follow-up in the control group (hazard ratio, 0.90; 95% CI, 0.83 to 0.99; P = 0.004). The rates of hospitalization or death were similar in the two groups. CONCLUSIONS: A multifactorial intervention, administered by nurses, did not result in a significantly lower rate of a first adjudicated serious fall injury than enhanced usual care. (Funded by the Patient-Centered Outcomes Research Institute and others; STRIDE ClinicalTrials.gov number, NCT02475850.).


Assuntos
Acidentes por Quedas/prevenção & controle , Lesões Acidentais/prevenção & controle , Administração dos Cuidados ao Paciente/métodos , Acidentes por Quedas/mortalidade , Acidentes por Quedas/estatística & dados numéricos , Lesões Acidentais/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Vida Independente , Masculino , Medicina de Precisão , Medição de Risco , Fatores de Risco
4.
Hum Brain Mapp ; 42(4): 871-892, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33325614

RESUMO

Aging and exercise have opposing effects on mnemonic discrimination task performance, which putatively taxes pattern separation mechanisms reliant on the dentate gyrus (DG) subfield of the hippocampus. In young adults, increasing cardiorespiratory fitness (CRF) has been shown to improve mnemonic discrimination task performance and increase left anterior DG/CA3 volume. It is unknown how these variables interact in cognitive aging, yet this knowledge is critical, given the established effects of aging on hippocampal plasticity. To investigate these relationships, 65 older adults (aged 55-85 years) completed a submaximal treadmill test to estimate CRF, a mnemonic discrimination task, and a high-resolution MRI scan to determine hippocampal subfield volumes. Our older adult sample demonstrated the lowest task accuracy in the condition with the greatest stimuli similarity and left DG/CA3 body volume significantly predicted accuracy in this condition. Our results did not provide support for relationships between CRF and task accuracy or CRF and DG/CA3 volume as evidenced in studies of young adults. Instead, CRF predicted bilateral subiculum volume in older adult women, not men. Altogether, these findings provide further support for a role of the DG in behavioral pattern separation in humans and suggest that CRF may have differential effects on hippocampal subfield integrity in older adult men and women. ClinicalTrials.gov identifiers: (a) Neuroimaging Study of Exercise and Memory Function, NCT02057354; (b) The Entorhinal Cortex and Aerobic Exercise in Aging, NCT02775760; (c) Physical Activity and Cognition Study, NCT02773121.


Assuntos
Envelhecimento/fisiologia , Aptidão Cardiorrespiratória/fisiologia , Giro Denteado/anatomia & histologia , Giro Denteado/fisiologia , Aprendizagem por Discriminação/fisiologia , Análise e Desempenho de Tarefas , Idoso , Idoso de 80 Anos ou mais , Região CA3 Hipocampal/anatomia & histologia , Região CA3 Hipocampal/diagnóstico por imagem , Região CA3 Hipocampal/fisiologia , Giro Denteado/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fatores Sexuais
5.
Hippocampus ; 30(5): 488-504, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31588607

RESUMO

Converging evidence suggests a relationship between aerobic exercise and hippocampal neuroplasticity that interactively impacts hippocampally dependent memory. The majority of human studies have focused on the potential for exercise to reduce brain atrophy and attenuate cognitive decline in older adults, whereas animal studies often center on exercise-induced neurogenesis and hippocampal plasticity in the dentate gyrus (DG) of young adult animals. In the present study, initially sedentary young adults (18-35 years) participated in a moderate-intensity randomized controlled exercise intervention trial (ClinicalTrials.gov; NCT02057354) for a duration of 12 weeks. The aims of the study were to investigate the relationship between change in cardiorespiratory fitness (CRF) as determined by estimated V˙O2MAX , hippocampally dependent mnemonic discrimination, and change in hippocampal subfield volume. Results show that improving CRF after exercise training is associated with an increased volume in the left DG/CA3 subregion in young adults. Consistent with previous studies that found exercise-induced increases in anterior hippocampus in older adults, this result was specific to the hippocampal head, or most anterior portion, of the subregion. Our results also demonstrate a positive relationship between change in CRF and change in corrected accuracy for trials requiring the highest level of discrimination on a putative behavioral pattern separation task. This relationship was observed in individuals who were initially lower-fit, suggesting that individuals who show greater improvement in their CRF may receive greater cognitive benefit. This work extends animal models by providing evidence for exercise-induced neuroplasticity specific to the neurogenic zone of the human hippocampus.


Assuntos
Região CA3 Hipocampal/fisiologia , Giro Denteado/fisiologia , Memória/fisiologia , Aptidão Física/fisiologia , Desempenho Psicomotor/fisiologia , Adolescente , Adulto , Exercício Físico/fisiologia , Exercício Físico/psicologia , Feminino , Humanos , Masculino , Força Muscular/fisiologia , Tamanho do Órgão/fisiologia , Aptidão Física/psicologia , Adulto Jovem
6.
Hippocampus ; 30(5): 526-541, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31647603

RESUMO

Rodent and human studies examining the relationship between aerobic exercise, brain structure, and brain function indicate that the hippocampus (HC), a brain region critical for episodic memory, demonstrates striking plasticity in response to exercise. Beyond the hippocampal memory system, human studies also indicate that aerobic exercise and cardiorespiratory fitness (CRF) are associated with individual differences in large-scale brain networks responsible for broad cognitive domains. Examining network activity in large-scale resting-state brain networks may provide a link connecting the observed relationships between aerobic exercise, hippocampal plasticity, and cognitive enhancement within broad cognitive domains. Previously, CRF has been associated with increased functional connectivity of the default mode network (DMN), specifically in older adults. However, how CRF relates to the magnitude and directionality of connectivity, or effective connectivity, between the HC and other DMN nodes remains unknown. We used resting-state fMRI and conditional Granger causality analysis (CGCA) to test the hypothesis that CRF positively predicts effective connectivity between the HC and other DMN nodes in healthy young adults. Twenty-six participants (ages 18-35 years) underwent a treadmill test to determine CRF by estimating its primary determinant, maximal oxygen uptake (V. O2max ), and a 10-min resting-state fMRI scan to examine DMN effective connectivity. We identified the DMN using group independent component analysis and examined effective connectivity between nodes using CGCA. Linear regression analyses demonstrated that CRF significantly predicts causal influence from the HC to the ventromedial prefrontal cortex, posterior cingulate cortex, and lateral temporal cortex and to the HC from the dorsomedial prefrontal cortex. The observed relationship between CRF and hippocampal effective connectivity provides a link between the rodent literature, which demonstrates a relationship between aerobic exercise and hippocampal plasticity, and the human literature, which demonstrates a relationship between aerobic exercise and CRF and the enhancement of broad cognitive domains including, but not limited to, memory.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Rede de Modo Padrão/fisiologia , Hipocampo/fisiologia , Rede Nervosa/fisiologia , Adulto , Rede de Modo Padrão/diagnóstico por imagem , Feminino , Previsões , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/diagnóstico por imagem , Adulto Jovem
7.
N Engl J Med ; 374(7): 611-24, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26886521

RESUMO

BACKGROUND: Serum testosterone concentrations decrease as men age, but benefits of raising testosterone levels in older men have not been established. METHODS: We assigned 790 men 65 years of age or older with a serum testosterone concentration of less than 275 ng per deciliter and symptoms suggesting hypoandrogenism to receive either testosterone gel or placebo gel for 1 year. Each man participated in one or more of three trials--the Sexual Function Trial, the Physical Function Trial, and the Vitality Trial. The primary outcome of each of the individual trials was also evaluated in all participants. RESULTS: Testosterone treatment increased serum testosterone levels to the mid-normal range for men 19 to 40 years of age. The increase in testosterone levels was associated with significantly increased sexual activity, as assessed by the Psychosexual Daily Questionnaire (P<0.001), as well as significantly increased sexual desire and erectile function. The percentage of men who had an increase of at least 50 m in the 6-minute walking distance did not differ significantly between the two study groups in the Physical Function Trial but did differ significantly when men in all three trials were included (20.5% of men who received testosterone vs. 12.6% of men who received placebo, P=0.003). Testosterone had no significant benefit with respect to vitality, as assessed by the Functional Assessment of Chronic Illness Therapy-Fatigue scale, but men who received testosterone reported slightly better mood and lower severity of depressive symptoms than those who received placebo. The rates of adverse events were similar in the two groups. CONCLUSIONS: In symptomatic men 65 years of age or older, raising testosterone concentrations for 1 year from moderately low to the mid-normal range for men 19 to 40 years of age had a moderate benefit with respect to sexual function and some benefit with respect to mood and depressive symptoms but no benefit with respect to vitality or walking distance. The number of participants was too few to draw conclusions about the risks of testosterone treatment. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT00799617.).


Assuntos
Fadiga/tratamento farmacológico , Terapia de Reposição Hormonal , Comportamento Sexual/efeitos dos fármacos , Testosterona/uso terapêutico , Caminhada/fisiologia , Idoso , Depressão/tratamento farmacológico , Método Duplo-Cego , Humanos , Libido/efeitos dos fármacos , Masculino , Antígeno Prostático Específico/sangue , Valores de Referência , Comportamento Sexual/fisiologia , Testosterona/efeitos adversos , Testosterona/sangue
8.
J Sports Sci Med ; 16(3): 396-406, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28912658

RESUMO

Incremental exercise consists of three domains of exercise intensity demarcated by two thresholds. The first of these thresholds, derived from gas exchange measurements, is defined as the metabolic threshold (V̇O2θ) above which lactate accumulates. Correctly and reliably identified, V̇O2θ is a non-invasive, sub-maximal marker of aerobic function with practical value. This investigation compared variability in selection of V̇O2θ among interpreters with different levels of experience as well as from auto-detection algorithms employed by a commercially available metabolic cart (MC). Ten healthy young men performed three replicates of incremental cycle exercise during which gas exchange measurements were collected breath-by-breath. Two experienced interpreters (E) and four novice interpreters (N) determined V̇O2θ from plots of specific response variables. Interpreters noted methods used and confidence in their selections. V̇O2θ was automatically determined by the MC. Interclass correlations indicated that E agreed with each other (mean difference, 21 mL·min-1) and with the MC (23 mL·min-1), but not with N (-664 to 364 mL·min-1); N did not agree among themselves. Despite good overall agreement between E and MC, differences >500 mL·min-1 were seen in 50% of individual cases. N expressed unduly higher confidence and used different V̇O2θ selection strategies compared with E. Experience and use of a systematic approach is essential for correctly identifying V̇O2θ. Current guidelines for exercise testing and interpretation do not include recommendations for such an approach. Data from this study suggests that this may be a serious shortcoming. Until an alternative schema for V̇O2θ detection is developed prospectively, strategies based on the present study will give practitioners a systematic and consistent approach to threshold detection.

9.
JAMA ; 314(6): 570-81, 2015 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-26262795

RESUMO

IMPORTANCE: Testosterone use in older men is increasing, but its long-term effects on progression of atherosclerosis are unknown. OBJECTIVE: To determine the effect of testosterone administration on subclinical atherosclerosis progression in older men with low or low-normal testosterone levels. DESIGN, SETTING, AND PARTICIPANTS: Testosterone's Effects on Atherosclerosis Progression in Aging Men (TEAAM) was a placebo-controlled, double-blind, parallel-group randomized trial involving 308 men 60 years or older with low or low-normal testosterone levels (100-400 ng/dL; free testosterone <50 pg/mL), recruited at 3 US centers. Recruitment took place between September 2004 and February 2009; the last participant completed the study in May 2012. INTERVENTIONS: One hundred fifty-six participants were randomized to receive 7.5 g of 1% testosterone and 152 were randomized to receive placebo gel packets daily for 3 years. The dose was adjusted to achieve testosterone levels between 500 and 900 ng/dL. MAIN OUTCOMES AND MEASURES: Coprimary outcomes included common carotid artery intima-media thickness and coronary artery calcium; secondary outcomes included sexual function and health-related quality of life. RESULTS: Baseline characteristics were similar between groups: patients were a mean age of 67.6 years; 42% had hypertension; 15%, diabetes; 15%, cardiovascular disease; and 27%, obesity. The rate of change in intima-media thickness was 0.010 mm/year in the placebo group and 0.012 mm/year in the testosterone group (mean difference adjusted for age and trial site, 0.0002 mm/year; 95% CI, -0.003 to 0.003, P = .89). The rate of change in the coronary artery calcium score was 41.4 Agatston units/year in the placebo group and 31.4 Agatston units/year in the testosterone group (adjusted mean difference, -10.8 Agatston units/year; 95% CI, -45.7 to 24.2; P = .54). Changes in intima-media thickness or calcium scores were not associated with change in testosterone levels among individuals assigned to receive testosterone. Sexual desire, erectile function, overall sexual function scores, partner intimacy, and health-related quality of life did not differ significantly between groups. Hematocrit and prostate-specific antigen levels increased more in testosterone group. CONCLUSIONS AND RELEVANCE: Among older men with low or low-normal testosterone levels, testosterone administration for 3 years vs placebo did not result in a significant difference in the rates of change in either common carotid artery intima-media thickness or coronary artery calcium nor did it improve overall sexual function or health-related quality of life. Because this trial was only powered to evaluate atherosclerosis progression, these findings should not be interpreted as establishing cardiovascular safety of testosterone use in older men. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00287586.


Assuntos
Aterosclerose/induzido quimicamente , Espessura Intima-Media Carotídea , Testosterona/efeitos adversos , Idoso , Cálcio/análise , Vasos Coronários/química , Progressão da Doença , Método Duplo-Cego , Nível de Saúde , Humanos , Hipertensão , Masculino , Pessoa de Meia-Idade , Obesidade , Qualidade de Vida , Disfunções Sexuais Fisiológicas/complicações , Disfunções Sexuais Fisiológicas/etiologia , Testosterona/sangue , Testosterona/deficiência , Testosterona/uso terapêutico , Resultado do Tratamento
10.
Clin Trials ; 11(3): 362-375, 2014 06.
Artigo em Inglês | MEDLINE | ID: mdl-24686158

RESUMO

Background The prevalence of low testosterone levels in men increases with age, as does the prevalence of decreased mobility, sexual function, self-perceived vitality, cognitive abilities, bone mineral density, and glucose tolerance, and of increased anemia and coronary artery disease. Similar changes occur in men who have low serum testosterone concentrations due to known pituitary or testicular disease, and testosterone treatment improves the abnormalities. Prior studies of the effect of testosterone treatment in elderly men, however, have produced equivocal results. Purpose To describe a coordinated set of clinical trials designed to avoid the pitfalls of prior studies and to determine definitively whether testosterone treatment of elderly men with low testosterone is efficacious in improving symptoms and objective measures of age-associated conditions. Methods We present the scientific and clinical rationale for the decisions made in the design of this set of trials. Results We designed The Testosterone Trials as a coordinated set of seven trials to determine if testosterone treatment of elderly men with low serum testosterone concentrations and symptoms and objective evidence of impaired mobility and/or diminished libido and/or reduced vitality would be efficacious in improving mobility (Physical Function Trial), sexual function (Sexual Function Trial), fatigue (Vitality Trial), cognitive function (Cognitive Function Trial), hemoglobin (Anemia Trial), bone density (Bone Trial), and coronary artery plaque volume (Cardiovascular Trial). The scientific advantages of this coordination were common eligibility criteria, common approaches to treatment and monitoring, and the ability to pool safety data. The logistical advantages were a single steering committee, data coordinating center and data and safety monitoring board, the same clinical trial sites, and the possibility of men participating in multiple trials. The major consideration in participant selection was setting the eligibility criterion for serum testosterone low enough to ensure that the men were unequivocally testosterone deficient, but not so low as to preclude sufficient enrollment or eventual generalizability of the results. The major considerations in choosing primary outcomes for each trial were identifying those of the highest clinical importance and identifying the minimum clinically important differences between treatment arms for sample size estimation. Potential limitations Setting the serum testosterone concentration sufficiently low to ensure that most men would be unequivocally testosterone deficient, as well as many other entry criteria, resulted in screening approximately 30 men in person to randomize one participant. Conclusion Designing The Testosterone Trials as a coordinated set of seven trials afforded many important scientific and logistical advantages but required an intensive recruitment and screening effort.


Assuntos
Ensaios Clínicos como Assunto , Terapia de Reposição Hormonal/métodos , Projetos de Pesquisa , Testosterona/uso terapêutico , Idoso , Humanos , Masculino , Testosterona/sangue
11.
BMC Pulm Med ; 14: 125, 2014 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-25088030

RESUMO

BACKGROUND: The effectiveness of clinic-based pulmonary rehabilitation in advanced COPD is well established, but few data exist for less severe patients treated in alternative settings. The purpose of this study was to investigate whether a novel, community-based exercise program (CBE) was feasible and effective for patients with moderate COPD. METHODS: Nineteen patients with moderate COPD (mean FEV1 62%) and self-reported exercise impairment were randomized to 12-weeks of progressive endurance and strength training at a local health club under the guidance of a certified personal trainer, or to continuation of unsupervised habitual physical activity. Outcomes assessed at baseline and 12 weeks included session compliance, intensity adherence, treadmill endurance time, muscle strength, dyspnea, and health status. RESULTS: Compliance was 94% and adherence was 83%. Comparisons between CBE and control groups yielded the following mean (SEM) differences in favor of CBE: endurance time 134 (74) seconds versus -59 (49) seconds (P=0.041) and TDI 5.1 (0.8) versus -0.2 (0.5) (P<0.001). The CBE group increased muscle strength (weight lifted) by 11.8 kilograms per subject per week of training (P<0.001). SGRQ was not significantly changed. CONCLUSIONS: We demonstrated the feasibility and effectiveness of a novel community-based exercise program involving health clubs and personal trainers for patients with moderate COPD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01985529.


Assuntos
Serviços de Saúde Comunitária , Condicionamento Físico Humano/métodos , Doença Pulmonar Obstrutiva Crônica/reabilitação , Treinamento Resistido/métodos , Idoso , Idoso de 80 Anos ou mais , Dispneia/fisiopatologia , Feminino , Academias de Ginástica , Volume Expiratório Forçado , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Cooperação do Paciente , Resistência Física/fisiologia , Esforço Físico/fisiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Qualidade de Vida , Índice de Gravidade de Doença
12.
J Strength Cond Res ; 28(7): 1995-2006, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24276303

RESUMO

Conventional wisdom suggests that exercise training with a personal trainer (PTr) is more beneficial for improving health-related fitness than training alone. However, there are no published data that confirm whether fitness club members who exercise with a PTr in the fitness club setting obtain superior results compared with self-directed training. We hypothesized that club members randomized to receive an evidence-based training program would accrue greater improvements in lean body mass (LBM) and other fitness measures than members randomized to self-training. Men, aged 30-44 years, who were members of a single Southern California fitness club were randomized to exercise with a PTr administering a nonlinear periodized training program (TRAINED, N = 17) or to self-directed training (SELF, N = 17); both groups trained 3 days per week for 12 weeks. Lean body mass was determined by dual-energy x-ray absorptiometry. Secondary outcomes included muscle strength 1 repetition maximum (1RM), leg power (vertical jump), and aerobic capacity (V[Combining Dot Above]O2max). TRAINED individuals increased LBM by 1.3 (0.4) kg, mean (SEM) vs. no change in SELF, p = 0.029. Similarly, significantly greater improvements were seen for TRAINED vs. SELF in chest press strength (42 vs. 19%; p = 0.003), peak leg power (6 vs. 0.6%; p < 0.0001), and V[Combining Dot Above]O2max (7 vs. -0.3%; p = 0.01). Leg press strength improved 38 and 25% in TRAINED and SELF, respectively (p = 0.14). We have demonstrated for the first time in a fitness club setting that members whose training is directed by well-qualified PTrs administering evidence-based training regimens achieve significantly greater improvements in LBM and other dimensions of fitness than members who direct their own training.


Assuntos
Composição Corporal/fisiologia , Condicionamento Físico Humano/métodos , Condicionamento Físico Humano/fisiologia , Aptidão Física/fisiologia , Absorciometria de Fóton , Adulto , Índice de Massa Corporal , Peso Corporal , Academias de Ginástica , Humanos , Masculino , Força Muscular , Músculo Esquelético/fisiologia , Consumo de Oxigênio
13.
J Strength Cond Res ; 28(3): 661-71, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24566608

RESUMO

Sudden cardiac deaths experienced by firefighters in the line of duty account for the largest proportion of deaths annually. Several fire service standards for fitness and wellness have been recommended but currently only 30% of U.S. fire departments are implementing programs for this purpose. The Department of Homeland Security Science and Technology Directorate has initiated the Physiological Health Assessment System for Emergency Responders (PHASER) program aiming to reduce these line-of-duty deaths through an integration of medical science and sensor technologies. Confirming previous reports, PHASER comprehensive risk assessment has identified lack of physical fitness with propensity for overexertion as a major modifiable risk factor. We sought to determine if current levels of fitness and cardiovascular disease (CVD) risk factors in a contemporary cohort of firefighters were better than those reported over the past 30 years. Fifty-one firefighters from a Southern California department were characterized for physical fitness and CVD risk factors using standard measures. Overall, physical fitness and risk factors were not different from previous reports of firefighter fitness and most subjects did not achieve recommended fitness standards. Considering the lack of widespread implementation of wellness/fitness programs in the U.S. fire service together with our findings that low physical fitness and the presence of CVD risk factors persist, we issue a call to action among health and fitness professionals to assist the fire service in implementing programs for firefighters that improve fitness and reduce CVD risk factors. Fitness professionals should be empowered to work with fire departments lending their expertise to guide programs that achieve these objectives, which may then lead to reduced incidence of sudden cardiac death or stroke.


Assuntos
Morte Súbita Cardíaca/prevenção & controle , Bombeiros , Promoção da Saúde , Saúde Ocupacional/normas , Condicionamento Físico Humano/normas , Aptidão Física/fisiologia , Adulto , Glicemia/análise , Pressão Sanguínea , Composição Corporal , Colesterol/sangue , Teste de Esforço , Feminino , Volume Expiratório Forçado , Força da Mão , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Condicionamento Físico Humano/fisiologia , Esforço Físico/fisiologia , Medição de Risco , Fatores de Risco , Dobras Cutâneas , Capacidade Vital
14.
Bone ; 181: 117039, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38325649

RESUMO

CONTEXT: People living with spinal cord injury (SCI) are at high risk for bone fractures. Neural, hormonal and metabolic contributors to bone microarchitectural alterations are incompletely understood. OBJECTIVE: To determine the relationship of physical, metabolic and endocrine characteristics with bone microarchitecture, characterized using high-resolution peripheral quantitative computed tomography (HRpQCT) in SCI. DESIGN: Cross-sectional analyses of bone properties in people with SCI. PARTICIPANTS: Twenty adults with SCI and paraplegia (12) or motor incomplete quadriplegia (8). OUTCOME MEASURES: Distal tibia and radius HRpQCT parameters, including density, microstructure and strength by microfinite element anaysis (µFEA); sex hormones; metabolic and inflammatory markers. RESULTS: The mean age of the participants with SCI was 41.5 ± 10.3 years, BMI 25.7 ± 6.2 kg/m2, time since injury 10.4 ± 9.0 years. Participants with SCI had significantly lower median total (Z score - 3.3), trabecular (-2.93), and cortical vBMD (-1.87), and Failure Load by µFEA (-2.48) at the tibia than controls. However, radius vBMD, aBMD and microarchitecture were similar in participants with SCI and un-injured controls. Unexpectedly, C-Reactive Protein (CRP) was positively associated with tibial trabecular vBMD (ß = 0.77, p = 0.02), thickness (ß = 0.52, p = 0.04) and number (ß = 0.92, p = 0.02). At the radius, estradiol level was positively associated with total vBMD (ß = 0.59, p = 0.01), trabecular thickness (ß = 0.43, p = 0.04), cortical thickness (ß = 0.63, p = 0.01) and cortical porosity (ß = 0.74 p = 0.04). CONCLUSIONS: Radius vBMD and microarchitecture is preserved but tibial total, cortical and trabecular vBMD, and estimated bone strength are markedly lower and bone microarchitectural parameters substantially degraded in people with SCI. The alterations in bone microarchitecture in people with SCI are likely multifactorial, however marked degradation of bone microarchitecture in tibia but not radius suggests that unloading is an important contributor of site-specific alterations of bone microarchitecture after SCI. Fracture prevention in SCI should focus on strategies to safely increase bone loading. CLINICALTRIALS: gov registration #: (NCT03576001).


Assuntos
Fraturas Ósseas , Traumatismos da Medula Espinal , Adulto , Humanos , Pessoa de Meia-Idade , Densidade Óssea , Absorciometria de Fóton/métodos , Estudos Transversais , Rádio (Anatomia) , Tíbia/diagnóstico por imagem , Hormônios Esteroides Gonadais
15.
N Engl J Med ; 363(2): 109-22, 2010 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-20592293

RESUMO

BACKGROUND: Testosterone supplementation has been shown to increase muscle mass and strength in healthy older men. The safety and efficacy of testosterone treatment in older men who have limitations in mobility have not been studied. METHODS: Community-dwelling men, 65 years of age or older, with limitations in mobility and a total serum testosterone level of 100 to 350 ng per deciliter (3.5 to 12.1 nmol per liter) or a free serum testosterone level of less than 50 pg per milliliter (173 pmol per liter) were randomly assigned to receive placebo gel or testosterone gel, to be applied daily for 6 months. Adverse events were categorized with the use of the Medical Dictionary for Regulatory Activities classification. The data and safety monitoring board recommended that the trial be discontinued early because there was a significantly higher rate of adverse cardiovascular events in the testosterone group than in the placebo group. RESULTS: A total of 209 men (mean age, 74 years) were enrolled at the time the trial was terminated. At baseline, there was a high prevalence of hypertension, diabetes, hyperlipidemia, and obesity among the participants. During the course of the study, the testosterone group had higher rates of cardiac, respiratory, and dermatologic events than did the placebo group. A total of 23 subjects in the testosterone group, as compared with 5 in the placebo group, had cardiovascular-related adverse events. The relative risk of a cardiovascular-related adverse event remained constant throughout the 6-month treatment period. As compared with the placebo group, the testosterone group had significantly greater improvements in leg-press and chest-press strength and in stair climbing while carrying a load. CONCLUSIONS: In this population of older men with limitations in mobility and a high prevalence of chronic disease, the application of a testosterone gel was associated with an increased risk of cardiovascular adverse events. The small size of the trial and the unique population prevent broader inferences from being made about the safety of testosterone therapy. (ClinicalTrials.gov number, NCT00240981.)


Assuntos
Doenças Cardiovasculares/induzido quimicamente , Testosterona/efeitos adversos , Administração Cutânea , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Teste de Esforço , Géis , Humanos , Hiperlipidemias/complicações , Hipertensão/complicações , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Força Muscular/efeitos dos fármacos , Obesidade/complicações , Fatores de Risco , Testosterona/sangue , Testosterona/deficiência , Testosterona/uso terapêutico , Caminhada
16.
J Gerontol A Biol Sci Med Sci ; 78(Suppl 1): 25-31, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37325955

RESUMO

Testosterone, many steroidal androgens, and nonsteroidal ligands that bind to androgen receptor and exert tissue-specific transcriptional activity (selective androgen receptor modulators [SARMs]) are being developed as function-promoting therapies to treat functional limitations associated with aging and chronic diseases. This narrative review describes preclinical studies, mechanisms, and randomized trials of testosterone, other androgens, and nonsteroidal SARMs. Sex differences in muscle mass and strength and empiric use of anabolic steroids by athletes to increase muscularity and athletic performance provide supportive evidence of testosterone's anabolic effects. In randomized trials, testosterone treatment increases lean body mass, muscle strength, leg power, aerobic capacity, and self-reported mobility. These anabolic effects have been reported in healthy men, hypogonadal men, older men with mobility limitation and chronic diseases, menopausal women, and HIV-infected women with weight loss. Testosterone has not consistently improved walking speed. Testosterone treatment increases volumetric and areal bone mineral density, and estimated bone strength; improves sexual desire, erectile function, and sexual activity; modestly improves depressive symptoms; and corrects unexplained anemia in older men with low testosterone levels. Prior studies have not been of sufficient size or duration to determine testosterone's cardiovascular and prostate safety. The efficacy of testosterone in reducing physical limitations, fractures, falls, progression to diabetes, and correcting late-onset persistent depressive disorder remains to be established. Strategies to translate androgen-induced muscle mass and strength gains into functional improvements are needed. Future studies should evaluate the efficacy of combined administration of testosterone (or a SARM) plus multidimensional functional exercise to induce neuromuscular adaptations required for meaningful functional improvements.


Assuntos
Anabolizantes , Androgênios , Humanos , Feminino , Masculino , Idoso , Receptores Androgênicos/metabolismo , Anabolizantes/efeitos adversos , Testosterona/uso terapêutico , Antagonistas de Androgênios/uso terapêutico , Doença Crônica , Envelhecimento
17.
J Gerontol A Biol Sci Med Sci ; 78(Suppl 1): 61-66, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37325956

RESUMO

Physical activity and exercise training exert multiple and varied beneficial effects on a wide array of human tissues, making them therapeutic modalities that can prevent and treat age-related decline in physical function. The Molecular Transducers of Physical Activity Consortium is currently working to elucidate the molecular mechanisms underlying how physical activity improves and preserves health. Exercise training, especially when task specific, is an effective intervention for improving skeletal muscle performance and physical function in everyday activities. As seen elsewhere in this supplement, its adjunctive use with pro-myogenic pharmaceuticals may prove to be synergistic in effect. Behavioral strategies aiming to promote exercise participation and sustain adherence are being considered as additional adjuncts to further improve physical function in comprehensive, multicomponent interventions. One application of this combined strategy may be to target multimodal pro-myogenic therapies in prehabilitation to optimize physical preoperative health to enhance functional recovery postsurgery. We summarize here recent progress on biological mechanisms of exercise training, behavioral approaches to exercise participation, and the role task-specific exercise plays in synergy with pharmacologic therapies with a particular focus on older adults. Physical activity and exercise training in multiple settings should serve as the baseline standard of care around which other therapeutic interventions should be considered when the goal is restoring or increasing physical function.


Assuntos
Terapia por Exercício , Exercício Físico , Humanos , Idoso , Exercício Físico/fisiologia , Músculo Esquelético , Suplementos Nutricionais
18.
Andrology ; 11(1): 93-102, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181480

RESUMO

BACKGROUND: Most men diagnosed with prostate cancer today have organ-confined disease and low risk of disease recurrence after radical prostatectomy. Testosterone deficiency in prostate cancer survivors contributes to impaired health-related quality of life but testosterone treatment is viewed as a contraindication in this population. OBJECTIVES: We describe the design of the first randomized trial to determine the safety and efficacy of testosterone treatment in men who have undergone prostatectomy for non-aggressive prostate cancer and have symptomatic testosterone deficiency. METHODS: Surviving Prostate cancer while Improving quality of life through Rehabilitation with Testosterone Trial is a randomized, placebo-controlled, double-blind, parallel group trial in 142 men, ≥ 40 years, who have undergone radical prostatectomy for organ-confined prostate cancer, Gleason score ≤ 7 (3+4), Stage pT2, N0, M0 lesions and have symptomatic testosterone deficiency and undetectable prostate specific antigen for > 2 years after surgery. Eligible participants are randomized to weekly intramuscular injections of 100-mg testosterone cypionate or placebo for 12 weeks and followed for another 12 weeks. Primary endpoint is change from baseline in sexual activity. Secondary outcomes include change in sexual desire, erectile function, energy, lean and fat mass, physical and cognitive performance. Safety is assessed by monitoring prostate-specific antigen, lower urinary tract symptoms, hemoglobin, and adverse events. RESULTS: The trial is being conducted at two trial sites in Boston, MA and Baltimore, MD. As of July 30, 2022, 42 participants have been randomized. No prostate-specific antigen or clinical recurrence has been noted to-date. DISCUSSION: Recruitment was slowed by coronavirus disease 2019-related closures, slow subsequent ramp-up of research activities, and patient concerns about safety of testosterone treatment. Despite these challenges, participant retention has been high. CONCLUSION: The Surviving Prostate cancer while Improving quality of life through Rehabilitation with Testosterone Trial, a placebo-controlled, randomized trial, will determine whether testosterone replacement therapy is safe and efficacious in correcting symptoms of testosterone deficiency in prostate cancer survivors, and potentially inform clinical practice.


Assuntos
COVID-19 , Sobreviventes de Câncer , Neoplasias da Próstata , Masculino , Humanos , Qualidade de Vida , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Antígeno Prostático Específico , Testosterona/uso terapêutico , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
19.
J Gerontol A Biol Sci Med Sci ; 78(Suppl 1): 86-93, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37325959

RESUMO

BACKGROUND: Several candidate molecules that may have application in treating physical limitations associated with aging and chronic diseases are in development. Challenges in the framing of indications, eligibility criteria, and endpoints and the lack of regulatory guidance have hindered the development of function-promoting therapies. METHODS: Experts from academia, pharmaceutical industry, National Institutes of Health (NIH), and Food and Drug Administration (FDA) discussed optimization of trial design including the framing of indications, eligibility criteria, and endpoints. RESULTS: Mobility disability associated with aging and chronic diseases is an attractive indication because it is recognized by geriatricians as a common condition associated with adverse outcomes, and it can be ascertained reliably. Other conditions associated with functional limitation in older adults include hospitalization for acute illnesses, cancer cachexia, and fall injuries. Efforts are underway to harmonize definitions of sarcopenia and frailty. Eligibility criteria should reconcile the goals of selecting participants with the condition and ensuring generalizability and ease of recruitment. An accurate measure of muscle mass (eg, D3 creatine dilution) could be a good biomarker in early-phase trials. Performance-based and patient-reported measures of physical function are needed to demonstrate whether treatment improves how a person lives, functions, or feels. Multicomponent functional training that integrates training in balance, stability, strength, and functional tasks with cognitive and behavioral strategies may be needed to translate drug-induced muscle mass gains into functional improvements. CONCLUSIONS: Collaborations among academic investigators, NIH, FDA, pharmaceutical industry, patients, and professional societies are needed to conduct well-designed trials of function-promoting pharmacological agents with and without multicomponent functional training.


Assuntos
Fragilidade , Neoplasias , Sarcopenia , Idoso , Humanos , Envelhecimento , Sarcopenia/terapia , Ensaios Clínicos como Assunto
20.
PLoS One ; 18(2): e0281508, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36763576

RESUMO

Androgen deprivation therapy (ADT), a cornerstone of treatment for patients with locally advanced and metastatic prostate cancer, is associated with many adverse effects, including osteoporosis, sexual dysfunction, fatigue, and vasomotor symptoms. It is also associated with loss of muscle mass and increased adiposity. This change in body composition is likely the inciting event in the development of insulin resistance, an independent risk factor for diabetes mellitus and cardiovascular disease. Although the occurrence of insulin resistance during ADT has been reported, it remains unclear whether this insulin resistance is primarily hepatic or muscular. Similarly, the mechanisms that lead to insulin resistance also remain unknown. The ADT & Metabolism Study was designed to address these knowledge gaps, as the elucidation of the predominant site of insulin resistance will allow prevention strategies and the use of targeted, tissue-specific insulin-sensitizing agents in patients undergoing ADT. This prospective, mechanistic, single-center, 24-week, observational cohort study will enroll treatment-naïve adult men with prostate cancer about to undergo surgical or medical ADT for at least 24 weeks (ADT group; n = 50) and a control group of men who had undergone radical prostatectomy and are in remission (non-ADT group, n = 25). The primary outcome is to determine the site of insulin resistance (skeletal muscle or liver) using frequent sampling oral glucose tolerance test at baseline and 12 and 24 weeks after commencement of ADT (ADT group) or after enrollment in the study (non-ADT group). Secondary outcomes will assess changes in hepatic and intramyocellular fat (using magnetic resonance spectroscopy), inflammatory markers, adipokines, free fatty acids, and changes in body composition (assessed using dual-energy x-ray absorptiometry) and their correlation with the development of insulin resistance. Exploratory outcomes will include changes in muscle performance, physical function, physical activity, vitality, and sexual drive.


Assuntos
Resistência à Insulina , Neoplasias da Próstata , Masculino , Humanos , Idoso , Neoplasias da Próstata/metabolismo , Androgênios , Resistência à Insulina/fisiologia , Antagonistas de Androgênios/efeitos adversos , Estudos de Coortes , Estudos Prospectivos , Antineoplásicos Hormonais/uso terapêutico , Estudos Observacionais como Assunto
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