RESUMEN
OBJECTIVE: To investigate the relationships between percentage fat mass (%FM), percentage lean mass (%LM), and the ratio of %FM to %LM with pro-inflammatory adipokines and metabolic syndrome in individuals with chronic spinal cord injury (SCI). DESIGN: Observational, cross-sectional. Linear and logistic regression were used to examine the associations between the %FM, %LM, and the %FM to %LM ratio with inflammatory markers and metabolic syndrome, respectively. PARTICIPANTS: Seventy chronic SCI men and women. MAIN OUTCOME MEASURES: %FM, %LM, %FM to %LM ratio; fasting lipids, glucose, and tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and high-sensitivity c-reactive protein (hs-CRP); metabolic syndrome as determined by The International Diabetes Federation criteria. RESULTS: There were significant correlations between %FM, %LM and the %FM to %LM ratio with hs-CRP. The %LM beta coefficient value was negative and greater than the beta coefficient value for %FM. The %FM to %LM ratio had the strongest correlation with hs-CRP and showed the only significant relationship with IL-6. There were strong significant correlations between %FM, %LM and the %FM to %LM ratio with metabolic syndrome. However, the %FM to %LM ratio, again, showed the strongest relationship indicating that it may be the best predictor of metabolic syndrome. CONCLUSION: Both higher %FM and lower %LM affect cardiometabolic health and can be used as predictors for metabolic syndrome. However, the %FM to %LM ratio was the best predictor of systemic inflammation and cardiometabolic disorders in this group of SCI participants, suggesting that they both contribute to the statistical model.
Asunto(s)
Enfermedades Cardiovasculares , Síndrome Metabólico , Traumatismos de la Médula Espinal , Masculino , Humanos , Femenino , Índice de Masa Corporal , Densidad Ósea , Estudios Transversales , Proteína C-Reactiva , Interleucina-6 , Traumatismos de la Médula Espinal/complicaciones , Composición Corporal , Inflamación , Absorciometría de FotónRESUMEN
PURPOSE: The objectives of this paper are (1) to examine patterns of physical activity (PA) and sedentary behavior; (2) to describe development of a method to quantify movement dispersion; and (3) to determine the relationship between variables of movement (i.e., volume, intensity, and dispersion), volume of sedentary behavior, and estimated cardiorespiratory capacity in school-aged children. DESIGN AND METHODS: A secondary analysis of an existing data set with raw accelerometer data identified PA patterns of movement dispersion in school-aged children. Bar graphs visually depicted each participant's daily vector magnitude counts. The research team developed a dispersion variable-movement dispersion-and formula to provide a new quantification of daily PA patterns. Total movement dispersion represents both intensity and distribution of movement, whereas pure movement dispersion refers to the distribution of movement during the wear time, independent of intensity. Kendall's tau examined the relationship between several variables: body mass index percentile, average minutes of sedentary behavior, average minutes of light PA, average minutes of moderate-vigorous PA (MVPA), derived VO2 max, total movement dispersion, and pure movement dispersion. RESULTS: Three participants' activity graphs were presented as examples: (1) active, (2) inactive, and (3) mixed. The more active participant had the highest values for pure and total movement dispersion. The inactive participant had much lower pure and total movement dispersion values compared to the active participant. The mixed participant had high average minutes of MVPA yet lower pure and total movement dispersion values. Total movement dispersion had a significant correlation with average minutes of light PA (r = .406, p = .016) and average minutes of MVPA (r = .686, p < .001). Pure movement dispersion was significantly correlated with average minutes of light PA (r = .448, p = .008) and average minutes of MVPA (r = .599, p < .001). Average minutes of sedentary behavior (SB) were not significantly correlated with total (r = .041, p = .806) or pure movement dispersion (r = .165, p = .326). PRACTICE IMPLICATIONS: Movement dispersion may provide another tool to advance knowledge of PA, potentially leading to improved health outcomes. Raw accelerometer data, such as that gathered at the elementary school in this study, offer opportunities to identify school-aged children at risk for obesity, SB, and lack of PA.
Asunto(s)
Acelerometría , Conducta Sedentaria , Índice de Masa Corporal , Niño , Ejercicio Físico , Humanos , Instituciones AcadémicasRESUMEN
Exercise training beneficially moderates the effects of vascular aging. This study compared the efficacy of Peripheral Remodeling through Intermittent Muscular Exercise (PRIME), a novel training regimen, versus aerobic training on hemodynamic profiles in participants ≥70 years at risk for losing functional independence. Seventy-five participants (52 females, age: 76 ± 5 years) were assessed for hemodynamic and vascular function at baseline, after 4 weeks of either PRIME or aerobic training (Phase 1) and again after a further 8 weeks of aerobic and resistance training (Phase 2). Data were analyzed using 2 × 2 repeated-measures analysis of variance models on the change in each dependent variable. PRIME demonstrated reductions in brachial and aortic mean arterial pressure and diastolic blood pressure (p < .05) from baseline after Phase 1, which were sustained throughout Phase 2. Earlier and greater reductions in blood pressure following PRIME support the proposal that peripheral muscular training could beneficial for older individuals commencing an exercise program.
Asunto(s)
Entrenamiento de Fuerza , Rigidez Vascular , Anciano , Anciano de 80 o más Años , Presión Sanguínea/fisiología , Ejercicio Físico/fisiología , Femenino , Hemodinámica , Humanos , MasculinoRESUMEN
Evidence suggests a physically active lifestyle increases proportion of life lived free of disability. Unfortunately, physical activity participation in older adults is low, suggesting innovative strategies are needed. This case-report (1) examined daily activity routines from accelerometer data; and (2) utilized the movement patterns to "infuse" physical activity within the participant's normal routine. CASE-REPORT: A 60 year old wore an Actigraph GT3X+ accelerometer, on 2 separate days and weeks. Movement patterns, from "raw" accelerometer data, were presented to the participant to identify areas of high and low activity, with suggestions how to increase overall activity. Results indicated activity patterns were reproducible. Physical activity infusions increased movement counts by 34%, and moderate-vigorous physical activity (MVPA) by ~82minutes. DISCUSSION: Examination of "raw" accelerometer data identified distinct movement routines. Understanding these routines allowed for health provider/participant interaction that led to physical activity "infusions" which contributed to a large increase in MVPA, without major alterations to the individual's day.
RESUMEN
BACKGROUND: In 1999, type 2 diabetes mellitus (T2DM) was identified as an emerging epidemic in youth, and racial and ethnic minority youth were identified with high risk. Two decades later, no gold standard T2DM prevention intervention has been established for this population. OBJECTIVE: This study tests the efficacy of a telehealth diabetes prevention intervention for African American (AA) families with children with risk for T2DM. Concurrently, investigators aim to evaluate an implementation strategy for the uptake of the intervention by the University of Mississippi Medical Center's (UMMC) pediatric weight management clinic. METHODS: This single-arm trial will enroll 20 parents with overweight or obesity of children (8-11 years) with overweight or obesity, both of whom are at risk for T2DM. Parents will meet in small groups (5 parents per group) weekly for 11 weeks and then monthly for 4 monthly maintenance sessions via videoconference using Wi-Fi-enabled iPads with cellular connectivity. The intervention will be adapted from the National Diabetes Prevention Program and Power to Prevent, a diabetes prevention program tailored for AA families. The same lifestyle intervention facilitated by a racially concordant lifestyle coach trained in the Diabetes Prevention Program will be delivered to all groups (n=4). Participants will be recruited in-person during patient encounters at the UMMC's pediatric weight management clinic. Sessions will consist of dietary and physical activity behavior change strategies facilitated using problem-solving and goal-setting skills. The implementation strategy has 2 targets: the pediatric weight management clinic site and clinical team and parents of children at risk for T2DM engaged in intensive obesity treatment to prevent T2DM. The multifaceted implementation protocol includes 4 discrete strategies: creating a new clinical team, changing the service site, intervening with families, and promoting organizational readiness for change. RESULTS: Recruitment and enrollment began in December 2020, and the intervention is scheduled to be delivered to the first cohort of parents in March 2021. The results are expected to be submitted for publication beginning in November 2021 through 2022. The primary outcome measure for the pilot trial will include changes from baseline to 12 and 30 weeks in the child BMI z score and parent BMI. The implementation evaluation will include multiple measures of feasibility, acceptability, appropriateness, fidelity, and efficacy. This protocol was approved by the UMMC's Institutional Review Board (#2020V0249). CONCLUSIONS: The proposed intervention approach is supported by the scientific literature and is scalable given the current and future health care subsidies for telehealth. Findings from this pilot trial will begin to address critical barriers to defining a gold standard lifestyle intervention for AA families with children at risk for T2DM. If effective, the intervention could be feasibly disseminated to treat obesity and prevent T2DM in high-risk AA pediatric populations. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/25699.
RESUMEN
Recruitment planning is needed to establish a foundation for obesity prevention research with high risk, disadvantaged perinatal adolescent populations. In the context of developing clinical trial protocols, investigators partnered with Mississippi's Nutrition Program for Women, Infants and Children (WIC) and adopted the Clinical Trials Transformative Initiative (CTTI) framework for recruitment planning to identify and mitigate challenges to recruitment early in the clinical trial development process. The recruitment protocol consisted of 20 passive strategies grounded in principles of partner and community engagement and was flexible, accommodating, altruistic, community-focused, and minimally burdensome to partners and participants. The recruitment goal included 150 adolescent-coparticipant dyads and 145 dyads (96.7%) were successfully recruited. Investigators demonstrated the feasibility of recruiting a disadvantaged and vulnerable perinatal adolescent population that is underrepresented in health research, in one of the most persistently impoverished and poor health regions in the U.S. Four important aspects of recruitment planning using the CTTI framework are discussed including: (1) establishing partnerships with trusted community resources is a paramount investment; (2) dedicating time and resources to know and go to your community is invaluable; (3) fostering trust by offering convenient, continuous and clear communication; and (4) encouraging collaboration and participation through limiting partner and participant burden. Establishing organizational and community partnership requires a substantial amount of invaluable time and fosters recruitment success. Following the CTTI recommendations for recruitment planning led to a robust recruitment protocol that will be used in future intervention trials with an understudied perinatal adolescent population with high risk for poor maternal and fetal health outcomes.
Asunto(s)
Proyectos de Investigación , Poblaciones Vulnerables , Adolescente , Niño , Ensayos Clínicos como Asunto , Femenino , Humanos , Obesidad , Selección de Paciente , Embarazo , InvestigadoresRESUMEN
OBJECTIVE: The objective of this review is to evaluate the impact of electronic health (eHealth) interventions on physical activity and weight changes among pregnant and/or postpartum populations and to describe the sociodemographic characteristics of the study populations. INTRODUCTION: The American College of Obstetricians and Gynecologists recommends 20 minutes of daily physical activity during pregnancy and postpartum. Few pregnant women are physically active and among those who are, physical activity levels decline as pregnancy progresses and during postpartum. Behavioral eHealth interventions offer convenient and frequent accessibility at low cost and high reach. A search of the extant literature including PROSPERO, MEDLINE (PubMed), the Cochrane Database of Systematic Reviews and the JBI Database of Systematic Reviews and Implementation Reports revealed no published or in-progress reviews examining eHealth physical activity interventions among pregnant and/or postpartum populations. INCLUSION CRITERIA: Studies of eHealth interventions including pregnant and/or within one-year postpartum populations will be included. METHODS: This review will be conducted in accordance with JBI methodology for systematic reviews of effectiveness. The search strategy will aim to locate studies from the inception of each database. Citations will be collated, and duplicates removed. Titles and abstracts will be screened for eligibility against the inclusion criteria and relevant studies retrieved. Included studies will be appraised for methodological quality using JBI standardized critical appraisal instruments. Extracted data will include study methods, intervention design and outcomes (physical activity, weight, participant sociodemographic characteristics). The Grading of Recommendations, Assessment, Development and Evaluation approach for grading the certainty of evidence will be followed. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO CRD42020124611.
Asunto(s)
Ejercicio Físico , Telemedicina , Electrónica , Femenino , Humanos , Periodo Posparto , Embarazo , Literatura de Revisión como Asunto , Revisiones Sistemáticas como AsuntoRESUMEN
INTRODUCTION: Smoking, low education, obesity, and depressive symptoms are all associated with HIV health status, increased blood pressure, and inflammation, and constitute a syndemic burden that may contribute to poor health outcomes. The current study examined syndemic burden and health outcomes among women living with HIV. METHODS: Women were participants enrolled in the Women's Interagency HIV Study. Outcomes included blood pressure, HIV health status (HIV-1 RNA viral load and CD4 T-cell counts), and IL-6. Syndemic burden was defined as a count variable of low education, obesity, cigarette use, and depressive symptoms. RESULTS: Women (Nâ=â131) were an average of 60.54 years of age (SDâ=â8.86), and 49% were non-Hispanic Black. In multivariable analyses, syndemic burden was not significantly associated with SBP (Pâ=â0.342) or DBP (Pâ=â0.763), IL-6 (Pâ=â0.168), or CD4 cell count (Pâ=â0.846). However, syndemic burden was associated with increased viral load (age adjusted ßâ=â0.35, Pâ<â0.001). Comparing women with high versus low syndemic burden, also controlling for women's age, women with high syndemic burden had higher DBP and HIV viral load. DISCUSSION: Syndemic burden appeared to play an important role in HIV health status and could potentially increase the risk of HIV transmission. High syndemic burden, defined as at least two syndemic conditions, had the greatest effects of HIV viral load and DBP. Targeted interventions to address syndemic burden may help improve health outcomes in women living with HIV as well as reduce the risk of hypertension and HIV transmission.
Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Hipertensión/epidemiología , Inflamación/epidemiología , Sindémico , Carga Viral/efectos de los fármacos , Adulto , Presión Sanguínea , Estudios de Cohortes , Depresión/epidemiología , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/psicología , Estado de Salud , Humanos , Estudios Prospectivos , Calidad de VidaRESUMEN
Study objectives were to examine the relationships between physical activity, pain, and psychological distress in youth 8 to 17 years of age with sickle cell disease. Participants were 206 youth with sickle cell disease (M = 11.73 years, 54.9% female, 99.5% African American). Caregivers and youth completed a clinical psychosocial screening battery. Results revealed frequent pain (37.6%), moderate median pain intensity, and elevated median pain interference in youth. Lower caregiver-reported physical activity was associated with worse pain outcomes. Increased anxiety was also associated with worse pain outcomes. A better understanding of the relationship between physical activity/inactivity and pain will guide multifactorial treatment interventions.
Asunto(s)
Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/psicología , Ejercicio Físico/psicología , Dolor/psicología , Adolescente , Adulto , Niño , Femenino , Humanos , MasculinoRESUMEN
INTRODUCTION: The ability to maintain functional independence in a rapidly aging population results in an increased life expectancy without corresponding increases in health care costs. The accelerated decline in VËO2peak after the age of 65 yr is primarily due to peripheral tissue changes rather than centrally mediated factors. The purpose of this study was to determine whether the Peripheral Remodeling through Intermittent Muscular Exercise (PRIME) approach, consisting of a low-mass, high-repetition/duration skeletal muscle focused training regimen would provide superior functional benefits in participants older than 70 yr old and at risk for losing functional independence. METHODS: In this clinical trial, 107 participants were randomized to 4 wk of either standard aerobic training (AT) or PRIME (phase 1). This was followed by 8 wk of a progressive whole-body aerobic and resistance training (AT + RT) for all participants (phase 2). The major outcome measures were cardiorespiratory fitness (peak oxygen consumption [VËO2peak]), muscular fitness (1 repetition maximal strength [1RM]), and physical function (Senior Fitness Test [SFT] scores). Results were analyzed under a per-protocol criterion. RESULTS: Thirty-eight PRIME and 38 AT participants completed the 3-month protocols. VËO2peak, 1RM, and SFT scores all increased significantly after 12 wk for both treatment groups (P < 0.05). However, relative to AT, participants randomized to PRIME demonstrated a greater increase in VËO2peak (2.37 + 1.83 vs 1.50 + 1.82 mL·kg·min, P < 0.05), 1RM (48.52 + 27.03 vs 28.01 + 26.15 kg, P < 0.01) and SFT (22.50 + 9.98 vs 18.66 + 9.60 percentile, P < 0.05). CONCLUSIONS: Participants experienced greater increases in cardiorespiratory and muscular fitness and physical function when PRIME training was initiated before a combined AT + RT program. This novel exercise approach may be advantageous to individuals with other chronic disease conditions characterized by low functional capacity.
Asunto(s)
Capacidad Cardiovascular , Ejercicio Físico , Músculo Esquelético/fisiología , Consumo de Oxígeno , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Entrenamiento de FuerzaRESUMEN
Previously, we showed that FI34, a frailty index based on 34 health and function ability variables, is heritable and a reliable phenotypic indicator of healthy aging. We have now examined the relationship between major components of energy expenditure and the FI34 in participants of the Louisiana Healthy Aging Study. Resting metabolic rate was associated with FI34, even after adjustment for fat-free mass, fat mass, age, sex, thyroid hormones, and insulin-like growth factor 1 levels, in multiple regression analyses. In contrast, there was no association between total daily energy expenditure and FI34. Circulating creatine phosphokinase, a clinical marker of muscle damage, was also significantly associated with FI34. However, these associations of resting metabolic rate with FI34 were restricted to the oldest old (≥90 years) and absent in younger age groups. In oldest old men, the association of FI34 with creatine phosphokinase persisted, whereas in the oldest old women, only the association with resting metabolic rate pertained with the appearance of an effect of body size and composition. These results point toward an increasing metabolic burden for the maintenance of homeodynamics as health declines in nonagenarians, and this has implications for contraction of metabolic reserve that may potentially accelerate the path to disability.
Asunto(s)
Actividades Cotidianas , Envejecimiento/fisiología , Metabolismo Basal/fisiología , Metabolismo Energético , Músculo Esquelético/fisiología , Descanso/fisiología , Sarcopenia/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sarcopenia/fisiopatología , Adulto JovenRESUMEN
Advancing age is associated with an increase in physical impairment, functional limitations, disability, and loss of independence. Regular physical activity conveys health benefits, but the yield on physical function in the elderly, is less clear. Current exercise guidelines are focused predominantly on aerobic programs despite evidence that age-associated declines are mediated by peripheral tissue changes. The Fit for Life trial proposes a new paradigm of exercise training for the elderly that uses a low-mass high-repetition training regimen specifically focused on peripheral tissue beds or body regions (Regional Specific Training Stimulus - RSTS). RSTS is designed to deliver a localized stimulus to the peripheral vasculature, bone and muscle, without imposing a significant central cardiorespiratory strain. The purpose of this study is three-fold; 1) to derive effect sizes from the RSTS intervention by which to power a subsequent larger, confirmatory trial; 2) to assess fidelity of the RSTS intervention; and 3) to assess the interrelationship of the primary endpoints of physical impairment/fitness (VO(2peak), 1 repetition maximal contraction) and function (Senior Fitness Test scores) following two versions of a 4 + 8 week protocol. Men and women over 70 years, at risk for losing independence will be randomized to either 4 weeks of RSTS or "aerobic" exercise, followed by an identical 8 weeks of progressive whole-body training (aerobic plus resistance). The guiding hypothesis is that the magnitude of adaptation after 12 weeks will be greatest in those initially randomized to RSTS. Possible mediators of the intervention effect - physical impairment/fitness and function relationship, including vascular function, muscle mass, strength, and physiology will also be assessed.
Asunto(s)
Envejecimiento/fisiología , Ejercicio Físico/fisiología , Proyectos de Investigación , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Fuerza Muscular , Consumo de Oxígeno , Aptitud Física , Calidad de Vida , Entrenamiento de Fuerza/métodosRESUMEN
UNLABELLED: Elite endurance athletes typically have larger arteries contributing to greater skeletal muscle blood flow, oxygen and nutrient delivery and improved physical performance. Few studies have examined structural and functional properties of arteries in power athletes. PURPOSE: To compare the size and vasoreactivity of the brachial artery of elite power athletes to age-matched controls. It was hypothesized brachial artery diameters of athletes would be larger, have less vasodilation in response to cuff occlusion, but more constriction after a cold pressor test than age-matched controls. METHODS: Eight elite power athletes (age = 23 ± 2 years) and ten controls (age = 22 ± 1 yrs) were studied. High-resolution ultrasonography was used to assess brachial artery diameters at rest and following 5 minutes of forearm occlusion (Brachial Artery Flow Mediated Dilation = BAFMD) and a cold pressor test (CPT). Basic fitness measures included a handgrip test and 3-minute step test. RESULTS: Brachial arteries of athletes were larger (Athletes 5.39 ± 1.51 vs. CONTROLS: 3.73 ± 0.71 mm, p<0.05), had greater vasodilatory (BAFMD%: Athletes: 8.21 ± 1.78 vs. CONTROLS: 5.69 ± 1.56%) and constrictor (CPT %: Athletes: -2.95 ± 1.07 vs. CONTROLS: -1.20 ± 0.48%) responses, compared to controls. Vascular operating range (VOR = Peak dilation+Peak Constriction) was also greater in athletes (VOR: Athletes: 0.55 ± 0.15 vs. CONTROLS: 0.25 ± 0.18 mm, p<0.05). Athletes had superior handgrip strength (Athletes: 55.92 ± 17.06 vs. CONTROLS: 36.77 ± 17.06 kg, p<0.05) but similar heart rate responses at peak (Athletes: 123 ± 16 vs. CONTROLS: 130 ± 25 bpm, p>0.05) and 1 minute recovery (Athletes: 88 ± 21 vs. CONTROLS: 98 ± 26 bpm, p>0.05) following the step test. CONCLUSION: Elite power athletes have larger brachial arteries, and greater vasoreactivity (greater vasodilatory and constrictor responses) than age-matched controls, contributing to a significantly greater VOR. These data extend the existence of an 'athlete's artery' as previously shown for elite endurance athletes to elite power athletes, and presents a hypothetical explanation for the functional significance of the 'power athlete's artery'.
Asunto(s)
Arteria Braquial/fisiología , Deportes , Adulto , Arteria Braquial/diagnóstico por imagen , Estudios de Casos y Controles , Humanos , Ultrasonografía , Adulto JovenRESUMEN
UNLABELLED: The purpose of this study was to investigate the vasodilatory and vasoconstrictor responses of the brachial artery in patients with chronic heart failure (CHF) and controls (CON) before and after a period of training and detraining. METHODS: CHF (n = 10; age = 62 ± 8 yrs) and CON (n = 10; age = 55 ± 5 yrs) subjects completed 4 weeks of bilateral handgrip training (20 min; 60% of maximal handgrip strength; 15 grips*min(-1); 4 days*week(-1)). Handgrip strength was measured using a hand dynamometer. Brachial artery flow-mediated dilation (BAFMD) and cold pressor test (CPT) responses were determined using ultrasonography prior to training, at the end of 4 weeks of training and following 4 weeks of detraining. Absolute (mm) BAFMD and CPT responses were combined to yield a vascular operating range (VOR). RESULTS: Baseline BAFMD was higher in CON (CHF: 2.98 ± 1.49%; CON: 6.21 ± 1.21%; p = 0.01), while CPT responses were higher in CHF (CHF: 3.38 ± 0.83%; CON: 2.46 ± 0.62%; p = 0.05). Baseline VOR tended to be greater in the CON subjects (CHF: 0.28 ± 0.05 mm; CON: 0.32 ± 0.12 mm; p = 0.06). Training increased handgrip strength (â¼5%; p < 0.05, for both groups), BAFMD (CHF: 2.98 ± 1.49% to 3.75 ± 1.56%; CON: 6.21 ± 1.21% - 8.02 ± 1.75%; p = 0.01) and VOR (CHF: 0.28 ± 0.05 mm - 0.3 ± 0.09 mm; CON: 0.32 ± 0.12 mm - 0.42 ± 0.11 mm; p = 0.01). There were no significant changes in CPT responses. All markers approached pre-training values following detraining. CONCLUSION: Handgrip exercise increases strength, BAFMD and VOR in both CHF and CON subjects. These improvements are transient and return to pre-training values after removal of the training stimulus.
Asunto(s)
Arteria Braquial/fisiología , Insuficiencia Cardíaca/rehabilitación , Entrenamiento de Fuerza , Vasoconstricción/fisiología , Vasodilatación/fisiología , Adulto , Arteria Braquial/diagnóstico por imagen , Ejercicio Físico/fisiología , Antebrazo/irrigación sanguínea , Fuerza de la Mano/fisiología , Humanos , Persona de Mediana Edad , Flujo Sanguíneo Regional/fisiología , UltrasonografíaRESUMEN
OBJECTIVE: To examine the relationship of handgrip strength with forearm blood flow (BF) and vascular resistance (VR) in rheumatoid arthritis (RA) patients. METHODS: Forearm BF at rest (RBF) and after upper arm occlusion (RHBF), and handgrip strength were examined in 78 individuals (RA = 42 and controls (CT) = 36). Subsequently, VR at rest (RVR) and after occlusion (RHVR) were calculated. RESULTS: The patients' RBF (P = 0.02) and RHBF (P = 0.0001) were less, whereas RVR (P = 0.002) and RHVR (P = 0.0001) were greater as compared to the CTs. Similarly, handgrip strength was lower in the RAs (P = 0.0001). Finally, handgrip strength was directly associated with RBF (r = 0.43; P = 0.0001), and RHBF (r = 0.5; P = 0.0001), and inversely related to RVR (r = -0.3; P = 0.009) and RHVR (r = -0.3; P = 0.007). CONCLUSION: The present study uniquely identifies an association between regional measures of forearm blood flow and handgrip strength in patients and healthy control. In addition, this study confirms the presence of vascular and muscle dysfunction in patients with rheumatoid arthritis, as evidenced by lower forearm blood flow indices, at rest and following occlusion, and lower handgrip strength as compared to healthy individuals.
Asunto(s)
Artritis Reumatoide/fisiopatología , Antebrazo/irrigación sanguínea , Fuerza de la Mano/fisiología , Resistencia Vascular/fisiología , Adulto , Velocidad del Flujo Sanguíneo/fisiología , Enfermedades Cardiovasculares/fisiopatología , Estudios de Casos y Controles , Estudios Transversales , Femenino , Antebrazo/fisiopatología , Humanos , Masculino , Enfermedades Musculares/fisiopatología , Flujo Sanguíneo Regional , Adulto JovenRESUMEN
This study investigated the effects of powerlifting gear on training volume and performance, defined by the squat, bench press, and deadlift. Eighteen powerlifters (18-26 years) were randomized into either a group that trained and competed using compressive gear (CG) or without the gear (NON). Training volume, volume progression, and powerlifting performance were assessed before and after 10 weeks of training. Training volume increased in the first 4 weeks for both groups. Volume lifted for squat and the totals were greater in the CG. There was an increase in squat (19.05 ± 30.97 lb, p = 0.02), deadlift (19.05 ± 21.17 lb, p = 0.001), and the total score (44.00 ± 60.44 lb, p = 0.005) for both the groups. The improvements in squat (CG = 33.85 vs. NON = 5.74, p = 0.07) and totals (CG = 66.59 vs. NON = 23.67, p = 0.15) were greater in the CG. Both groups showed a significant and similar increase in the Wilks scores (+13.54 points, p = 0.03). There was a trend toward greater volume progression in those wearing CG during the initial stages of training. Both the groups significantly improved performance for the squat, and deadlift, and had higher totals, and Wilks scores, indicating significant strength gains. The greater magnitude of improvements in the squat and totals for the CG lifters suggests an ergogenic potential of training with powerlifting gear.
Asunto(s)
Rendimiento Atlético/fisiología , Circulación Sanguínea , Fuerza Muscular , Entrenamiento de Fuerza/instrumentación , Equipo Deportivo , Levantamiento de Peso/fisiología , Adolescente , Adulto , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Análisis Multivariante , Músculo Esquelético/fisiología , Adulto JovenRESUMEN
Leukocyte telomere length is widely considered a biomarker of human age and in many studies indicative of health or disease. We have obtained quantitative estimates of telomere length from blood leukocytes in a population sample, confirming results of previous studies that telomere length significantly decreases with age. Telomere length was also positively associated with several measures of healthy aging, but this relationship was dependent on age. We screened two genes known to be involved in telomere maintenance for association with the age-related decline in telomere length observed in our population to identify candidate longevity-associated genes. A single-nucleotide polymorphism located in the SIRT1 gene and another in the 3' flanking region of XRCC6 had significant effects on telomere length. At each bi-allelic locus, the minor variant was associated with longer telomeres, though the mode of inheritance fitting best differed between the two genes. No statistical interaction was detected for telomere length between the SIRT1 and XRCC6 variants or between these polymorphisms and age. The SIRT1 locus was significantly associated with longevity (P < 0.003). The frequency of the minor allele was higher in long-lived cases than in young controls, which coincides with the protective role of the minor variant for telomere length. In contrast, the XRCC6 variant was not associated with longevity. Furthermore, it did not affect the association of SIRT1 with exceptional survival. The association of the same variant of SIRT1 with longevity was near significant (P < 0.07) in a second population. These results suggest a potential role of SIRT1 in linking telomere length and longevity. Given the differences between this gene and XRCC6, they point to the distinct impact that alternate pathways of telomere maintenance may have on aging and exceptional survival.
Asunto(s)
Antígenos Nucleares/genética , Proteínas de Unión al ADN/genética , Longevidad/genética , Polimorfismo de Nucleótido Simple , Sirtuina 1/genética , Acortamiento del Telómero , Telómero/metabolismo , Región de Flanqueo 3' , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Antígenos Nucleares/metabolismo , Estudios de Casos y Controles , Proteínas de Unión al ADN/metabolismo , Femenino , Frecuencia de los Genes , Genotipo , Georgia , Humanos , Autoantígeno Ku , Escala de Lod , Louisiana , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Fenotipo , Modelos de Riesgos Proporcionales , Sirtuina 1/metabolismo , Análisis de Supervivencia , Adulto JovenRESUMEN
Recently, exercise has been recommended as a part of lifestyle modification for all hypertensive patients; however, the precise mechanisms of its effects on hypertension are largely unknown. Therefore, this study aimed to investigate the mechanisms within the brain that can influence exercise-induced effects in an animal model of human essential hypertension. Young normotensive WKY rats and SHR were given moderate-intensity exercise for 16 weeks. Blood pressure was measured bi-weekly by tail-cuff method. Animals were then euthanized; paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM), important cardiovascular regulatory centers in the brain, were collected and analyzed by real-time RT-PCR, Western blot, EIA, and fluorescent microscopy. Exercise of 16-week duration attenuated systolic, diastolic, and mean arterial pressure in SHR. Sedentary SHR exhibited increased pro-inflammatory cytokines (PICs) and decreased anti-inflammatory IL-10 levels in the PVN and RVLM. Furthermore, SHR(sed) rats exhibited elevated levels of ACE, AT1R, and decreased levels of ACE2 and receptor Mas in the PVN and RVLM. Chronic exercise not only prevented the increase in PICs (TNF-α, IL-1ß), ACE, and AT1R protein expression in the brain of SHR, but also dramatically upregulated IL-10, ACE2, and Mas receptor expression in SHR. In addition, these changes were associated with reduced plasma AngII levels, reduced neuronal activity, reduced NADPH-oxidase subunit gp91(phox) and inducible NO synthase in trained SHRs indicating reduced oxidative stress. These results suggest that chronic exercise not only attenuates PICs and the vasoconstrictor axis of the RAS but also improves the anti-inflammatory defense mechanisms and vasoprotective axis of the RAS in the brain, which, at least in part, explains the blood pressure-lowering effects of exercise in hypertension.
Asunto(s)
Encéfalo/metabolismo , Hipertensión/fisiopatología , Inflamación/metabolismo , Condicionamiento Físico Animal/fisiología , Sistema Renina-Angiotensina/fisiología , Animales , Presión Sanguínea , Western Blotting , Encéfalo/inmunología , Encéfalo/fisiopatología , Citocinas/biosíntesis , Ensayo de Inmunoadsorción Enzimática , Hipertensión/inmunología , Inflamación/fisiopatología , Microscopía Fluorescente , Estrés Oxidativo/fisiología , Ratas , Ratas Endogámicas SHR , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The search for longevity-determining genes in human has largely neglected the operation of genetic interactions. We have identified a novel combination of common variants of three genes that has a marked association with human lifespan and healthy aging. Subjects were recruited and stratified according to their genetically inferred ethnic affiliation to account for population structure. Haplotype analysis was performed in three candidate genes, and the haplotype combinations were tested for association with exceptional longevity. An HRAS1 haplotype enhanced the effect of an APOE haplotype on exceptional survival, and a LASS1 haplotype further augmented its magnitude. These results were replicated in a second population. A profile of healthy aging was developed using a deficit accumulation index, which showed that this combination of gene variants is associated with healthy aging. The variation in LASS1 is functional, causing enhanced expression of the gene, and it contributes to healthy aging and greater survival in the tenth decade of life. Thus, rare gene variants need not be invoked to explain complex traits such as aging; instead rare congruence of common gene variants readily fulfills this role. The interaction between the three genes described here suggests new models for cellular and molecular mechanisms underlying exceptional survival and healthy aging that involve lipotoxicity.
Asunto(s)
Envejecimiento/genética , Apolipoproteínas E/genética , Longevidad/genética , Proteínas de la Membrana/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Variación Genética/genética , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Esfingosina N-AciltransferasaRESUMEN
Despite the evidence describing the rapid vascular function modifications to commencement and cessation of large muscle exercises (i.e. cycling), no studies examined the time-course vascular modifications to localized training and detraining. This study aimed to examine the effects of 4-week rhythmic handgrip exercise training and 2-week detraining on reactive hyperemic forearm blood flow and vascular resistance in 11 young men. Rhythmic handgrip exercise was performed in the non-dominant forearm for 20 min/day, 5 days/week, at 60% of maximum voluntary contraction for 4 weeks, followed by 2 weeks of no training. Forearm blood flow and vascular resistance were evaluated, in both arms, at rest and following arterial occlusion. These vascular function indices were obtained in five visits; before, after 1 and 4 week(s) of training as well as after 1 and 2 week(s) of training cessation. Resting cardiovascular measures were not altered during the study period. A 2 (arms) x 5 (visits) ANOVA revealed significant arms-by-visits interactions for reactive hyperemic forearm blood flow (p = 0.02) and vascular resistance (p = 0.02). Subsequent comparison demonstrated increased trained forearm reactive hyperemic blood flow 1 week after training, then returned to pre-training values 1 week following training cessation. In contrast, vascular resistance decreased 1 week after training commencement, only to return to pretraining level 1 week after training cessation. These results indicate a rapid, unilateral improvement in regional reactive hyperemic blood flow and vascular resistance following localized exercise-training. However, the improvements are transient and return to pretraining levels 1 week after detraining.