RESUMO
BACKGROUND: Subclinical hyperthyroidism (SHyper) has been associated with increased risk of hip and other fractures, but the linking mechanisms remain unclear. OBJECTIVE: To investigate the association between subclinical thyroid dysfunction and bone loss. METHODS: Individual participant data analysis was performed after a systematic literature search in MEDLINE/EMBASE (1946-2016). Two reviewers independently screened and selected prospective cohorts providing baseline thyroid status and serial bone mineral density (BMD) measurements. We classified thyroid status as euthyroidism (thyroid-stimulating hormone [TSH] 0.45-4.49 mIU/L), SHyper (TSH < 0.45 mIU/L) and subclinical hypothyroidism (SHypo, TSH ≥ 4.50-19.99 mIU/L) both with normal free thyroxine levels. Our primary outcome was annualized percentage BMD change (%ΔBMD) from serial dual X-ray absorptiometry scans of the femoral neck, total hip and lumbar spine, obtained from multivariable regression in a random-effects two-step approach. RESULTS: Amongst 5458 individuals (median age 72 years, 49.1% women) from six prospective cohorts, 451 (8.3%) had SHypo and 284 (5.2%) had SHyper. During 36 569 person-years of follow-up, those with SHyper had a greater annual bone loss at the femoral neck versus euthyroidism: %ΔBMD = -0.18 (95% CI: -0.34, -0.02; I2 = 0%), with a nonstatistically significant pattern at the total hip: %ΔBMD = -0.14 (95% CI: -0.38, 0.10; I2 = 53%), but not at the lumbar spine: %ΔBMD = 0.03 (95% CI: -0.30, 0.36; I2 = 25%); especially participants with TSH < 0.10 mIU/L showed an increased bone loss in the femoral neck (%Δ BMD = -0.59; [95% CI: -0.99, -0.19]) and total hip region (%ΔBMD = -0.46 [95% CI: -1.05, -0.13]). In contrast, SHypo was not associated with bone loss at any site. CONCLUSION: Amongst adults, SHyper was associated with increased femoral neck bone loss, potentially contributing to the increased fracture risk.
Assuntos
Densidade Óssea , Fraturas Ósseas , Hipertireoidismo , Hipotireoidismo , Idoso , Doenças Assintomáticas , Feminino , Fraturas Ósseas/etiologia , Fraturas Ósseas/metabolismo , Fraturas Ósseas/prevenção & controle , Humanos , Hipertireoidismo/diagnóstico , Hipertireoidismo/epidemiologia , Hipertireoidismo/metabolismo , Hipotireoidismo/diagnóstico , Hipotireoidismo/epidemiologia , Hipotireoidismo/metabolismo , Masculino , Fatores de RiscoRESUMO
UNLABELLED: Hormone levels were compared over a 1-year period between elderly women who had sustained a hip fracture and women of similar age and functional ability. Our study suggests progressive hormonal changes that may contribute to severe bone loss during the year following hip fracture. INTRODUCTION: Alterations in hormones affecting the musculoskeletal system may increase risk of hip fracture or poor post-fracture recovery in postmenopausal women. Most studies lack appropriate reference groups, and thus cannot assess the extent to which these alterations are attributable to hip fracture. METHODS: Women aged ≥65 years hospitalized for an acute hip fracture (Baltimore Hip Studies, BHS-3; n = 162) were age-matched to 324 women enrolled in the Women's Health and Aging Study I, a Baltimore-based cohort with similar functional status to the pre-fracture status of BHS-3 women. Both studies enrolled participants from 1992 to 1995. Insulin-like growth hormone-1 (IGF-1), parathyroid hormone (PTH), 1,25 dihydroxyvitamin D [1,25(OH)2D], and osteocalcin were evaluated at baseline and 2, 6, and 12 months post-fracture, and at baseline and 12 months in the comparison group. Between-group differences in trajectories of each hormone were examined. RESULTS: Baseline mean IGF-1 levels were significantly lower in hip fracture patients than the comparison group (75.0 vs. 110.5 µg/dL; p < 0.001). Levels increased by 2 months post-fracture, but remained significantly lower than those in the comparison group throughout the 12-month follow-up (p < 0.01). Levels of PTH and osteocalcin were similar between groups at baseline, but rose during the year post-fracture to significantly differ from the comparison women (p < 0.001). 1,25(OH)2D levels did not differ between the hip fracture and comparison women at any time. CONCLUSIONS: Older women who have sustained a hip fracture have progressive changes in hormonal milieu that exceed those of women of similar health status during the year following fracture.
Assuntos
Fraturas do Quadril/sangue , Hormônios/sangue , Fraturas por Osteoporose/sangue , 25-Hidroxivitamina D 2/sangue , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Osteocalcina/sangue , Hormônio Paratireóideo/sangueRESUMO
BACKGROUND: Physical frailty is a clinical syndrome associated with aging and manifesting as slowness, weakness, reduced physical activity, weight loss, and/or exhaustion. Frail older adults often report that their major problem is "low energy", and there is indirect evidence to support the hypothesis that frailty is a syndrome of dysregulated energetics. We hypothesized that altered cellular energy production underlies compromised response to stressors in the frail. METHODS: We conducted a pilot study to assess muscle energetics in response to a mild isometric exercise challenge in women (n=30) ages 84-93 years. The frailty status was assessed by a validated physical frailty instrument. Localized phosphorus (P31) magnetic resonance spectroscopy with a 1.5T magnet was used to assess the kinetics of Phosphocreatine recovery in the tibialis anterior muscle following maximal isometric contraction for 30 seconds. RESULTS: Phosphocreatine recovery following exertion, age-adjusted, was slowest in the frail group (mean=189 sec; 95%CI: 150,228) compared to pre-frail (mean=152 sec; 95%CI: 107,197) and nonfrail subjects (mean=132 sec; 95%CI: 40,224). The pre-frail and frail groups had 20 sec (95%CI: -49,89) and 57 sec (95%CI: -31,147) slower phosphocreatine recovery, respectively, than the non-frail. This response was paralleled by dysregulation in glucose recovery in response to oral glucose tolerance test in women from the same study population. CONCLUSIONS: Impaired muscle energetics and energy metabolism might be implicated in the physical frailty syndrome.
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Exercício Físico/fisiologia , Fragilidade/fisiopatologia , Músculos/metabolismo , Fosfocreatina/metabolismo , Idoso de 80 Anos ou mais , Feminino , Idoso Fragilizado , Humanos , Projetos PilotoRESUMO
BACKGROUND: Incidence of hip fractures in men is expected to increase, yet little is known about consequences of hip fracture in men compared to women. It is important to investigate differences at time of fracture using the newest technologies and methodology regarding metabolic, physiologic, neuromuscular, functional, and clinical outcomes, with attention to design issues for recruiting frail older adults across numerous settings. OBJECTIVES: To determine whether at least moderately-sized sex differences exist across several key outcomes after a hip fracture. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study (Baltimore Hip Studies 7th cohort [BHS-7]) was designed to include equal numbers of male and female hip fracture patients to assess sex differences across various outcomes post-hip fracture. Participants were recruited from eight hospitals in the Baltimore metropolitan area within 15 days of admission and were assessed at baseline, 2, 6 and 12 months post-admission. MEASUREMENTS: Assessments included questionnaire, functional performance evaluation, cognitive testing, measures of body composition, and phlebotomy. RESULTS: Of 1709 hip fracture patients screened from May 2006 through June 2011, 917 (54%) were eligible and 39% (n=362) provided informed consent. The final analytic sample was 339 (168 men and 171 women). At time of fracture, men were sicker (mean Charlson score= 2.4 vs. 1.6; p<0.001) and had worse cognition (3MS score= 82.3 vs. 86.2; p<0.05), and prior to fracture were less likely to be on bisphosphonates (8% vs. 39%; p<0.001) and less physically active (2426 kilocalories/week vs. 3625; p<0.001). CONCLUSIONS: This paper provides the study design and methodology for recruiting and assessing hip fracture patients and evidence of baseline and pre-injury sex differences which may affect eventual recovery one year later.
Assuntos
Fraturas do Quadril/terapia , Recuperação de Função Fisiológica , Idoso , Baltimore , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores SexuaisRESUMO
The functional consequences of the age-associated decline in IGF-I are unknown. We hypothesized that low IGF-I levels in older women would be associated with poor muscle strength and mobility. We assessed this question in a population representative of the full spectrum of health in the community, obtaining serum IGF-I levels from women aged 70-79 yr, enrolled in the Women's Health and Aging Study I or II. Cross-sectional analyses were performed using 617 women with IGF-I levels drawn within 90 d of measurement of outcomes. After adjustment for age, there was an association between IGF-I and knee extensor strength (P = 0.004), but not anthropometry or other strength measures. We found a positive relationship between IGF-I levels and walking speed for IGF-I levels below 50 microg/liter (P < 0.001), but no relationship above this threshold. A decline in IGF-I level was associated with self-reported difficulty in mobility tasks. All findings were attenuated after multivariate adjustment. In summary, in a study population including frail and healthy older women, low IGF-I levels were associated with poor knee extensor muscle strength, slow walking speed, and self-reported difficulty with mobility tasks. These findings suggest a role for IGF-I in disability as well as a potential target population for interventions to raise IGF-I levels.
Assuntos
Fator de Crescimento Insulin-Like I/metabolismo , Músculo Esquelético/fisiologia , Atividades Cotidianas , Idoso , Envelhecimento/fisiologia , Composição Corporal/fisiologia , Peso Corporal/fisiologia , Estudos Transversais , Feminino , Força da Mão/fisiologia , Hormônio do Crescimento Humano/sangue , Humanos , Flebotomia , Desempenho Psicomotor/fisiologiaRESUMO
BACKGROUND: Clinical and subclinical hypothyroidism is associated with cognitive impairment. OBJECTIVE: This study investigated the association between thyroxine (T(4)) and thyroid-stimulating hormone (TSH) level and change over time in cognitive performance in a sample of older women with normal thyroid gland function. METHODS: T(4) and TSH were measured at baseline in 628 women (> or = 65 years) enrolled in the Women's Health and Aging Study, a community-based study of physically impaired women. Cognitive function was assessed at baseline and after 1, 2, and 3 years, using the Mini-Mental State Examination (MMSE). Incident cognitive decline was defined as a decrease of more than one point/year in MMSE score between baseline and the end of the follow-up. The analysis included 464 subjects with normal thyroid gland function with a baseline and at least one follow-up MMSE. RESULTS: At baseline there was no association between T(4) and TSH level and cognitive function. In longitudinal analysis, adjusting for age, race, level of education, and other covariates, compared with women in the highest T(4) tertile (8.1 to 12.5 microg/dL), those in the lowest tertile (4.5 to 6.5 microg/dL) had a greater decline in MMSE score (-0.25 point/year vs -0.12 point/year; p = 0.04). A total of 95 women (20.5%) had cognitive decline during the study period (mean MMSE decline, 5.5 points). Compared with women in the highest T(4) tertile, those in the lowest tertile had a twofold risk of cognitive decline (adjusted relative risk, 1.97; 95% CI, 1.10 to 3.50). The results were not modified by baseline cognitive and physical function. There was no association between baseline TSH level and change in cognitive function. CONCLUSIONS: In older women, low T(4) levels, within the normal range, were associated with a greater risk of cognitive decline over a 3-year period. Thyroid hormone levels may contribute to cognitive impairment in physically impaired women.
Assuntos
Envelhecimento/sangue , Transtornos Cognitivos/sangue , Transtornos Cognitivos/psicologia , Síndromes do Eutireóideo Doente/sangue , Síndromes do Eutireóideo Doente/psicologia , Tiroxina/sangue , Idoso , Análise de Variância , Distribuição de Qui-Quadrado , Estudos Transversais , Feminino , Humanos , Estudos ProspectivosRESUMO
OBJECTIVE: Previous studies exploring the relationship of neighborhood characteristics with metabolic conditions have focused on middle-aged adults but none have comprehensively investigated associations in older adults, a potentially vulnerable population. The aim was to explore the relationship of neighborhood characteristics with metabolic conditions in older women. DESIGN: Cross-sectional analysis. SETTING/PARTICIPANTS: We studied 384 women aged 70-79 years, representing the two-thirds least disabled women in the community, enrolled in the Women's Health and Aging Study II at baseline. Neighborhood scores were calculated from census-derived data on median household income, median house value, percent earning interest income, percent completing high school, percent completing college, and percent with managerial or executive occupation. Participants were categorized by quartile of neighborhood score with a higher quartile representing relative neighborhood advantage. Logistic regression models were created to assess the association of neighborhood quartiles to outcomes, adjusting for key covariates. MEASUREMENTS: Primary outcomes included metabolic conditions: obesity, diabetes, hypertension, and hyperlipidemia. Secondary outcomes included BMI, HbA1c, blood pressure and lipids. RESULTS: Higher neighborhood quartile score was associated with a lower prevalence of obesity (highest quartile=13.5% versus lowest quartile=36.5%; p<0.001 for trend). A lower prevalence of diabetes was also observed in highest (6.3%) versus lowest (14.4%) neighborhood quartiles, but was not significantly different (p= 0.24 for trend). Highest versus lowest neighborhood quartile was associated with lower HbA1c (-0.31%, p=0.02) in unadjusted models. Women in the highest versus lowest neighborhood quartile had lower BMI (-2.01 kg/m2, p=0.001) and higher HDL-cholesterol (+6.09 mg/dL, p=0.01) after accounting for age, race, inflammation, and smoking. CONCLUSION: Worse neighborhood characteristics are associated with adiposity, hyperglycemia, and low HDL. Further longitudinal studies are needed and can inform future interventions to improve metabolic status in older adults.
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Diabetes Mellitus/epidemiologia , Hiperlipidemias/epidemiologia , Hipertensão/epidemiologia , Obesidade/epidemiologia , Características de Residência/estatística & dados numéricos , Adiposidade , Idoso , Baltimore/epidemiologia , Pressão Sanguínea , Índice de Massa Corporal , HDL-Colesterol/sangue , Estudos Transversais , Diabetes Mellitus/sangue , Feminino , Hemoglobinas Glicadas/análise , Inquéritos Epidemiológicos , Humanos , Hiperlipidemias/sangue , Hipertensão/sangue , Obesidade/sangue , Prevalência , Grupos Raciais , Fumar/epidemiologiaRESUMO
The stimulatory effects of testosterone on erythropoiesis are very well known, but the mechanisms underlying the erythropoietic action of testosterone are still poorly understood, although erythropoietin has long been considered a potential mediator. A total of 108 healthy men >65 years old with serum testosterone concentration <475 ng/dL were recruited by direct mailings to alumni of the University of Pennsylvania and Temple University, and randomized to receive a 60-cm(2) testosterone or placebo patch for 36 months. Ninety-six subjects completed the trial. We used information and stored serum specimens from this trial to test the hypothesis that increasing testosterone increases haemoglobin by stimulating erythropoietin production. We used information of 67 men, 43 in the testosterone group and 24 in the placebo group who had banked specimens available for assays of testosterone, haemoglobin and erythropoietin at baseline and after 36 months. The original randomized clinical study was primarily designed to verify the effects of testosterone on bone mineral density. The primary outcome of this report was to investigate whether or not transdermal testosterone increases haemoglobin by increasing erythropoietin levels. The mean age ± SD of the 67 subjects at baseline was 71.8 ± 4.9 years. Testosterone replacement therapy for 36 months, as compared with placebo, induced a significant increase in haemoglobin (0.86 ± 0.31 g/dL, p = 0.01), but no change in erythropoietin levels (-0.24 ± 2.16 mIU/mL, p = 0.91). Included time-varying measure of erythropoietin did not significantly account for the effect of testosterone on haemoglobin (Treatment-by-time: ß = 0.93, SE = 0.33, p = 0.01). No serious adverse effect was observed. Transdermal testosterone treatment of older men for 36 months significantly increased haemoglobin, but not erythropoietin levels. The haematopoietic effect of testosterone does not appear to be mediated by stimulation of erythropoietin production.
Assuntos
Eritropoetina/sangue , Hematopoese/efeitos dos fármacos , Terapia de Reposição Hormonal , Testosterona/administração & dosagem , Administração Cutânea , Idoso , Biomarcadores/sangue , Método Duplo-Cego , Hemoglobinas/metabolismo , Humanos , Masculino , Philadelphia , Testosterona/sangue , Testosterona/deficiência , Fatores de Tempo , Adesivo Transdérmico , Resultado do Tratamento , Regulação para CimaRESUMO
OBJECTIVES: Frailty status is associated with altered glucose-insulin dynamics. Here, we sought to investigate whether alteration in the dynamics of other circulating energy metabolism hormones after oral glucose is associated with frailty status. DESIGN: Substudy of older women in a prospective cohort. SETTING: Baltimore, Maryland. PARTICIPANTS: Seventy-three community-dwelling women aged 84-95 years without a diagnosis of diabetes who were enrolled in the Women's Health and Aging Study II. MEASUREMENTS: We examined stimulus-response dynamics of free fatty acids (FFA), gut- (ghrelin,GLP-1) and adipocyte-derived hormones (leptin, adiponectin, resistin), growth hormone (GH), insulin-like growth factor 1 (IGF-1), and interleukin-6 (IL-6) at 0, 30, 60, 120, and 180-minutes after a 75-g glucose challenge according to frailty status (non-frail, pre-frail, or frail). RESULTS: On average, frail women had higher fasting levels of glucose-raising hormones (FFA, resistin, GH, and IL-6) and lower fasting levels of glucose-lowering hormones (ghrelin, adiponectin, GLP-1 and IGF-1) versus non-frail women but these results were not statistically significant. Frail women also had higher fasting levels of leptin with relative adiposity compared to their counterparts, suggestive of leptin-resistance. Integrated area under the curve (AUC) values for each hormone followed similar trends by frailty status. After age and BMI adjustment, frail versus non-frail women were more likely to be in the lowest tertile of fasting ghrelin levels and 120-min ghrelin levels (both p<0.05) in logistic regression analyses. No large differences were found for other hormones in adjusted models. CONCLUSIONS: Our findings suggest dysregulation of the orexigenic hormone ghrelin in the frailty syndrome. Further studies are needed to explore the role of ghrelin dysregulation in the clinical manifestation of frailty.
Assuntos
Metabolismo Energético , Idoso Fragilizado , Grelina/sangue , Glucose/metabolismo , Adipocinas/sangue , Adiposidade , Idoso de 80 Anos ou mais , Baltimore , Índice de Massa Corporal , Estudos de Coortes , Ácidos Graxos não Esterificados/sangue , Feminino , Avaliação Geriátrica , Teste de Tolerância a Glucose , Hormônio do Crescimento Humano/sangue , Humanos , Fator de Crescimento Insulin-Like I/análise , Interleucina-6/sangue , Estudos Longitudinais , Estudos ProspectivosRESUMO
BACKGROUND/OBJECTIVES: Vitamin D deficiency is associated with cardiovascular disease, osteoporosis, poor muscle strength, falls, fractures and mortality. Although older adults are at a higher risk of vitamin D deficiency, the relationship of serum 25-hydroxyvitamin D (25(OH)D) with all-cause and cardiovascular disease mortality has not been well characterized in the elderly. We hypothesized that low serum 25(OH)D levels predicted mortality in older adults. SUBJECTS/METHODS: Serum 25(OH)D as well as all-cause and cardiovascular disease mortality were examined in 1006 adults, aged > or =65 years, who participated in the InCHIANTI (Invecchiare in Chianti, Aging in the Chianti Area) study, a population-based, prospective cohort study of aging in Tuscany, Italy. Serum 25(OH)D levels were measured at the time of enrollment in 1998-1999, and participants were followed up for mortality. RESULTS: During 6.5 years of follow-up, 228 (22.7%) participants died, of whom 107 died due to cardiovascular diseases. Compared with participants in the highest quartile of serum 25(OH)D (>26.5 ng/ml) (to convert to nmol/l, multiply by 2.496), those in the lowest quartile (<10.5 ng/ml) had increased risk of all-cause mortality (Hazard Ratio (H.R.) 2.11, 95% Confidence Interval (95% C.I.): 1.22-3.64, P=0.007) and cardiovascular disease mortality (H.R. 2.64, 95% C.I.: 1.14-4.79, P=0.02), in multivariate Cox proportional hazards models that adjusted for age, sex, education, season, physical activity and other potential confounders. CONCLUSIONS: Older community-dwelling adults with low serum 25(OH)D levels are at higher risk of all-cause and cardiovascular disease mortality.
Assuntos
Doenças Cardiovasculares/mortalidade , Deficiência de Vitamina D/mortalidade , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/sangue , Causas de Morte , Feminino , Humanos , Itália/epidemiologia , Masculino , Modelos de Riscos Proporcionais , Estudos Prospectivos , Características de Residência , Resultado do Tratamento , Vitamina D/sangue , Deficiência de Vitamina D/sangueRESUMO
INTRODUCTION: The correlation between dehydroepiandrosterone sulfate (DHEAS) decline and age led to the hypothesis that DHEAS might be a marker of primary aging, though conflicting data from observational studies of mortality do not support this. We evaluated concurrent DHEAS and functional decline in a very old cohort to test if DHEAS change tracks with functional change during aging. METHODS: DHEAS and functional performance (gait speed, grip strength, Modified Mini-Mental State Examination [3MSE] score, and digit symbol substitution test [DSST] score) were measured in 1996-1997 and 2005-2006 in 989 participants in the Cardiovascular Health Study All Stars study (mean age 85.2 years in 2005-2006, 63.5% women and 16.5% African American). We used multivariable linear regression to test the association of DHEAS decline with functional decline. RESULTS: After adjustment, each standard deviation decrease in DHEAS was associated with greater declines in gait speed (0.12 m/s, p = .01), grip strength (0.09 kg, p = .03), 3MSE score (0.13 points, p < .001), and DSST score (0.14 points, p = .001) in women only. Additional adjustment for baseline DHEAS attenuated the association with grip strength but did not alter other estimates appreciably, and baseline DHEAS was unassociated with functional decline. CONCLUSIONS: In this cohort of very old individuals, DHEAS decline tracked with declines in gait speed, 3MSE score, and DSST score, but not grip strength, in women independent of baseline DHEAS level. DHEAS decline might be a marker for age-associated performance decline, but its relevance is specific to women.
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Sulfato de Desidroepiandrosterona/sangue , Avaliação Geriátrica , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Cognição , Estudos de Coortes , Feminino , Marcha , Força da Mão , Inquéritos Epidemiológicos , Humanos , Estudos Longitudinais , Masculino , Testes Neuropsicológicos , Fatores Sexuais , Estados UnidosRESUMO
The inflammatory cytokine interleukin-6 (IL-6) has been linked to poor health outcomes in older adults. Oxidative stress triggers the production of IL-6, and antioxidant micronutrients play a critical role in decreasing this inflammatory response. The authors sought to identify the relations between serum levels of antioxidant nutrients and IL-6 and mortality in older women. Levels of alpha- and beta-carotene, lycopene, lutein/zeaxanthin, alpha-cryptoxanthin, total carotenoids, retinol, alpha-tocopherol, zinc, and selenium were measured at baseline in 619 participants in Women's Health and Aging Study I (Baltimore, Maryland, 1992-1998). IL-6 was measured at baseline and at follow-up 1 and 2 years later, and all-cause mortality was determined over a 5-year period. Participants with the highest serum levels of alpha-carotene, total carotenoids, and selenium were significantly less likely to be in the highest tertile of serum IL-6 at baseline (p < 0.0001). Those with the lowest levels of alpha- and beta-carotene, lutein/zeaxanthin, and total carotenoids were significantly more likely to have increasing IL-6 levels over a period of 2 years. Those with the lowest selenium levels had a significantly higher risk of total mortality over a period of 5 years (hazard ratio = 1.54, 95% confidence interval: 1.03, 2.32). These findings suggest that specific antioxidant nutrients may play an important role in suppressing IL-6 levels in disabled older women.
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Antioxidantes/farmacologia , Inflamação/prevenção & controle , Interleucina-6/sangue , Mortalidade , Saúde da Mulher , Idoso , Idoso de 80 Anos ou mais , Antioxidantes/análise , Baltimore/epidemiologia , Carotenoides/sangue , Carotenoides/farmacologia , Estudos Transversais , Suplementos Nutricionais , Feminino , Idoso Fragilizado , Humanos , Inflamação/sangue , Interleucina-6/antagonistas & inibidores , Estudos Longitudinais , Estresse Oxidativo , Medição de Risco , Fatores de Risco , Selênio/sangue , Selênio/farmacologiaRESUMO
Frailty, which is a state of high vulnerability that imparts a high risk of developing adverse health outcomes, affects many elderly subjects, especially men and women aged 80 yr and older (1). Although many different definitions of frailty have been proposed (2), a large portion of the recent literature has focused on the definition developed by L. Fried et al. (1) using the data from the Cardiovascular Health Study. Although this definition has not been officially recognized as the "gold standard" for the diagnosis of frailty, nonetheless most of the studies on frailty in the last 5 yr have used this definition. Several mechanisms have been hypothesized to have an important role in the development of frailty, including inflammation, coagulation and oxidative stress (3). Many authors implicate age-related hormonal changes to be directly or indirectly involved in the development of the frailty syndrome (4). Alterations in hypothalamic- pituitary-testicular, hypothalamic-pituitary-adrenal (HPA) and GH-IGF-I axes that accompany aging have been associated with single components of frailty, such as reduced muscle strength, bone strength or poor mobility (5, 6). However, most of these studies have focused on single hormonal changes rather than evaluating the parallel effect of aging on multiple hormonal axes. In addition, no interventional studies have specifically targeted frail older subjects (7). Since frailty by definition is a multi-system disorder, it is unlikely that changes in one axis (leading to a change in a single hormone) will explain the complexity of the dysregulation leading to frailty. Therefore, global measures of endocrine dysregulation that can discriminate between specific endocrine diseases and endocrine senescence should be developed. Observational and interventional studies will be needed to better define the role of "hormonal dysregulation", alone and in combination with other pathways, in the development of frailty in older men.
Assuntos
Idoso Fragilizado , Hormônios/fisiologia , Idoso de 80 Anos ou mais , Envelhecimento , Ponte de Artéria Coronária/efeitos adversos , Hormônios/deficiência , Humanos , Masculino , Modelos Biológicos , PrevalênciaRESUMO
AIMS: Diabetes is associated with increased mortality in older adults, but the specific contributions of diabetes-associated clinical conditions and of increasing hyperglycaemia to mortality risk are unknown. We evaluated whether cardiovascular disease, comorbidities, or degree of hyperglycaemia, particularly severe hyperglycaemia, affected diabetes-related mortality risk in older, disabled women. METHODS: Six-year mortality follow-up of a random sample of 576 disabled women (aged 65-101 years), recruited from the Medicare eligibility list in Baltimore (MD, USA). All-cause and cardiovascular mortality were evaluated by diabetes status: no diabetes; diabetes with mild, moderate, and severe hyperglycaemia [defined by tertiles of glycosylated haemoglobin (GHB) among women with diabetes]. RESULTS: Diabetes with mild, moderate, and severe hyperglycaemia was associated with an increased hazard rate (HR) for all-cause mortality, even after adjustment for demographics, risks for cardiovascular disease, cardiovascular and non-cardiovascular conditions, and other known mortality risks. A dose-response effect was suggested [mild hyperglycaemia, HR 1.81, 95% confidence interval (CI) 1.03, 3.17; moderate hyperglycaemia, HR 2.02, 95% CI 1.34, 3.57; severe hyperglycaemia, HR 2.22, 95% CI 1.17, 4.25]. Women with diabetes had a significantly increased HR for non-cardiovascular death, but not for cardiovascular death, compared with those without diabetes. CONCLUSIONS: Diabetes, whether characterized by mild, moderate or severe hyperglycaemia, appears to be an independent risk factor for excess mortality in older disabled women and this risk may increase with increasing hyperglycaemia. This mortality risk is not completely explained by vascular complications, and involves non-cardiovascular deaths. Risks and benefits of diabetes management, including glycaemic control and management of vascular and other comorbidities, should be studied in older people with complications and comorbidities.