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1.
Am J Physiol Endocrinol Metab ; 326(5): E588-E601, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38477875

RESUMO

In rodents, loss of estradiol (E2) reduces brown adipose tissue (BAT) metabolic activity. Whether E2 impacts BAT activity in women is not known. BAT oxidative metabolism was measured in premenopausal (n = 27; 35 ± 9 yr; body mass index = 26.0 ± 5.3 kg/m2) and postmenopausal (n = 25; 51 ± 8 yr; body mass index = 28.0 ± 5.0 kg/m2) women at room temperature and during acute cold exposure using [11C]acetate with positron emission tomography coupled with computed tomograph. BAT glucose uptake was also measured during acute cold exposure using 2-deoxy-2-[18F]fluoro-d-glucose. To isolate the effects of ovarian hormones from biological aging, measurements were repeated in a subset of premenopausal women (n = 8; 40 ± 4 yr; BMI = 28.0 ± 7.2 kg/m2) after 6 mo of gonadotropin-releasing hormone agonist therapy to suppress ovarian hormones. At room temperature, there was no difference in BAT oxidative metabolism between premenopausal (0.56 ± 0.31 min-1) and postmenopausal women (0.63 ± 0.28 min-1). During cold exposure, BAT oxidative metabolism (1.28 ± 0.85 vs. 0.91 ± 0.63 min-1, P = 0.03) and net BAT glucose uptake (84.4 ± 82.5 vs. 29.7 ± 31.4 nmol·g-1·min-1, P < 0.01) were higher in premenopausal than postmenopausal women. In premenopausal women who underwent gonadotropin-releasing hormone agonist, cold-stimulated BAT oxidative metabolism was reduced to a similar level (from 1.36 ± 0.66 min-1 to 0.91 ± 0.41 min-1) to that observed in postmenopausal women (0.91 ± 0.63 min-1). These results provide the first evidence in humans that reproductive hormones are associated with BAT oxidative metabolism and suggest that BAT may be a target to attenuate age-related reduction in energy expenditure and maintain metabolic health in postmenopausal women.NEW & NOTEWORTHY In rodents, loss of estrogen reduces brown adipose tissue (BAT) activity. Whether this is true in humans is not known. We found that BAT oxidative metabolism and glucose uptake were lower in postmenopausal compared to premenopausal women. In premenopausal women who underwent ovarian suppression to reduce circulating estrogen, BAT oxidative metabolism was reduced to postmenopausal levels. Thus the loss of ovarian function in women leads to a reduction in BAT metabolic activity independent of age.


Assuntos
Tecido Adiposo Marrom , Fluordesoxiglucose F18 , Humanos , Feminino , Tecido Adiposo Marrom/metabolismo , Fluordesoxiglucose F18/metabolismo , Metabolismo Energético , Glucose/metabolismo , Tomografia por Emissão de Pósitrons , Estrogênios/farmacologia , Hormônio Liberador de Gonadotropina/metabolismo , Temperatura Baixa , Termogênese
2.
Lancet Healthy Longev ; 4(10): e561-e572, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37804846

RESUMO

BACKGROUND: Testosterone replacement therapy is known to improve sexual function in men younger than 40 years with pathological hypogonadism. However, the extent to which testosterone alleviates sexual dysfunction in older men and men with obesity is unclear, despite the fact that testosterone is being increasingly prescribed to these patient populations. We aimed to evaluate whether subgroups of men with low testosterone derive any symptomatic benefit from testosterone treatment. METHODS: We did a systematic review and meta-analysis to evaluate characteristics associated with symptomatic benefit of testosterone treatment versus placebo in men aged 18 years and older with a baseline serum total testosterone concentration of less than 12 nmol/L. We searched major electronic databases (MEDLINE, Embase, Science Citation Index, and the Cochrane Central Register of Controlled Trials) and clinical trial registries for reports published in English between Jan 1, 1992, and Aug 27, 2018. Anonymised individual participant data were requested from the investigators of all identified trials. Primary (cardiovascular) outcomes from this analysis have been published previously. In this report, we present the secondary outcomes of sexual function, quality of life, and psychological outcomes at 12 months. We did a one-stage individual participant data meta-analysis with a random-effects linear regression model, and a two-stage meta-analysis integrating individual participant data with aggregated data from studies that did not provide individual participant data. This study is registered with PROSPERO, CRD42018111005. FINDINGS: 9871 citations were identified through database searches. After exclusion of duplicates and publications not meeting inclusion criteria, 225 full texts were assessed for inclusion, of which 109 publications reporting 35 primary studies (with a total 5601 participants) were included. Of these, 17 trials provided individual participant data (3431 participants; median age 67 years [IQR 60-72]; 3281 [97%] of 3380 aged ≥40 years) Compared with placebo, testosterone treatment increased 15-item International Index of Erectile Function (IIEF-15) total score (mean difference 5·52 [95% CI 3·95-7·10]; τ2=1·17; n=1412) and IIEF-15 erectile function subscore (2·14 [1·40-2·89]; τ2=0·64; n=1436), reaching the minimal clinically important difference for mild erectile dysfunction. These effects were not found to be dependent on participant age, obesity, presence of diabetes, or baseline serum total testosterone. However, absolute IIEF-15 scores reached during testosterone treatment were subject to thresholds in patient age and baseline serum total testosterone. Testosterone significantly improved Aging Males' Symptoms score, and some 12-item or 36-item Short Form Survey quality of life subscores compared with placebo, but it did not significantly improve psychological symptoms (measured by Beck Depression Inventory). INTERPRETATION: In men aged 40 years or older with baseline serum testosterone of less than 12 nmol/L, short-to-medium-term testosterone treatment could provide clinically meaningful treatment for mild erectile dysfunction, irrespective of patient age, obesity, or degree of low testosterone. However, due to more severe baseline symptoms, the absolute level of sexual function reached during testosterone treatment might be lower in older men and men with obesity. FUNDING: National Institute for Health and Care Research Health Technology Assessment Programme.


Assuntos
Disfunção Erétil , Hipogonadismo , Humanos , Masculino , Disfunção Erétil/tratamento farmacológico , Hipogonadismo/tratamento farmacológico , Obesidade/tratamento farmacológico , Qualidade de Vida , Testosterona/uso terapêutico
3.
Am J Physiol Heart Circ Physiol ; 323(5): H975-H982, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36149770

RESUMO

Endothelial function (brachial artery flow-mediated dilation [FMD]) is reduced in estrogen-deficient postmenopausal women, mediated, in part, by reduced nitric oxide (NO) bioavailability, secondary to tetrahydrobiopterin (BH4) deficiency and oxidative stress. FMD is increased, but not fully restored, in postmenopausal women after acute intravenous vitamin C (VITC; superoxide scavenger) or oral BH4 supplementation. In vitro studies demonstrate that coadministration of VITC with BH4 prevents endothelial nitric oxide synthase (eNOS) uncoupling and reductions in NO by peroxynitrite. To investigate mechanisms of endothelial dysfunction in women, we assessed the separate and combined effects of VITC and BH4 to determine whether coadministration of VITC + BH4 improves FMD in healthy postmenopausal women (n = 19, 58 ± 5 yr) to premenopausal (n = 14, 36 ± 9 yr) levels, with exploratory testing in perimenopausal women (n = 8, 51 ± 3 yr). FMD was measured during acute intravenous infusions of saline (control) and VITC (∼2-3 g) ∼3 h after a single dose of oral BH4 (KUVAN, 10 mg/kg body wt) or placebo (randomized crossover, separated by ∼1 mo). Under the placebo condition, FMD was reduced in postmenopausal compared with premenopausal women during the saline infusion (5.6 ± 0.7 vs. 11.6 ± 0.9%, P < 0.001) and increased in postmenopausal women during VITC (+3.5 [1.4, 5.6]%, P = 0.001) and acute BH4 (+1.8 [0.37, 3.2]%, P = 0.01) alone. Coadministration of VITC + BH4 increased FMD in postmenopausal women (+3.0 [1.7, 4.3]%, P < 0.001), but FMD remained reduced compared with premenopausal women (P = 0.02). Exploratory analyses revealed that VITC + BH4 did not restore FMD in perimenopausal women to premenopausal levels (P = 0.045). Coadministration of VITC + BH4 does not restore FMD in menopausal women, suggesting that additional mechanisms may be involved.NEW & NOTEWORTHY Endothelial function is reduced across the menopausal stages related to increased oxidative stress associated with estrogen deficiency. In vitro studies demonstrate that coadministration of VITC with BH4 prevents endothelial nitric oxide synthase (eNOS) uncoupling and reductions in NO by peroxynitrite; however, this remains untested in humans. We demonstrate that the coadministration of BH4 + VITC does not restore endothelial function in perimenopausal and postmenopausal women to the level of premenopausal women, suggesting that other mechanisms contribute.


Assuntos
Óxido Nítrico Sintase Tipo III , Doenças Vasculares , Humanos , Feminino , Óxido Nítrico Sintase Tipo III/metabolismo , Endotélio Vascular/metabolismo , Ácido Peroxinitroso/metabolismo , Biopterinas/metabolismo , Biopterinas/farmacologia , Menopausa , Estrogênios/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo
4.
Lancet Healthy Longev ; 3(6): e381-e393, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35711614

RESUMO

Background: Testosterone is the standard treatment for male hypogonadism, but there is uncertainty about its cardiovascular safety due to inconsistent findings. We aimed to provide the most extensive individual participant dataset (IPD) of testosterone trials available, to analyse subtypes of all cardiovascular events observed during treatment, and to investigate the effect of incorporating data from trials that did not provide IPD. Methods: We did a systematic review and meta-analysis of randomised controlled trials including IPD. We searched MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE Epub Ahead of Print, Embase, Science Citation Index, the Cochrane Controlled Trials Register, Cochrane Database of Systematic Reviews, and Database of Abstracts of Review of Effects for literature from 1992 onwards (date of search, Aug 27, 2018). The following inclusion criteria were applied: (1) men aged 18 years and older with a screening testosterone concentration of 12 nmol/L (350 ng/dL) or less; (2) the intervention of interest was treatment with any testosterone formulation, dose frequency, and route of administration, for a minimum duration of 3 months; (3) a comparator of placebo treatment; and (4) studies assessing the pre-specified primary or secondary outcomes of interest. Details of study design, interventions, participants, and outcome measures were extracted from published articles and anonymised IPD was requested from investigators of all identified trials. Primary outcomes were mortality, cardiovascular, and cerebrovascular events at any time during follow-up. The risk of bias was assessed using the Cochrane Risk of Bias tool. We did a one-stage meta-analysis using IPD, and a two-stage meta-analysis integrating IPD with data from studies not providing IPD. The study is registered with PROSPERO, CRD42018111005. Findings: 9871 citations were identified through database searches and after exclusion of duplicates and of irrelevant citations, 225 study reports were retrieved for full-text screening. 116 studies were subsequently excluded for not meeting the inclusion criteria in terms of study design and characteristics of intervention, and 35 primary studies (5601 participants, mean age 65 years, [SD 11]) reported in 109 peer-reviewed publications were deemed suitable for inclusion. Of these, 17 studies (49%) provided IPD (3431 participants, mean duration 9·5 months) from nine different countries while 18 did not provide IPD data. Risk of bias was judged to be low in most IPD studies (71%). Fewer deaths occurred with testosterone treatment (six [0·4%] of 1621) than placebo (12 [0·8%] of 1537) without significant differences between groups (odds ratio [OR] 0·46 [95% CI 0·17-1·24]; p=0·13). Cardiovascular risk was similar during testosterone treatment (120 [7·5%] of 1601 events) and placebo treatment (110 [7·2%] of 1519 events; OR 1·07 [95% CI 0·81-1·42]; p=0·62). Frequently occurring cardiovascular events included arrhythmia (52 of 166 vs 47 of 176), coronary heart disease (33 of 166 vs 33 of 176), heart failure (22 of 166 vs 28 of 176), and myocardial infarction (10 of 166 vs 16 of 176). Overall, patient age (interaction 0·97 [99% CI 0·92-1·03]; p=0·17), baseline testosterone (interaction 0·97 [0·82-1·15]; p=0·69), smoking status (interaction 1·68 [0·41-6·88]; p=0.35), or diabetes status (interaction 2·08 [0·89-4·82; p=0·025) were not associated with cardiovascular risk. Interpretation: We found no evidence that testosterone increased short-term to medium-term cardiovascular risks in men with hypogonadism, but there is a paucity of data evaluating its long-term safety. Long-term data are needed to fully evaluate the safety of testosterone. Funding: National Institute for Health Research Health Technology Assessment Programme.


Assuntos
Insuficiência Cardíaca , Hipogonadismo , Infarto do Miocárdio , Idoso , Humanos , Masculino , Revisões Sistemáticas como Assunto , Testosterona
5.
J Appl Physiol (1985) ; 133(2): 403-415, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35771224

RESUMO

Aging is associated with reductions in cardiovagal baroreflex sensitivity (cBRS), which increases cardiovascular disease risk. Preclinical data indicate that low testosterone reduces cBRS. We determined whether low testosterone is associated with greater age-associated reductions in cBRS in healthy men. Twenty-six men categorized as young (N = 6; age = 31 ± 4 yr; testosterone = 535 ± 60 ng/dL), middle-aged/older with normal (N = 10; aged 56 ± 3 yr; testosterone = 493 ± 85 ng/dL) or low (N = 10; age = 57 ± 6 yr; testosterone = 262 ± 31 ng/dL) testosterone underwent recordings of beat-by-beat blood pressure and R-R interval during rest and two Valsalva maneuvers, and measures of carotid artery compliance. IL-6, C-reactive protein (CRP), oxidized LDL cholesterol, and total antioxidant status (TAS) were also measured in blood. Middle-aged/older men had lower cBRS compared with young men (17.0 ± 6.5 ms/mmHg; P = 0.028); middle-age/older men with low testosterone had lower cBRS (5.5 ± 3.2 ms/mmHg; P = 0.039) compared with age-matched men with normal testosterone (10.7 ± 4.0 ms/mmHg). No differences existed between groups during Phase II of the Valsalva maneuver; middle-aged/older men with low testosterone had reduced cBRS (4.7 ± 2.6 ms/mmHg) compared with both young (12.8 ± 2.8 ms/mmHg; P < 0.001) and middle-aged/older men with normal testosterone (8.6 ± 4.4 ms/mmHg; P = 0.046). There were no differences in oxidized LDL (P = 0.882) or TAS across groups (P = 0.633). IL-6 was significantly higher in middle-aged/older men with low testosterone compared with the other groups (P < 0.05 for all) and inversely correlated with cBRS (r = -0.594, P = 0.007). Middle-aged/older men had reduced carotid artery compliance compared with young, regardless of testosterone status (P < 0.001). These observations indicate that low testosterone in middle-aged/older men may contribute to reductions in cBRS. These data suggest that increased inflammation may contribute to reductions in cBRS.NEW & NOTEWORTHY Middle-aged/older men with low testosterone have accelerated reductions in cardiovagal BRS compared with middle-aged/older men with normal testosterone. Increased concentrations of the proinflammatory cytokine IL-6 appear to contribute to the reductions in cardiovagal BRS in men with low testosterone.


Assuntos
Barorreflexo , Testosterona , Adulto , Idoso , Antioxidantes/análise , Barorreflexo/fisiologia , Pressão Sanguínea/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Interleucina-6/análise , Interleucina-6/metabolismo , Masculino , Pessoa de Meia-Idade , Testosterona/análise , Testosterona/deficiência , Testosterona/fisiologia
6.
J Clin Endocrinol Metab ; 107(2): e500-e514, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34597384

RESUMO

CONTEXT: Vascular aging, including endothelial dysfunction secondary to oxidative stress and inflammation, increases the risk for age-associated cardiovascular disease (CVD). Low testosterone in middle-aged/older men is associated with increased CVD risk. OBJECTIVE: We hypothesized that low testosterone contributes to age-associated endothelial dysfunction, related in part to greater oxidative stress and inflammation. METHODS: This cross-sectional study included 58 healthy, nonsmoking men categorized as young (N = 20; age 29 ± 4 years; testosterone 500 ± 58 ng/dL), middle-aged/older with higher testosterone (N = 20; age 60 ± 6 years; testosterone 512 ± 115 ng/dL), and middle-aged/older lower testosterone (N = 18; age 59 ± 8 years; testosterone 269 ± 48 ng/dL). Brachial artery flow-mediated dilation (FMDBA) was measured during acute infusion of saline (control) and vitamin C (antioxidant). Markers of oxidative stress (total antioxidant status and oxidized low-density lipoprotein cholesterol), inflammation (interleukin [IL]-6 and C-reactive protein [CRP]), and androgen deficiency symptoms were also examined. RESULTS: During saline, FMDBA was reduced in middle-aged/older compared with young, regardless of testosterone status (P < 0.001). FMDBA was reduced in middle-aged/older lower testosterone (3.7% ± 2.0%) compared with middle-aged/older higher testosterone (5.7% ± 2.2%; P = 0.021), independent of symptoms. Vitamin C increased FMDBA (to 5.3% ± 1.6%; P = 0.022) in middle-aged/older lower testosterone but had no effect in young (P = 0.992) or middle-aged/older higher testosterone (P = 0.250). FMDBA correlated with serum testosterone (r = 0.45; P < 0.001), IL-6 (r = -0.41; P = 0.002), and CRP (r = -0.28; P = 0.041). CONCLUSION: Healthy middle-aged/older men with low testosterone appear to have greater age-associated endothelial dysfunction, related in part to greater oxidative stress and inflammation. These data suggest that low testosterone concentrations may contribute to accelerated vascular aging in men.


Assuntos
Envelhecimento/metabolismo , Doenças Cardiovasculares/epidemiologia , Endotélio Vascular/fisiopatologia , Testosterona/deficiência , Adolescente , Adulto , Idoso , Envelhecimento/sangue , Envelhecimento/imunologia , Velocidade do Fluxo Sanguíneo , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , Estudos Transversais , Endotélio Vascular/diagnóstico por imagem , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/imunologia , Pletismografia , Testosterona/sangue , Ultrassonografia Doppler , Adulto Jovem
7.
Contemp Clin Trials ; 104: 106356, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33716173

RESUMO

BACKGROUND: Up to 75% of hip fracture patients never recover to their pre-fracture functional status. Supervised exercise that includes strength training can improve functional recovery after hip fracture. The role of testosterone replacement for augmenting the effects of exercise in older women after hip fracture is unknown. METHODS: The Starting Testosterone and Exercise after Hip Injury (STEP-HI) Study is a 6-month Phase 3 multicenter randomized placebo-controlled trial designed to compare supervised exercise (EX) plus 1% testosterone topical gel, with EX plus placebo gel, and with enhanced usual care (EUC). Female hip fracture patients age ≥ 65 years are being recruited from clinical centers across the United States. Participants are community dwelling and enrolled within 24 weeks after surgical repair of the fracture. The EX intervention is a center-based program of progressive resistance training. The EUC group receives a home exercise program and health education. Participants receive dietary counseling, calcium and vitamin D. The primary outcome is the Six Minute Walk Distance. Secondary outcomes include physical performance measures, self-reported function and quality of life, and dual energy x-ray absorptiometry measures of body composition and bone mineral density. RESULTS: Enrollment, interventions, and follow-up are ongoing. We describe the impact of the coronavirus disease 2019 pandemic on the trial, including modifications made to allow continuation of the interventions and outcome data collection using remote video and audio technology. CONCLUSIONS: Results from the STEP-HI study are expected to have important clinical and public health implications for management of the growing population of hip fracture patients.


Assuntos
COVID-19 , Estado Funcional , Fraturas do Quadril/reabilitação , Treinamento Resistido/métodos , Testosterona , Teste de Caminhada/métodos , Absorciometria de Fóton/métodos , Administração Tópica , Idoso , Androgênios/administração & dosagem , Androgênios/efeitos adversos , Densidade Óssea , COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis/métodos , Feminino , Fraturas do Quadril/diagnóstico , Fraturas do Quadril/metabolismo , Fraturas do Quadril/psicologia , Humanos , Avaliação de Resultados em Cuidados de Saúde/métodos , Participação do Paciente/métodos , Recuperação de Função Fisiológica , SARS-CoV-2 , Telemedicina/métodos , Testosterona/administração & dosagem , Testosterona/efeitos adversos
8.
Artigo em Inglês | MEDLINE | ID: mdl-33572819

RESUMO

Although estradiol (E2) has been believed to be the most critical factor in the menopause-associated decrease in bone mineral density (BMD), the role of increasing follicle stimulating hormone (FSH) during menopause is relatively unclear. We determined the extent to which hip and lumbar spine BMD differ among the stages of menopause in healthy women, and whether BMD is associated with FSH and E2 levels. A cross-sectional study of 141 healthy women classified as premenopausal (Pre; 38 ± 6 yrs; mean ± SD, n = 30), early perimenopausal (EPeri; 50 ± 3yrs, n = 31), late perimenopausal (LPeri; 50 ± 4yrs, n = 30), early postmenopausal (EPost; 55 ± 3yrs, n = 24), or late postmenopausal (LPost; 62 ± 4 yrs, n = 26), was conducted. Spine/hip BMD and sex hormones were measured using dual-energy X-ray absorptiometry and enzymatic/colorimetric methods, respectively. Compared to EPeri, spine BMD was lower (p < 0.05) in LPeri, EPost, and LPost and hip BMD was lower (p < 0.05) in EPost and LPost. BMD was inversely associated with FSH (spine: r = -0.341; hip: r = -0.271, p < 0.05) and directly associated with E2 (spine: r = 0.274; hip: r = 0.256, p < 0.05). The menopause-related loss of spine and hip BMD is associated not only with low E2 but also higher FSH. Future studies are essential to delineating the mechanisms by which FSH regulates bone health in aging women.


Assuntos
Densidade Óssea , Menopausa , Absorciometria de Fóton , Estudos Transversais , Feminino , Hormônio Foliculoestimulante , Humanos
9.
Health Serv Res ; 56(2): 193-203, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33481263

RESUMO

OBJECTIVE: To evaluate the relationship between direct cognitive assessment introduced with the Medicare Annual Wellness Visit (AWV) and new diagnoses of dementia, and to determine if effects vary by race. DATA SOURCES: Medicare Limited Data Set 5% sample claims 2003-2014 and the HRSA Area Health Resources Files. STUDY DESIGN: Instrumental Variable approach estimating the relationship between AWV utilization and new diagnoses of dementia using county-level Welcome to Medicare Visit rates as an instrument. DATA COLLECTION/EXTRACTION METHODS: Three hundred twenty-four thousand three hundred and eighty-five fee-for-service Medicare beneficiaries without dementia when the AWV was introduced in 2011. PRINCIPAL FINDINGS: Annual Wellness Visit utilization was associated with an increased probability of new dementia diagnosis with effects varying by racial group (categorized as white, black, Hispanic/Latino, or Asian based on Social Security Administration data). Hazard ratios (95% confidence intervals) for new dementia diagnosis within 6 months of AWV utilization were as follows: 2.34 (2.13, 2.58) white, 2.22 (1.71, 2.89) black, 4.82 (2.94, 7.89) Asian, and 6.14 (3.70, 10.19) Hispanic (P < .001 for each). Our findings show that estimates that do not control for selection underestimate the effect of AWV on new diagnoses. CONCLUSIONS: Dementia diagnosis rates increased with AWV implementation with heterogenous effects by race and ethnicity. Current recommendations by the United States Preventive Services Task Force state that the evidence is insufficient to recommend for or against screening for cognitive impairment in older adults.


Assuntos
Demência/diagnóstico , Demência/etnologia , Medicare/estatística & dados numéricos , Testes de Estado Mental e Demência/estatística & dados numéricos , Idoso , Planos de Pagamento por Serviço Prestado , Feminino , Humanos , Revisão da Utilização de Seguros , Masculino , Grupos Raciais , Estados Unidos
10.
J Appl Physiol (1985) ; 130(1): 96-103, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33151774

RESUMO

Aging is associated with reductions in endothelial function, observations primarily reported using brachial artery ultrasound. There is growing interest in the use of peripheral artery tonometry (PAT) of microvessels in the fingertip to assess endothelial function because it is less technically demanding and has a high sensitivity and specificity for assessing coronary endothelial function. Moreover, similar to brachial artery flow-mediated dilation (FMD), PAT predicts cardiovascular disease outcomes. However, the relationship between PAT and FMD have yet to be examined in the context of aging. To address this question, reactive hyperemic index (RHI) using EndoPAT and FMD using brachial artery ultrasound were assessed after 5 min of forearm ischemia in 20 younger (18-40 yr old; 29 ± 4 yr) and 20 older (60-75 yr old; 65 ± 4 yr) healthy adult men. Higher values of both FMD and RHI indicate better endothelial function. Endothelial function assessed via brachial artery FMD was lower in older (4.8 ± 2.1%), compared with younger (7.5 ± 1.6%) men (P < 0.001). In contrast, the RHI assessed via PAT was greater in older (2.2 ± 0.6), compared with younger (1.8 ± 0.5) men (P = 0.014). FMD and RHI were not correlated (r = -0.15; P = 0.35). We conclude that PAT may not be an appropriate measure to evaluate age-associated changes in endothelial function.NEW & NOTEWORTHY Microvessel endothelial function assessed via finger plethysmography may not reflect age-associated reductions in large artery endothelial function assessed via brachial artery flow-mediated dilation.


Assuntos
Hiperemia , Vasodilatação , Adulto , Idoso , Envelhecimento , Artéria Braquial , Endotélio Vascular , Humanos , Masculino , Fluxo Sanguíneo Regional
11.
Obesity (Silver Spring) ; 28(11): 2125-2133, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33150745

RESUMO

OBJECTIVE: The purpose of this study was to determine whether suppression of ovarian function (gonadotropin-releasing hormone agonist [GnRHAG ]) for 24 weeks in premenopausal women approaching menopause causes changes in body composition and a decline in free-living physical activity energy expenditure (PAEE) and whether endurance exercise training attenuates the changes. METHODS: Premenopausal women who were approaching menopause (mean [SD]: age 46 [3] years, BMI 26.3 [4.8] kg/m2 ) were randomized to 24 weeks of GnRHAG (n = 14), GnRHAG + Exercise (n = 11), or placebo (n = 9). Endurance exercise was performed 4 days per week with the goal of expending 200 to 300 kcal per session. Primary outcome measurements included body composition by dual-energy x-ray absorptiometry, total daily energy expenditure (TDEE), and PAEE by doubly labeled water, and resting energy expenditure (REE) by indirect calorimetry. RESULTS: Changes in TDEE, PAEE, REE, or body composition were not different between groups. However, within the GnRHAG group, fat mass increased (mean [SE]: total 1.7 [0.4] kg, trunk 0.9 [0.2] kg, leg 0.6 [0.2] kg) and fat-free leg mass decreased (mean [SE]: -0.4 [0.2] kg) significantly. CONCLUSIONS: In premenopausal women approaching menopause, ovarian hormone suppression resulted in increased adiposity without alterations in TDEE, PAEE, or REE.


Assuntos
Metabolismo Energético/genética , Ovário/fisiopatologia , Pré-Menopausa/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-Idade , Ovário/efeitos dos fármacos
12.
Geroscience ; 42(6): 1699-1714, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32770384

RESUMO

Endothelial function declines progressively across stages of the menopause transition; however, the mechanisms contributing to this decline are unknown. We hypothesized that differences in endothelial function among pre-, peri, and postmenopausal women are related to differences in estradiol and oxidative stress. Brachial artery flow-mediated dilation (FMD) was measured in 87 healthy women categorized by menopause stage (24 premenopausal, 17 early and 21 late perimenopausal, and 25 postmenopausal) before and after 3 days of ovarian hormone suppression (gonadotropin releasing hormone antagonist [GnRHant]) alone, and an additional 3 days of GnRHant with concurrent transdermal estradiol or placebo add-back treatment. In 82 women, FMD during acute vitamin C (antioxidant) infusion was measured before and after GnRHant + add-back. Before GnRHant, FMD was different among groups (p < 0.005; reduced across stages of menopause). Vitamin C increased FMD in late peri- and post- (p < 0.005) but not pre- or early perimenopausal women (p > 0.54). After GnRHant alone, FMD decreased in pre- and peri- (p < 0.01), but not postmenopausal women, and was restored to premenopausal levels by estradiol add-back in the pre- and perimenopausal groups. Vitamin C improved FMD in pre-, peri-, and postmenopausal women on GnRHant + placebo. There was no effect of vitamin C on FMD in women on GnRHant + estradiol. These observations support the concept that the decline in endothelial function across the menopause transition is related to the loss of ovarian estradiol. The decline in estradiol may alter redox balance, thereby increasing oxidative stress and impairing endothelial function.


Assuntos
Endotélio Vascular , Menopausa , Endotélio Vascular/metabolismo , Estradiol/metabolismo , Feminino , Humanos , Oxirredução , Estresse Oxidativo
13.
Biol Sex Differ ; 11(1): 18, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32295637

RESUMO

Large elastic arterial stiffening and endothelial dysfunction are phenotypic characteristics of vascular aging, a major risk factor for age-associated cardiovascular diseases. Compared to men, vascular aging in women appears to be slowed until menopause, whereafter vascular aging accelerates to match that seen in men. These sex differences in vascular aging have been attributed to changes in sex hormones that occur with aging. Although the role of estradiol in vascular aging in women has been highlighted in recent aging research, little is known about the impact of declining testosterone concentrations in both sexes. Importantly, while androgen concentrations generally decline with age in men, there are data that indicate reductions in androgen concentrations in women as well. Evidence suggests that low testosterone is associated with impaired endothelial function and increased arterial stiffness in men, although the effect of androgens on vascular aging in women remains unclear. Testosterone may modulate vascular aging by mitigating the effects of oxidative stress and inflammation, although there is sex specificity to this effect. The purpose of this review is to present and summarize the research regarding sex differences in vascular aging in response to androgens, specifically testosterone. Because exercise is a potent lifestyle factor for slowing and reversing vascular aging, we briefly summarize the available literature regarding the regulatory function of testosterone on vascular adaptations to exercise training.


Assuntos
Envelhecimento/fisiologia , Doenças Cardiovasculares/fisiopatologia , Caracteres Sexuais , Testosterona/fisiologia , Animais , Exercício Físico/fisiologia , Humanos
14.
J Appl Physiol (1985) ; 128(5): 1373-1380, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32298212

RESUMO

Age-related declines in skeletal muscle mass (i.e., sarcopenia) contribute to physical disability in older women. Although a menopause-related increase in fat mass is well documented, whether menopause influences muscle mass and sarcopenia is unclear. We determined the extent to which skeletal muscle mass differs across the stages of the menopause transition in women and whether these differences are associated with estradiol or other sex hormones. This was a cross-sectional study of 144 healthy women (aged 30-70 yr) classified as premenopausal [n = 30, 38 ± 6 yr (means ± SD)], early (n = 31, 50 ± 3 yr) and late (n = 30, 50 ± 4 yr) perimenopausal, and early (n = 26, 55 ± 3 yr) and late (n = 27, 62 ± 4 yr) postmenopausal. Appendicular lean mass (ALM) adjusted by the square of height in meters (ALM index; ALMi) was assessed by dual-energy X-ray absorptiometry. ALMi was lower (P < 0.05) in late perimenopausal and postmenopausal compared with early perimenopausal, with no significant differences between other groups (premenopausal 6.6 ± 0.6, early perimenopausal 6.8 ± 0.8, late perimenopausal 6.1 ± 0.8, early postmenopausal 6.5 ± 1.1, and late postmenopausal 6.2 ± 0.9 kg/m2). The prevalence of sarcopenia (ALMi ≤ 5.67 kg/m2) was 7%, 3%, 30%, 27%, and 32% in premenopausal, early and late perimenopausal, and early and late postmenopausal groups, respectively. ALMi measured across menopause stages was inversely correlated to follicle-stimulating hormone (FSH; r = -0.28, P = 0.003) but not to estradiol (r = 0.088, P = 0.34). The menopause transition appears to be a vulnerable period for the loss of skeletal muscle mass that may begin during the late perimenopausal transition. Future studies are necessary to investigate the potential effect of FSH on skeletal muscle.NEW & NOTEWORTHY Our data suggest that the late perimenopausal stage may be a vulnerable period for the loss of skeletal muscle, potentially related to elevations in FSH.


Assuntos
Composição Corporal , Menopausa , Músculo Esquelético , Perimenopausa , Adulto , Idoso , Estudos Transversais , Feminino , Hormônio Foliculoestimulante , Humanos , Pessoa de Meia-Idade , Pré-Menopausa
15.
J Appl Physiol (1985) ; 128(4): 739-747, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32134713

RESUMO

Regular exercise enhances endothelial function in older men, but not consistently in estrogen-deficient postmenopausal women. Estradiol treatment improves basal endothelial function and restores improvements in endothelial function (flow-mediated dilation, FMD) to aerobic exercise training in postmenopausal women; however, estradiol treatment is controversial. Resveratrol, an estrogen receptor ligand, enhances exercise training effects on cardiovascular function and nitric oxide (NO) release in animal models, but impairs exercise training effects in men. We conducted a randomized cross-over, double-blinded, placebo-controlled pilot study to determine whether acute (single dose) resveratrol (250-mg tablet) or estradiol (0.05 mg/day transdermal patch) treatment enhances FMD at rest and after a single bout of moderate-intensity aerobic exercise in healthy estrogen-deficient postmenopausal women (n = 15, 58.1 ± 3.2 yr). FMD was measured before and after (30, 60, and 120 min) a 40-min bout of moderate-intensity treadmill exercise (60-75% peak heart rate) under the respective conditions (separated by 1-2 wk). FMD was higher (P < 0.05) before exercise and at all post-exercise time points in the resveratrol and estradiol conditions compared to placebo. FMD was increased from baseline by 120 min postexercise in the estradiol condition (P < 0.001), but not resveratrol or PL conditions. Consistent with our previous findings, estradiol also enhances endothelial function in response to acute endurance exercise. Although resveratrol improved basal FMD, there was no apparent enhancement of FMD to acute exercise and, therefore, may not act as an estradiol mimetic.NEW & NOTEWORTHY The benefits of endurance exercise training on endothelial function are diminished in estrogen-deficient postmenopausal women, but estradiol treatment appears to restore improvements in endothelial function in this group. We show that basal endothelial function is enhanced with both acute estradiol and resveratrol treatments in estrogen-deficient postmenopausal women, but endothelial function is only enhanced following acute endurance exercise with estradiol treatment.


Assuntos
Artéria Braquial , Estradiol , Idoso , Endotélio Vascular , Estrogênios , Feminino , Humanos , Masculino , Pós-Menopausa , Resveratrol/farmacologia , Vasodilatação
16.
Curr Dev Nutr ; 3(11): nzz113, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31737860

RESUMO

BACKGROUND: High-fat meal (HFM) consumption may induce transient postprandial atherogenic responses, including impairment of vascular endothelial function, in individuals with overweight/obesity. Red beetroot juice (RBJ) may modulate endothelial function and other measures of cardiometabolic health. OBJECTIVE: This study investigated the impact of acute and chronic RBJ consumption, including nitrate-dependent and -independent effects, on postprandial endothelial function and other cardiometabolic responses to a HFM. METHODS: Fifteen men and postmenopausal women with overweight/obesity were enrolled in this randomized, double-blind, placebo-controlled, 4-period, crossover clinical trial. Following an overnight fast, participants underwent baseline assessment of endothelial function (reactive hyperemia index; RHI) and hemodynamics, and biological sample collection. In random order, participants consumed 70 mL (acute visit) of: 1) RBJ, 2) nitrate-free RBJ (NF-RBJ), 3) placebo + nitrate (PBO + NIT), or 4) placebo (PBO), followed by a HFM. RHI was remeasured 4 h post-HFM, and hemodynamic assessment and biological sample collection were performed 1, 2, and 4 h post-HFM consumption. Participants consumed treatments daily for 4 wk (chronic visit), and assessments were repeated before/after the HFM (without consuming treatments). RESULTS: HFM consumption did not induce significant impairment of postprandial RHI. No significant differences in RHI were detected across treatment groups following acute or chronic exposure, despite increases in circulating nitrate/nitrite (NOx) concentrations in the RBJ and PBO + NIT groups compared with PBO and NF-RBJ (P < 0.0001 for all time points at the acute visit; P < 0.05 for all time points at the chronic visit). Although the HFM led to significant alterations in several secondary outcomes, there were no consistent treatment effects on postprandial cardiometabolic responses. CONCLUSIONS: HFM consumption did not impair postprandial endothelial function in this population, and RBJ exposure did not alter postprandial endothelial function or other outcomes despite increasing NOx concentrations. This trial is registered at clinicaltrials.gov as NCT02949115.

17.
Med Care ; 57(12): 984-989, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31584462

RESUMO

INTRODUCTION: The Medicare Annual Wellness Visit (AWV) is a preventive care visit introduced in 2011 as part of the Affordable Care Act provided without cost to beneficiaries. The AWV is associated with higher preventive services utilization. Although AWV utilization increased during 2011-2013, utilization was lower among ethnoracial minority beneficiaries who may benefit the most. OBJECTIVES: To determine if AWV utilization disparities have persisted using the most recent data available. RESEARCH DESIGN: The authors analyzed AWV utilization in 2011-2013 and 2015-2016 by beneficiary-reported race and ethnicity, adjusting for potential confounders. SUBJECTS: Weighted sample of 78,639,501 fee-for-service Medicare beneficiaries aged 66 years and older who participated in the Medicare Current Beneficiary Survey 2011-2013 or 2015-2016. MEASURES: AWV utilization was identified using Medicare claims. RESULTS: AWV utilization increased from 8.1% to 23.0% of all beneficiaries between 2011 and 2016. Compared with non-Hispanic white beneficiaries, utilization was significantly lower among non-Hispanic Black and non-Hispanic other race beneficiaries in both the minimally and fully-adjusted models. Hispanic/Latino beneficiaries had lower utilization in the minimally adjusted model, but not in the fully-adjusted model. In 2016, compared with non-Hispanic white beneficiaries, AWV utilization was 10.2 points lower for non-Hispanic black, 11.6 points lower for Hispanic/Latino, and 8.6 points lower for non-Hispanic other race beneficiaries, and these differences were attenuated after adjusting for all covariates to 6.8 points lower, 9.4 points lower, and 7.2 points lower, respectively. CONCLUSIONS: The AWV has the potential to increase the use of preventive care, improve health, and reduce ethnoracial disparities among Medicare beneficiaries, but realizing these goals will require increasing utilization by minority groups. If ethnoracial minority beneficiaries had used the AWV at the same rate as non-Hispanic white beneficiaries during the study period, then ~1.6 million additional AWVs would have been used.


Assuntos
Medicare/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Medicina Preventiva/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Planos de Pagamento por Serviço Prestado/estatística & dados numéricos , Feminino , Humanos , Masculino , Grupos Raciais/estatística & dados numéricos , Estados Unidos
18.
J Appl Physiol (1985) ; 126(6): 1533-1540, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30896357

RESUMO

Hyperhomocysteinemia is associated with endothelial dysfunction and increased cardiovascular disease (CVD). We determined whether elevated homocysteine (Hcy) and markers of Hcy metabolism were associated with the previously reported endothelial dysfunction across stages of the menopause transition. Brachial artery flow-mediated dilation (FMD) and plasma concentrations of Hcy, cysteine, and methionine were measured in healthy women (n = 128) 22-70 yr of age categorized as premenopausal (n = 35), perimenopausal (early: n = 16; late: n = 21), and postmenopausal (early: n = 21; late: n = 35). Dietary intake of micronutrients involved in Hcy metabolism (e.g., vitamins B6, B12, folate) was assessed in a subpopulation of women. Hcy and cysteine concentrations were progressively higher, and methionine was progressively lower across menopausal stages (all P < 0.005). The higher Hcy and cysteine concentrations correlated with lower circulating estradiol levels (r = -0.49 and -0.50, respectively, both P < 0.001). FMD was inversely correlated with Hcy (r = -0.25, P = 0.004) and cysteine (r = -0.39, P < 0.001) and positively correlated with methionine concentrations (r = 0.25, P = 0.005). Dietary intake of vitamins B6 and B12 (both P < 0.05) were lower in postmenopausal women. Vitamin B12 intake correlated with FMD (r = 0.22, P = 0.006). These data suggest that declines in estradiol across stages of the menopause transition may lead to elevations in Hcy and cysteine that may contribute to endothelial dysfunction in postmenopausal women. Future studies should examine whether targeting Hcy metabolism during the perimenopausal to early postmenopausal period with interventions, including diet, attenuates or reverses the decline in endothelial function in women. NEW & NOTEWORTHY Declines in circulating estradiol across the stages of the menopausal transition may lead to elevations in Hcy and cysteine concentrations that may contribute to endothelial dysfunction. Abnormalities in the Hcy metabolic pathways, possibly related to dietary deficiencies of vitamins B12 and B6 and folate, may contribute to elevations in Hcy and cysteine concentrations. Findings also suggest that higher cysteine levels may be more damaging to the vascular endothelium than Hcy.


Assuntos
Cisteína/sangue , Endotélio Vascular/fisiopatologia , Homocisteína/sangue , Menopausa/sangue , Doenças Vasculares/sangue , Doenças Vasculares/fisiopatologia , Adulto , Idoso , Artéria Braquial/fisiopatologia , Dieta , Estradiol/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Estado Nutricional/fisiologia , Pós-Menopausa/sangue , Saúde da Mulher , Adulto Jovem
19.
Front Med (Lausanne) ; 6: 327, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32039215

RESUMO

Prior evidence suggests that the choice of antihypertensive medication may influence functional status among older adults with hypertension, particularly in conjunction with exercise. In particular, angiotensin converting enzyme (ACE) inhibitors have shown potential to positively influence function. However, randomized, controlled trials are needed to confirm this hypothesis. This paper outlines an RCT designed to determine if choice of first-line antihypertensive medication influences functional and cardiovascular risk factor responses to exercise among older adults with hypertension. Two hundred and thirteen inactive, community-dwelling adults ≥60 years of age with hypertension and functional limitations will be recruited to engage in a 32-week intervention study. Participants will be randomized to one of three first-line antihypertensive agents: (1) the ACE inhibitor perindopril, (2) the AT1 receptor antagonist losartan, or (3) the thiazide diuretic hydrochlorothiazide (HCTZ). Six weeks after randomization, participants will begin a 20-week structured aerobic exercise intervention. Participants will perform two 45-min center-based sessions coupled with 60 min of home-based walking per week. The primary aim is to determine if perindopril improves self-paced gait speed when compared with losartan and HCTZ. The secondary aim is to determine the relative effect of perindopril on secondary outcomes such as: (a) exercise capacity, (b) body mass and composition, and (c) circulating indices of cardiovascular risk. This RCT is expected to identify differential effects of first-line antihypertensive medications when combined with physical exercise thus have potential implications for antihypertensive prescription guidelines for older adults. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03295734.

20.
J Appl Physiol (1985) ; 125(6): 1693-1701, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30188798

RESUMO

The cardiovascular effects of testosterone (T) are controversial. Low T has been associated with accelerated vascular aging, characterized by large elastic artery stiffening (decreased compliance), intimal-medial thickening (IMT), and endothelial dysfunction. Endurance exercise improves vascular function, but resistance training may increase arterial stiffness. We sought to determine whether T supplementation improved markers of vascular aging in men with low-normal T and whether T supplementation prevented arterial stiffness with resistance exercise. We studied 160 community-dwelling older men (66 ± 5 yr) with low-normal baseline total T levels (200-350 ng/dl). Participants were randomized to transdermal T gel targeting either a lower (400-550 ng/dl) or higher (600-1,000 ng/dl) T range or to placebo gel and to either progressive resistance training (PRT) or to no exercise for 12 mo. Carotid artery stiffness (arterial compliance) and carotid IMT were measured at baseline, 6 mo, and 12 mo. Endothelial function (brachial artery flow-mediated dilation) was measured in a subset (n = 86). Changes in carotid artery compliance, IMT, and endothelial function with either the lower or higher range of T supplementation were not different from placebo at 6 or 12 mo. There were no differences between PRT and no PRT groups, alone or with T supplementation, in changes in any of the vascular measures at either time point. Supplementation of T and PRT in older men with low-normal levels do not appear to improve or harm vascular function.NEW & NOTEWORTHY Increased promotion and prescription of testosterone (T) to aging men has raised concerns about potential adverse cardiovascular effects. We show that in older men with T levels in the low-normal range, 12 mo of T supplementation with or without resistance exercise did not improve or harm vascular function.

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