Sarcopenia Exacerbates Obesity-Associated Insulin Resistance and Dysglycemia: Findings from the National Health and Nutrition Examination Survey III

Sarcopenia often co-exists with obesity, and may have additive effects on insulin resistance. Sarcopenic obese individuals could be at increased risk for type 2 diabetes. We performed a study to determine whether sarcopenia is associated with impairment in insulin sensitivity and glucose homeostasis in obese and non-obese individuals.We performed a cross-sectional analysis of National Health and Nutrition Examination Survey III data utilizing subjects of 20 years or older, non-pregnant (N = 14,528). Sarcopenia was identified from bioelectrical impedance measurement of muscle mass. Obesity was identified from body mass index. Outcomes were homeostasis model assessment of insulin resistance (HOMA IR), glycosylated hemoglobin level (HbA1C), and prevalence of pre-diabetes (6.0≤ HbA1C<6.5 and not on medication) and type 2 diabetes. Covariates in multiple regression were age, educational level, ethnicity and sex.Sarcopenia was associated with insulin resistance in non-obese (HOMA IR ratio 1.39, 95% confidence interval (CI) 1.26 to 1.52) and obese individuals (HOMA-IR ratio 1.16, 95% CI 1.12 to 1.18). Sarcopenia was associated with dysglycemia in obese individuals (HbA1C ratio 1.021, 95% CI 1.011 to 1.043) but not in non-obese individuals. Associations were stronger in those under 60 years of age. We acknowledge that the cross-sectional study design limits our ability to draw causal inferences.Sarcopenia, independent of obesity, is associated with adverse glucose metabolism, and the association is strongest in individuals under 60 years of age, which suggests that low muscle mass may be an early predictor of diabetes susceptibility. Given the increasing prevalence of obesity, further research is urgently needed to develop interventions to prevent sarcopenic obesity and its metabolic consequences

Prevenci\uf3n de insuficiencia cardiaca en pacientes con diabetes

La cardiomiopat\ueda diab\ue9tica se caracteriza por fibrosis intersticial notoria. Las causas postuladas incluyen microangiopat\ueda, neuropat\ueda del sistema nervioso aut\uf3nomo, y factores metab\uf3licos. Una ra\uedz com\ufan de estas alteraciones patol\uf3gicas es la hiperglucemia o la hiperinsulinemia, ambas de las cuales son notorias en la diabetes tipo 2, que se acompa\uf1a de la incidencia m\ue1s alta de morbilidad y mortalidad de origen cardiovascular. La importancia relativa de cada factor es motivo de debate; es probable que estos dos factores, adem\ue1s de los factores de riesgo concomitantes que se observan en diab\ue9ticos (dislipemias, hipertensi\uf3n, obesidad, anormalidades de la coagulaci\uf3n), contribuyen al espectro de enfermedad mioc\ue1rdica en la diabetes. El tema de esta revisi\uf3n es una explicaci\uf3n de estas alteraciones patol\uf3gica

Sex Differences in the Association of Body Composition and Cardiovascular Mortality.

Background To determine whether differences in body composition contribute to sex differences in cardiovascular disease (CVD) mortality, we investigated the relationship between components of body composition and CVD mortality in healthy men and women. Methods and Results Dual energy x-ray absorptiometry body composition data from the National Health and Nutrition Examination Survey 1999-2004 and CVD mortality data from the National Health and Nutrition Examination Survey 1999-2014 were evaluated in 11&nbsp;463 individuals 20&nbsp;years of age and older. Individuals were divided into 4 body composition groups (low muscle mass-low fat mass-the referent; low muscle-high fat; high muscle-low fat, and high muscle-high fat), and adjusted competing risks analyses were performed for CVD versus non-CVD mortality. In women, high muscle/high fat mass was associated with a significantly lower adjusted CVD mortality rate (hazard ratio [HR], 0.58; 95% CI, 0.39-0.86; P=0.01), but high muscle/low fat mass was not. In men, both high muscle-high fat (HR, 0.74; 95% CI, 0.53-1.04; P=0.08) and high muscle-low fat mass (HR, 0.40; 95% CI, 0.21-0.77; P=0.01) were associated with lower CVD. Further, in adjusted competing risks analyses stratified by sex, the CVD rate in women tends to significantly decrease as normalized total fat increase (total fat fourth quartile: HR, 0.56; 95% CI, 0.34-0.94; P&lt;0.03), whereas this is not noted in men. Conclusions Higher muscle mass is associated with lower CVD and mortality in men and women. However, in women, high fat, regardless of muscle mass level, appears to be associated with lower CVD mortality risk. This finding highlights the importance of muscle mass in healthy men and women for CVD risk prevention, while suggesting sexual dimorphism with respect to the CVD risk associated with fat mass

Associations of insulin resistance and dysglycemia with sarcopenia, obesity, and sarcopenic obesity, in adults 60 years or older, adjusted for age, sex, race, and education.

1<p>Ratio of HOMA IR in sarcopenic obese group to HOMA IR in reference group (neither sarcopenic nor obese) where HOMA IR is the Homeostatic Model Assessment of Insulin Resistance.</p>2<p>Ratio of HbA1C in sarcopenic obese group to HbA1C in reference group (neither sarcopenic nor obese) where HbA1C is the blood level of glycosylated hemoglobin.</p>3<p>Pre-diabetes is defined as a 1) HbA1C ≥6% but <6.5%, OR fasting glucose ≥5.5 but <7 mmol/L, 2) no self-reported DM, <b><u>and</u></b> 3) absence of DM medications.</p

Urinary cortisol and cardiovascular events in women vs. men: The multi-ethnic study of atherosclerosis

Research suggests that women experience greater cardiovascular ischemic effects from stress than men. Visceral adiposity is an endocrine tissue that differs by sex and interacts with stress hormones. We hypothesized that urinary cortisol would be associated with increased cardiovascular events and change in coronary artery calcium score (CAC) in women, and these relationships would vary by central obesity. In the Multi-Ethnic Study of Atherosclerosis Stress Ancillary study, cortisol was quantified by 12-h overnight urine collection. Central obesity was estimated by waist-hip ratio (WHR). Multivariable Cox models estimated the relationship between cortisol and cardiovascular events and assessed for moderation by WHR. The relationship between cortisol and change in CAC Agatston score was assessed by Tobit regression models. 918 patients were analyzed with median follow up of 11 years. There was no association between urinary cortisol and cardiovascular events in the cohort. However, in individuals with below median WHR, higher urinary cortisol levels (upper tertile) were associated with higher cardiovascular event rates in the full cohort, women, and men, but not in groups with above median WHR. There was significant moderation by WHR in women, but not men, whereby the association between elevated cortisol and increased cardiovascular events diminished as WHR increased. Urinary cortisol was associated with increased change in CAC in women (P = 0.003) but not men, without moderation by WHR. Our study highlights associations between cortisol and subclinical atherosclerosis in women, and moderation of the relationship between cortisol and cardiovascular events by central obesity in both genders

Association Between Measures of Body Composition and Coronary Calcium: Findings From the Multi‐Ethnic Study of Atherosclerosis

Background Obesity, as measured by body mass index, is widely recognized as a risk factor for the development of cardiovascular disease. However, the role of body composition components such as fat and lean mass is not well studied. Methods and Results A total of 3129 patients who underwent computed tomography scans for quantification of coronary artery calcification and had bioelectrical impedance analysis of body composition (fat mass and fat-free mass) during exam 5 of MESA (Multi-Ethnic Study of Atherosclerosis) were included in this cross-sectional analysis. Multivariable adjusted linear regression analysis was performed to assess the relationship between both fat mass and fat-free mass to prevalent coronary artery calcification, a marker of subclinical coronary artery disease quantified by both the coronary artery calcification (CAC) Agatston score and the spatially weighted calcium score. CAC and spatially weighted calcium score were natural log-transformed for analysis as continuous variables. Fat-free mass, but not fat mass, was independently associated with CAC. There was a 7.6% prevalence risk difference for CAC&gt;0 per 10 kg. Fat-free mass was also significantly associated with natural log of CAC (coefficient=0.272, P&lt;0.001). Both fat-free mass and fat mass were positively associated with natural log of spatially weighted calcium score, with risk difference coefficients of 0.729 and 0.359, respectively (P&lt;0.001). Conclusions In this cross-sectional study, higher lean mass by bioelectrical impedance analysis and, to a lesser extent, higher fat mass by bioelectrical impedance analysis were significantly associated with higher coronary calcium, a marker of subclinical cardiovascular disease. Further exploration of the relationship between components of body composition and the development of cardiovascular disease is warranted

Descriptive statistics (median with inter-quartile range, or percentage).

<p>*Those in the NHANES III sample who were older than 20 years and not pregnant, but were excluded because they were missing bioelectrical impedance or body mass index measurement.</p