[Abdominal obesity in ELSA-Brasil (Brazil's Longitudinal Study of Adult Health): construction of a latent gold standard and evaluation of the accuracy of diagnostic indicators]

Patterns of metabolic syndrome and associated factors in women from the ELSA-Brasil: a latent class analysis approach

This study aimed to identify patterns of metabolic syndrome among women and estimate their prevalence and relationship with sociodemographic and biological characteristics. In total, 5,836 women were evaluated using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Patterns of metabolic syndrome were defined via latent class analysis, using the following metabolic abnormalities as indicators: abdominal obesity, hyperglycemia, hypertension, hypertriglyceridemia, and reduced HDL cholesterol. The relationship between these patterns and individual characteristics was assessed using latent class analysis with covariates. Three patterns of metabolic syndrome were identified: high metabolic expression, moderate metabolic expression, and low metabolic expression. The first two patterns represented most women (53.8%) in the study. Women with complete primary or secondary education and belonging to lower social classes were more likely to have higher metabolic expression. Black and mixed-race women were more likely to have moderate metabolic expression. Menopausal women aged 50 years and older were more often classified into patterns of greater health risk. This study addressed the heterogeneous nature of metabolic syndrome, identifying three distinct profiles for the syndrome among women. The combination of abdominal obesity, hyperglycemia, and hypertension represents the main metabolic profile found among ELSA-Brasil participants. Sociodemographic and biological factors were important predictors of patterns of metabolic syndrome.

Combined Effect of Leisure-Time Physical Activity and Sedentary Behavior on Abdominal Obesity in ELSA-Brasil Participants

INTRODUCTION

Abdominal obesity is a pattern of obesity that has been considered a public health problem. Physical activity is considered an important factor for the prevention of abdominal obesity. Increased time in sedentary behavior has been associated with negative health outcomes, including abdominal obesity.

OBJECTIVE

The aim of this study was to investigate which combination of leisure-time physical activity and sedentary behavior contributes most to the prevention of abdominal obesity in adults participating in ELSA-Brasil (Longitudinal Study of Adult Health).

METHODS

The study was cross-sectional and participants from the first follow-up of the ELSA-Brasil cohort (2012-2014) were analyzed. The independent variables were physical activity, assessed by IPAQ, and sedentary behavior, assessed by a standard questionnaire applied in ELSA-Brasil; the dependent variable was abdominal obesity, determined by waist circumference. The covariates analyzed were the following: age, education, binge drinking, smoking and menopause. The associations between the dependent variable and the independent variables were analyzed using logistic regression. The odds ratio with 95 CI% was estimated.

RESULTS

For men, the combinations were more significant when they were more physically active and spent less time on the sedentary behaviors analyzed, on both a weekday and a weekend day. For menopausal women, both younger and older, all associations of the combinations between sufficient leisure-time physical activity and little time spent in sedentary behaviors contributed to the prevention of abdominal obesity. In non-menopausal women, positive associations were observed in almost all combinations between leisure-time physical activity and sedentary behaviors, with some results that were not statistically significant among younger women.

CONCLUSIONS

Our results showed that being sufficiently active and reducing the time spent in sedentary behavior was the combination that contributed the most to the prevention of abdominal obesity, both in men and women.

The Visceral Adiposity Index Is a Better Predictor of Excess Visceral Fat in Military Pilots: A Cross-sectional Observational Study

INTRODUCTION

Visceral adipose tissue (VAT) is related to cardiometabolic risk. Estimating it using the visceral adiposity index (VAI) could identify this risk in the Brazilian Air Force (BAF) aviator population. The aim here is to verify the predictive capacity of the VAI for identifying visceral fat areas compared to traditional obesity indicators in BAF pilots.

MATERIALS AND METHODS

Forty male BAF pilots were recruited. The study was conducted in two stages: the first applied a structured questionnaire to characterize the sample and identify sedentary behavior and the second obtained nutritional, anthropometric, and body composition data, carrying out biochemical and magnetic resonance imaging tests and investigating physical activity level in this stage. The comparison of the predictive capacity of the VAI with that of other adiposity indicators (body mass index [BMI], waist circumference, waist-height ratio, waist-hip ratio, and neck circumference) for detecting increased VAT and the determination of the optimal cutoff points for the different adiposity indicators were carried out using receiving operating characteristic (ROC) curves. An association was verified between the adiposity indicators and excess visceral fat using Poisson regression analysis with robust variance.

RESULTS

The VAI presented a better predictive capacity for VAT (area under the ROC curve = 0.941), while the BMI did not present diagnostic accuracy (95% CI < 0.5). The strength of the association with high visceral fat was also greater for the VAI than for the other indicators evaluated.

CONCLUSIONS

The VAI was shown to be a better predictor of excess VAT in relation to the other indicators studied. As it is a more easy-access and lower-cost technique than resonance, it enables greater applicability in tracing and monitoring the visceral obesity of a large contingent of military personnel.

Cut points of the conicity index as an indicator of abdominal obesity in individuals undergoing hemodialysis: An analysis of latent classes

OBJECTIVES

Abdominal obesity favors the involvement of cardiometabolic complications in renal patients on hemodialysis. Thus, the aim of the study was to identify the cut-points of the conicity index in individuals undergoing hemodialysis.

METHODS

This was a cross-sectional study carried out with 953 individuals undergoing hemodialysis in clinics in a metropolitan region of southeastern Brazil. The conicity index was calculated using the following mathematical equation: waist circumference/0.109 × √weight/height. The receiver operating characteristic (ROC) curve was calculated from the analysis of latent classes by cross-validation through a latent variable of abdominal obesity. This latent variable was defined using the response pattern of the observed anthropometric variables considering the presence and absence of abdominal obesity: waist circumference, waist-to-height ratio, and body shape index. The cut-points identified were elucidated by the area under the curve (AUC), Youden index, sensitivity, and specificity.

RESULTS

The cut-points for the conicity index found for both sexes were similar, resulting in a cut-point for men of 1.275 (AUC, 0.921; Youden index, 0.666), with a sensitivity and specificity of 83% and 83.6%, and a cut-point for women of 1.285 (AUC, 0.921; Youden index, 0.679), with a sensitivity and specificity of 78.6% and 89.3%, respectively.

CONCLUSIONS

The conicity index showed high discriminatory power for the identification of abdominal obesity in hemodialysis patients, therefore it can be a simple and easily accessible tool to be incorporated into clinical practice in this population.

Conicity-index predicts all-cause mortality in Chinese older people: a 10-year community follow-up

BACKGROUND

Abdominal obesity (AO) has been regarded as the most dangerous type of obesity. The Conicity-index (C-index) had a high ability to discriminate underlying AO. The purpose of this study was to determine the ability of C-index to predict all-cause mortality among non-cancer Chinese older people.

METHODS

The participants were residents of the Wanshou Road community in Beijing, China. Receiver operating curve (ROC) curves were used to determine the sensitivity and specificity of the best cut-off values for different anthropometric measures for predicting all-cause mortality. The area under the curve (AUC) of the ROC curves were calculated to compare the relative ability of various anthropometric measures to correctly identify older people in the community where all-cause mortality occurs. Included subjects were grouped according to C-index tertiles. The association between C-index and all-cause mortality was verified using Kaplan-Meier survival analysis and different Cox regression models.

RESULTS

During a mean follow-up period of 9.87 years, 1821 subjects completed follow-up. The average age was 71.21 years, of which 59.4% were female. The ROC curve results showed that the AUC of the C-index in predicting all-cause mortality was 0.633. Kaplan-Meier survival curves showed a clear dose-response relationship between C-index and all-cause mortality. With the increase of C-index, the survival rate of the study population showed a significant downward trend (P < 0.05). Adjusted for age, gender, hip circumference, systolic blood pressure, diastolic blood pressure, fasting blood glucose (FBG), 2-h postprandial blood glucose (2hPG), glycosylated hemoglobin, high-density lipids protein (LDL), triglyceride, serum creatinine, serum uric acid, urine albumin-creatinine ratio (UACR), Mini-Mental State Examination (MMSE), smoking history, and drinking history, COX regression analysis showed that in the model adjusted for all covariates, the risk of all-cause mortality in tertile 3 was 1.505 times that in tertile 1, and the difference was statistically significant.

CONCLUSIONS

The C-index is an independent risk factor for all-cause mortality in the non-cancer Chinese older people.

Social position and anthropometric status among adults in the ELSA-Brasil study: a latent class analysis

The objective of the present study was to evaluate the association between social position and anthropometric status in women and men Brazilian adult. This was a cross-sectional study that used baseline data collected from 2008 to 2010 for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil, in Portuguese), in the six major Brazilian state capital cities. A total of 15,105 active and retired civil servants aged from 35 to 74 years. Two latent variables were defined by latent class analysis, social position and anthropometric status. Both constructs and the analyses were separately evaluated by sex. Associations were assessed using multivariate logistic regression analysis with adjustment for age, self-reported skin color/race, and marital status. Around 44% of the women and 26% of the men were classified as overweight or obese. Social position tended to be lower in women (43.2%) and higher among men (40.4%). Heavier women were more likely to be black and brown-skinned, whereas slimmer women were more likely to be white. After adjustment, women's weight increased as social position decreased (OR = 1.52; 95%CI: 1.36-1.70), whereas in men weight decreased as social position decreased (OR = 0.87; 95%CI: 0.76-0.99). Social position affected the anthropometric status of women and men differently, with body patterns also being affected by ethnicity/skin color, showing the potentiality of taking the intersectional perspective when investigating the possible social determinants of the phenomenon.