Is waist-to-height ratio the best predictive indicator of hypertension incidence? A cohort study.

BACKGROUND: The best anthropometric indicator to verify the association between obesity and hypertension (HTN) has not been established. We conducted this study to evaluate and compare the discriminatory power of waist-to-height ratio (WHtR) in relation to body mass index (BMI) and waist circumference (WC) in predicting HTN after 13 years of follow-up. METHODS: This study was an observational prospective cohort study performed in the city of Firminópolis, in Brazilian's midwest. The cohort baseline (phase 1) was initiated in 2002 with the evaluation of a representative sample of the normotensive population (≥ 18 years of age). The incidence of HTN was evaluated as the outcome (phase 2). Sociodemographic, dietary and lifestyle variables were used to adjust proportional hazards models and evaluate risk of HTN according to anthropometric indices. The areas under the receiver operating characteristic (ROC) curves were used to compare the predictive capacity of these indices. The best HTN predictor cut-offs were obtained based on sensitivity and specificity. RESULTS: A total of 471 patients with a mean age of 38.9 ± 12.3 years were included in phase 1. The mean follow-up was 13.2 years, and 207 subjects developed HTN. BMI, WC and WHtR were associated with risk of HTN incidence and had similar power in predicting the disease. However, the associations were only significant for women. The cut-off points with a better HTN predictive capacity were in agreement with current recommendations, except for the WC in men. CONCLUSIONS: The results suggest that both overall obesity (BMI) and central obesity (WC and WHtR) anthropometric indicators can be used in this population to evaluate the risk of developing hypertension.

Predictors of overweight/obesity in a Brazilian cohort after 13 years of follow-up.

BACKGROUND: Obesity is a chronic complex disease with an increasing prevalence around the world. Prospective studies in adult cohorts are needed to provide information about predictors of new-onset overweight/obesity on population-based levels. The aim of this study was to identify factors associated with the risk of an adult individual become overweight/obese after 13 years of follow-up. METHODS: Second phase of an observational population-based prospective cohort study in a small town in the Midwest region of Brazil. A representative sample of the adult population (≥18 years) was assessed in 2002 (phase 1). Anthropometric, sociodemographic, dietary intake and lifestyle data were collected. After 13 years of follow-up (2015), the same variables were re-evaluated (phase 2). New-onset overweight/obesity was the outcome variable. RESULTS: A total of 685 subjects were included with a mean age in phase 1 of 42.7 ± 13.8 years and 56.1 ± 13.8 years in phase 2, the mean follow-up time was 13.2 years and female sex counted for 66.3% of the sample. Total weight gain was 5.9 ± 10.2 Kg, body mass index increased 2.6 ± 3.8 Kg/m2 and waist circumference (WC) values increased 8.0 ± 10.5 cm. The prevalence of overweight/obesity went from 49.1% in phase 1 to 69.8% in phase 2 (p < 0.001). The factors associated with a decreased risk of new-onset overweight/obesity were ages between 50 and 64 (RR 0.40; CI 0.24-0.67 - p = 0.001) and ≥65 years (RR 0.15; CI 0.06-0.35 - p < 0.001), being part of the second quartile of fat consumption (RR 0.59; CI 0.35-0.97 - p = 0.041), no alcohol consumption (RR 0.59; CI 0.37-0.93 - p = 0.024) and smoking (RR 0.58; CI 0.39-0.86 - p = 0,007) in phase 1. CONCLUSIONS: We identified in thirteen years of follow-up that older ages, a moderate fat consumption compared to low consumption, no alcohol consumption and smoking habit were related to a decreased risk of new-onset overweight/obesity. Obesity prevention actions must focus on subjects at younger ages and include policies to reduce alcohol consumption.