Combining general and central measures of adiposity to identify risk of hypertension: a cross-sectional survey in rural India.

AIM: In three socioeconomically diverse regions of rural India, we determined the optimal cut-offs for definition of overweight, the prevalence of overweight, and the relationships between measures of overweight and risk of hypertension. SUBJECTS AND METHODS: Villages were randomly sampled within rural Trivandrum, West Godavari, and Rishi Valley. Sampling of individuals was stratified by age group and sex. Cut-offs for measures of adiposity were compared using area under the receiver operating characteristic curve. Associations between hypertension and definitions of overweight were assessed by logistic regression. RESULTS: Of 11 657 participants (50 % male; median age 45 years), 29.8 % had hypertension. Large proportions were overweight as defined by body mass index (BMI) ≥ 23 kg/m2 (47.7 %), waist circumference (WC) ≥ 90 cm for men or ≥ 80 cm for women (39.6 %), waist-hip ratio (WHR) ≥ 0.9 for men or ≥ 0.8 for women (65.6 %), waist-height ratio (WHtR) ≥ 0.5 (62.5 %), or by BMI plus either WHR, WC or WHtR (45.0 %). All definitions of overweight were associated with hypertension, with optimal cut-offs being at, or close to, the World Health Organization (WHO) Asia-Pacific standards. Having overweight according to both BMI and a measure of central adiposity was associated with approximately twice the risk of hypertension than overweight defined by only one measure. CONCLUSIONS: Overweight, as assessed by both general and central measures, is prevalent in rural southern India. WHO standard cut-offs are appropriate in this setting for assessing risk of hypertension. However, combining BMI with a measure of central adiposity identifies risk of hypertension better than any single measure. The risk of hypertension is significantly greater in those centrally and generally overweight than those overweight by a single measure.

Hypertension in Rural India: The Contribution of Socioeconomic Position.

Background Various indicators of socioeconomic position (SEP) may have opposing effects on the risk of hypertension in disadvantaged settings. For example, high income may reflect sedentary employment, whereas greater education may promote healthy lifestyle choices. We assessed whether education modifies the association between income and hypertension in 3 regions of South India at different stages of epidemiological transition. Methods and Results Using a cross-sectional design, we randomly selected villages within each of rural Trivandrum, West Godavari, and Rishi Valley. Sampling was stratified by age group and sex. We measured blood pressure and anthropometry and administered a questionnaire to identify lifestyle factors and SEP, including education, literacy, and income. Logistic regression was used to assess associations between various components of SEP and hypertension, and interaction analyses were used to determine whether educational attainment modified the association between income and hypertension. Trivandrum, the region of highest SEP, had the greatest prevalence of hypertension, whereas Rishi Valley, the lowest SEP region, had the least. Overall, greater income was associated with greater risk of hypertension. In interaction analyses, there was no evidence that educational attainment modified the association between income and hypertension. Conclusions Education is widely considered to ameliorate the risk of hypertension in high-income countries. Why this effect is absent in rural India merits investigation.