Determinants of Waist-to-Height Ratio and Its Relation to Hypertension among School Children in India: A Multicenter Study.

OBJECTIVE: To study the factors associated with waist-to-height ratio (WHtR) among school children aged 5-15 y and its association with hypertension. METHODS: In this cross-sectional study, data on background characteristics, socioeconomic status (SES), anthropometric parameters, and blood pressure were obtained from school children from three states of India. WHtR ≥ 0.5 was defined as obesity and hypertensives were defined based on Fourth Report criteria. Descriptive statistics were applied and multiple linear regression was done to identify factors associated with WHtR. A receiver operating characteristics (ROC) analysis was used to evaluate the predictive ability of WHtR to predict hypertension RESULTS: The mean WHtR among the 12,068 students was 0.40 (± 0.05) and it showed a U-shaped distribution with age with trough at 10 y of age for both genders. Mean WHtR was higher among residents of Manipur, among boys and hypertensives. WHtR was positively associated with weight > 30 kg, male gender, schools with high SES, Manipur and Goa region, and negatively associated with age > 10 y. The area under the ROC curve of WHtR for diagnosis of hypertension was low 0.544 (95% CI 0.532, 0.556). CONCLUSION: There is a nonlinear relation between age, gender, and WHtR, which varies by geographical region and HT. This would need to be kept in mind while using it to identify obesity in children, though its discriminant value for hypertension is low.

Prevalence and determinants of hypertension in apparently healthy schoolchildren in India: A multi-center study.

Background Hypertension in children is often under recognized, especially in developing countries. Data from rural areas of developing countries is particularly lacking. Objectives To study prevalence of hypertension and its determinants in apparently health school children from predominantly rural populations of India. Methods Apparently healthy schoolchildren ( n = 14,957) aged 5-15 years (mean (standard deviation) age 10.8 (2.8) years; 55.5% boys) at four predominantly rural sites in separate states of India were studied. Systolic and diastolic blood pressures were recorded by trained staff in addition to age, gender, height, weight, type of school and season. Waist circumference was also recorded in 12,068 children. Geographic location and type of school (government, government-aided or private) were used to determine socio-economic status. Results Systolic and/or diastolic hypertension was present in 3443 (23%) children. Systolic hypertension was present in 13.6%, diastolic hypertension in 15.3% and both in 5.9%. Isolated systolic hypertension was present in 7.7% while isolated diastolic hypertension was present in 9.4%. On univariate analysis, age, gender, geographical location, socio-economic status, season and anthropometric parameters (z-scores of height, weight and waist circumference, waist/height ratio and body mass index) were all significantly related to risk of hypertension ( p < 0.0001 for each). Similar association was observed with weight group (normal, overweight and obese). Multiple regression analysis showed lower age, female gender, richer socio-economic status, certain geographical locations, higher weight and larger waist circumference to be independently associated with a greater risk of hypertension. Conclusion There is a high prevalence of hypertension in apparently healthy schoolchildren even in predominantly rural areas of India. Screening and management programs targeted to high risk groups identified may prove cost-effective.