Body Mass Index (BMI), Waist Circumference (WC) and Waist to Height Ratio (Whtr) as a Screening Tool for Detection of Cardio Metabolic Risk Factors among Adolescents in Kerala

Central obesity is a cardio metabolic risk factor. A comparative study was done to assess the effectiveness of BMI, WC and WHtR and blood pressure as a screening tool to detect cardio metabolic risk factors among adolescents and identify their relationship using a descriptive comparative research design. The sample consisted of 518 adolescents from 9 urban schools from two districts in Kerala by a multistage random sampling. Height, weight, waist circumference as well as Blood Pressure was collected using validated and reliable instruments. Demographic details were collected using a questionnaire. Ethical clearance from IRB and administrative permission besides subjects’ consent were obtained prior to data collection. Data was analyzed using SPSSvs.18 in accordance with objectives laid down.

The study found substantial number of adolescents as overweight, obese as well as hypertensive as ear marked by their BMI, WC and WHtR. The WHtR and WC showed highly significant positive correlation (r= .916, p<0.001). The WC showed the same with SBP (r-.433, p<0.001) as well as DBP (r=.339, p<0.001). Highly significant positive correlation (r=.313, p<0.001) was found between WHtR and SBP as well as with DBP (r=.210, p<0.001). Systolic and diastolic BP showed highly significant positive correlation (r=.739, p<0.001). BMI was found to have significant weak positive correlations with WC (r= 0.146, p = 0.001) and with WHtR (r=137, p=0.002). A stepwise linear regression analysis done with blood pressure (SBP & DBP) as dependent variables indicated WC, and WHtR to be predictive of systolic and diastolic BP (p<0.001) followed by BMI (p=0.007) for systolic BP. The results indicate WC (p<0.001) being superior to WHtR (p<0.001) BMI (p<0.01) in predicting hypertension. The study affirms WC and WHtR as a convenient, cost effective and discriminative tool for predicting cardio metabolic risk.