Predictive capacity of anthropometric indicators of body fat in identifying hypertension in adolescents

Background : Hypertension (HTN) is a major health problem affecting different populations including adolescents worldwide, and it is strongly associated with obesity. Objectives : This study examined the predictive capacity of anthropometric proxies of body fat and determined the threshold values that would identify HTN among Nigerian adolescents. Setting and Design : A cross-sectional study with a total of 2228 in-school adolescents aged 12-16 years. Materials and Methods : Participants were evaluated for physical characteristics including five anthropometric indices of body fat and blood pressure. Receiver operating characteristics curves were used for the analysis of sensitivity, specificity, area under curve (AUC) of the fat indices in detecting HTN. Results : All body fat indicators with the exception of waist-to-height ratio in boys, had significant (P < 0.0005) AUC with total fat mass (TFM) in girls and waist circumference (WC) in boys as the best fat indicators for predicting systolic HTN in adolescents. The TFM cut-point for girls was 8.0 kg and the WC cut-point for boys was 66.3 cm. Both TFM and WC demonstrated a stronger association with systolic HTN than other fat indicators in both genders. The likelihood of a girl developing HTN is 1.1 (95% confidence interval [CI] =1.05-1.20) times with a unit increase in TFM, while boys with unhealthy WC had 3.2 (95% CI = 1.83-5.67) times odd of developing HTN compared to their healthy peers. Conclusions : This study showed that TFM and WC are useful tools for detecting HTN in Nigerian adolescent girls and boys, respectively. The fat indicators used in this study generally showed low predictive capacity.