The relationship between body composition and selected metabolic syndrome markers in black adolescents in South Africa: the PLAY study.

OBJECTIVE

To determine the relationship between body composition and selected markers of the metabolic syndrome in black adolescents.

METHODS

The group consisted of 232 adolescent boys and girls aged 15-19 y attending two secondary schools in a low socio-economic status area of Potchefstroom, South Africa. Body mass (kg), stature (cm), and waist (WC) and hip circumferences were measured using standard methods. Body mass index and waist:hip ratio were calculated. Percentage body fat and lean body mass were measured by air displacement plethysmography. Fasting plasma insulin, fasting glucose, homeostasis model assessment of insulin resistance (HOMA-IR), systolic blood pressure (SBP), and diastolic blood pressure were measured.

RESULTS

Children with a high body fat percentage (boys >20%, girls >25%) had significantly higher serum leptin concentration than children with normal body fat percentage (boys, P = 0.005; girls, P < 0.0001). Girls with a high body fat percentage also reported significantly higher SBP (P = 0.004), diastolic blood pressure (P = 0.03), plasma insulin (P = 0.004), and HOMA-IR (P = 0.004) than girls with normal body fat percentage. Body fat percentage had a significant positive association with HOMA-IR (P = 0.02) and SBP (P = 0.02), respectively. A significant positive correlation was also found between plasma leptin concentration and body mass index (P < 0.0001), WC (P < 0.0001), body fat percentage (P < 0.0001), and fat:height index (P < 0.001).

CONCLUSION

A significant positive association was found between body fat percentage and both SBP and HOMA-IR, respectively. Girls with a high body fat percentage had significantly higher BP, plasma insulin, and HOMA-IR than girls with normal body fat percentage, indicating risk of non-communicable diseases.