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

Abstract

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.