Relationship between measures of fatness, lipids and ethnicity in a cohort of adolescent boys

The investigators were invited into a boys' high school to assess the lipid risk profile of a single year cohort and advise on how the findings could be incorporated into a healthy lifestyle program. The aim of the study was to investigate the relationship between measures of fatness, ethnicity and cardiac risk factors in a cohort of adolescent boys.

Anthropometric measurements of weight, height, waist and hips were used to calculate body mass index (BMI) and waist to hip ratio (WHR); percent total body fat (%TBF) was estimated by bioelectric impedance analysis. Demographic and behavioral variables were assessed by questionnaire. Total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), triglyceride (TG), apolipoprotein A1 (apoA1), apoliproprotein B (apoB) and insulin were measured in 137 subjects; low-density lipoprotein (LDL-C) was calculated.

The study sample was comprised of 139 boys aged 15.7 +/- 0.04 years; 46% were Caucasians, 41% were East Asians and 13% were from the Indian subcontinent (South Asian). The crude mean BMI, %TBF and waist measurements were not significantly different between the ethnic groups. South Asians had a higher mean WHR than East Asians (p < 0.004; ANOVA), and also had higher mean %TBF than Caucasians when BMI was adjusted for, and lower BMI than either of the other groups when adjusted for waist (ANCOVA). There was no difference between groups in lipid profiles except for a higher apoB in East Asians compared with Caucasians (p < 0.04). Twenty-two percent of the subjects had TC higher than the desirable level for children (4.5 mmol/l), 7.3% had low HDL-C (<0.9 mmol/l) and 4.3% had high LDL-C (>3.5 mmol/l). Overweight and hypercholesterolemia had individual prevalences of around 20%, while hyperinsulinemia was 48%.

The present study confirms that the relationship between BMI and %TBF is dependent on ethnicity, even in adolescent subjects of similar age and gender. The assessment of cardiovascular risk on a school year and age basis would suggest that there are enough affected individuals to support at least a nontargeted intervention which focuses on healthy eating and physical activity.