Coronary heart disease risk factors in male adolescents, with particular reference to smoking and blood lipids

Abstract

Purpose: To examine coronary heart disease (CHD) risk factors, particularly blood lipids and smoking, in adolescent boys in the Sydney Metropolitan area, and to investigate possible differences between boys from English-speaking (ESB) and non–English-speaking backgrounds (NESBs). Methods: Male volunteers aged 15–18 years were recruited from the senior years of four secondary schools in different geographical areas of Sydney. Body mass index (BMI), waist–hip ratio (WHR), blood lipids, and percent body fat were measured. Behavioral variables were estimated by questionnaire. Results: A total of 110 boys were recruited; 74% were from an ESB. Mean WHR (0.836 ± 0.045), waist circumference (80.6 ± 9.4 cm), and percent body fat (21.0 ± 6.3) were similar across age groups. Atherogenicity of the lipid profile, as measured by the ratio of total cholesterol to high-density lipoprotein cholesterol (TC:HDL-C), was lower in boys aged 15 years than in any other age group ( p < .05). TC:HDL-C was strongly associated with BMI ( r = .57; p < .0001) and WHR ( r = .35; p < .01). Smokers had higher BMI, were less active and had lower HDL-C ( p < .001) and higher TC:HDL-C ( p < .0001) than nonsmokers. Smoking, even of short duration, and quite moderate consumption of cigarettes (6/day) were associated with a deterioration of the lipid profile. Boys from NESBs had a higher degree of risk in all of the factors examined. Conclusions: Regular smoking of short duration has an appreciable impact on lipid and lipoprotein concentrations in this sample of Australian adolescent boys. Boys from an NESB appear to be at greater risk of developing CHD in later life.