Analysis of the relationship between total cholesterol, age, body mass index among males and females in the WHO MONICA Project

OBJECTIVE: To explore the relationship between hypercholesterolaemia, age and BMI among females and males. DESIGN: Population-based cross-sectional survey. SUBJECTS: The data came from the initial surveys of the WHO MONICA Project. In all, 27 populations with 48 283 subjects ( 24 017 males and 24 266 females) aged 25 - 64 y were used for the analysis. MEASUREMENTS: Total cholesterol, weight, height, BMI, prevalence of hypercholesterolaemia (PHC) defined as cholesterol greater than or equal to6.5 mmol/l, and the prevalence of obesity (POB) defined as BMI greater than or equal to30 kg/m(2). RESULTS: PHC increased with age, with PHC in males being significantly higher than in females at age range 25 - 49 y and significantly lower than in females at age range 50 - 64 y. Age-related increase in hypercholesterolaemia was steeper in females than in males. There was a statistically significant positive association between hypercholesterolaemia and BMI. Multiple logistic regression analysis revealed a negative statistically significant ( P<0.001) effect modification involving age and BMI on the risk of having hypercholesterolaemia both in females and males. The relation between PHC and BMI became weaker in higher age groups, with no statistically significant association in females aged 50 - 64 y. CONCLUSION: Public health measures should be directed at the prevention of obesity in young adults since the strongest effect of obesity on the risk of hypercholesterolaemia has been found in subjects aged 25 - 39 y.