Serum non-high-density lipoprotein cholesterol concentration: Profile and prevalence of high levels among adolescent Nigerian students

Background/Aim: Non-high-density lipoprotein cholesterol (non-HDL-C) concentration include both cholesterol-rich and triglycerides-rich atherogenic apolipoprotein B-containing lipoproteins. The present study described the distribution and estimated the prevalence of high serum non-HDL-C levels in adolescent Nigerian students. Methods: This was a case control study, conducted in an urban secondary school. The study population consists of a total of 98 students, aged 10-16 years (49 subjects with high BMI ( ≥ 85th percentile) and 49 controls with normal BMI (5th to < 85th percentile). The first school in an alphabetically arranged list was selected. The participants were randomly selected and matched for age and sex. The serum concentrations of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), triglycerides (TG) and low-density lipoprotein-cholesterol (LDL-C) were determined, using automated analyzer with commercially available kits. The serum non-HDL-C concentration was determined from the difference between the TC and HDL-C concentrations. Results: The prevalence of elevated (borderline plus abnormal) non-HDL-C concentrations in overweight/obese and normal-weight participants were 26.5% (95% CI=26.3-26.6) and 8.2% (95% CI = 5.9-14.5) respectively; Z-test statistic = 2.666, p < 0.01. In overweight/obese participants, the prevalence rates of “borderline” and “abnormal” serum non-HDL-C levels were 24.5% and 2.0%, respectively. The corresponding prevalence rates in normal-weight participants were 8.2% and zero percent, respectively. The frequency of high non-HDL-C was higher in participants whose waist-to-height ratio (WHtR) was ≥ 0.5 than those with WHtR < 0.5. The risk of high serum non-HDL-C level was 2.5-fold higher in girls than boys. The mean serum non-HDL-C concentrations in overweight/obese and normal weight participants were 101.4±23.3mg/dl and 93.6±24.8mg/dl, respectively; p>0.05. The mean serum non-HDL-C in overweight/obese boys was 3.9mg/dl higher than that of normal weight boys and for the girls, this difference was 10.8mg/dl. Conclusion: The risk of developing a significantly elevated non-HDL-C level is greater in overweight/obese than normal-weight adolescents and this risk is also greater in girls.