Difference in Serum Non-High-Density Lipoprotein Cholesterol Levels in terms of Sex, Age, and Physique in Children and Adolescents

Recent studies have suggested that childhood non-high-density lipoprotein cholesterol (non-HDL-C) levels are as good as other lipoprotein measures in predicting subclinical atherosclerosis in adulthood 1, 2). Kit et al. reported serum lipids trends among youths in the US aged 6 – 19 years during 1988 – 2010 3). They documented that non-HDL-C levels varied in terms of sex, age, race/ethnicity, and study time. In addition, Srinivasan et al. stressed that serum non-HDL-C levels were related to both body mass index (BMI) and waist circumference 4). Recently, Shim et al. published an interesting paper 5). They reported reference values for the triglyc-eride (TG)-to-high-density lipoprotein cholesterol (HDL-C) ratio and non-HDL-C in Korean children and adolescents aged 10 – 19 years. This paper will be useful for the study of childhood lipoprotein, but there are some concerns. In this study there were no data about the constitution of physique in the subjects. In addition, there was no information about the prevalence of obesity and leanness in the general children population in Korea. Moreover, obesity is commonly associated with a combined dyslipidemia pattern with mild elevation in total cholesterol and low-density lipoprotein cholesterol levels, moderate-to-severe elevation in TG level, and low HDL-C levels 6). Therefore, there was some possibility that the serum non-HDL-C levels were affected by the differences in the subjects' physique, especially obesity. I think the serum non-HDL-C levels in normal physique subjects would be appropriate for the development of the reference values. Furthermore, I am interested in serum non-HDL-C levels in obese children among the Korean children. We previously reported the reference ranges for the non-HDL-C levels in Japanese children and adolescents 7). of age) in girls 8). Sugiura et al. reported the differences in serum lipid levels in lean and obese children using same subjects we previously reported 9). In this study, the subjects were classified based on the percentage of overweight: lean (≤20%), normal (20%, 20%), mild obesity (≥ 20%, 30%), moderate obesity (≥ 30%, 50%), and severe obesity (≥ 50%). They reported that the median values of serum non-HDL-C levels of normal physique children were U shaped according to aging. The median values of non-HDL-C levels of normal physique children were lower than those of obese children in all ages and both sexes. The median values of serum non-HDL-C levels increased according to the severity of obesity. The difference between the median values of serum non-HDL-C levels of …