This is the first Asian study to estimate the percentage of children and adolescents, including those with hypertension and diabetes, eligible for pharmacological treatment according to AAP guidelines. The prevalence of hypercholesterolemia, high LDL-C, high TG, and low HDL-C concentrations among Korean children and adolescent is 6.5%, 4.7%, 10.1%, and 7.1%, respectively. Twenty percent had at least one type of dyslipidemia. Furthermore, almost 0.41% of children and adolescents would qualify for lipid-lowering pharmacological treatment according to the AAP guidelines.
Several major studies such as Lipid Research Clinics Prevalence Study and NHANES have provided age- and sex-specific references for concentrations of lipids in children and adolescents in the United States 
. These studies also showed that sex, race, and ethnic differences exist in lipid profiles and in the prevalence of dyslipidemia. However, these studies did not provide information about Asian children.
The 50th, 75th, 90th, and 95th percentile values for cholesterol concentrations from the KNHANES IV adolescents aged 10 to 18 years were 152, 171, 191, and 200 mg/dL, respectively, for boys and 160, 176, 194, and 205 mg/dL, respectively, for girls. In comparison, the percentile values calculated from the United States NHANES 1999 to 2006 data for white boys aged 6 to 17 years were 157, 177, 195, and 212 mg/dL, respectively, and those for white girls were 162, 182, 201, and 219 mg/dL, respectively 
. Thus, Korean children and adolescents showed less hypercholesterolemia than white children did from the United States (6.5% vs. 9.3%). In addition, the 50th, 75th, 90th, and 95th percentiles for LDL-C concentrations were 87, 104, 119, and 127 mg/dL, respectively, for Korean boys and 90, 106, 121, and 132 mg/dL, respectively, for girls. The corresponding numbers for white boys from the United States were 85, 103, 124, and 136 mg/dL, respectively, and those for girls were 88, 104, 122, and 133 mg/dL, respectively 
. The mean and 50th percentiles were similar between Koreans and white individuals from the United States, but the 95th percentile values for Koreans were less than those obtained for white individuals from the United States. Thus, Korean children and adolescents showed less incidence of high LDL-C dyslipidemia than white from the United States (4.7% vs. 7.7%).
The TG profile also showed a similar pattern. The 50th and 95th percentiles for TG concentrations were 73 and 189 mg/dL for Korean boys and 80 and 181 mg/dL for girls. In comparison, the percentiles calculated from the United States NHANES data from 1988 to 1994 for white boys 12 to 19 years of age were 76 and 205 mg/dL, respectively, and those for white girls were 80 and 218 mg/dL, respectively. The 5th and 50th percentiles for HDL-C concentrations were 35 and 48 mg/dL for Korean boys and 37 and 50 mg/dL for girls. In comparison, the percentiles calculated from the NHANES 1988 to 1994 data for white boys aged 4 to 19 years were 37 and 53 mg/dL, respectively, and those for white girls were 36 and 54 mg/dL, respectively 
. Korean children and adolescents showed less incidence of high TG but higher incidence of low HDL-C than that shown by white in the United States (10.1% vs. 12.1%; 7.1% vs. 8.5%). However, the prevalence of total dyslipidemia (at least one abnormal lipid concentration) in Korean children and adolescents according to guidelines of the NCEP and AHA was 19.7%, which was comparable with the value (20.3%) for subjects from the United States 
. That might be due to single high TG or low HDL-C in Korean subjects, as previously mentioned 
. Nonetheless, the 95th percentiles for TC and LDL-C and the 5th percentile for HDL-C in Korean were 203 mg/dL, 129 mg/dL, and 49 mg/dL, respectively. The 90th percentile for TG concentrations was 150 mg/dL. Thus, it would be suitable for Korean children and adolescents to follow the AAP guidelines for dyslipidemia to prevent CVD in adulthood by lifestyle modification or medical intervention.
Gender differences in lipid concentrations also existed in Korean children and adolescents, as reported in other previous studies 
. Girls had higher TC and LDL-C than did boys. Girls also tended to have higher HDL-C than did boys did after the age of 12–13 years, which corresponded to the period of pubertal development. Thus, girls had a higher prevalence of hypercholesterolemia and high LDL-C, which was different from the findings in their white counterparts in the United States. In the United States, boys showed a higher prevalence of hypercholesterolemia and high LDL-C. This phenomenon is observed in other Asian countries as well 
. The prevalence of hypercholesterolemia and high LDL-C in females is higher than those in males in subjects older than 50 years of age in Korea and China 
. Asian females may have a higher prevalence of dyslipidemia in both adolescence and after menopause.
In Korea, like in other Asian countries, the prevalence of CVD was much lower than that in Western countries 50 years ago 
. However, cardiovascular disease morbidity and mortality in Korea has been projected to increase both in absolute number and as a proportion of total disease burden, and the mortality rate associated with CVD increased up to 27.6% in a recent assessment 
. This trend is common in all East-Asian countries 
. However, CVD and its mortality rate in US have declined by more than 56 percent 
. That might partially be due to the availability of drug and non-drug strategies that could reduce CVD. The prevalence of hypercholesterolemia, high LDL-C, and high TG continue to decrease in the United States in spite of relative increase in obesity 
. However, plasma lipid concentrations increased in Korean children like in other Asian populations 
. In addition, the detection rate of hypercholesterolemia increased from 9.1% to 21.3% in Japanese children similar to Korean 
. One of the reasons could be the westernized lifestyle changes with the economic development in these regions, especially the consumption of diets rich in fat, sugar, and cholesterol 
Dyslipidemia is one of the most important modifiable risk factors for cardiovascular diseases 
. Although ethnic differences exist in the prevalence of dyslipidemia, the estimated 10-Year Risk of Coronary Heart Disease does not differ according to ethnicity 
. Asians are known to have the same risk of CVD in spite of the lower prevalence of dyslipidemia 
. Furthermore, Asians have other risk factors for CVD, such as hypertension and diabetes. In our study, the prevalence of hypertension was up to 19.2% and in hypertensive subjects, the relative risk of dyslipidemia increased by 1.474 times. Furthermore, the age-adjusted prevalence of hypertension in Korean adults was 34.7%, which is higher than that (29.5%) in the United States 
. The prevalence of type 2 diabetes mellitus in Korea is estimated to be 7.3%, according to a report by KNHANES III, 2005, an approximately five-fold increase from the value of 30 years ago 
. The estimated prevalence of diabetes mellitus among Koreans is even higher than in the U.S. population in 2030. Furthermore, 0.09% of children and adolescents were newly diagnosed with diabetes, which was comparable to the findings in Asians in the SEARCH for Diabetes in Youth Study. 
The risk of CVD estimated from the NCEP guideline and predicted using the Framingham model in Koreans was similar to that in the American population (Korea, 4.7% vs. the U.S., 5.3%) 
. Therefore, adult dyslipidemia patients have been treated according to NCEP or AHA guidelines with some modifications 
. On the basis of these and our own results, we suggest that dyslipidemia in Korean and other Asian children and adolescents should be managed according to the recommendations in the AAP guidelines.
There were some limitations in the present study. First, we were unable to estimate precisely the number of children and adolescents who were potentially eligible for pharmacological treatment because information regarding family history of CVD was not collected in KNHANES-IV. Second, the subject who was suspected diabetes with high LDL-C and high HbA1c was not included as they were not fasting state. If they were included the adolescent potentially eligible for pharmacological treatment would further increase.
We made the references of each lipid and lipoprotein concentrations in Korean children and adolescents aged 10–18 years. The estimated national prevalence of any type of pediatric dyslipidemia by using the NECP and AHA guidelines was 19.7%. Furthermore, at least 0.41% of Korean children and adolescents are eligible for pharmacological treatment according to the AAP guidelines. These findings provide useful information not only for Korean but also for Asian ethnicity in planning programs targeting the prevention of CVD through lipid control from childhood.