Adolescent cholesterol levels: How high is too high?

According to a recently published report in Circulation, official journal of the American Heart Association, the current National Cholesterol Education Program's (NCEP) method for diagnosing elevated lipoprotein levels in the young is inaccurate because it lumps together children of both sexes ranging from 2 to 19 years. For that population, the NCEP defines a "borderline high" lipoprotein level as one that is at or above the 75th percentile; a "high" level is one that is above the 95th percentile.

According to Ian Janssen, PhD, and Courtney J. Jolliffee, MSc, of Queen University in Kingston, Ont., authors of the Circulation article ("Distribution of lipoproteins by age and gender in adolescents"), the analysis needs to be sliced more finely.

"Lipoprotein concentrations change considerably with normal growth and maturation and vary by gender," Janssen and Jolliffee said. "Adolescents should not be misdiagnosed simply because they are on a different part of the growth curve."

Age and gender-specific risk curves, the authors recommend, should be used to define percentile cut-off points for the risk of cardiovascular disease in adolescence. For the total cholesterol level, for example, borderline-to-high cut-off points should be 86th percentile for males and 78th percentile for females; a "high" total cholesterol level should be based on the 97th percentile for boys and the 94th percentile for girls. Cut-off points for low-density lipoprotein, HDL, and triglycerides would be adjusted similarly to account for age and gender.