New criteria of normal serum lipid levels in Japanese children: The nationwide study

Aim : To make new criteria of serum lipid levels in current Japanese children using the large nationwide data provided from Japan Association of Health Service for the analysis. Methods : The subjects were schoolchildren who received screening and care programs for lifestyle related diseases since 1993 1999. Serum total cholesterol (TC), high-density lipoprotein cholesterol (HDLC) and triglyceride (TG) levels were measured, and low-density lipoprotein cholesterol (LDLC) levels were calculated. Serum lipid levels were analyzed by age and sex. For each serum lipid, we extracted age- and sex-specific group which the mean value was not statistically different from that in 1999 by Student's t-test analysis. Results : The level below the 75th percentile was defined to be acceptable, from the 75th to 95th to be borderline and over the 95th to be high in TC/LDLC. The level below the fifth percentile in HDLC was defined to be low and the level over the 95th percentile in TG to be high. Therefore, TC level was categorized as follows: acceptable <190 mg/dL; borderline 190-219 mg/dL; and high >220 mg/dL. The LDLC level was also categorized into: acceptable <110 mg/dL; borderline 110-139 mg/dL; and high >140 mg/dL. The cut-off value in TG was determined to be 140 mg/dL and in HDLC was 40 mg/dL. Conclusions : This new criteria should prove valuable in health strategies for rational prevention and intervention in children. It should be emphasized to provide some intervention for Japanese children immediately.