Relationship between lipid abnormalities and insulin resistance in Japanese school children

Objective - Dyslipidemia and insulin resistance (IR) are risk factors for coronary heart disease (CHD) in adults. To help prevent the development of CHD, it may be useful to understand the relationship between lipid abnormalities and IR during childhood. Methods and Results - IR was assessed by the homeostasis model approximation index. We studied 1175 Japanese school children (642 boys and 533 girls), aged between 7 and 12 years. Obesity was defined by the body mass index standard deviation score (BMISD) (obese: BMISD >= 2.0). BMISD was most significantly associated with IR in nonobese children (P = 0.000). Associations of IR with lipid-related parameters were affected by BMISD. After being corrected by BMISD, in nonobese children, log triglycerides (TG), apoB and low-density lipoprotein (LDL) size in boys and log TG, LDL size, and high-density lipoprotein (HDL) cholesterol in girls were still significantly associated with IR (P = 0.000 to 0.017). In obese children, all parameters except for LDL cholesterol in boys and LDL size in girls were significantly associated with IR (P = 0.000 to 0.030). Multiple regression analysis showed that log TG and LDL size in nonobese children, log TG in obese boys and LDL size in obese girls were independently associated with IR. Children with IIb and IV hyperlipidemia had significantly higher IR than those with normolipidemia and IIa, even after correcting for BMISD and age. Conclusion - Our results suggest that in addition to controlling body weight, it may be important for school children to characterize lipid phenotypes to prevent progression to CHD and/or type 2 diabetes and to identify subjects who are at high risk for these disorders.