Comparison of insulin resistance and serum high-sensitivity C-reactive protein levels according to the fasting blood glucose subgroups divided by the newly recommended criteria for fasting hyperglycemia in 10 059 healthy Koreans

The increment for the prevalence of diabetes mellitus and impaired glucose tolerance warrants lowering the cutoffs of normoglycemia to help predict the future development of diabetes. The aim of this study was to find out whether insulin resistance and high-sensitivity C-reactive protein (hsCRP), a nontraditional cardiovascular risk factor, were related to the fasting glucose level, even in normoglycernic range that was categorized by the newly recommended criteria by the American Diabetes Association. Among the participants undergoing medical checkup program at Kangbuk Samsung Hospital, 10059 subjects (5535 men and 4524 women; mean age, 45 years) with normal fasting glucose levels, as defined by the newly recommended criteria (< 5.6 mmol/L), were enrolled in this study. The blood pressures, body mass index (BMI), fasting blood glucose, fasting insulin, lipid batteries, and hsCRP levels were checked. The homeostatic model assessment-insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check indexes (QUICKI) were calculated. All subjects were subdivided into 4 groups according to the fasting glucose level. The HOMA-IR, QUICKI, and log-transformed (log) hsCRP, or log(hsCRP), level significantly increased according to the increment in fasting glucose, and these associations were consistent after adjustment for age and BMI, except for the log(hsCRP) (P = .124 after adjustment). Log(hsCRP) increased as the HOMA-IR increased and as the QUICKI decreased, and when multiple regression analysis was done with log(hsCRP) as the dependent variable, age, high BMI, male sex, high HOMA-IR, hypertriglyceridemia, and low high-density lipoprotein cholesterol were the significant predictor for log(hsCRP). In conclusion, the insulin resistance indexes and hsCRP increased gradually even in the normal fasting glucose range, as categorized by the newly recommended criteria for abnormal fasting glucose levels, supporting the rationale for expanding the range of fasting hyperglycemia. (c) 2006 Elsevier Inc. All rights reserved.