Potential effect of insulin resistance and cardiovascular risk factors on metabolic syndrome in subjects with normal fasting plasma glucose levels

The prevalence of metabolic syndrome has progressively increased with increasing fasting plasma glucose (FPG) levels. This study aimed to investigate the influence of insulin resistance and cardiovascular risk factors on metabolic syndrome in individuals with normal FPG. Study subjects with FPG levels below 100 mg/dL were divided into 5 groups depending on the exact FPG levels. We then evaluated the association of metabolic syndrome with insulin resistance and total cholesterol/ high density lipoprotein-cholesterol ratio (TC/HDL ratio). The odds ratio of insulin resistance in the level of HOMA-IR above 2.34 group 3.483(95 % CI, 1.110?～?10.932)] was significantly increased in the group of FPG level from 93 mg/dL to 99 mg/dL compared to the group below 80 mg/dL. The odds ratio of metabolic syndrome in the group of FPG level from 89 mg/dL to 92 mg/dL 2.459, (95%CI, 1.275?～?4.741)] and 93 mg/dL to 99 mg/dL 2.079, (95%CI, 1.052?～?4.110)] was significantly increased compared to the group below 80 mg/dL after adjusting age, sex, smoking status, physical activity, heavy drinking, TC/HDL ratio. Higher FPG levels within the normoglycemic range may constitute a risk of insulin resistance and is associated more strongly with the risks of metabolic syndrome.