Factors responsible for age-related elevation in fasting plasma glucose: a cross-sectional study in Japanese men

Abstract To evaluate the factors associated with age-related increase in fasting plasma glucose (FPG) in Japanese men with normal fasting glucose, we measured FPG, fasting immunoreactive insulin, glycated hemoglobin, total cholesterol, triglyceride, and high-density lipoprotein cholesterol levels in health check examinees. Subjects with FPG less than 6.1 mmol/L together with glycated hemoglobin less than 5.6% were enrolled in the study. The homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA- β were used as the indices of insulin sensitivity and insulin secretion, respectively. Fasting plasma glucose increased significantly with age ( r = 0.30, P β decreased significantly with age ( r = 0.24, P r = 0.06, not significant), whereas body mass index and serum triglyceride were associated with HOMA-IR ( r = 0.49, P r = 0.33, P β -cell function rather than with insulin resistance. Further analyses were performed by comparing 3 groups: low FPG (FPG P β -cell function is already deteriorated when the FPG level is greater than 5.6 mmol/L.