Relationship between early–phase insulin secretion and blood glucose variability in subject with normal glucose regulation

Objective To investigate the relationship between early–phase insulin secretion and blood glucose variability in subject with normal glucose regulation. Methods Three hundred and thirty–nine individuals with normal body weight and normal glucose regulation, including 169 males and 170 females ranging from 20 to 69 years, were recruited from 10 hospitals in China. The mean amplitude of glycemic excursions (MAGE) observed by continuous glucose monitoring system was used assessing blood glucose variability. ΔI30/ΔG30 during oral glucose tolerance test was used to assess early–phase insulin secretion, whereas baseline insulin secretion by HOMA–β. Insulin sensitivity was evaluated by HOMA–IR and insulin sensitivity index (ISIc)resulting from Cederhom formula. Results The mean of MAGE in 339 normal subjects was (1.92±0.89)mmol/L. According to quartiles of MAGE, the subjects were divided into 4 groups, namely the Group A (MAGE 2.41 mmol/L). Adjustment for age, sex and HOMA–IR, the ΔI30/ΔG30 levels of Group A and B were both higher than those of Group C and D (P 0.05). Spearman correlation analysis showed that the MAGE level was positively correlated with age (r=0.157, P=0.004), and negatively correlated with ΔI30/ΔG30 (r=–0.270, P<0.001). Multiple regression analysis indicated that the ΔI30/ΔG30 was the independent influential factor of MAGE (β=–0.246, P<0.001). Conclusion The blood glucose excursions in subject with normal glucose regulation may be closely related to the function of early–phase insulin secretion. Key words: Blood glucose; Insulin