Effects of nateglinide on insulin secretion and dynamic glucose change in newly diagnosed type 2 diabetic patients

Abstract

Objective To observe the effects of nateglinide treatment on insulin secretion and dynamic glucose change in newly diagnosed type 2 diabetic patients. Methods A total of 36 newly diagnosed type 2 diabetic patients were enrolled in this study. According to the levels of fasting plasma glucose (FPG), all the subjects were divided into group A (FPG 5.0-6.9 mmol/L; n=12), group B (FPG 7.0-8.9 mmol/L; n=12), and group C (FPG 9.0-11.1 mmol/L; n=12). All the subjects underwent continue glucose monitor (CGM) for 72 hours within 3 days after the oral glucose tolerance-insulin release test (OGTT-IRT). After 24 hours of CGM, the participants underwent the nateglinide-oral glucose tolerance-insulin release test (NAT-OGTT-IRT), and received single 10-minute preprandial nateglinide (120 mg) during the test and after that. Data in the same group before and after the intervention were compared by matched pair t test, while one-way ANOVA was used for the comparison between groups. Results Compared with the group C, the increase of the ratio of insulin increase and glucose increase 30 minutes after glucose load(ΔI30 /ΔG30)was significantly raised in the group A and group B ((9.6±2.1), (5.2±1.7), and (0.6±0.4) U/mol, respectively; F=7.431, P<0.01). Compared with that in the first day of CGM, the amplitude of glycemic excursions (AGE) of the three groups showed a significant decrease in the third day ((4.9±1.5) mmol/L vs (10.5±2.1) mmol/L, (4.9±1.6) mmol/L vs (10.2±1.9) mmol/L, (8.6±1.6) mmol/L vs (10.4±2.2) mmol/L, respectively; P<0.01) . The AGE was decreased more significantly in the group A and group B compared with the group C (F=24.950, P<0.01). Compared with that in the first day, there were a longer duration when plasma glucose achieved the target level after taking nateglinide in the third day of CGM in the group A and group B ((16.5±1.2) h vs (21.3±0.4) h, (11.3±1.6) h vs (17.7±1.2) h, respectively; t values were -12.782 or -11.296, P<0.01). However, no significant difference was found in the group C. Conclusions Nateglinide can stimulate insulin release, decrease glycemic fluctuation and prolong the duration that plasma glucose achieves the target level in the newly diagnosed type 2 diabetic patients. Moreover, nateglinide may exert more effective role in type 2 diabetic patients with lower FPG levels. Key words: Nateglinide; Type 2 diabetes mellitus; Oral glucose tolerance test