Relationship between serum betatrophin levels and the first-phase of glucose-stimulated insulin secretion.

AIMS: To examine circulating betatrophin concentrations in subjects with different glucose tolerance status and to investigate the relationship between serum betatrophin levels and first-phase of glucose-stimulated insulin secretion.

METHODS: Serum betatrophin concentrations were measured in 110 age- and sex-matched subjects: 47 newly diagnosed type 2 diabetes mellitus (T2DM), 29 impaired glucose tolerance (IGT) and 34 normal glucose tolerance (NGT). Oral glucose tolerance test and intravenous glucose tolerance test were performed to assess glucose tolerance and first-phase of glucose-stimulated insulin secretion.

RESULTS: Serum betatrophin levels were significantly higher in the T2DM and IGT group than in the NGT group (2.10±1.16ng/mL vs 0.77±0.44ng/mL, 1.73±1.28ng/mL vs 0.77±0.44ng/mL; P<0.01). The AIR and AUC among the three groups showed a progressive decrease from the NGT to IGT group with the lowest value in the T2DM group (P<0.01). Betatrophin were found to be positively correlated with BMI, waist circumference (WC), homeostatic model assessment of insulin resistance (HOMA-IR) and triglyceride (TG), and inversely associated with HDL-c (all P<0.01), but not significantly correlated with 0-10min insulin the area under the curve (AUC) and acute insulin response (AIR) (P>0.05). Stepwise multiple regression analysis showed that HOMA-IR and TG were independently related to betatrophin (P<0.05).

CONCLUSION: Serum betatrophin concentrations were higher in T2DM and IGT, and were closely related to glucolipid disorder, insulin resistance, but not related to the first-phase of glucose-stimulated insulin secretion.