Association between serum osteocalcin and glucose/lipid metabolism in Chinese Han and Uygur populations with type 2 diabetes mellitus in Xinjiang: two cross-sectional studies

BACKGROUND: Recent studies have shown osteocalcin (OC) plays an important role in regulating glucose and lipid metabolism. Thus, the aim of this study was to investigate the association of OC with glucose and lipid metabolism in patients with type 2 diabetes mellitus (T2DM) in the Chinese Han and Uygur population. METHODS: A total of 1397 T2DM patients (705 Han and 692 Uygur T2DM patients) were enrolled in the present study. Lipid profile, glucose metabolic indices and total OC (TOC) were measured. Homeostasis model assessment of β-cells function (HOMA-β), insulin sensitivity (HOMA-IS) and insulin resistance (HOMA-IR) were also calculated in all participants. Pearson/Spearman correlation analysis and multivariate stepwise regression analysis were adopted to test the relationships between OC and those parameters. RESULTS: Uygur T2DM patients had significantly higher body mass index (BMI), hemoglobin A1C (HbA1C) and lower TOC compared with their Han counterparts (all P < 0.05). HbA1C was negatively associated with TOC in all Uygur and Han T2DM patients (Total: Uygur: t = −3.468, P = 0.001; Han: t = −4.169, P < 0.001). BMI was inversely associated with TOC in all Uygur T2DM patients (Males: t = −2.893, P = 0.014; Females: t = −2.250, P = 0.027, respectively). Multivariate stepwise regression analysis showed that TOC was positively correlated with HOMA-β in the Uygur male group (β = 2.101, P = 0.040) and negatively associated with BMI in all Uygur T2DM patients (Males: β = −1.563, P = 0.011; Females: β = −1.284, P = 0.016, respectively). No significant differences were observed between TOC and lipid profiles in all participants (all P > 0.05). CONCLUSION: There were differences in the associations between TOC and glucose metabolism in Han and Uygur T2DM patients, indicating genetic factors may play a role in modulating OC and glucose metabolism in different ethnic population.