The correlation between Betatrophin and islet beta cell function and other metabolic indexes in type one and type two diabetes mellitus

Abstract

Objective To observe the change of circulating Betatrophin in patients with type 1 or type 2 diabetes mellitus (T1DM, T2DM) and analyze the correlation between serum Betatrophin levels and metabolism-related indexes. Methods A total of 154 people (80 healthy controls, 30 T1DM, 44 T2DM were enrolled in the study. Anthropometrics and blood Biochemical indexes of metabolism were measured, and serum betatrophin was measured with enzyme-linked immunosorbent assay kit. Comparison among the three groups was tested with univariate analysis of variance, correlation between Betatrophin and anthropometrics and biochemical indicators with linear correlation analysis, and factors influencing betatrophin with multivariate linear regression. Results Serum Betatrohpin level [(3.57±0.48)ng/ml vs.(2.26±0.54)ng/ml, P<0.05], fasting blood glucose[(12.3±2.4)mmol/L vs.(4.8±2.6)mmol/L, P<0.05], 2-hour postprandial blood glucose[(23.1±3.2)mmol/L vs.(7.2±3.1)mmol/L, P<0.05], glycosylated hemoglobin (HbA1c)[(9.9±3.5)% vs.(5.3±2.4)%, P<0.05] were significantly increased in patients with T1DM compared with healthy controls; while fasting C peptide [(0.12±0.08)ng/ml vs. (0.47±0.16)ng/ml, P<0.05], 2-hour postprandial C peptide [(0.14±0.09)ng/ml vs. (1.06±0.49)ng/ml, P<0.05], HOMA-β(26.20±12.70 vs. 82.93±48.12, P<0.05) were significantly reduced in patients with T1DM compared with healthy controls. In T1DM patients, serum Betatrophin concentration was correlated with age(r=0.417, P<0.05), HbA1c(r=0.475, P<0.05), fasting blood glucose(r=0.386, P<0.05), 2-hour postprandial blood glucose(r=0.367, P<0.05), and HOMA-β (r=-0.400, P<0.05). HOMA-β, fasting blood glucose, age and HbA1c were the main influencing factors of serum Betatrophin level. Serum Betatrophin level [(4.87±0.65)ng/ml vs.(2.26±0.54)ng/ml, P<0.05], triglycerides [(2.20±1.60)mmol/L vs. (1.36±0.76)mmol/L, P<0.05], fasting blood glucose[(8.9±2.8)mmol/L vs.(4.8±2.6)mmol/L, P<0.05], 2-hour postprandial blood glucose[(17.7±4.2)mmol/L vs.(7.2±3.1)mmol/L, P<0.05], fasting insulin[(15.30±8.60)μU/ml vs.(5.02±2.34)μU/ml, P<0.05], fasting C peptide[(1.93±1.60)ng/ml vs.(0.47±0.16)ng/ml, P<0.05], 2-hour postprandial C peptide[(5.20±2.70)ng/ml vs.(1.06±0.49)ng/ml, P<0.05], HbA1c[(7.9±2.2)% vs.(5.3±2.4)%, P<0.05], HOMA-IR (4.70±2.30 vs. 1.59±0.94, P<0.05) were higher in T2DM patients compared with healthy controls, and HOMA-β (57.50±22.30 vs. 82.93±48.12, P<0.05) was contrary. In patients with T2DM, serum Betatrophin concentration was positively correlated with age(r=0.442, P<0.05), fasting blood glucose(r=0.362, P<0.05), fasting insulin(r=0.312, P<0.05), HbA1c(r=0.486, P<0.05), triglycerides(r= 0.270, P<0.05), low-density lipoprotein cholesterol(r= 0.294, P<0.05), HOMA-IR(r=0.436, P<0.05), and negatively related with high-density lipoprotein cholesterol(r=-0.257, P<0.05) and HOMA-β (r=-0.365, P<0.05). Body mass index, HOMA-IR, HOMA-β, fasting insulin and age were the main influencing factors of Betatrophin in patients with T2DM. Serum Betatrophin concentration was higher in T2DM patients than in T1DM patients [(4.87±0.65)ng/ml vs. (3.57±0.48)ng/ml, P<0.05]. Conclusion Betatrophin may be associated with the carbohydrate metabolism and function of islet beta cells in diabetic patients, and with serum lipid metabolic disorder in T2DM patients. It may be involved in the development of diabetes. Key words: Diabetes mellitus; Betatrophin; Islet beta cells; Lipid metabolism