Study On Relationship Between 25-hydroxyvitamin D3,Osteocalcin Levels And Islet Function In Type 2 Diabetes Mellitus Patients

OBJECTIVE: To investigate the relationship between Vitamin D(VitD),osteocalcin(OC)levels and islet function in type 2 diabetes mellitus(T2DM)patients.METHODS: A total of 501 type 2 diabetes mellitus patients were selected,who was from the First Affiliated Hospital of Guangxi Medical University,from October,2015 to March,2016,including 309 males and 192 females.According to the serum 25-hydroxyvitamin D3 concentration,455 subjects were divided into deficiency group(n=165),insufficiency group(n=189)and sufficiency group(n=101).According to quartile of osteocalcin,413 subjects were divided into below P25 group(n=98),P25-P75 group(n=210),above P75 group(n=210).All patients' clinical data were collected,including gender,age,height,weight,systolic blood pressure,diastolic blood pressure,blood lipid,glycated hemoglobin(HbA1C),fasting blood glucose and 2-h postprandial plasma glucose(PBG2h),25-hydroxyvitamin D3(25(OH)D3),osteocalcin and other indexes.167 patients were tested IVGTT.The acute phase of insulin reaction(AIR0-10min)and the area under the C-peptide curve in 10 minutes(AUCCP0-10min)were used to assess the function of the first-phase insulin secretion function.AUCCP0-30 min,AUCCP0-180 min and HOMA-? were used to assess the function of early stage of insulin secretion,general insulin secretion and basal insulin secretion,respectively.HOMA-IR was used to evaluate the insulin resistance.Collectively discussing whether there was a correlation between25-hydroxyvitamin D3,osteocalcin levels and the islet function in type 2diabetes mellitusRESULTS: 1.In our research,455 patients tested serum25-hydroxyvitamin D3 concentration.There were 165 patients(36.3%)in VitD deficiency group,189 patients(41.5%)in insufficiency group and 101 patients(22.2%)in sufficiency group.A total of 77.8%(354 cases)were shortage of VitD.The prevalence of shortage of VitD is higher in female than in male.2.The incidence rates of diabetic nephropathy and diabetic peripheral neuropathy in different VitD levels groups were significantly different(P < 0.05).The prevalence of diabetic nephropathy and diabetic peripheral neuropathy is higher in VitD deficiency group.3.There were significant differences between osteocalcin with Hb A1 C,PTH,Scr,and incidence rate of diabetic peripheral neuropathy(P<0.05).Below P25 group of osteocalcin has high HbA1 C and high prevalence rate of diabetic peripheral neuropathy,but PTH and creatinine are low.4.In overweight-obesity group,age less than 60 years old and over 60 years old,and both for male and female T2 DM patients,VitD was positively correlated with AUCCP0-180 min.And in age less than 60 years old group,VitD and AUCCP0-30 min have a positive correlation.And vitamin D was negatively correlated with HOMA-IR in normal weight group,age less than 60 years old group and female group.5.There is significant positive correlation were found between with serum OC concentration with AUCCP0-30 min and AUCCP0-180 min innormal weight group.And it also has significant positive correlation with AUCCP0-180 min in male group.CONCLUSION: 1.The shortage of VitD was common in T2 DM patients.2.Low VitD level may increase the prevalence rate of diabetic nephropathy and diabetic peripheral neuropathy in T2 DM patients.3.In T2 DM patients,low osteocalcin level may have high prevalence rate of diabetic peripheral neuropathy.4.Sufficient levels of vitamin D may be beneficial to general insulin secretion in overweight-obesity,age less than 60 years old and over 60 years old,and both for male and female T2 DM patients,and improve early stage of insulin secretion in age less than 60 years old T2 DM patients.And it also can improve insulin resistance of normal weight,elder,male T2 DM patients.5.High level of osteocalcin may increase general insulin secretion of normal weight and male T2 DM patients.