Correlation Between Serum 25-Hydroxyvitamin D Level And Carotid Artery Intima-Media Thickness In Type 2 Diabetic Patients

Objective:Macroangiopathy has become one of the main cause of death in type 2 diabetic patients.Atherosclerosis is one of the important mechanisms of type 2 diabetic macroangiopathy,which can predict the risk of cardiovascular events in type 2 diabetic patients. The carotid artery intimal-medial thickness(IMT)is an early indicator of atherosclerosis.Vitamin D is a fat soluble vitamin. Vitamin D not only plays a role in the regulation of cacium phosphorus and bone metabolism,but also is related to the occurrence of cardiovascular events in type 2 diabetic patients.The purpose of our study is to evaluate the correlation between serum 25-hydroxy vitamin D[25(OH)D]level and carotid IMT in type 2 diabetic patients.Methods:Totally 132 hospitaled patients with type 2 diabetes mellitus were choosed from the Department of Endocrinology in the First Affiliated Hospital of Chongqing Medical University.They were aged 64.45±8.34 years(48 cases were men and 84 cases were women). The patients were divided into quartiles according to the level of serum 25(OH)D. The patients were spanided into normal group and atherosclerotic group by C-IMT.All the subjects received an interview including age,gender,history of smoking,duration of type 2 diabetes,history of hypertension.Body height,body weight, body mass index(BMI) and blood pressure were collected.Fasting plasma glucose(FPG),hemoglobin A1c(Hb A1c),low density lipoprotein-cholesterol(LDL-C), high density lipoprotein-cholesterol(HDL-C), total cholesterol(TC), triglyceride(TG)were measured.Serum 25(OH)D was measured using electro-chemiluminescence assay.C-IMT,peak systolic velocity(PSV),end diastolic velocity(EDV)were measured by ultrasongraphy.Results:Comparing with group Q3,patients in group Q1 had a significantly higher C-IMT(P=0.027).C-IMT in groups Q1 and Q2 were significantly higher than in group Q4(P=0.000,P=0.002).However there was no significant difference between Q1 and Q2 groups. Similarly, there was no significant difference between Q3 and Q4 groups.Prevalence of carotid atherosclerotic plaque in group Q1 was significantly higher than in groups Q2,Q3 and Q4(P=0.004,P=0.002,P=0.000).The carotid PSV were lower for patients in group Q1 compared with those in group Q3(P=0.031). Similarly, carotid EDV were significantly lower in group Q1 than in groups Q2,Q3 and Q4(P=0.003,P=0.002,P=0.038).Comparing with normal group,patients in atherosclerotic group had a significantly lower 25(OH)D levels(P=0.000).Pearson correlation analysis showed that carotid IMT was negatively related with the 25(OH)D(r=-0.348,P=0.000).Muhivariate regression analysis revealed that 25(OH)D was a predictor of carotid IMT in this cohort(B=-0.012,P=0.000).Conclusion:Serum 25(OH)D level is negatively correlated with carotid IMT.The low level of serum25(OH)D may be a risk factor for atherosclerosis in type 2 diabetic patients.