Is vitamin D status a predictor glycaemic regulation and cardiac complication in type 2 diabetes mellitus patients?

Objective: To evaluate vitamin D as a predictor of glycaemic regulation in type 2 diabetes mellitus patients.

Research Design And Methods: In observational study 171 type 2 diabetic patients who are followed for median (range) of 10.15 (3-18) years. Mean ± SD age was 56 ± 10. Plasma 25-hydroxyvitamin D3 levels were determined by high-performance liquid chromatography/tandem mass spectrometry on baseline samples. Vitamin D deficiency was defined as a 25-OHD level of less than 20 ng/ml. Vitamin D levels between 20 and 30 ng/ml are termed 'insufficient'. Vitamin D levels greater than 30 ng/ml are termed 'optimal'.

Results: 125 patients have vitamin D deficiency, 14 patients have insufficient and the others have optimal. Vitamin D levels were not associated with sex, age, BMI, HDL, LDL, kreatinin, hypertension and smoking. But vitamin D deficiency patients had more longer duration (p=0.011), more higher uric acid (p=0.021), fasting glucose (p=0.037), postprandial glucose (p=0.001) and HbA1c (p=0.026).

Conclusions: In our study type 2 diabetic patients have 73% of vitamin D deficiency. Vitamin D deficiency predicts higher fasting and postprandial blood glucose and diabetes disregulation. Type 2 DM patients and low 25-OH vitamin D levels could increased cardiovascular disease directly or indirectly (low HDL and high uric acid in 25-OH vitamin D <20 ng/ml). Whether vitamin D substitution improves prognosis remains to be investigated.