Vitamin D status in type 2 diabetic patients and its association with glycemic control, lipids and microalbuminuria: a pilot study

ABSTRACT

The objective of the present study was to determine the vitamin D status of type 2 diabetic patients and correlate the levels with glycemic control, lipids and microalbuminuria. A pilot study was conducted on 192 randomly selected type 2 diabetic patients of both sexes from different ethnic backgrounds, in the age group of 35-65 years, with or without hypertension and dyslipidemia, who attended the medical OPD at GMC Hospital Ajman from January to April 2013. A questionnaire was used to obtain sociodemographic and clinical details about the patients. American Diabetic Association Criteria [2013] were used for diagnosis. Patients were classified into three groups according to their total vitamin D status deficient [10- < 20 ng/mL], insufficient [20-30 ng/mL], Sufficient [optimum >3050 ng/mL]. Fasting blood specimens were analysed for glucose, total vitamin D, calcium, phosphorus, lipoproteins and HbA1C levels in addition to routine kidney functions using Cobas 601 analyzer [Roche]. Morning urine specimens were analyzed for Urinary Albumin Excretion Rate [UAER] using DCA 2000 analyzer [Bayer] employing Turbidimetric Inhibition Immunoassay. UAER between 30-300 microg/mg creatinine was described as microalbuminuria. Vitamin D deficiency and insufficiency was found among 96.8% of type 2 diabetic patients. Serum calcium and phosphorus levels and routine kidney function tests were normal. Plasma glucose, lipoprotein and HbA1C levels were significantly elevated [p < 0.05] in patients with raised UAER compared to patients with normal UAER. HbA1C and LDLc showed a negative correlation with vitamin D levels. The presence of elevated UAER, HbA1C and LDLc levels in type 2 diabetic patients with low vitamin D levels suggest the role of vitamin D deficiency in the pathogenesis of type 2 diabetes mellitus and its complications. The results of the pilot study will be used in carrying out our study on large cohort of type 2 diabetics and identify the role of vitamin D deficiency in its pathogenesis and complications. In the meantime, it is suggested that proper exposure to sun in addition to regular intake of vitamin D and calcium may delay the development of type 2 diabetes and its complications