Abstract
Abstract
Objective: An association between serum levels of vitamin D and glycaemic control in type-2 diabetes mellitus (DM) patients has been reported in some of the studies carried out in the West. However, there are no reports on this relationship in Pakistani diabetic patients. The aim of this study was to ascertain whether vitamin D levels have any influence on glycaemic control in Pakistani patients with type-2 DM.
Methods: In a cross-sectional survey, relationship between serum levels of 25-hydroxy vitamin D (25(OH)D) and glycated haemoglobin (HbA1C) was examined in 141 type-2 diabetic patients including 102 males and 39 females; age range 22 to 70 years, visiting the Aga Khan University Hospital during July 2013-April 2014. Venous blood was collected and analyzed for serum/plasma levels of 25(OH)D and related biomarkers using kit methods. HbA1C levels 7.0% were taken as indicators of good and poor glycaemic control, respectively. An association between 25(OH)D and HbA1C was investigated using regression analysis.
Results: Percent vitamin D deficiency (serum level of 25(OH)D < 20 ng/ml) was significantly higher in patients with poor glycaemic control compared to patients with good glycaemic control (58.7% vs. 30.6%; p-value=0.006). Binary logistic regression analysis revealed positive association between vitamin D deficiency and poor glycaemic control while adjusting for BMI, serum levels of albumin, alanine aminotransferase and alkaline phosphatase (OR, 4.86 (95% CI, 1.9-11.9; p-value126mg/dl.9 They had not received any vitamin D supplementation during the past 6 months and were free from any of the chronic diseases such as liver disease, uraemia, cancer or lung disease. The study had the approval from the Ethics Review Committee of the Aga Khan University. Medical records of these patients were obtained and those whose HbA1C levels were done within one week of their recruitment were included in this study. One hundred and forty one patients including 102 males and 39 females fulfilled the criterion and were selected for analysis of 25(OH)D and other related biomarkers.
Ten ml blood with at least 4 hours of fasting was collected and serum was analyzed for 25(OH)D, parathyroid hormone (PTH), calcium, alkaline phosphatase (ALP), phosphate, albumin, alanine aminotransferease (ALT) and creatinine using kit methods (Roche Diagnostics, Indianapolis, IN). For statistical analysis of the data, patients were divided into 2 groups on the basis of their glycaemic control: Good glycaemic control (HbA1C 7.0%) as per guidelines of American Diabetes Association.10 Demographic and clinical characteristics in these groups were compared using statistical tests such as chi-square for comparing proportions and Independent sample t test for comparing mean values. Binary logistic regression was applied to study the association between hypovitaminosis D and its relationship with poor glycaemic control. Pearson\\\'s correlation was used for correlation between serum levels of 25(OH)D and concentrations of HbA1C. A p-value of