Association between 25-hydroxyvitamin D and hemoglobin A1c levels in patients with type 2 diabetic kidney disease

Abstract

Introduction Vitamin D is suggested to influence glucose homeostasis. An inverse relationship between serum 25-hydroxyvitamin D (25(OH)D) and glycemic control in non-chronic kidney disease (CKD) patients with type 2 diabetes was reported. We aimed to examine this association among type 2 diabetes patients with CKD. Objectives To examine the relation between plasma 25-hydroxyvitamin D3 (25(OH)D3) levels and glycemic state in diabetic patients at various stages of CKD. Patients and methods A total of 70 participants (40 men and 30 women) with a mean age of 65.3±11.5 years suffering from type 2 diabetes mellitus with various stages of CKD were recruited. Blood for glycated hemoglobin (HbA1c), serum 25(OH)D3, renal profile, and estimated glomerular filtration rate was drawn at enrollment. Correlation and regression analyses were carried out to assess the relationship of serum 25(OH)D, HbA1c, and other metabolic traits. Results Our study shows the following results: Most of the participants are urban with age range from 50 to 70 years. Forty percent of the participants are with good glycemic control, 30% with moderate control, and 30% with bad control. Fifty percent of the patients were at CKD stage 3. Stage 5 patients differed significantly from stages 1 to 4 patients where they were younger, with lowest mean HbA1C value and a much higher mean 25(OH)D level (around twice of stage 1 patients). Half of the cases are vitamin D deficient, nearly a third of them are insufficient, and about 20% are sufficient. The level of 25(OH)D3 correlates inversely with the level of HbA1C irrespective of estimated glomerular filtration rate or the age of the patients. Conclusion The present study reported a significant inverse relationship between serum 25 (OH)D3 and HbA1c levels in type 2 diabetics with suboptimal glycemic control and concomitant different stages of CKD.