The relationship of vitamin D levels with hemogram indices and metabolic parameters in patients with type 2 diabetes mellitus

Background: Vitamin D deficiency and Type 2 Diabetes (T2DM) are two important health problems that have rapidly increased prevalences in recent years. Chronic inflammation and susceptibility to infection are the characteristic features of T2DM. Vitamin D deficiency has been associated with high serum inflammatory marker levels due to its immunomodulatory effect. Moreover, studies have pointed out that vitamin D insufficiency could be associated with T2DM. Additionally, in recent years, inflammatory markers derived from hemogram have been associated with diabetes and its complications. Therefore, in our study, vitamin D levels, metabolic markers (i.e., serum uric acid, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol), and hemogram indices were analyzed in well controlled and poorly controlled T2DM patients. Furthermore, we compared those variables in vitamin D deficient and non-deficient groups. Methods: Laboratory data, including vitamin D and hemogram markers, were compared between poorly and well controlled T2DM patients who visited the outpatient internal medicine clinics of our institution. Results: A total of 240 T2DM individuals were included in the present study: 170 individuals had vitamin D deficiency and 70 individuals had normal vitamin D levels, who served as controls. The median neutrophil to lymphocyte ratio (NLR) value was 2.2 (0.74-7.4) in the vitamin D deficient group and 2.02 (0.73-5.56) in the vitamin D normal group (p = 0.025). Among the study parameters, the NLR and glycated hemoglobin (HbA1c) levels showed a significant positive correlation (r = 0.30, p < 0.001). The sensitivity and specificity of the NLR to predict vitamin D deficiency were determined as 60% and 49%, respectively (AUC: 0.59, p = 0.03, 95% CI: 0.51-0.67). The sensitivity and specificity of the NLR to predict an improved control of diabetes were 72% and 45%, respectively (AUC: 0.67, p < 0.001, 95% CI: 0.60-0.74). Conclusions: We think that NLR can be helpful in follow up of T2DM and vitamin D deficiency.