Vitamin D affects neutrophil-to-lymphocyte ratio in patients with type-2 diabetes mellitus.

AIMS/INTRODUCTION Chronic inflammation is an underlying feature of type-2 diabetes mellitus (T2DM). Hypovitaminosis-D is associated with T2DM, but whether it contributes to chronic inflammation is unclear. We examined the effects of vitamin D on various immune markers to evaluate its contribution to systemic inflammation in T2DM. MATERIALS AND METHODS We retrospectively analyzed data from T2DM patients, pre-diabetics, and non-diabetic control patients (N=9746). Demographic and clinical variables were evaluated using descriptive statistics and generalized linear regression. A stratified analysis based on total serum vitamin D was also performed. RESULTS Neutrophil count was a significant predictor of 1, 5-anhydroglucitol (1,5-AG) and HbA1c in pre-diabetics (1,5-AG: β=-0.719, P 0.05 for all). Among pre-diabetics, those who were vitamin D deficient had the highest NLR (P=0.040). Among diabetics, those who were vitamin D deficient had the highest neutrophil count (P=0.001), lowest lymphocyte count (P=0.016), and highest NLR (P<0.001). CONCLUSIONS The NLR is strongly influenced by serum vitamin D level. Given the high prevalence of hypovitaminosis-D and elevated NLR among chronic disease patients and the elderly, our results suggest that clinical interpretation of NLR as a predictive marker of T2DM-related inflammation should consider vitamin D level, age, and pre-existing morbidity.