Vitamin D and Elevated Serum Uric Acid as Novel Predictors and Prognostic Markers for Type 2 Diabetes Mellitus

AIM: To ascertain the active role of uric acid and vitamin D as potential biomarkers for impaired glucose metabolism among people living with type 2 diabetes mellitus (T2DM) in Turkish community. SUBJECTS AND METHODS: This study was based on 680 patients with T2DM and 680 healthy subjects aged between 25 and 70 years, who visited the diabetes and endocrinology department of Istanbul Mega Medipol University Teaching Hospital, Istanbul, Turkey, during January 2016 to April 2018. The investigated biochemical indices included lipid profiles (low-density lipoprotein [LDL], high-density lipoprotein, total cholesterol, and triglyceride [TG]), uric acid, blood pressure (BP), serum creatinine, glycosylated hemoglobin (HbA1c), thyroid-stimulating hormone (TSH), postprandial glucose, and any related comorbidities. RESULTS: This study reported significant differences between family history duration of patients with T2DM of ≤5 and >5 years when compared to that of control subjects with respect to body mass index (BMI), smoking habit, sheesha smoking, income, family history of metabolic syndrome, hypertension, coronary heart disease, and nephropathy. Similarly, significant differences were found between patients with T2DM (with family history T2DM duration of less than 5 years and more than 5 years in contrast to healthy subjects’ level of LDL, TG, fasting blood glucose, HbA1c, systolic BP (SBP), bilirubin, albumin, magnesium, potassium, calcium, number of sleeping hours, and TSH. We uncovered the correlation between serum uric acid level with the clinical biochemical indices related to T2DM: serum calcium (r = 0.336), magnesium (r = 0.272), potassium (r = 0.205), HbA1c (r = 0.638), fasting blood glucose (P = 0.486), bilirubin (r = 0.251), albumin (r = 0.285), LDL (r = 0.322), TG (r = 0.434), diastolic BP (DBP) (r = 0.392), SBP (r = 0.344), BMI (r = 0.482), waist circumference (WC) (r = 0.366), age (r = 0.217), number of sleeping hours (r = 0.275), and TSH (r = 0.445). Multivariate stepwise logistic regression showed that variables, such as serum vitamin D, uric acid, TSH, HbA1c, DBP, WC, BMI, and SBP, were considered at higher risk as significant (P < 0.001) predictors for T2DM. CONCLUSION: The results suggest strong positive correlation between serum uric acid level with BP (SBP and DBP), age, BMI, and WC among patients with T2DM. This study ascertains that an increase in uric acid level may be due to elevated level of HbA1c, metabolic syndrome, diabetes, obesity, and/or hypertension.