Study of Vitamin D Status and its Correlation with Glycated Haemoglobinin Type 2 Diabetes Mellitus

Introduction: Few published researches have surveyed the correlation between Vitamin D status and glycaemic control in type 2 diabetes mellitus (T2DM). The present study was conducted to investigate the status of vitamin D and its correlation with glycated haemoglobin in type 2 diabetes mellitus. Method: A cross-sectional single centre study was conducted in 2440 patients with T2DM attending the Diabetes Centre at King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia between January 2018 and December 2018. Eligible patients were 20 years or older. Results: There were 2440 patients with T2DM. Vitamin D deficiency (25-OHD<50 nmol/l) was found 47.5%. Patients with HbA1c<7% were younger than patients with HbA1c 7%-9% and >9% (55.3 ±16.0 vs. 58.4 ±15.2 vs. 57.1 ±15.4 respectively, p<0.0001). The mean 25-OHD concentration was statistically significant lower in patients with Hba1c>9% compared to patients with Hba1c<7% and 7%-9% (49.7 ±27.0 vs. 61.8 ±31.4 vs. 56.9 ±28.8 respectively, p<0.0001). The frequency of vitamin D deficiency was statistically significant higher in patients with Hba1c>9% compared to patients with Hba1c<7% and 7%-9% (40% vs. 48% vs. 61% respectively, p<0.0001). The frequency of vitamin D deficiency was upward across HbA1c groups as age advanced with highest frequency of vitamin D deficiency was found to be statistically significant in HbA1c>9% compared to HbA1c< and 7%-9% groups in the age group 50-59 years and ≥60 years with males most frequently predominant than females in all age group associated with HbA1c 7%-9% and 9%. HbA1c was significantly positively correlated with age whereas 25-OHD concentration was significantly negatively correlated with age. Conclusions: We report vitamin D deficiency and its inverse association with Glycated Haemoglobin in type 2 Diabetes Mellitus.