Vitamin D Deficiency as a Factor Associated with Cognitive Impairment in Patients with Type 2 Diabetes Mellitus

Abstract

Objective: Vitamin D as an essential nutrient is increasingly being studied and reported to have roles in diabetes and cognitive function through its antioxidant, anti-inflammatory, and neuroprotective functions. This study aimed to investigate vitamin D deficiency as a factor associated with cognitive impairment in Type 2 Diabetes Mellitus patients. Materials and Methods: This case-control study was conducted at the diabetic center and neurology outpatient clinic at Prof. Dr. I.G.N.G Ngoerah Hospital in Denpasar, Indonesia between September and December 2022. Cases had a score of < 26 on the Montreal Cognitive Assessment questionnaire (Indonesian version) controls had a score ≥26. Vitamin D levels were assessed using serum 25-hydroxyvitamin D levels. The cut-off for vitamin D deficiency was obtained through the receiver operating curve characteristic. Results: In total 31 cases and 31 controls were included. The cut-off for vitamin D deficiency was <24.6 ng/ml. Patients with T2DM and vitamin D deficiency had an increased association with cognitive impairment (OR 3.8; 95% CI [1.1 to 13.4]) compared to patients without vitamin D deficiency. Other independent factors associated with cognitive impairment in T2DM were low education levels (OR 5.4; 95% CI [1.3 to 22.2]) and diabetes duration of more than 5 years (OR 4.1; 95% CI [1.1 to 14.4]). Conclusion: Vitamin D deficiency is one of the factors associated with cognitive impairment in T2DM patients.