Serum Vitamin D Associated with Insulin Secretory Function in Impaired Fasting Glucose Subjects

摘要

Background: Impaired fasting glucose (IFG) is a prediabetic condition and is a high-risk state for developing diabetes and associated complications. The aim of this study was to explore the association of vitamin D with insulin secretory function among the IFG subjects. Materials and Methods: This was a prospective cross-sectional study conducted in the Department of Biochemistry and Cell Biology, Bangladesh University of Health Sciences (BUHS), Dhaka, Bangladesh; from June 2016 to May 2017, on forty-six (46) IFG subjects. Serum blood glucose was measured by glucose-oxidase method, Fasting serum lipid profile (Total cholesterol, TG and HDL-c); liver enzyme like alanine aminotransferase (ALT) was measured by enzymatic-colorimetric method; Serum creatinine was measured by colorimetric kinetic method; Serum Insulin and vitamin D [25(OH)D] were measured by ELISA method; insulin secretory capacity (HOMA%B) and insulin sensitivity (HOMA%S) were calculated by Homeostasis Model Assessment (HOMA) using HOMA-CIGMA software. Results: Among 46 IFG subjects, 22 (47.8%) were male and rest 24 (52.2%) were female and their mean age was 40 (±8) years. Mean fasting serum glucose level of the study subjects was 6.33 (±0.23) mmol/l and mean postprandial serum glucose level was 7.23 (±0.41) mmol/l. Mean serum vitamin D level of the study subjects was 26.54 (±8.83) ng/ml. Mean HOMA%S, HOMA%B and HOMA%IR of the total study subjects were 48.34 (±16.70), 102.16 (±23.13) and 2.28 (±0.70) respectively. Insulin secretory capacity (HOMA%B) was significantly higher (p = 0.047) in the subjects having higher vitamin D [25(OH)D level ≥ 20 ng/ml] compared to the subjects having lower vitamin D [25(OH)D levels < 20 ng/ml]. Conclusion: High prevalence of hypovitaminosis D exists among IFG subjects. Vitamin D is associated with insulin secretory function in IFG subjects. Population based prospective studies using larger sample size should be done to confirm the results.