Does vitamin D status correlate with insulin resistance in obese prediabetic patients? An Egyptian multicenter study.

Background: The link between Vitamin-D deficiency and type 2 diabetes (T2D) is well-established. Since prediabetic obese populations have the greatest risk to develop to T2D, it was important in our study to examine serum 25(OH) D3 concentration among prediabetic obese patients and to evaluate the correlation between serum level of vitamin D and BMI, FBS, HOMA IR and HbA1c among prediabetes patients.

Methods: A multicenter case control study was carried out among 101 prediabetic persons & 50 controls, after obtaining consent from subjects and clearance from institutional ethics committee. Serum vitamin D level, Plasma levels of glycosylated hemoglobin (HbA1c) and fasting insulin levels were measured by ELISA in both groups enrolled in the study.

Results: The prevalence of vitamin-D deficiency/insufficiency was (73.3%) (n = 74) among 101 prediabetic obese individuals. Also, A significant inverse correlation was observed between vitamin D levels & body mass index(r = - 0.28, P = 0.004); fasting blood sugar (r = - 0.22, P = 0.002); HOMA insulin resistance (r = - 0.25 P = 0.01); HbA1C (r = - 0.2, P= 0.004).

Conclusions: High prevalence of vitamin D deficiency exists among obese prediabetic individuals and there is significant inverse correlation between BMI, FBS, HOMA IR, HbA1c and vitamin D level.