Relationship between Vitamin D level and Insulin Resistance According to Obesity Level

Abstract

Introduction: Obesity and metabolic syndrome are universal health problems. There is increasing evidence that vitamin D deficiency is a risk factor in the development of insulin resistance(IR). This study was aimed to investigate the relationship between vitamin D level and IR in obese patients.
 Method: The study included 95 adult, obese patients, without a history of hypertension, diabetes mellitus, and hyperlipidemia. Fasting blood glucose, insulin, 25-OH-vitamin D, and serum lipid levels were measured and the HOMA-IR level was calculated. The patients were divided into 3 groups according to their obesity level.
 Results: Seventy-eight (82.1%) of patients were female and vitamin D deficiency was found in 77.9% of the patients. The median HOMA-IR level of the group with and without vitamin D deficiency was 3.57, and 2.39, respectively (p = 0.029). 
 There weren't any significant differences in gender, BMI, and vitamin D levels between the groups with /without IR.
 No difference was found between obesity level groups in terms of age, gender, and vitamin D level. However, while insulin level and IR level increased significantly in morbid obese patients, this relationship could not be demonstrated in super-obese patients. 
 Conclusion: This study is the first study investigating the relationship between vitamin D-HOMA-IR in morbid and super obese patients. No statistically significant linear correlation was found between vitamin D and HOMA-IR level, but vitamin D deficiency was more common in the group with IR. Additional studies are needed to explain the relationship between the level of obesity and the effect of vitamin D on IR.