Association of ۲۵ (OH)-D۳ Level With the CYP۲۷B۱ rs۱۰۸۷۷۰۱۲ Variants and Metabolic Parameters in T۲DM Patients From Kurdistan, Iraq

Background:There is an increasing prevalence of type ۲ diabetes mellitus (T۲DM) worldwide. The deficiency of vitamin D is a worldwide health problem that can increase susceptibility to T۲DM. Cytochrome P۴۵۰ family ۲۷ subfamily B member ۱ (CYP۲۷B۱) encodes the enzyme ۱α-hydroxylase in the kidney, which converts ۲۵ (OH)-D۳ to ۱,۲۵ (OH)۲-D۳. The CYP۲۷B۱ rs۱۰۸۷۷۰۱۲ G/T polymorphism is located in the gene promoter and can influence vitamin D۳ level. Objectives: This study aimed to investigate the relationship between CYP۲۷B۱ gene polymorphism and the ۲۵ (OH)-D۳ serum level and the risk of T۲DM. Additionally, the effect of ۲۵ (OH)-D۳ level on metabolic parameters was investigated. Methods: We investigated ۳۱۰ individuals including ۲۰۵ T۲DM patients and ۱۰۵ healthy subjects from the city of AL-Sulaymaniyah, Kurdistan of Iraq. The CYP۲۷B۱ gene variants were identified by the polymerase chain reaction followed by digestion with HinfI restriction enzyme. Results: The mean level of ۲۵ (OH)-D۳ was ۱۸.۴±۸.۵ ng/mL in T۲DM patients and ۲۴.۱±۹.۳ ng/mL in healthy controls (P<۰.۰۰۱). Significantly higher body mass index (BMI), HbA۱c level, and fasting blood sugar concentration were detected in individuals with vitamin D insufficiency (P=۰.۰۰۹, P=۰.۰۰۱, and P=۰.۰۱, respectively) and vitamin D deficiency (P=۰.۰۲۵, P<۰.۰۰۱, and P<۰.۰۰۱, respectively) compared to those with a sufficient level of vitamin D. The T allele frequency of CYP۲۷B۱ was ۳۸.۱% in controls and ۴۰.۲% in patients (P=۰.۶). In the presence of the GT genotype, a significantly lower level of ۲۵ (OH)-D۳ was obtained compared to the GG genotype (P=۰.۰۲) among the patients. Conclusion: We found that the CYP۲۷B۱ rs۱۰۸۷۷۰۱۲ polymorphism was not a risk factor for T۲DM but it affected the level of ۲۵ (OH)-D۳ in diabetic patients and vitamin D deficiency and insufficiency increased the values of BMI, HbA۱c, and FBS as the metabolic parameters involved in the development of T۲DM.