Comparative Study on the Effect of Vitamin D Level, Biochemical Changes and its Receptor Polymorphism in Diabetes Mellitus ( Type 1 , 2 ) for Iraqi Patients

Abstract

Diabetes mellitus is one of the chronic diseases. Diabetes causes high blood glucose level due to pancreatic B cell dysfunction. Vitamin D is considered to be an environmental and genetic factor that affects the onest of Type 1 Diabetes Mellitus and Type 2 Diabetes Mellitus and may help in the management of the diabetes mellitus. This study was carried to correlate between Vitamin D level, Vitamin D receptor in rs2228570 SNP and some clinical parameters with T1DM compared to T2DM of Iraqi patients. The study consisted of a total (100) subjects divided into three groups 25 controls, 45 patients with T2DM and 30 patients with T1DM. The healthy subjects were (17 males and 8 females) with age ranged (7 – 50) years, T1DM subjects (n=30) were (14 male and 16 female) with age ranged (3.0 – 16 years) and T2DM subjects (n=45) were (31 males and 15 females) with age ranged (23-72 )years. The study was carried out at the Al-Yarmouk Teaching Hospital for T2DM and controls and at Child's Central Teaching Hospital for T1DM and controls. The period was from January 2017 to April 2017. Molecular analysis involved DNA extraction and Polymerase Chain Reaction (PCR) and Restriction Fragment Length Polymorphism (RFLP) which were carried out to detect the genetic polymorphism of VDR gene FOK1 SNP for all individuals of this study. Molecular analysis was conducted in the Laboratory of Biotechnology Research Center / Al-Nahrain University. The results showed that (age, sex, body mass index) for patients and control group were not significant while for the level of fasting blood sugar showed significant differences (P≤0.001) comparing to control. Glycated III Hemoglobin and HOMA IR were shown to be significantly different between patients in type 1 and 2 of diabetes mellitus (P≤ 0.05). The results of total cholesterol, TG, LDL and VLDL in T2DM patients were significantly higher compared with control (P ≤ 0.05), However lipid profile in T1DM patients and control group showed non significant difference (P ≥ 0.05). The concentration of Calcium ion in T1DM was significantly higher when compared with control group while it did not show any relation between T2DM patients. The Level of vitamin D was significantly higher between T1DM, T2DM compared with control group (P≤0.05). Logistic regression test revealed non significant association between (TT), (CC) and (CT) genotypes with T1DM (Odds Ratio=1.36, 95%Confidence Interval =0.42-4.43, P=0.425 and OR=1.00, 95%CI=0.35- 2.90, P=0.608 and O.R=0.46, 95%CI=0.16-1.38, P=0.138 respectively) and also showed that T allele acts as etiological factor (OR=1.45, 95%CI= 0.68- 3.12, P=0.224 ). For T2DM genotypes (TT), (CC) and (CT) were non significantly with ( OR=1.59, 95%CI= 0.39-6.45, P=0.394 and OR= 1.43 95%CI = 0.54-3.80, P=0.322 and OR=0.54, 95%CI= 0.20-1.45, P=0.171 respectively) and showed that C allele acts as etiological factor OR = 1.07 95%CI = 0.52-2.19, P=0.455). The study shows a correlation between Vitamin D deficiency and high level of glucose with DM patient. There no association between (FOK1) polymorphism and diabetes mellitus, but this study shows which allele distribution and genotype are act as preventive factor and which are act as etiological factor in both types.