ApaI and Fok1 Variants of Vitamin D Receptor Gene Associated with Metabolic Syndrome Among Jordanian Women.

Objectives: The association between vitamin D receptor (VDR) polymorphisms and metabolic syndrome (MS) remains debatable. The current study aimed to determine the correlation of VDR gene polymorphisms with MS among Jordanian women.

Methods: This case-control study enrolled 100 women with MS and 100 age-matched women as control at Al-Hikma Modern Hospital in Jordan between January 2019 and January 2020. The levels of glycated hemoglobin, fasting glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and 25-hydroxy vitamin D (25(OH)D) were determined from serum samples of all participants. DNA was extracted from whole blood samples, and VDR gene polymorphisms Apa1, Taq1, Bsm1, and Fok1 were analyzed by polymerase chain reaction and restriction fragment length polymorphism.

Results: There was a significant difference between MS patients and control in terms of body mass index (34.3±3.1 vs. 28.1±2.5), glycated hemoglobin (5.9±1.1 vs. 4.6±1.2), fasting blood glucose (6.4±1.6 vs. 5.2±1.4), and total cholesterol (6.5±1.2 vs. 5.3±1.8). The results also demonstrated a statistical difference in the number of MS patients and control with 25(OH)D deficiency (69.0 vs. 33.0), 25(OH)D insufficiency (25.0 vs. 42.0), and 25(OH)D sufficiency (6.0 vs. 25.0) (p < 0.001). MS was significantly associated with VDR polymorphisms among Apa1 and Fok1 genes. The genotype distribution for CC (47.0% vs. 53.0%; p = 0.002) and CA (37.0% vs. 45.0%; p = 0.001) genotypes among Apa1 VDR polymorphism, as well as among TT genotype (38.0% vs. 20.0%; p = 0.025) among Fok1 VDR gene polymorphism significantly differed between MS patients and healthy individuals. However, no associations were detected among Taq1 and Bsm1 VDR genotypes.

Conclusions: VDR gene polymorphism of Apa1 and Fok1 variants may increase the risk of metabolic syndrome among Jordanian women.