A meta-analysis of the association of ApaI, BsmI, FokI, and TaqI polymorphisms in the vitamin D receptor gene with the risk of polycystic ovary syndrome in the Eastern Mediterranean Regional Office population

The results of case-control studies on the association between vitamin D receptor gene (VDR) polymorphisms and polycystic ovary syndrome (PCOS) are inconclusive.

We aimed to more precisely evaluate the correlation between the ApaI, BsmI, FokI, and TaqI VDR gene polymorphisms and PCOS susceptibility.

PubMed, Scopus, Science Citation Index, and Google Scholar databases were searched to retrieve related reports released up to the end of 2020. To evaluate the association strength of the VDR gene polymorphisms with PCOS risk, pooled ratios (OR) with a 95% confidence interval were determined.

In total, 1,119 subjects (560 PCOS cases and 559 controls) from 7 studies were included which met the inclusion criteria. A statistically significant association between the TaqI polymorphism and PCOS susceptibility was found in the Eastern Mediterranean Regional Office population (T vs. t: OR = 0.715; TT vs. tt: OR = 0.435, p < 0.001; TT vs. Tt+tt: OR = 0.696, p = 0.01; tt vs. TT+Tt: OR = 1.791, p < 0.001). It was found that the ApaI variant was a risk factor in the dominant inheritance model (AA vs. Aa+aa: OR = 1.466, p = 0.01) and the FokI polymorphism was a protective factor in the recessive inheritance model (ff vs. FF+Ff: OR = 0.669, p = 0.04). The VDR BsmI polymorphism did not show association with PCOS susceptibility.

Our meta-analysis revealed that the VDR ApaI in the dominant model, VDR FokI in the recessive model, and VDR TaqI polymorphisms in all genetic models are associated with vulnerability to PCOS. However, further studies with a larger sample size are required.