| BackgroundPolycystic ovary syndrome(PCOS)is one of the most common disorders affecting the endocrine and reproductive health of women of reproductive age.There is abundant evidence that a combination of genetic and environmental factors contributes to the disease.Therefore,the study on the genetic characteristics of PCOS has increasingly become the focus of researchers.Vitamin D,as a steroid hormone,plays a physiological role mediated by vitamin D receptor(VDR).Studies have found that VDR can be involved in a variety of diseases related to metabolic disorders,including PCOS.When VDR expression is abnormal,certain physiological regulatory functions of the body will be reduced.At present,a large number of studies have reported the correlation between PCOS and VDR polymorphism,but the specific relationship has not been determined.Therefore,this study aims to the latest study to evaluate the relationship between,to provide certain basis for the etiology of PCOS,and can predict the risk of the vulnerable groups and formulate intervention measures,to achieve stable clinical manifestation of PCOS,prevent or slow down the occurrence of metabolic disease,in order to improve the quality of life of patients with PCOS and health status.ObjectiveTo explore the correlation between Apa-I,Bsm-I,Taq-I,Fok-I and Truq-I polymorphisms of VDR gene and PCOS,and to provide a basis for genetic analysis of PCOS susceptibility factors.Method1.Literature searchThe CNKI and Wanfang databases in Chinese and Pub Med,Embase,Medline and Cochrane databases in English were searched respectively,and case-control studies on Apa-I,Bsm-I,Taq-I,Fok-I and Truq-I polymorphisms and PCOS of VDR genes were collected.The time span of literature retrieval is from the establishment of the database to December 2020.At the same time,manual retrieval was conducted to obtain relevant references that could be included in the study.Chinese search terms include: polycystic ovary syndrome,vitamin D receptor,gene polymorphism,mutation,mutation,mutation and gene variation;English search words included Polycystic ovary syndrome,PCOS,vitamin D receptor,VDR,gene polymorphism,mutation,variation and so on.2.Literature was screened according to inclusion and exclusion criteriaInclusion criteria:(1)Type of literature: previously published case-control studies;(2)Target population: diagnostic criteria for PCOS patients were Rotterdam(2003)criteria or NIH diagnostic criteria;(3)PCR was used to identify the polymorphisms of each site.(4)The studied population should conform to the Hardy-Weinberg equilibrium(HWE).Exclusion criteria :(1)review articles,animal studies,medical records(cases)reports or studies that have not been published,and literature from which complete data cannot be extracted;(2)Low-quality literature with incomplete data or unclear description;(3)the control group did not meet the Hardy-Weinberg balance;(4)Literature without OR value OR whose OR value cannot be calculated from data.3.Data extraction and statistical analysisThe data extraction contents of the selected target literature included: the name of the first author,publication time,study location,ethnicity,source of the study control group(based on hospital or population-based),sample size of the PCOS group and the normal control group,genotyping detection method and distribution frequency of each group of genotypes.Statistical analysis was performed using software Stata 14.0.ResultA total of 19 studies were included.Meta-analysis results showed that there was no significant difference in the polymorphism of Bsm-I,VDR Fok-I and VDR Truq-I of VDR gene between PCOS group and control group(P > 0.05).The study of Apa-I polymorphism of VDR gene found that,compared with the control group,the allelic model(A vs C)(OR0.0.88;95% CI 0.80 ～ 0.97;P = 0.008),dominant model(AA+AC vs CC)(OR 0.78;95%CI 0.63 ～ 0.96;P = 0.017),homozygous model(AA vs CC)(OR 0.72;95% CI 0.59 ～ 0.89;P = 0.02),the differences were statistically significant,while the implicit model(AA vs AC+CC)(OR 0.86;95% CI 0.73 ～ 1.001;P = 0.066),the difference was not statistically significant;The polymorphism of VDR Taq-I(T > C)was observed in the dominant model(TC+TT vs CC)(OR 0.69;95% CI 0.50 ～ 0.96;P = 0.025)and the difference between the two groups was statistically significant.At the same time,subgroup analysis showed that VDR Apa-I(A > C)polymorphism was not significantly associated with Asian population.The allele model in the Caucasian population(A vs C)(OR 0.88;95% CI 0.79 ～ 0.98;P =0.026),homozygous model(AA vs CC)(OR 0.75;95% CI 0.59 ～ 0.95;P = 0.018),dominant model(AA+AC vs CC)(OR 0.79;95% CI 0.64 ～ 0.98;P = 0.032)the difference between the two groups was also statistically significant;VDR Taq-I recessive gene model(TT vs TC+CC)(OR 1.83;95% CI 1.20 ～ 2.81;P = 0.005)was associated with susceptibility to PCOS in Asian population,but not in Caucasian population.ConclusionIn summary,(1)polycystic ovary syndrome is not associated with VDR Bsm-I,VDR Fok-I and VDR Truq-I polymorphisms;(2)The AA/AC genotype and A allele of VDR Apa-I gene and the dominant genotype(TT + TC)of VDR Taq-I polymorphism gene were protective factors of PCOS susceptibility.(3)The recessive genotype(TT)of VDR Taq-I may be a risk gene in the Asian population. |
