The Association Study Of The Polymorphic CAG Repeat In Exon1 Of Androgen Receptor Gene With Metabolic Syndrome And Its Components In Men

Objective This study from the molecular level and the angle of genetics,to investigate the correlations between the length of CAG repeat in AR and Metabolic Syndrome and its components among Hui and Han nationalities in Ningxia,and we further research the polymorphic CAG repeat and the components of MS.Methods This study used cluster sampling method to choose subjects from Yinchuan and Wuzhong city community residents in Ningxia region,and finally,953 subjects were enrolled in the study on the basis of the inclusion criteria.Measured all subjects` height,weight and blood pressure,and detected the biochemical indicators,including high-density lipoprotein cholesterol(HDL-C),triglycerides(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),fasting blood glucose(FBG),fasting insulin(FINS)and sex hormone levels,and body mass index(BMI),free testosterone(FT),insulin resistance index(HOMA-IR),insulin sensitive index(HOMA-IS)and islet beta cell function index(HOMA-?)were calculated through the formula.Based on the principle of capillary electrophoresis method,the CAG repeat sequence length of AR was tested by the 3730 xl sequencing machine and the sequencing results were identified by Gene Mapper4.1 software.The general demographic and clinical data of the subjects were described by SPSS 23.0 s oftware,and the associations between the polymorphic CAG repeat in exon1 of androgen receptor gene and Metabolic Syndrome and its components were analyzed.Results1.The general situation of the subjects1.1 According to the diagnostic criteria of MS,a total of 317 patients with MS and accounted for 33.26% of all the subjects;636 cases of NMS,and 107 cases have no m etabolic disorder(11.23%),107 cases have one kind of metabolic disorder(25.92%),282 cases have two kinds of metabolic disorder(29.59%).1.2 Compared with the NMS group,MS group has a higher levels of E2,SBP,DBP,BMI,FBG,HOMA-IR,TG and TC.While has a lower levels of TT,E2/TT,HDL-C,HOMA-IS and HOMA-?.1.3 With the metabolic disorder components increased,the levels of SBP,DBP,BMI,FBG,HOMA-IR,TG and TC elevated,and the levels of HDL-C and HOMA-IS reduced.2 The test results and frequency distribution of the polymorphic CAG repeat of AR gene2.1 All people` range of the CAG repeat number was from 10 to 35,the mean was 22.85�2.90,the highest frequency was 22.2.2 317 cases of MS` range of the CAG repeat number was from 14 to 35,the mean was 22.78�2.96,the higher frequency were 22(20.19%)and 21(13.56%);636 cases of NMS` range of the CAG repeat number was from 10 to 35,the mean was 22.88�2.87,the higher frequency were 22(21.38%)and 24(14.15%);the range of the CAG repeat number in 107 cases of people with no metabolic disorder was from 10 t o 35,the mean was 22.95�3.31,the higher frequency were 22(27.10%),24(14.59%)and 23(14.02%);the range of the CAG repeat number in 147 cases of people with one metabolic disorder was from 15 to 30,the mean was 22.90�2.85,the higher frequency were 22(28.57%)and 24(26.53%);the range of the CAG repeat number in 282 cases of people with two metabolic disorders was from 10 to 35,the mean was 22.84�2.71,the higher frequency were 22(23.05%)and 21(14.18%).2.3 Comparison between each of two groups which from the above mentioned five groups,found that the CAG repeat number of AR did not see obvious difference.3 The association of the polymorphic CAG repeat of AR gene with Metabolic Syndrome3.1 The number of the patients with MS in the lower CAG repeat length group was 99(36.3%),and the number in the higher CAG repeat length group was 218(32.1%).The polymorphic CAG repeat of AR gene have no d ifference on t he prevalence of MS.3.2 The number of the people with no metabolic disorder in the lower CAG repeat length group was 21(7.7%),the number of the people with one or two metabolic disorders was 70(25.6%)and 83(30.4%),respectively.And the number of the people with no metabolic disorder in the higher CAG repeat length group was 86(12.6%),the number of the people with one or two metabolic disorders was 177(26.0%)and 199(29.3%),respectively.The composition ratio of the number of metabolic disorders between lower and higher group was no difference.4 The association of the polymorphic CAG repeat of AR gene with the levels of sex hormone and MS` components4.1 There was no a ssociation between the polymorphic CAG repeat and all kinds of sex hormone;Each sex hormone between lower and higher CAG repeat length group was no difference.4.2 The negative correlation between the polymorphic CAG repeat and SBP is significantly,the correlation is independent of age,BMI,TT and FBG.And there was a positive correlation between the polymorphic CAG repeat and HDL-C,the correlation is independent of BMI,TG and TC.The polymorphic CAG repeat is not related to DBP,TC,TG,LDL-C,FBG,FINS,HOMA-IR,HOMA-IS and HOMA-?.4.3 The SBP of the lower CAG repeat length group is higher than the higher CAG repeat length group,however,HDL-C is opposite.But the variates of DBP,TC,TG,LDL-C,FBG,FINS,HOMA-IR,HOMA-IS and HOMA-? between lower and higher CAG repeat length group was no difference.4.4 The number of the people with hypertension in the lower CAG repeat length group was 194(71.1%),and the number in the higher CAG repeat length group was 414(60.9%),the lower CAG repeat length group had a higher prevalence of hypertension.Logistic regression analysis indicated that the subjects with lower CAG repeats had a significantly increased risk for hypertension.The risk of hypertension in men with lower CAG repeats was 1.4 times higher as men with higher CAG repeats.The CAG repeat length and abnormal HDL-C or TG,overweight or obesity,diabetes and high blood sugar had no correlation.Conclusion The frequency distribution of the polymorphic CAG repeat of AR in those five groups(No metabolic disorder group,one metabolic disorder group,two metabolic disorder group,MS and NMS group)is consistent.The polymorphic CAG repeat of AR and the genetic susceptibility of MS has no correlation.The correlation analysis between the CAG repeat length of AR and MS` components showed that,there was a positive correlation between the polymorphic CAG repeat and HDL-C,and the polymorphic CAG repeat was positively related to SBP,after adjustment for age influence factors and its correlation is still existed.The levels of HDL-C and SBP between the lower and higher CAG repeat length group was different..The lower CAG repeat length will cause HDL � C reduced and SBP elevated.The related analysis showed that the lower CAG repeat length group had a higher prevalence of hypertension,and the risk of hypertension in men with lower CAG repeats was 1.4 times higher as men with higher CAG repeats.