A Study On The Relationship Between SOST Gene Polymorphism And The Protein Expression With Bone Metabolism In Postmenopausal Women With Type 2 Diabetes In Shihezi Of Xinjiang

Objective:To detect the levels of bone metabolism indicators and bone mineral density(BMD),SOST gene polymorphism and Sclerostin in postmenopausal women with type 2 diabetes(T2DM)in Shihezi of Xinjiang,and then the relationship among the indicators was analyzed in order to provide theoretical basis for revealing the pathogenesis of the disease.Methods:1.A total of 136 samples were enrolled in this study.The subjects were divided into 4 groups according to OGTT or history of diabetes and BMD:Group A is a group with normal glucose tolerance(NGT)and normal bone mass,Group B is a group with normal glucose tolerance and abnormal bone mass,Group C is a group with T2DM and normal bone mass,Group D is a group with T2DM and abnormal bone mass.2.General data of the subjects,including age,menopausal age,height,weight,waist circumference,hip circumference and other general clinical baseline data,were determined and recorded.And then body mass index(BMI)and waist-to-hip ratio(WHR)was calculated.Fasting Plasma Glucose(FPG),Triglyceride(TG),High Density Lipoprotein Cholesterol(HDL-C),Low Density Lipoprotein Cholesterol(LDL-C),Blood Calcium(Ca),blood phosphorus(P)and alkaline phosphatase(ALP)and other biochemical indicators were measured by automatic biochemical analyzer.Hemoglobin A1c(HbA1c)was surveyed by high pressure liquid chromatography method.Dual-energy X-ray absorptiometry(DEXA)was used to detected BMD(L1-4)and BMD(femoral neck).3.The distribution of SOST gene rs851054,rs851056,rs1230399 and rs10534024 loci genotypes were determined by time-of-flight mass spectrometry.4.The level of sclerostin expression in serum was determined by enzyme-linked immunosorbent assay(ELISA).5.SPSS 17.0 software was used for statistical analysis,and the measurement data were expressed as mean±standard deviation.T-test was used to compare the mean of two groups,ANOVA was used to compare the mean of multiple groups,and covariance analysis was used if the baseline data were not uniform.The distribution of SOST gene rs851054,rs851056,rs1230399 and rs10534024 loci genotypes were tested by Hardy-Weinberg equilibrium coincidence test.?~2 was used for comparative analysis of genotype and allele frequencies.The multiple linear regression analysis was used to analyze the influencing factors of BMD.p<0.05 was the cut-off for statistical significant.Results:1.The comparison of general data among the four groups showed that there was no difference in BMI,WHR,but the data of age and menopause years were uneven.Therefore,covariance analysis was used to exclude the influence of age and menopause years on the comparison of other indexes.2.Comparison of glucose metabolism indexes by covariance analysis showed the expression levels of FPG in C group(7.69±3.20)and D group(7.42±1.86)were higher than A group(5.31±2.18)(P<0.01).Meanwhile,compared with A group(5.95±0.87),the level of HbA1C in C group(7.21±1.34)and D group(7.48±1.14)also increased(p<0.01).Comparison of lipid metabolism indexes by covariance analysis showed that TG in B group(1.51±0.98)and D group(1.70±1.00)were all lower than A group(2.51±1.76)(p<0.05);HDL and LDL was found no significant difference between groups(p>0.05).The comparison of bone metabolism indexes by covariance analysis showed that BMD(L1-4)in B group(0.84±0.17)and D group(0.91±0.12)was lower than A group(1.19±0.13)(p<0.01).At the same time,compared with group A(0.90±0.12),the expression levels of BMD(femoral neck)in B group(0.71±0.10)and D group(0.74±0.11)was lower,too(p<0.01).3.SOST gene locus genotype and allele frequencies distribution:SOST gene rs851054,rs851056,rs1230399,rs10534024 loci genotypes are consistent with Hardy-Weinberg equilibrium in the study population.The genotype frequencies of SOST rs851054 locus AA,AG and GG were 12.9%,48.5%,38.6%,respectively.The A and G allele frequencies were respectively 37.1%and62.9%.The genotype frequencies of SOST rs851056 locus CC,CG and GG were 9.9%,51.5%,38.6%,respectively.The allele frequencies C and G were 35.6%,64.4%,respectively.The genotype frequencies of SOST rs1230399 locus TT,TC and CC were 71.8%,26.7%,1.5%,respectively.The allele frequencies T and C were 85.2%and 14.8%,respectively.The genotype frequencies of SOST rs10534024 locus TCC.TCC,TCC.DEL and DEL.DEL were 7.4%,39.3%,53.3%,respectively.The allele frequencies TCC and DEL were 27.0%and 73.0%,respectively.Among the four sites of SOST gene,only the genotype and allele frequencies of rs851056 were statistically different between group A and group C,group A and group D(p<0.01),no statistical difference was found in the other three sites.4.Comparison of general clinical metabolic indexes between different SOST gene genotypes:SOST gene rs851054 locus:In B group,TG(2.11±1.19,1.30±0.80)was higher in GG genotype than AG/AA genotype(p<0.05).SOST gene rs851056locus:In B group,HDL(1.25±0.28,1.67±0.24),Ca(2.27±0.07,2.37±0.13),ALP(75.42±14.40,120.50±15.93)in GG genotype were lower than GC/CC genotype(p<0.05).In D group,BMD(L1-4)(1.02±.09,0.90±0.11)in GG genotype was higher than GC/CC genotype(p<0.05).SOST gene rs1230399locus:In A group,compared with TT genotype,BMI(26.52±3.20,24.01±1.85)in TC/CC genotype was lower(p<0.05),BMD(L1-4)(1.16±0.10,1.27±0.15)in TC/CC genotype was higher(p<0.05).SOST gene rs10534024 locus:Compared with DEL.DEL genotype,LDL(2.49±.86,3.55±0.88)in TCC.DEL/TCC.TCC genotype of C group was higher(p<0.05).BMD(femoral neck)(0.76±0.10,0.69±0.13)in TCC.DEL/TCC.TCC genotype of D group was lower.5.The analysis of sclerostin expression level:Comparison of sclerostin between groups showed:compared with A group[276.88(133.36,416.15)],the levels of sclerostin in B group[887.06(573.53,1099.65)]and D group[1100.21(212.33,1387.75)]were higher(p<0.05).Correlation analysis between sclerostin and various indicators showed that serum sclerostin level was negatively correlated with BMI and BMD(L1-4)(r=-0.178,-0.270,p=0.039,0.002)in postmenopausal women.6.Multiple linear regression analysis of the influencing factors of BMD in D group:multiple linear regression analysis was performed for BMD(L1-4)and BMD(femoral neck)as the dependent variables,genotype(X1),age(X2),menopausal years(X3),BMI(X4),WHR(X5),FPG(X6),HbA1c(X7),TG(X8),HDL(X9),LDL(X10),Ca(X11),P(X12),ALP(X13),serum sclerostin(X14)as independent variables.And the results showed that in D group,the positive influencing factor of BMD(L1-4)was HbA1c,while the negative factors were FPG,HDL,rs851056.The positive factor of BMD(femoral neck)was BMI,while the negative factors were WHR,FPG and HDL,rs10534024.Conclusion:1.In postmenopausal T2DM women in Shihezi area of Xinjiang,the mutation of SOST gene loci may affect the coding of SOST protein,which will increase the expression of SOST protein and then lead to the change of bone metabolism indicators and BMD.2.In postmenopausal women with T2DM and abnormal bone mass,high BMI and high HbA1c were the protective factors of BMD,while high WHR,high FPG,high HDL,and rs851056,rs10534024 mutation were the risk factors of BMD.