Association of a -1997G-->T polymorphism of the collagen Ialpha1 gene with bone mineral density in postmenopausal Japanese women

Genetic variants that affect collagen Ialpha1 metabolism may be important in the development of osteoporosis or osteoporotic fractures. A -1997G-->T polymorphism in the promoter of the collagen Ialpha1 gene (COL1A1) was shown to be associated with bone mineral density (BMD) for the lumbar spine in postmenopausal Spanish women. The relation of this polymorphism to BMD in Japanese women or men has now been examined in a population-based study. The subjects (1,110 women, 1,126 men) were 40 to 79 years of age and were randomly recruited for a population-based prospective cohort study of aging and age-related diseases. BMD for the lumbar spine, right femoral neck, right trochanter, and right Ward's triangle was measured using dual-energy x-ray absorptiometry. Genotypes for the -1997G-->T polymorphism of COL1A1 were determined with a fluorescence-based allele-specific DNA primer assay system. When all women were analyzed together, BMD for the lumbar spine and trochanter was significantly lower in subjects with the COL1A1 *G/*G genotype than in those in the combined group of COL1A1 *G/*T and COL1A1 *T/*T genotypes. When postmenopausal women were analyzed separately, BMD for the femoral neck and trochanter was also significantly lower in those with the COL1A1 *G/*G genotype than in those with the COL1A1 *G/*T genotype or those in the combined group of COL1A1*G/*T and COL1A1 *T/*T genotypes. BMD was not associated with -1997G-->T genotype in premenopausal women or in men. Multivariate regression analysis revealed that -1997G-->T genotype affected BMD at various sites with a variance of 0.46-0.62% for all women and 0.61-1.01% for postmenopausal women. The -1997G-->T genotype was not related to the serum concentration of osteocalcin, the serum activity of bone-specific alkaline phosphatase, or the urinary excretion of deoxypyridinoline or cross-linked N-telopeptides of type I collagen in men or in premenopausal or postmenopausal women. These results suggest that COL1A1 is a susceptibility locus for reduced BMD in postmenopausal Japanese women.     

绝经后女性CYP19基因Val80及OPG基因A163G多态性与骨密度的相关性研究

探讨细胞色素P450 19 (CYP19) 基因Val80多态性及护骨素(OPG) 基因A163G多态性与绝经后女性骨密度 (BMD) 的关系。随机选择居住在重庆的绝经后女性200例, 采用多聚酶链反应-限制性片段长度多态性法检测Val80及A163G多态性, 采用Norland公司XR-46系列双能X线骨密度仪测量股骨近端及腰椎BMD。 200名绝经后女性中Val80基因型GG、GA及AA的频率分别为19.5％、44.5％及36.0％; A163G基因型GG、GC 及CC的频率分别为: 13.0％, 42.0％及45.0％; 基因型频率分布均符合Hardy-Weinberg平衡 (P＞0.05)。协方差分析及多元逐步回归分析显示CYP19基因第3外显子Val80多态性与绝经后女性BMD无相关性 (P＞0.05)。除大转子外, A163G位点AG/GG/AG+GG基因型者股骨颈、Ward’s三角及腰椎BMD均较AA基因型者低, A163G基因型与股骨颈、Ward’s三角及腰椎BMD有相关性 (P＜0.05)。OPG基因启动子区A163G多态性分布存在明显的种族差异, 且与绝经后女性BMD有一定关联, AA型对BMD具有一定的保护作用, G等位基因是BMD降低的危险因素。     

Association of CYP19 Gene Polymorphism with Vertebral Fractures in Japanese Postmenopausal Women

This study investigates aromatase gene polymorphism, which might influence bone strength in terms of mineral density and quality. We explored the relationship between CYP19 polymorphisms and vertebral fractures in postmenopausal Japanese women. In addition, we compared estrogen and testosterone levels in Japanese postmenopausal women with and without fractures. Osteoporotic postmenopausal women showed higher incidences of vertebral fractures than osteopenic women or women with normal lumbar bone mineral density (L2-4 BMD). Estrogen concentrations in postmenopausal women were associated with BMD; however, no association was found between sex hormone levels and the presence of fractures. The C allele rs2470152 was significantly associated with increased risk of vertebral fractures (P = 0.04), whereas none of the CYP19 polymorphisms showed differences in sex steroid levels between subjects with and without fractures. Allelic variants of aromatase genes appear to interact to influence the risk of vertebral fractures in postmenopausal Japanese women.     

北京地区汉族妇女雌激素受体基因XbaI多态性与骨密度和体重指数的关系

为探讨北京地区汉族妇女雌激素受体（ER）基因XbaI多态性与骨密度的关系,采用双能X线吸收仪检测腰椎、股骨及前臂骨密度;采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）法,对179例北京地区汉族妇女ER基因XbaI多态性进行分析。北京地区汉族妇女ER基因XX、Xx和xx基因型频率分布为0.302、0.464和0.234,绝经前与绝经后妇女XbaI型基因频率分布有明显差异,绝经后妇女腰椎骨密度（0.836±0.18）g/cm²明显低于绝经前妇女（1.038±0.14);绝经后妇女骨质疏松症的发病率为54%。ER基因XbaI基因型频率分布有明显的种族差异并受绝经影响,ER基因XbaI基因型与骨密度无明显相关性。与体重和BMI有明显相关性。     

Association of a polymorphism of the CC chemokine receptor-2 gene with bone mineral density

The possible association of the 190G-->A (Val64Ile) polymorphism of the CC chemokine receptor-2 gene (CCR2) with bone mineral density (BMD) was examined in 2215 subjects (1125 men, 1090 women), all of whom were community-dwelling individuals aged 40 to 79 years. Among men aged < 60 years, BMD for the distal radius, lumbar spine, or Ward's triangle was significantly greater in those with the AA genotype than in those with the GG or GA genotypes. For postmenopausal women, BMD for the distal radius or femoral neck was significantly greater in those with the AA genotype than in those with the GG or GA genotypes. In contrast, for men aged > or =60 years and for premenopausal women, BMD was not associated with the CCR2 genotype. These results suggest that CCR2 may be a new candidate for a susceptibility locus for bone mass in middle-aged men and postmenopausal women.     

Association of serum sex steroid levels and bone mineral density with CYP17 and CYP19 gene polymorphisms in postmenopausal women in Turkey

Many clinical conditions, including osteoporosis, are associated with serum levels of sex steroids. Enzymes that regulate rate-limiting steps of steroidogenic pathways, such as CYP17 and CYP19, are also regarded as significant factors that may cause the development of these conditions. We investigated the association of two common polymorphisms, in the promoter region (T→C substitution) of CYP17 and exon 3 (G→A) of CYP19, with bone mineral density (BMD) in the lumbar spine and femoral neck and serum androgen/estradiol, in a case-control study of 172 postmenopausal women aged 62.3 ± 9.6 years (mean ± SD). The CYP17 TC genotype was significantly overrepresented in patients compared to controls, and TC genotype neck T-score and lumbar T-score values were significantly higher in patients compared to controls. CYP17 TC and TT genotype testosterone and DHEA-SO(4) levels were lower in patients compared to controls. All three genotypes of CYP19 had almost the same distribution among patients. The CYP19 AG genotype, however, was most frequent among controls. CYP19 lumbar BMD levels were close to each other among the different genotypes; however, AA and AG genotypes were significantly lower in patients. Testosterone and DHEA-SO(4) levels in the CYP19 GG genotype were higher compared to those of the other genotypes in patients but not in controls. CYP19 GA individuals had lower E(2) levels and lower BMD in controls and patients. Femoral neck BMD and lumbar T-score were also diminished with GA transition. In conclusion, CYP17 and CYP19 gene polymorphisms were found to be associated with osteoporosis in postmenopausal women in Turkey.     

Association of estrogen receptor beta gene polymorphism with bone mineral density

Chromosomal mapping of the human estrogen receptor beta (ERbeta) gene by fluorescence in situ hybridization (FISH) reveals that ERbeta is located at human chromosome 14, region q23-24.1, where the aberration of DNA copy number in the bone disorders is frequently involved. Then, we investigated the association between dinucleotide (cytosine-adenine; CA) repeat polymorphism located in the flanking region of ERbeta gene and bone mineral density (BMD) in 204 healthy postmenopausal Japanese women. The genotype was classified into "A" through "O" according to the number of the repeats, from 18 to 32. BMD was expressed in Z score (a deviation from the weight-adjusted average BMD of each age using the standard deviation as a unit). When we separate the subjects into two groups bearing at least one I allele (26 CA repeats) and those who did not, the former subjects had significantly higher Z score of L2-4 BMD (mean +/- standard deviation; 0.674 +/- 1.53 vs 0.128 +/- 1.38; P = 0.027). These data suggest that genetic variation at the ERbeta locus may be associated with some determinants for BMD and the possible involvements of this polymorphism in the cause of postmenopausal osteoporosis in Japanese women.     

Association of the 163A/G and 1181G/C osteoprotegerin polymorphism with bone mineral density.

The aim of the study was to investigate the distribution of 163 A/G osteoprotegerin gene promoter and 1181 G/C osteoprotegerin exon 1 polymorphisms in a group of women with different hormonal status and to analyze their relationship with BMD. Osteoprotegerin polymorphisms and BMD were analyzed in 332 women (69 premenopausal and 263 postmenopausal). BMD was quantified at the lumbar spine (L 2-4), femoral neck, and total hip. Genotyping for the presence of different polymorphisms was performed using the Custom Taqman ((R)) SNP Genotyping assays. There were not significant differences in BMD according to 163 A/G genotype. However, significant differences in lumbar spine BMD were found according to 1181 G/C alleles. Thus, women with CC genotype had significant higher BMD at the lumbar spine than those with GC or GG genotype. No differences were found in femoral neck and total hip BMD. In age-adjusted models, the 1181 G/C OPG polymorphism explained 2.2% of BMD variance at the spine, 0.3% at the femoral neck, and 0.9% at the total hip in the whole group. In the subgroup of premenopausal women, the polymorphism was strongly related to spine BMD, and explained 11.5% of the variance, whereas body weight explained 7.9%. The 1181 G/C polymorphism was associated with lumbar spine BMD in Spanish women. Premenopausal women with the CC genotype had a higher BMD.     

Microsomal triglyceride transfer protein -493T variant reduces IDL plus LDL apoB production and the plasma concentration of large LDL particles

The microsomal triglyceride transfer protein (MTP) is essential for the synthesis and secretion of apolipoprotein B (apoB)-containing lipoproteins. We investigated the role the MTP -493G/T gene polymorphism in determining the apoB-100 secretion pattern and LDL heterogeneity in healthy human subjects. Groups of carriers of the T and the G variants (n = 6 each) were recruited from a cohort of healthy 50-yr-old men. Kinetic studies were performed by endogenous [(2)H(3)]leucine labeling of apoB and subsequent quantification of the stable isotope incorporation. apoB production rates, metabolic conversions, and eliminations were calculated by multicompartmental modeling (SAAM-II). LDL subfraction distribution was analyzed in the entire cohort (n = 377). Carriers of the MTP -493T allele had lower plasma LDL apoB and lower concentration of large LDL particles [LDL-I: 136 +/- 57 (TT) vs. 175 +/- 55 (GG) mg/l, P < 0.01]. Kinetic modeling suggested that MTP -493T homozygotes had a 60% lower direct production rate of intermediate-density lipoprotein (IDL) plus LDL compared with homozygotes for the G allele (P < 0.05). No differences were seen in production rates of large and small VLDL, nor were there any differences in metabolic conversion or elimination rates of apoB between the genotype groups. This study shows that a polymorphism in the MTP gene affects the spectrum of endogenous apoB-containing lipoprotein particles produced in humans. Reduced direct production of LDL plus IDL appears to be related to lower plasma concentrations of large LDL particles.     

Variants of the microsomal triglyceride transfer protein gene are associated with plasma cholesterol levels and body mass index.

The microsomal triglyceride transfer protein (MTP) is required for the assembly and secretion of apolipoprotein B (apoB)-containing lipoproteins from liver and intestine. We set out to study the phenotypic modulation of all common genetic variants in the MTP gene. In addition, we aimed at characterizing the association between the various polymorphisms. A total of 564 healthy men were genotyped for the MTP -493 G/T, -400 A/T, and -164 T/C promoter polymorphisms, as well as the Q/H 95, I/T 128, Q/E 244, and H/Q 297 missense polymorphisms. The -493 G/T, -164 T/C, and I/T 128 polymorphisms showed to be in almost complete linkage disequilibrium. Subjects homozygous for the less common -493 T, -164 C, and T 128 alleles showed significantly lower plasma total and LDL cholesterol levels and plasma LDL apoB levels, and also significantly higher body mass index (BMI) and plasma insulin levels compared with carriers of the common alleles. The associations between plasma total cholesterol and MTP -493 genotype was verified in a cohort consisting of 1,117 disease-free control subjects of the West of Scotland Coronary Prevention Study (WOSCOPS). None of the other polymorphisms showed any significant change in either lipid and lipoprotein levels or anthropometric variables.In summary, two promoter polymorphisms and one missense polymorphism in the MTP gene alter plasma total and LDL cholesterol levels, plasma LDL apoB levels, BMI, and insulin levels. This may, in turn, have implications for genetic regulation of cardiovascular risk factors.     

The influence of polymorphism of -493G/T MTP gene promoter and metabolic syndrome on lipids, fatty acids and oxidative stress

The aim of this study was to investigate the effect of the microsomal triglyceride transfer protein (MTP) -493G/T polymorphism on clinical and biochemical parameters in relation to the presence of metabolic syndrome (MS). A group of 270 participants, 143 men and 127 women [50 men/36 women fulfilled the International Diabetes Federation (IDF) criteria of MS], was categorized on the basis of the MTP -493G/T polymorphism: GG homozygotes (Group GG) and carriers of the T allele (Group TT+TG). In men with MS, the presence of the T allele was associated with elevated concentrations of plasma insulin (by 48%, P<.01) and nonesterified fatty acids (by 49%, P<.05); homeostasis model assessment for insulin resistance index was higher by 64% (P<.05). Carriers of the T allele were further characterized by elevated plasma concentrations of total cholesterol (by 14%, P<.05) and by increased triglycerides in plasma (by 95%, P<.01) and in very low-density lipoprotein (by 106%, P<.01). They also had lower concentrations of n-6 polyunsaturated fatty acids in plasma phospholipids (by 3.5%, P<.05), lower Delta5-desaturase activities (by 18%, P<.05) and elevated concentrations of conjugated dienes in low-density lipoprotein (by 29%, P<.01). No significant differences between Groups GG and TT+TG were found in men without MS and in women with and without MS. Our results imply evidence for interactive effects of genetic, metabolic and gender-specific factors on several components of metabolic syndrome, which can increase the risk for cardiovascular disease.     

Association of T869C gene polymorphism of transforming growth factor-β1 with low protein levels and anthropometric indices in osteopenia/osteoporosis postmenopausal Thai women

Osteoporosis is the most common metabolic bone disease; it is an important health problem among postmenopausal women. We evaluated the association of three polymorphisms, T869C, C-509T and G915C, of the TGF-β1 gene with bone mineral density (BMD) serum TGF-β1 levels in 278 postmenopausal female osteopenia/osteoporosis subjects and 95 postmenopausal female control subjects. Serum TGF-β1 levels were significantly lower in osteopenia/osteoporosis subjects than in control subjects. Serum TGF-β1 levels of the CT+CC (T869C) genotype group were significantly lower in osteopenia/osteoporosis subjects than in control subjects (11.3 vs 15.8 ng/mL). There was a significant difference in the CT+CC (T869C) genotype frequencies between the osteopenia/osteoporosis and control subjects (74.18 vs 60.22%; OR = 1.90, 95%CI = 1.16-3.12). In the age group of more than 50 years, subjects with the TC+CC genotype of T869C polymorphism had significantly increased risk of osteopenic/ osteoporotic bones at L1 (OR = 2.36, 95%CI = 1.37-4.07), L2 (OR = 1.71, 95%CI = 1.01-2.90), L3 (OR = 2.21, 95%CI = 1.23-3.98), L4 (OR = 1.74, 95%CI = 1.00-3.03) and the femoral neck (OR = 1.80, 95%CI = 1.04-3.12). The CT+CC genotype of the T869C polymorphism of the TGF-β1 gene was found to be associated with lower serum TGF-β1 in osteopenia/osteoporosis subjects and increased risk of osteopenic and osteoporotic fracture at L1-4, femoral neck and total hip in postmenopausal Thai women. Logistic regression analysis showed that T869C polymorphism is a significant risk factor for osteopenia/ osteoporosis. We concluded that T869C polymorphism of the TGF-β1 gene has an impact on decreased serum TGF-β1 levels and influences susceptibility to osteopenia/osteoporosis in Thai women.     

Association of an aromatase TTTA repeat polymorphism with circulating estrogen, bone structure, and biochemistry in older women

Osteoporosis is a disease that is strongly genetically determined. Aromatase converts androgens to estradiol in postmenopausal women, therefore polymorphisms of the gene for this enzyme may be associated with bone mass and fracture. We investigated the association of the TTTA microsatellite polymorphism in intron 4 of the aromatase (CYP19) gene with bone mineral density (BMD) and fracture in 1,257 women aged 70 yr and greater. The data obtained were stratified based on the presence or absence of a [TTTA]n of 7 (A2), determined from a preliminary analysis of hip dual-energy X-ray absorptiometry BMD, which was present in 27% of the population. The presence of an A2 allele was associated with a higher free estradiol index (0.52 +/- 0.49, P = 0.049) compared with the absence of an A2 allele (0.47 +/- 0.45); higher BMD at all sites of the hip (3.4% total hip, 2.3% femoral neck, 3.6% intertrochanter, 4.1% trochanter) and the lumbar spine (12.7%); higher values for the calcaneal quantitative ultrasound parameters broadband ultrasound (1.3%), speed of sound (0.4%), and stiffness (3.7%); and higher peripheral quantitative computed tomography measures for total (3.4%), trabecular (3.3%), and cortical BMD (3.3%) and the derived stress strain index (SSI) parameters SSI polar (6.4%) and SSI x (6.8%) values. A lower deoxypryridinoline creatinine ratio was observed in subjects with an A2 allele (30.3 +/- 10.4 vs. 27.1 +/- 9.1, P = 0.03). The A2 allele was associated with a lower prevalence of vertebral fracture in subjects who were osteoporotic (odds ratio 0.27, confidence interval 0.09-0.79). Therefore, a common polymorphism of the aromatase gene, perhaps in linkage disequilibrium with a functionally significant CYP19 polymorphism, is associated with bone structure and bone turnover, either by local effects or by effects on circulating bioactive estrogen.     

绝经后健康妇女甲状旁腺激素基因多态性与骨密度的关系

利用限制性片段长度多态性分析（RFLP）研究北京地区绝经后妇女甲状旁腺激素（PTH）基因多态性与骨密度的关系。筛选健康、无亲缘关系的绝经后妇女185例, 应用双能X射线骨密度仪（DEXA）检测腰椎等部位的骨密度,用PCR-RFLP方法检测绝经后妇女的PTH基因型。绝经后健康妇女中bb、Bb、BB三种基因型的分布频率分别为7.56%、28.11%和64.32%。方差分析显示前臂部位骨密度与PTH基因相关。除华氏三角区外,BB基因型各部位的骨密度值均高于Bb、bb基因型。Logistic回归分析结果显示,bb基因型组骨质疏松与正常妇女存在显著差异（P＜0.001）。 PTH基因中B基因型可能对维持骨量具有一定的作用。     

Gene–gene interactions in RANK/RANKL/OPG system influence bone mineral density in postmenopausal women

Receptor activator of nuclear factor κB (RANK) is one of the proteins in regulation of osteoclastogenesis via RANK/RANKL/OPG. Gene that codes for RANK protein (TNFRSF11A) was associated with osteoporotic fractures in a recent genome-wide association study. As variations in the RANK gene could alter its expression and activity, the aim of our study was to evaluate the influence of four RANK gene polymorphisms on bone mineral density (BMD) and biochemical markers.We evaluated 467 postmenopausal women and 117 elderly men. All subjects were genotyped for the presence of RANK polymorphisms ?670G>C, +34694C>T, +34901G>A and +35966insdelC. BMD and biochemical markers were measured.Significant associations of +35966insdelC with BMD at lumbar spine (BMD-ls), total hip (BMD-th) and femoral neck (BMD-fn) were found in postmenopausal women (p = 0.020, 0.024 and 0.034), but not in men. Significant gene–gene interaction was proved for two RANK polymorphisms in combination with OPG and RANKL polymorphisms studied previously in postmenopausal women. Firstly, RANK/RANKL (+34901G>A/?290C>T) combination was associated with BMD-fn, BMD-th and BMD-ls (p = 0.034, 0.016 and 0.050), and secondly, RANK/OPG combination (+35966insdelC/K3N) showed influence on BMD-fn and BMD-ls (p = 0.043 and 0.039).Our results suggest that gene–gene interactions between RANK and OPG, and RANK and RANKL influence BMD in postmenopausal women.     

CYP17, SRD5A2, CYP1B1, and CYP2D6 gene polymorphisms with prostate cancer risk in North Indian population

To investigate the involvement of the CYP17, SRD5A2, CYP1B1, and CYP2D6 variants with prostate cancer, a case-control study of 100 patients and an equal number of age-matched control men was conducted. There appears to be a nonsignificant increase with risk of prostate cancer for individuals carrying one copy of the CYP17 A2 allele (OR, 1.80; 95% CI, 0.99-3.29, P=0.05). The risk was increased in individuals having two A2 alleles (OR; 2.81, 95% CI, 1.06-7.40, P=0.03). Compared with men having the VV genotype of SRD5A2 gene, there was no significant association between the VL genotype and the risk of prostate cancer (OR; 0.54, 95% CI; 0.29-1.03, P=0.06). There was no difference in the occurrence of the genotype LL between controls and prostate cancer patients (OR; 0.90, 95% CI; 0.43-1.89, P=0.79). There was a nonsignificant increased risk of prostate cancer for individuals carrying the CYP1B1Leu/Val genotype (OR, 1.70, 95% CI, 0.91-3.17, P =0.09), which was increased in those having the Val/Val allele (OR, 3.38; 95% CI, 1.13-10.07, P=0.02). Relative to men homozygous for the wild-type allele in CYP2D6 gene, those heterozygous for the B allele had an odds ratio of 1.78 (95% CI, 0.76-4.17, P=0.18) for patients, and for homozygous individuals, it was 1.95 (0.55-6.93, P=0.30). These observations have suggested that the CYP17 A2/A2, CYP1B1 Val/Val, and CYP2D6 genotypes may be associated with an altered risk of prostate cancer, while the CYP2D6 and SRD5A2 V89L polymorphism have no association with its risk in the North Indian population.     

Association of the A-204C polymorphism in the cholesterol 7alpha-hydroxylase gene with variations in plasma low density lipoprotein cholesterol levels in the Framingham Offspring Study.

The first reaction of the catabolic pathway of cholesterol is catalyzed by CYP7 and serves as the rate-limiting step and major site of regulation of bile acid synthesis in the liver. A common A to C substitution at position -204 of the promoter of CYP7 gene has been associated with variations in plasma LDL-cholesterol concentrations but the effect of this polymorphism is unknown in the general population. The aim of the present study was therefore to investigate the association of this polymorphism to lipoprotein levels in a population-based sample of 1139 male and 1191 female Framingham Offspring participants. In men, the C variant was associated with higher plasma concentrations of LDL-cholesterol and this association remained significant after adjustment for familial relationship, age, BMI, smoking, alcohol intake, the use of beta-blockers, and apoE genotype. The C variant was also associated with an increased TC/HDL ratio in men. Variance components analysis indicated that allelic variability at nucleotide -204 of the CYP7 gene and polymorphism of the apoE gene accounted for 1 and 5% of the variation of plasma LDL-cholesterol concentrations, respectively. In women, however, there was no relationship between LDL-cholesterol and the A-204C polymorphism but subjects homozygous for the CC genotype had significantly lower triglyceride levels than heterozygotes. Moreover, no significant relationship was found between the A-204C variants and lipoprotein particle diameter or the prevalence of coronary heart disease in both genders. Thus, our results show that the A-204C polymorphism in the CYP7 gene is associated with statistically significant variations in LDL-C and triglyceride concentrations in men and women, respectively, but the cumulative effects of these variations on atherosclerotic risk remain uncertain.