Genome-wide association study identifies a novel susceptibility gene for serum TSH levels in Chinese populations.

Thyroid-stimulating hormone (TSH) is a sensitive indicator of thyroid function. High and low TSH levels reflect hypothyroidism and hyperthyroidism, respectively. Even within the normal range, small differences in TSH levels, on the order of 0.5-1.0 mU/l, are associated with significant differences in blood pressure, BMI, dyslipidemia, risk of atrial fibrillation and atherosclerosis. Most of the variance in TSH levels is thought to be genetically influenced. We conducted a genome-wide association study of TSH levels in 1346 Chinese Han individuals. In the replication study, we genotyped four candidate SNPs with the top association signals in an independent isolated Chinese She cohort (n = 3235). We identified a novel serum TSH susceptibility locus within XKR4 at 8q12.1 (rs2622590, Pcombined = 2.21 × 10(-10)), and we confirmed two previously reported TSH susceptibility loci near FOXE1 at 9q22.33 and near CAPZB at 1p36.13, respectively. The rs2622590_T allele at XKR4 and the rs925489_C allele near FOXE1 were correlated with low TSH levels and were found to be nominally associated to patients with papillary thyroid carcinoma (PTC) (OR = 1.41, P= 0.014 for rs2622590_T, and OR = 1.61, P= 0.030 for rs925489_C). The rs2622590 and rs925489 genotypes were also correlated with the expression levels of FOXE1 and XKR4, respectively, in PTC tissues (P = 2.41 × 10(-4) and P= 0.02). Our findings suggest that the SNPs in XKR4 and near FOXE1 are involved in the regulation of TSH levels.

Robust evidence for five new Graves' disease risk loci from a staged genome-wide association analysis.

Graves' disease (GD), characterized by autoantibodies targeting antigens specifically expressed in thyroid tissues causing hyperthyroidism, is triggered by a combination of genetic and environmental factors. However, only a few loci for GD risk were confirmed in the various ethnic groups, and additional genetic determinants have to be detected. In this study, we carried out a three-stage study in 9529 patients with GD and 9984 controls to identify new risk loci for GD and found genome-wide significant associations in the overall populations for five novel susceptibility loci: the GPR174-ITM2A at Xq21.1, C1QTNF6-RAC2 at 22q12.3-13.1, SLAMF6 at 1q23.2, ABO at 9q34.2 and an intergenic region harboring two non-coding RNAs at 14q32.2 and one previous indefinite locus, TG at 8q24.22 (Pcombined < 5 × 10(-8)). The genotypes of corresponding variants at 14q32.2 and 8q24.22 were correlated with the expression levels of C14orf64 and a TG transcript skipping exon 46, respectively. This study increased the number of GD loci with compelling evidence and indicated that non-coding RNAs might be potentially involved in the pathogenesis of GD.

Functional SNPs in the SCGB3A2 promoter are associated with susceptibility to Graves' disease.

Graves' disease (GD) is one of the most common human autoimmune diseases, and recent data estimated a prevalence of clinical hyperthyroidism of 0.25-1.09% in the population. Several reports have linked GD to the region 5q12-q33; and a locus between markers D5s436 and D5s434 was specifically linked to GD susceptibility in the Chinese population. In the present study, association analysis was performed using a large number of single-nucleotide polymorphisms (SNPs) at this locus in 2811 patients with GD recruited from different geographic regions of China. The strongest associations with GD in the combined Chinese Han cohorts were mapped to two SNPs in the promoter (pSNP) of SCGB3A2 [SNP76, rs1368408, P = 1.43 x 10(-6), odds ratio (OR) = 1.28 and SNP75, -623 - -622, P = 7.62 x 10(-5), OR = 1.32, respectively], a gene implicated in immune regulation. On the other hand, pSNP haplotypes composed of the SNP76 (rs1368408)+SNP74 (rs6882292) or SNP76+SNP75 (-623 approximately -622, AG/T) variants are correlated with high disease susceptibility (P = 0.0007, and P = 0.0192, respectively) in this combined Chinese Han cohort. Furthermore, these haplotypes were associated with reduced SCGB3A2 gene expression levels in human thyroid tissue, while functional analysis revealed a relatively low efficiency of SCGB3A2 promoters of the SNP76+SNP75 and SNP76+SNP74 haplotypes in driving gene expression. These results suggest that the SCGB3A2 gene may contribute to GD susceptibility.

Identification of steroid biosynthetic defects in genotype-proven heterozygous individuals for 17alpha-hydroxylase/17,20-lyase deficiency.

OBJECTIVE: P450c17 deficiency (17alpha-hydroxylase/17,20-lyase deficiency, 17OHD) is a rare form of congenital adrenal hyperplasia caused by CYP17A1 gene mutations. The D487_F489 deletion in exon 8 and Y329fs in exon 6 are relatively frequent mutations of the CYP17A1 gene in China that completely abolish the enzyme activity of P450c17. However, little remains known about steroid biosynthetic functions in carriers with these mutations in a single allele of the CYP17A1 gene, who are assumed to have 50% P450c17 activity. We investigated adrenal steroidogenic function in genotype-proven heterozygotes carrying such mutations in the CYP17A1 gene in vivo. PATIENTS AND DESIGN: Eight patients and fourteen family members from five families with 17OHD were recruited. The mutations of the CYP17A1 gene in these individuals were screened by sequencing. The hormonal response to cosyntropin (ACTH) was evaluated in the 14 genotype-proven carriers and 45 age- and gender-matched normal controls. RESULTS: Fourteen carriers of the CYP17A1 mutation - seven with the D487_F489 deletion, six with Y329fs and one with H373L - were identified from the five families with 17OHD. Compared with normal controls, carriers showed lower basal and ACTH-stimulated cortisol levels but higher ACTH-stimulated corticosterone levels. The ratios of corticosterone to cortisol in the genotype-proven heterozygotes were higher than those of the normal controls at the baseline and after cosyntropin stimulation. Similarly, the progesterone levels and the ratios of progesterone to 17-hydroxyprogesterone in the male heterozygotes were also higher than those of the normal controls, both before and after ACTH stimulation. CONCLUSION: Genotype-proven carriers of the CYP17A1 mutation who lack apparent clinical symptoms exhibit decreased adrenal 17alpha-hydroxylase activity and altered adrenal gland reserve for steroid biosynthesis.

A splice site mutation combined with a novel missense mutation of LHCGR cause male pseudohermaphroditism.

Leydig cell hypoplasia (LCH) is a rare form of male pseudohermaphroditism caused by inactivating mutations in the luteinizing hormone receptor gene (LHCGR). The majority of LHCGR mutations are located in the coding sequence, resulting in impairment of either LH/CG binding or signal transduction. We report a Chinese family with two siblings (46, XY and 46, XX) carrying a missense mutation (c. 455 T>C, p. Ile152Thr) and a splice site mutation (c. 537-3 C>A). Computational analysis of the missense mutation in the three-dimensional structural model predicted it might influence the distribution of hydrogen bonds and intermolecular contacts between the hormone and receptor. Consistent with these findings, in vitro mutant analysis revealed a marked impairment of human chorionic gonadotropin binding and signal transduction. The splice-acceptor mutation (c. 537-3 C>A) resulted in abnormal splicing of LHCGR mRNA, skipping exon 7. This report expands the genotypic spectrum of LHCGR mutations, with relevant implications for the molecular analysis of this gene.

Assessment of Molecular Subtypes in Thyrotoxic Periodic Paralysis and Graves Disease Among Chinese Han Adults: A Population-Based Genome-Wide Association Study.

Importance: Thyrotoxic periodic paralysis (TPP) is a potentially lethal complication of hyperthyroidism. However, only 1 specific susceptibility locus for TPP has been identified. Additional genetic determinants should be detected so that a prediction model can be constructed. Objective: To investigate the genetic architecture of TPP and distinguish TPP from Graves disease cohorts. Design, Setting, and Participants: This population-based case-control study used a 2-stage genome-wide association study to investigate the risk loci of TPP and weighted genetic risk score to construct a TPP prediction model with data from a Chinese Han population recruited in hospitals in China from March 2003 to December 2015. The analysis was conducted from November 2014 to August 2016. Main Outcomes and Measures: Loci specifically associated with TPP risk and those shared with Graves disease and prediction model of joint effects of TPP-specific loci. Results: A total of 537 patients with TPP (mean [SD] age, 35 [11] years; 458 male) 1519 patients with Graves disease and no history of TPP (mean [SD] age, 38 [13] years; 366 male), and 3249 healthy participants (mean [SD] age, 46 [10] years; 1648 male) were recruited from the Han population by hospitals throughout China. Two new TPP-specific susceptibility loci were identified: DCHS2 on 4q31.3 (rs1352714: odds ratio [OR], 1.58; 95% CI, 1.35-1.85; P = 1.24 × 10-8) and C11orf67 on 11q14.1 (rs2186564: OR, 1.50; 95% CI, 1.29-1.74; P = 2.80 × 10-7). One previously reported specific locus was confirmed on 17q24.3 near KCNJ2 (rs312729: OR, 2.08; 95% CI, 1.83-2.38; P = 8.02 × 10-29). Meanwhile, 2 risk loci (MHC and Xq21.1) were shared by Graves disease and TPP. After 2 years of treatment, the ratio of persistent thyrotropin receptor antibody positivity was higher in patients with TPP than in patients with Graves disease and no history of TPP (OR, 3.82; 95% CI, 2.04-7.16; P = 7.05 × 10-6). The prediction model using a weighted genetic risk score and 11 candidate TPP-specific single-nucleotide polymorphisms had an area under the curve of 0.80. Conclusions and Relevance: These findings provide evidence that TPP is a novel molecular subtype of Graves disease. The newly identified loci, along with other previously reported loci, demonstrate the growing complexity of the heritable contribution to TPP pathogenesis. A complete genetic architecture will be helpful to understand the pathophysiology of TPP, and a useful prediction model could prevent the onset of TPP.

The mimecan gene expressed in human pituitary and regulated by pituitary transcription factor-1 as a marker for diagnosing pituitary tumors.

CONTEXT: Mimecan, a secretory protein, belongs to a family of small leucine-rich proteoglycans (SLRPs). The physiological functions of mimecan have not been fully understood. OBJECTIVE: We hypothesize that the mimecan gene expressed in the human pituitary and regulated by pituitary transcription factor-1 (Pit-1) might act as a marker for diagnosing pituitary tumors. DESIGN: The clinical aspect of our work was a cross-sectional study. SETTING AND PATIENTS: In total, 20 pituitary tumor samples were collected from January 1, 2002, to December 30, 2002, in Ruijin Hospital, Shanghai, China. INTERVENTION: The number of pituitary tumors was limited. Collection of more pituitary tumor samples for additional observation will be necessary. MAIN OUTCOME MEASURES: The main outcomes were measured by Northern blot, in situ hybridization, immunohistochemical analysis, and so on. RESULTS: The mimecan gene was expressed at a moderate level in the mouse pituitary gland by Northern blot analysis. Expression of mimecan mRNA and protein is also observed in the human anterior pituitary gland. Luciferase reporter analysis and electrophoretic mobility shift assays show that Pit-1 activates the human mimecan promoter through Pit-1 response element sites. In addition, our data also show that almost all the ACTH- or GH-positive pituitary tumors likely express mimecan protein, and only a portion of prolactin-, TSH-, FSH-, and LH-positive pituitary tumors express mimecan protein. CONCLUSIONS: This work provides insight into the regulating mechanism of mimecan in pituitary and suggests that mimecan may be an unidentified pituitary secretory protein, and certain pituitary cells secreting ACTH or GH also secrete mimecan.

[Study of the impact of candidate genes on bone mineral density in postmenopausal women].

OBJECTIVE: To investigate the impact of multiple candidate genes on bone mineral density in postmenopausal women. METHODS: Bone mineral density (BMD) at lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry (DEXA) in 205 postmenopausal women. Polymerase chain reaction (PCR) and direct sequencing technique were used to identify osteoprotegerin gene polymorphism. Parathyroid hormone, calcitonin receptor, osteocalcin and leptin receptor genes were evaluated through PCR and restriction fragment length polymorphism. Leptin gene was genotyped by PCR and agarose electrophoresis. RESULTS: One G-1181C single nucleotide polymorphism was found in the first exon of the osteoprotegerin gene. After adjustment for age and body mass index, women who were with the CC genotype of osteoprotegerin gene or the bb genotype of parathyroid hormone gene had the highest BMD value at the lumbar spine, which was (1.042 +/- 0.142) g/cm(2) and (1.196 +/- 0.133) g/cm(2), respectively. No association was found among calcitonin receptor, osteocalcin, leptin and leptin receptor genes with BMD in postmenopausal women. Multivariate regression analysis found that the osteoprotegerin, parathyroid hormone and osteocalcin genes associated with the variance of BMD at the lumbar spine, and the parathyroid gene associated with the variance of BMD at the femoral neck. CONCLUSIONS: There is some association between osteoprotegerin, parathyroid hormone genes and BMD in postmenopausal women. However, no relationship has been found among calcitonin receptor, osteocalcin, leptin and leptin receptor genes with BMD in postmenopausal women. The osteoprotegerin gene may be the useful genetic marker for osteopenia in postmenopausal women.

A complex heterozygous mutation of His373Leu and Asp487-Ser488-Phe489 deletion in human cytochrome P450c17 causes 17alpha-hydroxylase/17,20-lyase deficiency in three Chinese sisters.

Cytochrome P450c17 deficiency is one of the rare forms of enzyme disorders in steroid biosynthesis, resulting from defects in 17alpha-hydroxylase and 17,20-lyase activities. The disease is caused by the mutations in CYP17 gene, inherited in an autosomal recessive pattern. We reported a Chinese family with three sisters suffering from P450c17 deficiency based on their clinical features and molecular genetics. The patients were found to be compound heterozygotes with two different mutations. Screened by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), a heterozygous point mutation His373Leu was detected in the exon 6 of CYP17 gene which was proved to be derived from paternal allele. The other allele contained nine-base pair deletion, located in exon 8, eliminating codons 487-489 (Asp-Ser-Phe) near the carboxy-terminus of P450c17. The mother and the brother have been demonstrated to be carriers of deletion mutation through restriction enzyme analysis. Both mutations have been reported previously in Asia. This is the first report of the molecular genetic study of 17alpha-hydroxylase/17,20-lyase deficiency in mainland China with a novel compound heterozygous mutation.

[A case report and pedigree study of a single point mutation in RET proto-oncogene and type 2B multiple endocrine neoplasia].

OBJECTIVE: To determine the relationship between a single point mutation in RET proto-oncogene and the occurrence of multiple endocrine neoplasia type 2B (MEN-2B) in a Chinese pedigree. METHODS: We used the methods of polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR) and direct gene sequencing of PCR products by an automated DNA sequencer to scan the entire exon 16 of RET proto-oncogene in the tumor (c)DNA from one patient with MEN-2B and the leukocyte DNA from this patient and both of his parents. RESULTS: We found the same mutation Met(ATG)-->Thr(ACG) at codon 918 in exon 16 of RET proto-oncogene in both the tumor (c)DNA and leukocyte DNA of the MEN-2B patient in the form of homozygous missense mutation, but there was no corresponding mutation in leukocytes DNA of his parents. CONCLUSION: We propose that in Chinese population, the point mutation M918T is also associated with the onset of MEN-2B and this case of MEN-2B is sporadic. Thus it may provide a genetic basis for the early diagnosis and treatment of patients suffering from MEN-2B and their at-risk family members in Chinese population.

[The relationship between body composition measured with bioelectric impedance analysis and bone mass in female].

OBJECTIVE: To investigate the effect of fat mass and fat-free mass on bone mineral density (BMD) in pre- and postmenopausal women. METHODS: 282 premenopausal women with regular menstruation and 205 postmenopausal women were enrolled in this study. BMD at lumbar spine (L(2 - 4)) and femoral neck (FN) were measured with dual-energy X-ray absorptiometry (DEXA). Fat mass and fat-free mass were measured with bioelectric impedance analysis (BIA). Height, weight, waist and hip circumference were recorded. Body mass index (BMI) and waist hip ratio (WHR) were calculated. RESULTS: Fat mass and fat-free mass were significantly positively correlated with L(2 - 4) and FN BMD in both pre- and postmenopausal women (P < 0.01). Multiple regression analysis showed that in premenopausal women, fat-free mass and age were significant determinants of L(2 - 4) BMD (R(2) = 0.077, P = 0.000), while fat-free mass, age and BMI were significant determinants of FN BMD (R(2) = 0.130, P = 0.000). In postmenopausal women, fat mass and age were significant determinants of BMD at L(2 - 4) and FN (R(2) were 0.153 and 0.184 respectively, P = 0.000). CONCLUSIONS: Fat mass and fat-free mass have different effects on BMD in pre- and postmenopausal women. Fat-free mass is a significant determinant of BMD in premenopausal women, while fat mass contributes most to BMD in postmenopausal women.

[The relationships between changes of serum osteoprotegerin, nuclear factor-kappa B ligand receptor activator, and age, menopause, bone biochemical markers and bone mineral densities in women aged 20 - 75].

OBJECTIVE: To investigate the relationships between the serum levels of osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B ligand (RANKL) with age, menopause, bone biochemical markers and bone mineral densities (BMDs) in pre- and postmenopausal women and to determine the contributing factors for serum OPG and RANKL. METHODS: 504 pre- and postmenopausal women aged between 20 and 75 years were enrolled in this study. BMDs at lumbar spine and proximal femur were measured with dual-energy X-ray absorption meter. The serum osteocalcin (BGP), OPG, RANKL and urinary type I collagen (NTx) were also tested. RESULTS: Age was positively related with serum OPG (r = 0.442, P < 0.001) and was negatively in association with serum RANKL (r = -0.263, P < 0.001). Postmenopausal women showed higher levels of serum OPG [(107.6 +/- 3.0) ng/L], while their serum concentrations of RANKL [(4.7 +/- 0.4) ng/L] and RANKL/OPG ratios (0.045 +/- 0.004) were significantly lower than those of premenopausal women [(72.0 +/- 1.8) ng/L, (5.8 +/- 0.3) ng/L and 0.099 +/- 0.008]. Neither serum OPG nor RANKL or RANKL/OPG was in association with BMDs at lumbar spine or proximal femur after adjustment of age, years-since-menopause (YSM) and body mass index. Serum OPG was positively related with urinary NTx/creatinine. Serum RANKL was negatively related with serum BGP. Serum OPG, RANKL and RANKL/OPG showed no differences among normal, osteopenic and osteoporotic postmenopausal women. In multiple regression analysis, YSM, age and bone markers were the independent contributors to OPG-RANKL system. CONCLUSIONS: The elevation of serum OPG along with age might be a compensatary mechanism against the accelerated bone resorption, while the decreased level of serum RANKL might be helpful for restoring the reduced bone formation in postmenopausal women. YSM, age, together with bone tune-over markers were the main factors affecting serum concentrations of OPG and RANKL.

[Effect of berberine on the differentiation of adipocyte].

OBJECTIVE: To observe the effect of berberine on the differentiation of 3T3-L1 preadipocytes into adipocytes and to elucidate its mechanism. METHODS: 3T3-L1 preadipocytes were cultured and then divided into 7 groups into whose media were added berberine of the concentrations of 0, 0.1, 1, 10, and 100 micro mol/L, 100 nmol/Linsulin, and 10 micro mol/L berberine + 100 nmol/L insulin. The proliferation of 3T3-L1 preadipocytes was detected by MTT method. The accumulation of lipid in the cytoplasm of differentiated adipocytes was observed by oil red O staining. The peroxisome proliferation activated receptor gamma2 (PPARgamma2) mRNA and protein were detected by RT-PCR and Western blotting respectively. RESULTS: MTT method showed that the absorbance at 570 nm of 3T3-L1 preadipocytes increased by 17% (P < 0.01), 36% (P < 0.001), and 22% (P < 0.05) in the groups of 1, 10, and 100 micro mol/L berberine, by 53% (P < 0.0001)in the group of 100 nmol/L insulin, and by 66% in the group of 10 micro mol/L berberine + 100 nmol/L insulin. There were less and smaller lipid droplets in the 3T3-L1 adipocytes treated with berberine as compared with the untreated control cells and only 10% - 20% of the treated cells displayed big lipid drops. RT-PCR showed that berberine significantly reduced the expression of PPARgamma2 mRNA by 48% (P < 0.01) in the course of 3T3-L1 adipocyte differentiation. Western blotting showed that berberine inhibited the expression of PPARgamma2 protein. CONCLUSION: Berberine promotes the proliferation of 3T3-L1 preadipocytes, decreases the accumulation of lipid drops therein, and inhibits the terminal differentiation of adipocyte, which may be associated with its effect on decreasing the expression of PPARgamma2 mRNA and protein, suggesting that berberine has advantages in the treatment of obesity patients with type 2 diabetes.

[Combined effect of interleukin-6 and estrogen receptor gene polymorphisms on bone mass in postmenopausal women].

OBJECTIVE: To examine the individual and combined effects of interleukin-6 (IL-6) and estrogen receptor (ER) gene polymorphisms on the Z score of bone mineral density (BMD). METHODS: BMD at lumbar spine (L(2 - 4)) and femoral neck (FN) were analyzed in 205 postmenopausal Chinese women by dual energy X-ray absorptiometry. Polymorphic 3'flanking region of IL-6 gene and the allelic variance in ER gene PvuII and XbaI sites were studied by polymerase chain reaction. Serum alkaline phosphatase, osteocalcin and urinary pyridinolin were also measured. RESULTS: There were D/D, D/E, C/D, C/C and E/E 5 genotypes of IL-6 gene in our samples, 193 of 205 women were D/D or D/E types. No difference of BMD at L(2 - 4) or FN was found between D/D and D/E types. For the PvuII and XbaI polymorphisms in these IL-6 D/D and D/E genotypes, the FN BMD was higher in pp in comparison with Pp (P = 0.036), and lumbar spine BMD was higher in XX type, comparing with Xx and xx genotype (P = 0.005 and 0.031, respectively). Women without Px haplotype had elevated BMD at L(2 - 4) (P = 0.029) and a trend for higher BMD at FN (P = 0.056) than those with it. Combining the women with IL-6 D/D, D/E genotypes and ER gene Px haplotypes, the L(2 - 4) BMD in those of DD * without Px haplotype showed a tendency to be higher than those of DD * with Px haplotype (P = 0.057), and was significantly increased than those of DE * with Px haplotypes (P = 0.036). CONCLUSION: The introduction of ER gene Px haplotype in the analysis of IL-6 gene might identify individuals with a reduced bone mass more precisely.

[Relationship between body composition and bone mineral density in healthy premenopausal women].

OBJECTIVE: To investigate the relative contribution of fat mass and lean mass on bone mineral density (BMD) in premenopausal healthy women. METHODS: The BMD at lumbar spine, proximal femur and total body, together with fat mass and lean mass was determined by dual-energy X-ray absorptiometry (DEXA), the body height, weight, waist, and hip circumference were also measured, and body mass index (BMI) and waist-hip ratio were calculated in 282 premenopausal women. RESULTS: Fat mass was a major determinant for BMI, BMI and lean mass were positively related with L2-4, proximal femur and total body BMD (P = 0.000 for all), and lean mass were the only independent factor contributing to L2-4 (standardized coefficient beta = 0.282, P = 0.000), proximal femur (beta = 0.336, P = 0.000) and total body BMD (beta = 0.361, P = 0.000) in stepwise regression analysis. The relationship between BMI and BMD was further improved after controlling fat mass, while decreased or even lost when controlling lean mass. CONCLUSIONS: Lean mass was an important factor determining BMD in premenopausal women.

[Association of calcitonin receptor gene polymorphism with bone mineral density in Shanghai women].

OBJECTIVE: To investigate the association of calcitonin receptor (CTR) gene polymorphism with bone mineral density (BMD) in premenopausal and postmenopausal women. METHODS: CTR genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 184 premenopausal women and 199 postmenopausal women in Shanghai area. BMD at lumbar spine (L2-4) and femoral neck (FN) were measured by dual-energy X-ray absorptiometry (DEXA). RESULTS: The distribution of CTR genotypes in 383 Shanghai women were CC genotype 83.8%, TC genotype 14.6%, TT genotype 1.6%, respectively. BMD at FN of CC genotype was significantly higher than TC and TT genotypes (P < 0.01) in postmenopausal women. But there was no difference in BMD of different CTR genotypes in premenopausal women. Multiple regression analysis showed that CTR genotypes were associated with FN BMD in postmenopausal women (P < 0.05). CONCLUSIONS: The polymorphism of CTR gene was associated with BMD in postmenopausal women.

An independent positive relationship between the serum total osteocalcin level and fat-free mass in healthy premenopausal women.

CONTEXT: It is widely reported that osteocalcin is negatively associated with fat mass. However, there are few reports describing its correlation with fat-free mass, particularly in women. OBJECTIVES: The objective of the current study was to investigate the possible relationship between osteocalcin and fat-free mass in healthy, nonobese women. DESIGN AND SETTING: This study was performed in a tertiary university teaching hospital. SUBJECTS: A total of 504 healthy women aged 20-75 years were enrolled. MAIN OUTCOME MEASURES: Body composition was measured using a bioelectronics impedance analyzer. The serum concentrations of total osteocalcin, estradiol, leptin, osteoprotegerin, the receptor activator of nuclear factor-κB ligand, IGF-I, fasting plasma glucose, and urinary N-terminal telopeptide of type I collagen were tested. The bone mineral densities (BMDs) at the lumbar spine and proximal femoral neck were measured by dual-energy X-ray absorptiometry. RESULTS: The serum total osteocalcin level had a significant positive association with fat-free mass (r = 0.168, P = .007) after adjusting for age, fat mass, menopausal status, estradiol, fasting glucose, leptin, osteoprotegerin, receptor activator of nuclear factor-κB ligand, IGF-I, N-terminal telopeptide of type I collagen, BMDs, and waist and hip circumference. Analysis in pre- and postmenopausal women demonstrated that this association was only present in premenopausal women (r = 0.190, P = .005). The multiple stepwise regression analysis revealed that hip circumference, femoral neck-BMD, fat mass, leptin, osteocalcin, and age are the contributors to the changes in fat-free mass in premenopausal women (adjusted R(2) = 0.521, P < .001). CONCLUSION: The serum level of total osteocalcin was positively associated with fat-free mass independent of age, fat mass, leptin, and other confounders in premenopausal women.

A refined study of FCRL genes from a genome-wide association study for Graves' disease.

To pinpoint the exact location of the etiological variant/s present at 1q21.1 harboring FCRL1-5 and CD5L genes, we carried out a refined association study in the entire FCRL region in 1,536 patients with Graves' disease (GD) and 1,516 sex-matched controls by imputation analysis, logistic regression, and cis-eQTL analysis. Among 516 SNPs with P<0.05 in the initial GWAS scan, the strongest signals associated with GD and correlated to FCRL3 expression were located at a cluster of SNPs including rs7528684 and rs3761959. And the allele-specific effects for rs3761959 and rs7528684 on FCRL3 expression level revealed that the risk alleles A of rs3761959 and C of rs7528684 were correlated with the elevated expression level of FCRL3 whether in PBMCs or its subsets, especially in CD19(+) B cells and CD8(+) T subsets. Next, the combined analysis with 5,300 GD cases and 4,916 control individuals confirmed FCRL3 was a susceptibility gene of GD in Chinese Han populations, and rs3761959 and rs7528684 met the genome-wide association significance level (P(combined) = 2.27×10(-12) and 7.11×10(-13), respectively). Moreover, the haplotypes with the risk allele A of rs3761959 and risk allele C of rs7528684 were associated with GD risk. Finally, our epigenetic analysis suggested the disease-associated C allele of rs7528684 increased affinity for NF-KB transcription factor. Above data indicated that FCRL3 gene and its proxy SNP rs7528684 may be involved in the pathogenesis of GD by excessive inhibiting B cell receptor signaling and the impairment of suppressing function of Tregs.

The effects of bisphenol A (BPA) exposure on fat mass and serum leptin concentrations have no impact on bone mineral densities in non-obese premenopausal women.

OBJECTIVES: Bisphenol A (BPA) exposure may promote obesity, but its effect on bone mineral density (BMD) has not been reported in humans. We aimed to examine the relationships between BPA exposure, body composition, serum estradiol, leptin, osteocalcin levels and BMDs in healthy premenopausal women. DESIGN AND METHODS: In this cross-sectional study, a total of 246 healthy premenopausal women aged 20 years and older with regular menstrual cycles were investigated. Body mass index (BMI), fat mass, fat-free mass and BMDs were measured by DXA. Serum estradiol, leptin, osteocalcin, urinary BPA and NTx levels were also tested. RESULTS: Urinary BPA levels were positively associated with fat mass (r=0.193, p=0.006) and leptin (r=0.236, p=0.001) but not with fat-free mass after adjusting for age and BMI. BPA was not associated with serum estradiol levels, BMDs, or bone resorption marker NTx and bone formation parameter osteocalcin, either. A multivariate stepwise regression analysis confirmed that serum leptin levels were positively influenced by fat mass (ß=0.746, p<0.001) and BPA (ß=0.127, p=0.01) but negatively correlated with fat-free mass (ß=-0.196, p<0.001). However, the changes of BMDs at the lumbar spine (ß=0.298, p<0.001) and femoral neck (ß=0.305, p<0.001) were primarily explained by fat-free mass, and were irrelevant of the fat mass, leptin or BPA exposure. CONCLUSIONS: Although BPA exposure is related with increased amount of fat mass and elevated serum leptin levels, it has neutral effect on BMDs in premenopausal women, possibly due to the exclusive role of fat-free mass, which is unrelated to BPA in determining BMDs.

Two unusual cases of intractable hyperthyroidism responsive to octreotide: Munchausen syndrome or not?

BACKGROUND: The effective treatment for patients with resistant hyperthyroidism is difficult. METHODS: In this case report with 4-year follow-up data, we present 2 unusual cases of hyperthyroidism that were unresponsive to almost all antithyroid treatments including total thyroidectomy, but both were controlled with octreotide. RESULTS: Cases 1 and 2 were both middle-aged women. They presented thyrotoxicosis with a low serum concentration of TSH and thyroidal radioactive iodine uptake (RAIU). The underlying causes, such as thyroiditis, metastatic thyroid cancer and struma ovarii were explored. Iodine-induced hyperthyroidism, particularly factitious hyperthyroidism was highly suspected, but there was no direct evidence to establish these diagnoses. In spite of good compliance, their thyrotoxicosis could not be controlled with large doses of PTU or MMI. ß-blocker, methylprednisolone, radio-iodine therapy and even thyroidectomy were all attempted and failed. Short-acting octreotide was first administered to case 1 and then to case 2. Thyroid function improved greatly within 3 days in both cases. The doses of octreotide were tapered down to twice a week with consistent efficacy. During the follow-up periods, case 1 required octreotide 0.1mg twice per week and case 2 is on thyroid replacement therapy due to hypothyroidism. The recurrences of hyperthyroidism in both cases were again rapidly controlled with the increased dose of octreotide in case 1 and re-started the usage of octreotide in case 2. CONCLUSIONS: The etiology of thyrotoxicosis in these 2 cases is not clear. In the absence of struma ovarii or wide-spread follicular thyroid cancer, factitious hyperthyroidism due to Munchausen syndrome should be considered first. The efficacy of the off-label use of octreotide in hyperthyroidism was highly effective (only) in these 2 cases.