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Background: Hypoparathyroidism (hypo-PT) is rare, and studies on hypo-PT, especially during pregnancy and lactation, are limited.Design and Setting: This was a retrospective study on a relatively large case series in a single center from mainland China.Methods: A total of 19 patients with 25 pregnancies, diagnosed with hypo-PT before pregnancy, were enrolled. Data on clinical characteristics and treatment strategies at onset time and around pregnancy period were collected.Results: During pregnancy, except for 2 patients with missing data, 5 patients with 6 pregnancies (6/23, 26.1%) experienced improved hypo-PT condition, defined as an increased serum calcium level; 4 patients with 4 pregnancies (4/23, 17.4%) experienced worsened hypo-PT condition, defined as a more than 0.2 mmol/L decline in the serum calcium level; and 3 patients with 3 pregnancies (3/23, 13.0%) remained in stable hypo-PT condition. The prevalence of adverse pregnancy outcomes was 30.4% (4/23 for preterm delivery; 3/23 for miscarriage). The serum calcium and 24-hour urine calcium levels significantly increased during lactation compared with pregnancy (2.57 ± 0.34 vs 1.99 ± 0.11 mmol/L, P < 0.001; 12.28 ± 5.41 vs 8.63 ± 3.22 mmol/L, P = 0.013), and 5 patients with 5 lactations (5/12, 41.7%) developed hypercalcemia in the first 2 months after delivery.Conclusions: Female patients with hypo-PT had different changes in calcium homeostasis and a high prevalence of adverse outcomes during pregnancy. Thus, they should be monitored closely to maintain the optimal serum calcium level. Decreasing drug dosage during the lactation period should be considered to avoid hypercalcemia. [ABSTRACT FROM AUTHOR]

Background: Autoimmune polyendocrine syndrome type 1 (APS1) is a hereditary disease caused by mutations in the AIRE gene with both endocrine and non-endocrine organ involvement. The existing data from China are limited, and this study aims to describe the phenotypes and genetic characterization in Chinese APS1 patients. In this single-center, retrospective, observational study, comprehensive endocrine and extra-endocrine manifestations were collected, and genetic analysis in AIRE was conducted in patients with APS1 between the years of 1984 and 2018 at Peking Union Medical College Hospital.Results: In total, 13 patients from 12 unrelated families were enrolled, seven of whom were female, with hypoparathyroidism, chronic mucocutaneous candidiasis, and Addison's disease being the most frequently observed manifestations. Up to 84.7% presented with two or three of the above-mentioned manifestations, and nearly 4.9 ± 1.8 components presented in patients aged 21.2 ± 7.9 years old. Several less common phenotypes, such as myeloproliferative disease, pure red cell aplasia, renal tubular acidosis, asplenia, autoimmune hepatitis, and ankylosing spondylitis, were also observed in patients. Altogether, seven different AIRE mutations were found in six patients, four of which (K161fs, G208V, A246fs, and L308F) had not been previously reported in patients with APS1.Conclusion: We have provided a comprehensive profile of Chinese patients with APS1, with less commonly observed features being observed in addition to more regularly seen manifestations. Additionally, different AIRE mutations that were observed have expanded the genetic spectrum, which will help with future understanding of the molecular pathogenesis of APS1. [ABSTRACT FROM AUTHOR]

The efficacy and safety of intravenous ibandronate were evaluated in postmenopausal osteoporosis women in China. In this multicenter, positive drug-controlled study, 158 postmenopausal osteoporotic women were randomized to receive 2 mg ibandronate given intravenously once every 3 months or 70 mg alendronate given orally once per week. All women also received supplemental calcium (500 mg) and vitamin D (200 IU) daily. One hundred fifty-one patients completed the 1-year study. Ibandronate produced mean increases in bone mineral density (BMD) by 4.27% at the lumbar spine, 3.48% at the femoral neck, and 2.03% at the trochanter. Mean increases in BMD by 4.24% at the lumbar spine, 2.72% at the femoral neck, and 2.99% at the trochanter were observed in the alendronate group. No significant difference was found between the two groups in BMD in all sites measured. Significant decreases in serum c-telopeptide of type I collagen (CTX) and alkaline phosphatase (ALP) were found in the two groups after 1 and 3 months of treatment, respectively; these serum CTX and ALP levels were then maintained at the decreased levels throughout the study period (12 months). No changes of stature were found in the patients of the two groups. Adverse events were similar in the two groups, except more mild muscle pain was observed in the first month after infusion of ibandronate than with oral alendronate (P < 0.001). The results observed in Chinese patients may support the observation that intravenous ibandronate significantly reduced bone resorption and increased BMD with good tolerance in Chinese postmenopausal osteoporotic women. Use of intravenous ibandronate possibly could potentially improve compliance as compared with other oral bisphosphonates because it may avoid the peptic side effects of oral bisphosphonate. [ABSTRACT FROM AUTHOR]

Background: Vitamin D (VD) insufficiency or deficiency is a frequent comorbidity in Chinese women with postmenopausal osteoporosis (PMO). The present study aimed to investigate 25-hydroxyvitamin D [25(OH) D] improvement and calcium-phosphate metabolism in Chinese PMO patients treated with 70 mg of alendronate sodium and 5600 IU of vitamin D3 (ALN/D5600).Methods: Chinese PMO women (n = 219) were treated with 12-month ALN/D5600 (n = 111) or calcitriol (n = 108). Changes in 25(OH) D at month 12 were post hoc analyzed by the baseline 25 (OH) D status using the longitudinal analysis. The main safety outcome measures included serum calcium and phosphate and 24-h urine calcium, and the repeated measures mixed model was used to assess the frequencies of the calcium-phosphate metabolic disorders.Results: Absolute change in mean serum 25(OH) D level was the greatest in VD-deficient patients and least in VD-sufficient patients at months six and 12 (both, P < 0.01). Serum calcium level remained significantly lower in the ALN/D5600 treatment group than in the calcitriol treatment group throughout the 12 months. Mean 24-h urine calcium slightly increased in the ALN/D5600 treatment group and significantly increased in the calcitriol treatment group (+ 1.1 and + 0.9 mmol/L at months six and 12; both, P < 0.05). Calcitriol treatment was associated with more frequent hypercalciuria at month six (9.4% vs. 18.5%, P = 0.05), but not at month 12 (12.3% vs. 13.0%).Conclusion: Baseline VD status predicted 25(OH) D improvement in PMO patients on 12-month ALN/D5600 treatment. The daily use of 0.25 μg of calcitriol was associated with more frequent hypercalciuria at month six, compared to ALN/5600 treatment, necessitating the safety re-evaluation of calcitriol at a higher dosage. [ABSTRACT FROM AUTHOR]

Background: Osteoporotic vertebral fractures cause pain and disability, which result in a heavy socioeconomic burden. However, the incidence and cost of vertebral fractures in China are unknown. We aimed to assess the incidence and cost of clinically recognized vertebral fractures among people aged 50 years and older in China from 2013 to 2017., Materials and Methods: This population-based cohort study was conducted by using Urban Employee Basic Medical Insurance (UEBMI) and Urban Resident Basic Medical Insurance (URBMI) data in China from 2013 to 2017, which covered more than 95% of the Chinese population in urban areas. Vertebral fractures were identified by the primary diagnosis (i.e. International Classification of Diseases code or text of diagnosis) in UEBMI and URBMI. The incidence and medical cost of these clinically recognized vertebral fractures in urban China were calculated., Results: A total of 271 981 vertebral fractures (186 428, 68.5% females and 85 553, 31.5% males) were identified, with a mean age of 70.26 years. The incidence of vertebral fractures among patients aged 50 years and over in China increased ~1.79-fold during the 5 years, from 85.21 per 100 000 person-years in 2013 to 152.13 per 100 000 person-years in 2017. Medical costs for vertebral fractures increased from US$92.74 million in 2013 to US$505.3 million in 2017. Annual costs per vertebral fracture case increased from US$3.54 thousand in 2013 to US$5.35 thousand in 2017., Conclusion: The dramatic increase in the incidence and cost of clinically recognized vertebral fractures among patients aged 50 and over in urban China implies that more attention should be given to the management of osteoporosis to prevent osteoporotic fractures., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Hypoparathyroidism (hypo-PT) is rare, and studies on hypo-PT, especially during pregnancy and lactation, are limited., Design and Setting: This was a retrospective study on a relatively large case series in a single center from mainland China., Methods: A total of 19 patients with 25 pregnancies, diagnosed with hypo-PT before pregnancy, were enrolled. Data on clinical characteristics and treatment strategies at onset time and around pregnancy period were collected., Results: During pregnancy, except for 2 patients with missing data, 5 patients with 6 pregnancies (6/23, 26.1%) experienced improved hypo-PT condition, defined as an increased serum calcium level; 4 patients with 4 pregnancies (4/23, 17.4%) experienced worsened hypo-PT condition, defined as a more than 0.2 mmol/L decline in the serum calcium level; and 3 patients with 3 pregnancies (3/23, 13.0%) remained in stable hypo-PT condition. The prevalence of adverse pregnancy outcomes was 30.4% (4/23 for preterm delivery; 3/23 for miscarriage). The serum calcium and 24-hour urine calcium levels significantly increased during lactation compared with pregnancy (2.57 ± 0.34 vs 1.99 ± 0.11 mmol/L, P < 0.001; 12.28 ± 5.41 vs 8.63 ± 3.22 mmol/L, P = 0.013), and 5 patients with 5 lactations (5/12, 41.7%) developed hypercalcemia in the first 2 months after delivery., Conclusions: Female patients with hypo-PT had different changes in calcium homeostasis and a high prevalence of adverse outcomes during pregnancy. Thus, they should be monitored closely to maintain the optimal serum calcium level. Decreasing drug dosage during the lactation period should be considered to avoid hypercalcemia., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Vitamin D (VD) insufficiency or deficiency is a frequent comorbidity in Chinese women with postmenopausal osteoporosis (PMO). The present study aimed to investigate 25-hydroxyvitamin D [25(OH) D] improvement and calcium-phosphate metabolism in Chinese PMO patients treated with 70 mg of alendronate sodium and 5600 IU of vitamin D 3 (ALN/D5600)., Methods: Chinese PMO women (n = 219) were treated with 12-month ALN/D5600 (n = 111) or calcitriol (n = 108). Changes in 25(OH) D at month 12 were post hoc analyzed by the baseline 25 (OH) D status using the longitudinal analysis. The main safety outcome measures included serum calcium and phosphate and 24-h urine calcium, and the repeated measures mixed model was used to assess the frequencies of the calcium-phosphate metabolic disorders., Results: Absolute change in mean serum 25(OH) D level was the greatest in VD-deficient patients and least in VD-sufficient patients at months six and 12 (both, P < 0.01). Serum calcium level remained significantly lower in the ALN/D5600 treatment group than in the calcitriol treatment group throughout the 12 months. Mean 24-h urine calcium slightly increased in the ALN/D5600 treatment group and significantly increased in the calcitriol treatment group (+ 1.1 and + 0.9 mmol/L at months six and 12; both, P < 0.05). Calcitriol treatment was associated with more frequent hypercalciuria at month six (9.4% vs. 18.5%, P = 0.05), but not at month 12 (12.3% vs. 13.0%)., Conclusion: Baseline VD status predicted 25(OH) D improvement in PMO patients on 12-month ALN/D5600 treatment. The daily use of 0.25 μg of calcitriol was associated with more frequent hypercalciuria at month six, compared to ALN/5600 treatment, necessitating the safety re-evaluation of calcitriol at a higher dosage.

Osteogenesis imperfecta (OI) is a group of hereditary disorders characterized by decreased bone mass and increased fracture risk. The majority of OI cases have an autosomal dominant pattern of inheritance and are usually caused by mutations in genes encoding type I collagen. OI cases of autosomal recessive inheritance are rare, and OI type XI is attributable to mutation of the FKBP10 gene. Here, we used next-generation sequencing and Sanger sequencing to detect mutations in FKBP10 and to analyze their relation to the phenotypes of OI type XI in three Chinese patients. We also evaluated the efficacy of zoledronic acid treatment in these patients. Two of the affected patients had novel compound heterozygous mutations, one patient with c.343C>T (p.R115X) in exon 2 and c.1085delC (p.A362fsX1) in exon 7, and the other patient with c.879C>G (p.Y293X) in exon 5 and c.918-3C>G in intron 5. In the third proband, we identified a homozygous single base-pair duplication, c.831dupC (p.G278RfsX95) in exon 5. In conclusion, we report for the first time that these novel pathogenic mutations of FKBP10 can lead to the extremely rare type XI OI without contractures, which expands the genotypic spectrum of OI. The phenotypes of these patients are similar to patients with types III or IV OI, and zoledronic acid is effective in increasing BMD, inhibiting bone resorption biomarkers and reducing fractures of these patients.

Background: Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessively inherited disease characterized by excessive wasting of renal tubular magnesium and calcium. FHHNC is associated with various mutations in CLDN16 and CLDN19., Cases: Two children from a consanguineous family of Chinese Han origin demonstrated manifestations of rickets, polyuria, polydipsia, hematuria and failure to thrive. Hypomagnesaemia (0.49-0.50mmol/L), hypercalciuria or a trend to hypercalciuria (24hour urine calcium: 3.8-5.1mg/kg/day), and secondary hyperparathyroidism (serum PTH level: 94.7-200pg/mL) were revealed upon laboratory examination. Using targeted next-generation sequencing and subsequent confirmation by Sanger sequencing, a novel homozygous mutation was identified in the CLDN16 gene of both FHHNC patients. This specific mutation, a 16bp deletion followed by a 23bp insertion in exon 3, led to the generation of a premature termination codon. The parents and an unaffected sister were all heterozygous carriers of this mutation., Conclusions: We detected a novel mutation in CLDN16 for the first time. The clinical and genetic findings from this study will help to expand the understanding of this rare disease, FHHNC., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Aim: Oral risedronate is effective in the treatment of postmenopausal osteoporosis when administered daily, weekly, or monthly. In this 1-year, randomized, double-blind, multicenter study we compared the weekly 35-mg and daily 5-mg risedronate dosing regimens in the treatment of Chinese postmenopausal women with osteoporosis or osteopenia., Methods: Postmenopausal women with primary osteoporosis or osteopenia were randomly assigned to the weekly group or daily group (n=145 for each) that received oral risedronate 35 mg once a week or 5 mg daily, respectively, for 1 year. The subjects' bone mineral densities (BMDs), bone turnover markers (P1NP and β-CTX), new vertebral fractures, and adverse events were assessed at baseline and during the treatments., Results: All subjects in the weekly group and 144 subjects in the daily group completed the study. The primary efficacy endpoint after 1 year, ie the mean percent changes in the lumbar spine BMD (95% CI) were 4.87% (3.92% to 5.81%) for the weekly group and 4.35% (3.31% to 5.39%) for the daily group. The incidences of clinical adverse events were 48.3% in the weekly group and 54.2% in the daily group., Conclusion: The weekly 35-mg and daily 5-mg risedronate dosing regimens during 1 year of follow-up show similar efficacy in improving BMDs and biochemical markers of bone turnover in Chinese postmenopausal women with osteoporosis or osteopenia. Moreover, the two dosing regimens exhibit similar safety and tolerability.

Objective: The aim of this study was to evaluate the effect of low-dose alendronate (ALN) treatment on bone mineral density (BMD) and bone turnover markers in Chinese postmenopausal women with osteopenia and osteoporosis., Methods: This study was a large-sample, randomized, open-label, prospective, multicenter, clinical trial with a 12-month follow-up. A total of 639 postmenopausal women (aged 62.2 ± 7.0 y) with osteopenia or osteoporosis were randomized into two groups: low-dose ALN (70 mg every two weeks) and standard-dose ALN (70 mg weekly). All patients were also supplemented with calcium (600 mg) and vitamin D3 (125 IU) daily. BMD (measured by dual-energy x-ray absorptiometry; Hologic and Lunar) and levels of serum bone turnover markers (bone resorption marker, carboxy-telopeptide of type I collagen; bone formation marker, alkaline phosphatase) were assessed at baseline and at 3, 6, and 12 months of treatment. BMD and bone turnover markers were compared between the baseline and the end of treatment, and the changes in BMD and bone turnover markers were also compared between the low-dose ALN group and the standard-dose ALN group., Results: No significant differences in age, years since menopause, body mass index, BMD, 25-hydroxy vitamin D level, and serum biochemical markers were found at baseline between the two dose groups. A total of 558 (87.3%) and 540 (84.5%) women completed the treatment at the 6th and 12th months, respectively. After the 12-month treatment, lumbar spine and hip BMD increased and serum bone turnover markers decreased significantly in both of the treatment groups (P < 0.01), and no differences in percentage changes in BMD at the lumbar spine, femoral neck, and hip were found between the low-dose group (5.60%, 3.87%, and 3.28%, respectively) and the standard-dose group (5.07%, 2.93%, and 3.80%, respectively; P > 0.05). However, levels of serum alkaline phosphatase and carboxy-telopeptide of type I collagen in the standard-dose group decreased moderately compared with those in the low-dose group (P < 0.05 and P < 0.01). The women tolerated the two doses of ALN quite well. Adverse effects were similar in the two groups., Conclusions: Treatment with low-dose ALN (70 mg every two weeks) in women with postmenopausal osteopenia or osteoporosis effectively increases lumbar spine and hip BMD, similar to treatment with standard-dose ALN. Low-dose ALN may be a cost-effective and safe protocol for treating osteopenia or osteoporosis in Chinese women.

Tumor-induced osteomalacia (TIO) is an acquired form of hypophosphatemia. Tumor resection leads to cure. We investigated the clinical characteristics of TIO, diagnostic methods, and course after tumor resection in Beijing, China, and compared them with 269 previous published reports of TIO. A total of 94 patients with adult-onset hypophosphatemic osteomalacia were seen over a 6-year period (January, 2004 to May, 2010) in Peking Union Medical College Hospital. After physical examination (PE), all patients underwent technetium-99m octreotide scintigraphy ((99) Tc(m) -OCT). Tumors were removed after localization. The results demonstrated that 46 of 94 hypophosphatemic osteomalacia patients had high uptake in (99) Tc(m) -OCT imaging. Forty of them underwent tumor resection with the TIO diagnosis established in 37 patients. In 2 patients, the tumor was discovered on PE but not by (99) Tc(m) -OCT. The gender distribution was equal (M/F = 19/20). Average age was 42 ± 14 years. In 35 patients (90%), the serum phosphorus concentration returned to normal in 5.5 ± 3.0 days after tumor resection. Most of the tumors (85%) were classified as phosphaturic mesenchymal tumor (PMT) or mixed connective tissue variant (PMTMCT). Recurrence of disease was suggested in 3 patients (9%). When combined with the 269 cases reported in the literature, the mean age and sex distribution were similar. The tumors were of bone (40%) and soft tissue (55%) origins, with 42% of the tumors being found in the lower extremities. In summary, TIO is an important cause of adult-onset hypophosphatemia in China. (99) Tc(m) -OCT imaging successfully localized the tumor in the overwhelming majority of patients. Successful removal of tumors leads to cure in most cases, but recurrence should be sought by long-term follow-up., (Copyright © 2012 American Society for Bone and Mineral Research.)

The age-specific rates of hip fractures have been declining in most countries in the West but a few studies suggest that the rates might be increasing in areas of Asia that are undergoing urbanization. We previously conducted a population-based study of hip fracture rates in Beijing, China, in 1990 to 1992 that included validation of hip fracture cases. Using a similar approach to validate cases, we estimated the age-specific hip fracture rates in Beijing, China, for 2002 to 2006. Specifically, we obtained hospital discharge data for hip fractures that were reported to the Beijing Bureau of Public Health. To confirm the diagnoses, Beijing residence, and find cases missed by the public records we checked individual cases in the public health records against medical records in a random sample of Beijing hospitals. The rates from public health data were adjusted for these under- and overestimations. We found that between 1990 and 1992 and 2002 and 2006, the adjusted age-specific rates of hip fracture over age 50 years increased 2.76-fold (95% confidence interval [CI], 2.68-2.84) in women and 1.61-fold (95% CI, 1.56-1.66) in men. Over age 70 years, the age-specific rates increased 3.37-fold (95% CI, 3.28-3.47) in women and 2.01-fold (95% CI, 1.95-2.07) in men. From 2002 to 2006, the rates over age 50 years increased 58% in women and 49% in men. We conclude that the rate of hip fracture has been rising very rapidly in Beijing, China. Therefore, the burden of hip fractures may be shifting rapidly from the West to urbanizing areas of the East., (Copyright © 2012 American Society for Bone and Mineral Research.)

Objective: To investigate the distribution of calcium-sensing receptor (CASR) gene polymorphisms in healthy young women of Han nationality in Beijing area and to explore the association of CASR genotypes and serum calcium, parathormone (PTH) level in healthy women., Methods: 202 healthy young women aged (27 +/- 5) years of Han nationality in Beijing area were recruited in this study. Whole blood genome DNA was extracted with QIAGEN DNA extraction kit. A986S and G990R genotypes were determined with mutagenically separated polymerase chain reaction (MS-PCR) and PCR-restriction fragment length polymorphisms (RFLP), respectively. Serum calcium, albumin, phosphorus, PTH were determined., Results: (1) There were A986S and G990R polymorphisms in healthy young women of Han nationality in Beijing. The frequencies of genotypes were as follows: SS absent, AA 95.0% and AS 5.0% for A986S, RR21.3%, GR51.0% and GG27.7% for G990R. Hardy-Weinberg equilibrium was evident. (2) In subjects carrying AA and AS genotype, serum Ca was (2.46 +/- 0.09) mmol/L vs (2.45 +/- 0.08) mmol/L, calcium adjusted by albumin was (2.31 +/- 0.10) mmol/L vs (2.30 +/- 0.09) mmol/L, serum P was (1.23 +/- 0.14) mmol/L vs (1.24 +/- 0.11) mmol/L, serum PTH was (41.6 +/- 18.6) ng/L vs (50.0 +/- 25.1) ng/L. There were no significant differences among them. (3) In subjects carrying GG, GR and RR genotype, serum Ca was (2.44 +/- 0.10), (2.46 +/- 0.08) and (2.48 +/- 0.08) mmol/L; calcium adjusted by albumin was (2.30 +/- 0.10), (2.32 +/- 0.09) and (2.32 +/- 0.10) mmol/L; serum P was (1.22 +/- 0.13), (1.24 +/- 0.15) and (1.20 +/- 0.15) mmol/L, serum PTH was (37.6 +/- 16.0), (42.1 +/- 20.2) and (45.9 +/- 18.1) ng/L. There were significant difference in serum Ca, calcium adjusted by albumin and PTH (P = 0.042, 0.020 and 0.014, respectively)., Conclusions: (1) There are A986S and G990R polymorphisms in CASR gene in Han nationality in Beijing area. The frequencies of genotypes are as follows: SS absent, AA 95.0% and AS 5.0% for A986S, RR21.3%, GR51.0% and GG27.7% for G990R. Hardy-Weinberg equilibrium is evident. A and G alleles are more common. It is indicated that the distribution of CASR gene polymorphisms in Chinese is different from that in Caucasians. (2) G990R polymorphism is associated with serum calcium and PTH levels in healthy women. Subjects with R allele have higher levels of serum calcium and PTH. There is no correlation between A986S polymorphism and serum calcium or PTH.

Objective: To investigate the association between bone mineral density (BMD) and leptin receptor (LEPR) polymorphism (Gln223 Arg) in young women and postmenopausl osteoporotic women., Methods: BMD values were determined by dual energy X-ray absorptiometry. The Gln223 Arg genotypes of LEPR were analyzed by using polymerase chain reaction-restriction fragment length polymorphism method., Results: Hardy-Weinberg equilibrium was evident for LEPR polymorphism. The subjects carrying the GG genotype of LEPR had significantly higher BMD at lumbar spine as compared with the subjects with GA and AA genotype in young women [(1.213 +/- 0.127) g/cm(2) vs (1.154 +/- 0.124) g/cm(2), P < 0.05]. There were no significant differences in BMD at the proximal femur among GG, GA and AA genotype in young women. No significant differences in BMD at all sites were observed among GG, GA and AA genotype in postmenopausl osteoporotic women. Correlation was found between BMD and leptin receptor polymorphism (Gln223 Arg) at lumbar spine (r = -0.151, P < 0.05)., Conclusion: Leptin receptor polymorphism (Gln223 Arg) has association with peak bone mass in young women, which may be used as genetic marker in predicting the risk of developing osteoporosis in Chinese women of Han nationality.

Objective: To determine whether vitamin D receptor(VDR) gene start codon polymorphisms and 3'-end region polymorphisms exerted a combined influence on bone mineral density(BMD) in Han postmenopausal women in Beijing area., Methods: The VDR Fok I and 3'-end region genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 110 unrelated postmenopausal women. BMD was measured at the lumbar spine (L(2-4)), femoral neck(Neck), Ward's triangle(Ward's) and trochanter (Troch) using duel-energy X-ray absorptiometry., Results: The frequencies distribution of Fok I, Apa I, Bsm I and Taq I alleles in this cohort all followed the Hardy-Weinberg equilibrium. No significant association of Fok I, Apa I or Taq I genotype with BMD in postmenopausal women was found when these polymorphisms were considered independently, except for Bsm I genotype. When a combined analysis of VDR gene Fok I and 3'-end region polymorphisms was carried out, cross-genotyping Fok I and Apa I polymorphisms was significantly associated with BMD at the L(2-4) (P<0.001), and cross-genotype of Fok I and Taq I was also significantly associated with BMD at the Neck and Troch sites (P<0.05). However, cross-genotyping Fok I and Bsm I polymorphisms was not significantly associated with BMD. Cross-genotyping Apa I and Bsm I or Taq I polymorphisms was not associated with BMD in postmenopausal women, either., Conclusion: Although Fok I polymorphisms of VDR gene were not significantly associated with BMD in postmenopausal women, VDR gene Fok I and 3'-region polymorphisms (Apa I and Taq I) had a combined effect on the BMD in postmenopausal women.