Trabecular Bone Score as a More Sensitive Tool to Evaluate Bone Involvement in MEN1-related Primary Hyperparathyroidism.

CONTEXT: The skeletal involvement of multiple endocrine neoplasia type 1-related primary hyperparathyroidism (MHPT) is not exactly the same as that of sporadic primary hyperparathyroidism (SHPT). Trabecular bone score (TBS) as a texture parameter has been reported to reflect trabecular bone damage. OBJECTIVE: This study aimed to compare the clinical characteristics, especially the skeletal involvement, between patients with MHPT and SHPT. METHODS: The clinical characteristics were retrospectively collected in 120 patients with MHPT and compared with 360 patients with SHPT in the same period. Dual-energy X-ray absorptiometry were conducted in some patients with MHPT, in whom bone mineral density (BMD) and calculated TBS derived from lumbar spine dual-energy X-ray absorptiometry images were compared with those of patients with SHPT. RESULTS: Although the duration of disease in the MHPT group was longer, the age at hospital visit was significantly lower than that in the SHPT group (43.5 [interquartile range, 31.5-52.0] vs 52.0 [interquartile range, 40.5-61.0], P < .001). The proportion of skeletal involvement in the MHPT group was significantly lower. However, in the subgroup of MHPT cases (n = 86) with data of BMD, there was no significant difference in skeletal involvement from SHPT cases matched for gender and age. Although the BMD and TBS in the lumbar spines of patients with MHPT were lower than those of patients with SHPT (BMD: 0.91 ± 0.18 g/cm2 vs 1.01 ± 0.17 g/cm2; TBS: 1.22 ± 0.14 vs 1.29 ± 0.11, P < .001). According to TBS, among 34 patients with MHPT with normal BMD, 15 patients had bone microstructure damage. CONCLUSION: The cancellous bone microarchitecture was more severely damaged in patients with MHPT according to TBS, which suggested that TBS could be a sensitive supplemental index in addition to BMD to identify bone-involvement risk in patients with MHPT.

The preliminary study on cardiac structure and function in Chinese patients with primary hyperparathyroidism.

Purpose: Recent evidences show that primary hyperparathyroidism (PHPT) patients have a high prevalence of cardiovascular diseases. However, the reported changes in cardiac status are inconsistent in previous studies. The present work evaluated the cardiac structure and function in PHPT patients by echocardiography. Methods: PHPT patients and age- and sex-matched healthy controls were enrolled in this case-control study. Biochemical parameters were retrospectively collected from PHPT patients. Cardiac function and structure were assessed in all subjects using echocardiography. Results: A total of 153 PHPT patients and 51 age- and sex-matched healthy controls were enrolled in this study. The mean serum calcium and parathyroid hormone (PTH) levels in PHPT patients were 2.84 ± 0.28mmol/L and 206.9 (130.0, 447.5) pg/ml, respectively. Left ventricular ejection fraction (LVEF) and early to late mitral annular velocity (E/A) were significantly lower in PHPT patients than in healthy controls (68.2 ± 6.0 vs. 70.7 ± 16.7%, 1.0 ± 0.5 vs. 1.4 ± 0.5, respectively, p both < 0.05). The left ventricular mass index (LVMI) and the relative wall thickness (RWT) were not significantly different between the two groups. However, the difference in LVEF between PHPT patients without hypertension and diabetes and the control groups disappeared. The majority of PHPT patients had normal cardiac geometry; however, a proportion of them exhibited concentric remodeling (normal LVMI, RWT≥0.42). Serum calcium, corrected calcium, ionized calcium and PTH were inversely related to E/A, whereas serum phosphorus and 24-hour urine calcium were positively related to E/A. Furthermore, biochemical parameters were not correlated with LVEF. Conclusions: These findings demonstrate that PHPT patients exhibit diastolic cardiac dysfunction reflected by decreased E/A, as well as possible cardiac structural abnormalities. The serum calcium, phosphorus, and parathyroid hormone levels may influence cardiac structure and function.

Hyperparathyroidism in a Large Cohort of Chinese Patients With Tumor-induced Osteomalacia.

CONTEXT: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by excessive production of fibroblast growth factor 23 (FGF23) by a tumor. Hyperparathyroidism (HPT) including secondary HPT (SHPT) and tertiary HPT (THPT) in TIO patients, which is believed to be associated with phosphate supplementation, has not been well documented. OBJECTIVES: To clarify the prevalence, clinical characteristics, and risk factors for HPT in a large cohort of Chinese patients with TIO in our hospital. DESIGN, SETTING, AND PARTICIPANTS: This retrospective study enrolled 202 patients with TIO. MAIN OUTCOME MEASUREMENTS: Occurrence of HPT in patients with TIO. RESULTS: HPT was observed in 91 patients (91/202, 45.1%): 84 patients (41.6%) with SHPT and 7 patients (3.5%) with THPT. All patients with THPT underwent parathyroidectomy and only 1 patient experienced recurrence. Compared with patients without HPT, patients with SHPT had longer disease duration, higher rate of phosphate and calcitriol supplementation, lower serum calcium, lower urine calcium excretion, and higher urine phosphate excretion. Compared with patients with SHPT, patients with THPT had even longer disease duration and a higher rate of phosphate and calcitriol supplementation. PTH levels showed positive correlation with intact FGF23 and 1,25-dihydroxyvitamin D levels, but not 25-hydroxy vitamin D level in patients with TIO. Multivariate logistic regression analysis showed that long disease duration and phosphate supplementation were independently associated with occurrence of HPT in patients with TIO. Further logistic regression analysis and restricted cubic spline model revealed dose-response relationship between cumulative dose of phosphate supplementation and PTH levels. CONCLUSIONS: HPT is common in patients with TIO. To avoid the occurrence of HPT in patients with TIO, timely diagnosis and tumor resection is necessary and an excessive dose of phosphate supplementation is not suggested before surgery.

Bone characteristics of autosomal dominant hypophosphatemic rickets patients.

OBJECTIVE: Autosomal dominant hypophosphatemic rickets (ADHR) is a rare disease caused by activating mutations in fibroblast growth factor 23 (FGF23) gene. With FGF23 activation, ADHR is a good model to explore the effects of FGF23 on skeletal development and mineralization. However, the bone microarchitecture of ADHR patients is poorly investigated. This study aims to illustrate the bone properties of ADHR patients and clarify the effect of FGF23 on load bearing and non-load bearing bone. METHODS: Bone microarchitectures of 11 ADHR subjects and sex- and age-matched healthy controls were analyzed by HR-pQCT. The effect of FGF23 mutations on load bearing and non-load bearing bone was explored by comparison of bone microarchitecture in distal radius and distal tibia. The BMD, bone microarchitecture and bone strength were compared between 7 ADHR patients and 7 age- and sex-matched XLH patients. RESULTS: Among 11 subjects with FGF23 mutations, 10 patients presented with obvious symptoms, five of which had received 1-3 years of iron supplement, neutral phosphate, and calcitriol treatments. The symptomatic patients presented with low bone density and fractures in X rays, with decreased Z score of aBMD (L1-L4: -1.3 ± 1.4, femoral neck: -2.1 ± 1.8, total hip: -1.85 ± 1.6). Compared with controls, HR-pQCT analysis of 5 untreated ADHR patients showed increased total area (+61.6 %, p = 0.03) and cortical perimeter (+17.2 %, p = 0.03) in distal radius. No significant differences were found in other parameters in distal radius. In distal tibia, the patients presented obvious defects in cancellous bone, with decreased trabecular vBMD (-62.9 %, p = 0.003), trabecular BV/TV (-48.7 %, p = 0.003) and trabecular number (-42.2 %, p = 0.001). The trabecular separation (+113.3 %, p = 0.007) and trabecular network inhomogeneity (+226.7 %, p = 0.001) were accordingly increased. In addition to another 5 treated patients, the bone microarchitecture changes revealed similar pattern, but the increase of total area and cortical perimeter in distal radius was no longer statistically significant. The non-symptomatic ADHR patient demonstrated slightly decreased total vBMD, trabecular vBMD and trabecular BV/TV in distal tibia. The changing pattern of bone geometry and microarchitecture of ADHR patients were similar to XLH patients but showed less deficit and stronger bone strength. CONCLUSION: ADHR patients presented increased total area and cortical perimeter in distal radius, and obvious defect in cancellous bone in distal tibia. FGF23 have impairment effect on trabecular bone especially in weight bearing site.

Eldecalcitol increases bone mineral density in Chinese osteoporotic patients without vitamin D or calcium supplementation.

Eldecalcitol increased bone mineral density (BMD) and prevented vertebral fractures in vitamin D-sufficient osteoporotic subjects. However, the effect of eldecalcitol on BMD under vitamin D insufficiency is unknown. We examined the effect of eldecalcitol on BMD compared with alfacalcidol in osteoporotic patients without vitamin D or calcium supplementation. This is a randomized, double-blind, active comparator trial. 265 Chinese osteoporotic patients were randomly assigned to receive 0.75 µg eldecalcitol or 1.0 µg alfacalcidol for 12 months without vitamin D or calcium supplementation. Baseline calcium intakes were less than 550 mg/day and mean serum 25-hydroxyvitamin D [25(OH)D] was below 43 nmol/L in both groups. Baseline BMD tended to be lower in patients with lower calcium intake and serum 25(OH)D. Lumbar BMD increased by 2.05% higher in eldecalcitol than alfacalcidol group at 12 months. Total hip and femoral neck BMD also increased by 1.33 and 1.78%, respectively, in the eldecalcitol than the alfacalcidol group. The effect of eldecalcitol on BMD was not affected by serum 25(OH)D or calcium intake. The incidence of adverse events was not different between the two groups. Incidence of hypercalcemia in the edecalcitol group was not affected by serum 25(OH)D. In conclusion, baseline BMD tended to be lower in patients with low calcium intake and serum 25(OH)D. Eldecalcitol increased lumbar and hip BMD more than alfacalcidol regardless of serum 25(OH)D or calcium intake without vitamin D or calcium supplementation. These results suggest that eldecalcitol is effective in increasing the BMD of osteoporotic patients regardless of vitamin D status or calcium intake.Clinical Trial Registration number JAPIC CTI 152904.

Clinical characteristics associated with bone mineral density improvement after 1-year alendronate/vitamin d3 or calcitriol treatment: Exploratory results from a phase 3, randomized, controlled trial on postmenopausal osteoporotic women in China.

Baseline and on-treatment characteristics, including age, obesity, calcium intake, and bone turnover markers, may predict the bone mineral density (BMD) response in women with postmenopausal osteoporosis (PMO) to 1 to 2 years of antiresorptive therapy and/or vitamin D supplementation. This study aimed to explore clinical characteristics associated with 12-month BMD improvement in Chinese women with postmenopausal osteoporosis (PMO).In this post hoc analysis of a previous phase 3 multicenter, randomized controlled trial, Chinese PMO women who were treated with once weekly alendronate 70 mg/vitamin D3 5600 IU (ALN/D5600) or once daily calcitriol 0.25 mcg, and had measurements of 1-year lumbar spine BMD (LS-BMD) and on-treatment bone turnover markers (BTMs) were included in the analysis.In Chinese PMO patients on ALN/D5600, 1-year LS-BMD change was negatively correlated with age (ß = -0.00084, P < .01), dietary calcium (ß = -0.0017, P = .07), and procollagen type 1 N-terminal propeptide (P1NP) change at month 6 (ß = -0.000469, P = .0016), but positively with body mass index (BMI) (ß = 0.00128, P = .08); baseline P1NP above the median was associated with a significantly greater BMD percentage change at the lumbar spine (P = .02) and the total hip (P = .0001). In the calcitriol group, a significant 1-year LS-BMD increase was associated with BMI (ß = 0.0023, P = .02), baseline P1NP (ß = 0.00035, P = .0067), history of prior vertebral fracture(s) (ß = 0.034, P < .0001) and baseline serum 25(OH)D level (ß = -0.00083, P = .02).The presented findings from Chinese postmenopausal osteoporotic women suggested clinically meaningful baseline and on-treatment characteristics predicting BMD improvement after 1 year of ALN/D5600 treatment, which differed from calcitriol treatment with baseline identifiable associations. The study remained exploratory and further accumulation of evidence is needed.

Vertebral fractures among breast cancer survivors in China: a cross-sectional study of prevalence and health services gaps.

BACKGROUND: Breast cancer survivors are at high risk for fracture due to cancer treatment-induced bone loss, however, data is scarce regarding the scope of this problem from an epidemiologic and health services perspective among Chinese women with breast cancer. METHODS: We designed a cross-sectional study comparing prevalence of vertebral fractures among age- and BMI-matched women from two cohorts. Women in the Breast Cancer Survivors cohort were enrolled from a large cancer hospital in Beijing. Eligibility criteria included age 50-70 years, initiation of treatment for breast cancer at least 5 years prior to enrollment, and no history of metabolic bone disease or bone metastases. Data collected included sociodemographic characteristics; fracture-related risk factors, screening and preventive measures; breast cancer history; and thoracolumbar x-ray. The matched comparator group was selected from participants enrolled in the Peking Vertebral Fracture Study, an independent cohort of healthy community-dwelling postmenopausal women from Beijing. RESULTS: Two hundred breast cancer survivors were enrolled (mean age 57.5 ± 4.9 years), and compared with 200 matched healthy women. Twenty-two (11%) vertebral fractures were identified among breast cancer survivors compared with 7 (3.5%) vertebral fractures in the comparison group, yielding an adjusted odds ratio for vertebral fracture of 4.16 (95%CI 1.69-10.21, p < 0.01). The majority had early stage (85.3%) and estrogen and/or progesterone receptor positive (84.6%) breast cancer. Approximately half of breast cancer survivors reported taking calcium supplements, 6.1% reported taking vitamin D supplements, and only 27% reported having a bone density scan since being diagnosed with breast cancer. CONCLUSIONS: Despite a four-fold increased odds of prevalent vertebral fracture among Chinese breast cancer survivors in our study, rates of screening for osteoporosis and fracture risk were low reflecting a lack of standardization of care regarding cancer-treatment induced bone loss.

Tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO), also known as oncogenic osteomalacia, is a rare paraneoplastic syndrome characterized by hypophosphatemia resulting from decreased tubular phosphate reabsorption, with a low or inappropriately normal level of active vitamin D. The culprit tumors of TIO could produce fibroblast growth factor 23 which plays a role in regulating renal Pi handling and 25-hydroxyvitamin D 1α-hydroxylase activity. Chronic hypophosphatemia could eventually lead to inadequate bone mineralization, presenting as osteomalacia. The diagnosis should be considered when patients manifest as hypophosphatemia and osteomalacia, or rickets and needs to be differentiated from other disorders of phosphate metabolism, such as the inhereditary diseases like X-linked hypophosphataemic rickets, autosomal dominant hypophosphataemic rickets, autosomal recessive hypophosphataemic rickets and acquired diseases like vitamin D deficiency. Localization of responsible tumors could be rather difficult since the vast majority are very small and could be everywhere in the body. A combination of thorough physical examination, laboratory tests and imaging techniques should be applied and sometimes a venous sampling may come into handy. The technology of somatostatin-receptor functional scintigraphy markedly facilitates the localization of TIO tumor. Patients undergoing complete removal of the causative neoplasm generally have favorable prognoses while a few have been reported to suffer from recurrence and metastasis. For those undetectable or unresectable cases, phosphate supplements and active vitamin D should be administrated and curative intended radiotherapy or ablation is optional.

Effects of Enhanced Exercise and Combined Vitamin D and Calcium Supplementation on Muscle Strength and Fracture Risk in Postmenopausal Chinese Women.

Objective To observe the effects of enhanced exercise and combined vitamin D and calcium supplementation on muscular strength and fracture occurrence in postmenopausal women with a high risk of osteoporosis.Methods Totally 614 postmenopausal women at high risk factors of osteoporosis were enrolled in Dongcheng district of Beijing and randomized into four groups:group A(control group,n=173),group B(regular Tai Chi exercise,n=171),group C(calcium 600 mg/d+VitD3 800 U/d,n=139),and group D[calcium 600 mg/d+25 hydroxyl vitamin D(25OHD) 0.25 µg/d,n=131].Muscular strength was measured at baseline and one and two years after intervention.Bone turnover markers were measured at baseline and during the two-year follow-up.Falls and fractures were recorded.Results The incidence of 25OHD<50 nmol/L was approximately 92.6%.During the follow-up,the left grip strength decreased significantly two years after intervention(t=-3.252,P=0.001)in group A.Right grip strength decreased significantly in group B(t=2.460,P=0.015)while left grip strength improved significantly in group C(t=-2.051,P=0.043)one year after intervention.In group D,muscular strength in both 12-month and 24-month did not change compared with baseline(both P>0.05).Furthermore,serum procollagen type I N-terminal propeptide elevated significantly in group A(t=-2.962,P=0.004),group B(t=-2.888,P=0.005),and group C(t=-2.441,P=0.016),whereas ß-C-terminal telopeptide of type I collagen decreased significantly in group B(t=2.285,P=0.024)and group D(t=2.596,P=0.011)two years after intervention.Conclusion Enhanced exercise and combined calcium vitamin D supplementation may help sustain muscle strength in postmenopausal women,while calcium and vitamin D supplementation may improve muscular strength within a short period of time.

Clinical and genetic findings in a Chinese family with VDR-associated hereditary vitamin D-resistant rickets.

Hereditary vitamin D-resistant rickets (HVDRR) is a rare autosomal recessive disorder characterized by severe rickets, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. This disorder is caused by homogeneous or heterogeneous mutations affecting the function of the vitamin D receptor (VDR), which lead to complete or partial target organ resistance to the action of 1,25-dihydroxy vitamin D. A non-consanguineous family of Chinese Han origin with one affected individual demonstrating HVDRR was recruited, with the proband evaluated clinically, biochemically and radiographically. To identify the presence of mutations in the VDR gene, all the exons and exon-intron junctions of the VDR gene from all family members were amplified using PCR and sequenced. The proband showed rickets, progressive alopecia, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. She also suffered from epilepsy, which is rarely seen in patients with HVDRR. Direct sequencing analysis revealed a homozygous missense mutation c.122G>A (p.C41Y) in the VDR gene of the proband, which is located in the first zinc finger of the DNA-binding domain. Both parents had a normal phenotype and were found to be heterozygous for this mutation. We report a Chinese Han family with one individual affected with HVDRR. A homozygous missense mutation c.122G>A (p.C41Y) in the VDR gene was found to be responsible for the patient's syndrome. In contrast to the results of treatment of HVDRR in other patients, our patient responded well to a supplement of oral calcium and a low dose of calcitriol.

Craniometaphyseal dysplasia with obvious biochemical abnormality and rickets-like features.

BACKGROUND: Craniometaphyseal dysplasia (CMD) is a rare genetic disorder that is characterized by progressive sclerosis of the craniofacial bones and metaphyseal widening of long bones, and biochemical indexes were mostly normal. To further the understanding of the disease from a biochemical perspective, we reported a CMD case with obviously abnormal biochemical indexes. CASE REPORT: A 1-year-old boy was referred to our clinic. Biochemical test showed obviously increased alkaline phosphatase (ALP) and parathyroid hormone (PTH), mild hypocalcemia and hypophosphatemia. Moreover, significant elevated receptor activator of nuclear factor kappa-B ligand (RANKL) level, but normal ß-C-terminal telopeptide of type I collagen (ß-CTX) concentration were revealed. He was initially suspected of rickets, because the radiological examination also showed broadened epiphysis in his long bones. Supplementation with calcium and calcitriol alleviated biochemical abnormality. However, the patient gradually developed osteosclerosis which was inconformity with rickets. Considering that he was also presented with facial paralysis and nasal obstruction symptom, the diagnosis of craniometaphyseal dysplasia was suspected, and then was confirmed by the mutation analysis of ANKH of the proband and his family, which showed a de novo heterozygous mutation (C1124-1126delCCT) on exon 9. CONCLUSIONS: Our study revealed that obvious biochemical abnormality and rickets-like features might present as uncommon characteristics in CMD patients, and the calcium and calcitriol supplementation could alleviate biochemical abnormalities. Furthermore, although early osteoclast differentiation factor was excited in CMD patient, activity of osteoclast was still inert.

Surgical Treatments of Tumor-Induced Osteomalacia Lesions in Long Bones: Seventeen Cases with More Than One Year of Follow-up.

BACKGROUND: Tumor-induced osteomalacia is a rare and fascinating paraneoplastic syndrome usually caused by a small, benign phosphaturic mesenchymal tumor. Most tumors are treated surgically, but we are unaware of any reports that compare the results of curettage and segmental resection for lesions in long bones. METHODS: Seventeen patients (ten male and seven female) with tumor-induced osteomalacia lesions in long bones, who underwent surgical treatment from December 2004 to August 2013 in our hospital, were included in this retrospective study. The mean follow-up (and standard deviation) was 35 ± 27 months (range, twelve to 116 months). The characteristics of the tumor and the effects of different surgical treatments (curettage compared with segmental resection) were evaluated. RESULTS: All patients showed typical clinical characteristics of tumor-induced osteomalacia, including elevated serum fibroblast growth factor-23 (FGF-23); 82% of tumors were in the epiphysis, and 82% grew eccentrically. The mean maximum diameter of the tumors was 2.4 ± 2.0 cm. The complete resection rates were similar for curettage (67%) and segmental resection (80%). However, the recurrence rate after curettage (50%) was higher than that after segmental resection (0%). The complete resection rate for secondary segmental resection (75%) was not different from that for primary segmental resection (83%). All of our cases of tumor-induced osteomalacia were caused by phosphaturic mesenchymal tumors. After successful removal of tumors, serum FGF-23 returned to normal within twenty-four hours and serum phosphorus levels returned to normal at a mean of 6.5 ± 3.5 days. CONCLUSIONS: Most lesions in long bones are located in the epiphysis, so curettage is first suggested to maintain joint function. If curettage is incomplete or there is a recurrence, secondary segmental resection should be considered curative. Changes of serum FGF-23 and phosphorus levels before and after the operation may be of prognostic help.

Effect of low-dose alendronate treatment on bone mineral density and bone turnover markers in Chinese postmenopausal women with osteopenia and osteoporosis.

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: an important cause of adult-onset hypophosphatemic osteomalacia in China: Report of 39 cases and review of the literature.

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.

FGF23 analysis of a Chinese family with autosomal dominant hypophosphatemic rickets.

Autosomal dominant hypophosphatemic rickets (ADHR; MIM 193100) is a hereditary disorder characterized by isolated renal phosphate wasting, hypophosphatemia, and inappropriately normal 1,25-dihydroxyvitamin D(3) levels. Recent studies have shown that the fibroblast growth factor 23 (FGF23) gene is responsible for this disease. FGF23 protein is a phosphaturic factor that is elevated in several diseases associated with hypophosphatemia and rickets but varies with disease status in ADHR. In the present study we observed a Chinese family of Han ethnic origin diagnosed with ADHR. The proband is a 30-year-old woman with no history of rickets but with multiple tooth abscesses as a young adult. She presented with progressive painful swelling of the left ankle after a blunt trauma at 26 years of age. She developed back pain, generalized weakness, and fatigue, and she could barely walk at age 27. She was found to have severe hypophosphatemia, low ratio of phosphorus tubule maximum (TmP) to glomerular filtration rate (GFR) (TmP/GFR), and elevated alkaline phosphatase at age 28. Her brother, 26 years old, presented with fatigue at 24 years of age and is normophosphatemic. The parents of this family had no history of rickets or hypophosphatemia. Direct sequence analysis of genomic DNA demonstrated a single heterozygous c.527G>A (p.R176Q) mutation in the FGF23 gene in three family members, including the proband, her brother, and their mother. Intact FGF23 assay of seven time points during the oral phosphate loading test showed no significant relationship between intact FGF23 and serum phosphorus levels of the subject with ADHR and a control. It is probably the first report of a Chinese family with ADHR.

Infusion of ibandronate once every 3 months effectively decreases bone resorption markers and increases bone mineral density in Chinese postmenopausal osteoporotic women: a 1-year study.

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.

[Clinical features of Gorham-Stout syndrome and literature review].

OBJECTIVE: To describe the clinical presentations, radiographic findings and histological pathology of bones, diagnosis, treatment options and prognosis for patients with Gorham-Stout syndrome (GSS). METHODS: Clinical data of 5 GSS patients seen from January 1980 to January 2008 were reviewed. RESULTS: (1) There were 2 males and 3 females, aged 15 years to 37 years (mean age was 30.2 years). (2) All of them had osteolysis, but the site and extent of involved bones were not the same. Three cases had large amount of bloody pleural effusion and two of them had also chylous effusion. All of the 5 cases had no evidence of malignancies. Four cases accepted bone biopsy. Among them,2 cases having local puncture and open biopsy showed typical bone pathologic manifestations. (3) Various forms of treatment including bisphosphonates, calcium supplementation, active vitD3 treatment, local radiation therapy and surgical ligation of thoracic duct were tried. (4) Follow up and clinical outcomes: the two cases, who had only bone osteolysis remained stable. Of the other three cases who had bone osteolysis associated with pleural effusion, one patient needed interrupted effusion drainage with stable bone impairment and the other two cases were out of contact. CONCLUSIONS: GSS is a rare disorder characterized by progressive osteolysis. The clinical presentations of this disease are variable and depend on the sites of involvement. There were no standard therapy available. Prognosis depends on the site of involvement, extent of the disease and presence of complications. Those who have pleural effusion had poor prognosis.