Sex-differential testosterone response to long-term weight loss.

OBJECTIVES: Obesity-associated gonadal dysfunction is a common comorbidity in patients seeking weight loss interventions. We examined the incremental effect of weight loss on gonadal axes in men and women over 3 years. Changes in sex hormones were compared between dietary intervention (Diet) and bariatric procedures: Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and laparoscopic adjustable gastric banding (LAGB). Additional analysis assessed changes in corticotropic, somatotropic and thyroid axes after weight loss interventions. METHODS: This prospective, observational study included 61 adults with Body Mass Index >30 kg/m2, mean age 51 (SD = 11) years. Endocrine parameters were measured at baseline and at 6 timepoints over 36-months. RESULTS: For each 1 kg of weight lost, between baseline and 36 months, total testosterone increased by 0.6% (95% CI: 0.2%, 1.0%, p = 0.002) in males and decreased by 0.8% (95% CI: -1.4%, -0.3%, p = 0.003) in females. These changes remained statistically significant when controlled for age and for menopausal status in females. At 36 months, in comparison with Diet, RYGB women had lower total testosterone by 54% (95% CI: -90%, -17%, p = 0.004), reduced free androgen index (FAI) by 65% (95% CI; -114%, -17%, p = 0.009) while SG had reduced FAI by 39% (95% CI; -77%, 0%, p = 0.05). No such differences between groups were noted for male subjects. Adrenocorticotropic hormone declined by 0.3% (95% CI: 0.0, -0.5%, p = 0.05), insulin-like growth factor-1 increased by 0.4% (95% CI; 0.2%, 0.7%, p = 0.005), without such thyrotrophin change for each 1 kg of weight loss, for entire cohort, over 36 months. CONCLUSIONS: The testosterone changes observed in this study were proportional to the amount of weight loss. In females, reduction in androgens was independent of age and menopausal status and more pronounced after bariatric procedures. This study finding warrants further clinical research to explore an impact of androgen reduction on functional and cognitive status in postmenopausal women. The observed changes in pituitary hormones may contribute to the metabolic benefits of bariatric surgery.

Multimorbidity clusters potentially superior to individual diseases for stratifying fracture risk in older people: a nationwide cohort study.

RATIONALE: Comorbidities are common in fracture patients, but the interaction between fracture and comorbidities remains unclear. This study aimed to define specific multimorbidity clusters in older adults and quantify the association between the multimorbidity clusters and fracture risk. METHODS: This nationwide cohort study includes 1.7 million adults in Denmark aged ≥50 years who were followed from 2001 through 2014 for an incident low-trauma fracture. Chronic diseases and fractures were identified from the Danish National Hospital Discharge Register. Latent class analysis and Cox's regression were conducted to define the clusters and quantify fracture risk, respectively. RESULTS: The study included 793 815 men (age: 64 ± 10) and 873 524 women (65.5 ± 11), with a third having ≥1 chronic disease. The pre-existent chronic diseases grouped individuals into low-multimorbidity (80.3% in men, 83.6% in women), cardiovascular (12.5%, 10.6%), malignant (4.1%, 3.8%), diabetic (2.4%, 2.0%) and hepatic clusters (0.7%, men only). These clusters distinguished individuals with advanced, complex, or late-stage disease from those having earlier-stage disease. During a median follow-up of 14 years (IQR: 6.5, 14), 95 372 men and 212 498 women sustained an incident fracture. The presence of multimorbidity was associated with a significantly greater risk of fracture, independent of age and sex. Importantly, the multimorbidity clusters had the highest discriminative performance in assessing fracture risk, whereas the strength of their association with fracture risk equalled or exceeded that of both the individual chronic diseases most prevalent in each cluster and of counts-based comorbidity indices. CONCLUSIONS: Future fracture prevention strategies should take comorbidities into account. Multimorbidity clusters may provide greater insight into fracture risk than individual diseases or counts-based comorbidity indices.

Effects of bariatric surgery and dietary intervention on insulin resistance and appetite hormones over a 3 year period.

To examine an impact of three types of bariatric surgery compared with dietary intervention (DIET), on concurrent changes in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and appetite hormones over 3 years. Fifty-five adults were studied during phase of weight loss (0-12 months) and during weight stability (12-36 months) post intervention. Measurements of HOMA-IR, fasting and postprandial PYY and GLP1, adiponectin, CRP, RBP4, FGF21 hormones and dual-Xray absorptiometry were performed throughout the study. All surgical groups achieved significant reductions in HOMA-IR with greatest difference between Roux-en-Y gastric bypass and DIET (- 3.7; 95% CI - 5.4, - 2.1; p = 0.001) at 12-36 months. Initial (0-12 months) HOMA-IR values were no different to DIET after adjustment for the lost weight. During 12-36 months, after controlling for treatment procedure and weight, for every twofold increase in postprandial PYY and adiponectin, HOMA-IR decreased by 0.91 (95% CI - 1.71, - 0.11; p = 0.030) and by 0.59 (95% CI - 1.10, - 0.10; p = 0.023) respectively. Initial, non-sustained changes in RBP4 and FGF21 were not associated with HOMA-IR values. While initial rapid weight loss reduces insulin resistance, the enhanced secretions of PYY and adiponectin may contribute to weight-independent improvements in HOMA-IR during weight stability.Clinical trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12613000188730.

Association of Multimorbidity and Excess Mortality After Fractures Among Danish Adults.

Importance: Limited knowledge about interactions among health disorders impedes optimal patient care. Because comorbidities are common among patients 50 years and older with fractures, these fractures provide a useful setting for studying interactions among disorders. Objective: To define multimorbidity clusters at the time of fracture and quantify the interaction between multimorbidity and fracture in association with postfracture excess mortality. Design, Setting, and Participants: This nationwide cohort study included 307 870 adults in Denmark born on or before January 1, 1951, who had an incident low-trauma fracture between January 1, 2001, and December 31, 2014, and were followed up through December 31, 2016. Data were analyzed from February 1 to March 31, 2022. Main Outcomes and Measures: Fracture and 32 predefined chronic diseases recorded within 5 years before the index fracture were identified from the Danish National Hospital Discharge Register. Death was ascertained from the Danish Register on Causes of Death. Latent class analysis was conducted to identify multimorbidity clusters. Relative survival analysis was used to quantify excess mortality associated with the combination of multimorbidity and fractures at specific sites. Results: Among the 307 870 participants identified with incident fractures, 95 372 were men (31.0%; mean [SD] age at fracture, 72.3 [11.2] years) and 212 498 were women (69.0%; mean [SD] age at fracture, 74.9 [11.2] years). During a median of 6.5 (IQR, 3.0-11.0) years of follow-up, 41 017 men (43.0%) and 81 727 women (38.5%) died. Almost half of patients with fractures (42.9%) had at least 2 comorbidities. Comorbidities at fracture were categorized as low-multimorbidity (60.5% in men and 66.5% in women), cardiovascular (23.7% in men and 23.5% in women), diabetic (5.6% in men and 5.0% in women), malignant (5.1% in men and 5.0% in women), and mixed hepatic and/or inflammatory (5.1% in men only) clusters. These clusters distinguished individuals with advanced, complex, or late-stage disease from those with earlier-stage disease. Multimorbidity and proximal or lower leg fractures were associated with increased mortality risk, with the highest excess mortality found in patients with hip fracture in the malignant cluster (1-year excess mortality: 40.8% [95% CI: 38.1%-43.6%]). The combination of multimorbidity and fracture compounded the association with mortality, conferring much greater risk than either alone. Conclusions and Relevance: Concomitant illnesses were common and clustered into distinct multimorbidity clusters that were associated with excess postfracture mortality. The compound contribution of multimorbidity to postfracture excess mortality highlights the need for more comprehensive approaches in these high-risk patients. The analytical approach applied to fracture could also be used to examine other sentinel health events.

Roux-en-Y gastric bypass and gastric sleeve surgery result in long term bone loss.

OBJECTIVES: Little is known about the long-term skeletal impact of bariatric procedures, particularly the increasingly commonly performed gastric sleeve surgery (GS). We examined bone density (BMD) change following three types of bariatric surgery Roux-en-Y gastric bypass (RYGB), GS and laparoscopic adjustable gastric banding (LAGB), compared with diet, over 36 months. METHODS: Non-randomized, prospective study of participants with severe obesity (n = 52), undergoing weight-loss interventions: RYGB (n = 7), GS (n = 21), LAGB (n = 11) and diet (n = 13). Measurements of calciotropic indices, gut hormones (fasting and post prandial) peptide YY (PYY), glucagon-like peptide 1 (GLP1) and adiponectin together with dual-X-ray absorptiometry and quantitative computed tomography scans were performed thorough the study. RESULTS: All groups lost weight during the first 12 months. Despite weight stability from 12 to 36 months and supplementation of calcium and vitamin D, there was progressive bone loss at the total hip (TH) over 36 months in RYGB -14% (95% CI: -12, -17) and GS -9% (95% CI: -7, -10). In RYGB forearm BMD also declined over 36 months -9% (95% CI: -6, -12) and LS BMD declined over the first 12 months -7% (95% CI: -3, -12). RYGB and GS groups experienced significantly greater bone loss until 36 months than LAGB and diet groups, which experienced no significant BMD loss. These bone losses remained significant after adjustment for weight loss and age. RYGB and GS procedures resulted in elevated postprandial PYY, adiponectin and bone turnover markers up to 36 months without such changes among LAGB and diet participants. CONCLUSIONS: RYGB and GS but not LAGB resulted in ongoing TH bone loss for three postoperative years. For RYGB, bone loss was also observed at LS and non-weight-bearing forearms. These BMD changes were independent of weight and age differences. We, therefore, recommend close monitoring of bone health following RYGB and GS surgeries.

SEVERE HYPERTRIGLYCERIDEMIA ASSOCIATED WITH EVEROLIMUS TREATMENT AFTER HEART TRANSPLANTATION.

OBJECTIVE: Everolimus, a mammalian target-ofrapamycin (mTOR) inhibitor, is increasingly used post-transplantation due to favorable effects on renal function and malignancy risk when compared to other immunosuppressive treatments such as calcineurin inhibitors. However, it can confer adverse effects such as dyslipidemia, which is not underpinned by any long-term screening and management of dyslipidemia in heart transplant recipients treated with everolimus. METHODS: We report a case of severe hypertriglyceridemia which developed after commencement of everolimus in a heart transplant recipient with a background of Dunnigan-type familial partial lipodystrophy. RESULTS: The patient is a 36-year-old woman who underwent heart transplantation for dilated cardiomyopathy. About 11 weeks following commencement of everolimus as part of her antirejection medication regime, serum triglyceride level concentration peaked at 5,093 mg/dL (normal, 0.0 to 177.2 mg/dL). There were no clinical complications with triglycerides at this elevated level and it improved substantially following cessation of everolimus and initiation of a high dose intravenous insulin-dextrose infusion. CONCLUSION: This case highlights dyslipidemia as a potential complication of everolimus treatment and that appropriate screening is important as lipid lowering medication can effectively control levels and minimize adverse outcomes.

A Risk Assessment Tool for Predicting Fragility Fractures and Mortality in the Elderly.

Existing fracture risk assessment tools are not designed to predict fracture-associated consequences, possibly contributing to the current undermanagement of fragility fractures worldwide. We aimed to develop a risk assessment tool for predicting the conceptual risk of fragility fractures and its consequences. The study involved 8965 people aged ≥60 years from the Dubbo Osteoporosis Epidemiology Study and the Canadian Multicentre Osteoporosis Study. Incident fracture was identified from X-ray reports and questionnaires, and death was ascertained though contact with a family member or obituary review. We used a multistate model to quantify the effects of the predictors on the transition risks to an initial and subsequent incident fracture and mortality, accounting for their complex interrelationships, confounding effects, and death as a competing risk. There were 2364 initial fractures, 755 subsequent fractures, and 3300 deaths during a median follow-up of 13 years (interquartile range [IQR] 7-15). The prediction model included sex, age, bone mineral density, history of falls within 12 previous months, prior fracture after the age of 50 years, cardiovascular diseases, diabetes mellitus, chronic pulmonary diseases, hypertension, and cancer. The model accurately predicted fragility fractures up to 11 years of follow-up and post-fracture mortality up to 9 years, ranging from 7 years after hip fractures to 15 years after non-hip fractures. For example, a 70-year-old woman with a T-score of -1.5 and without other risk factors would have 10% chance of sustaining a fracture and an 8% risk of dying in 5 years. However, after an initial fracture, her risk of sustaining another fracture or dying doubles to 33%, ranging from 26% after a distal to 42% post hip fracture. A robust statistical technique was used to develop a prediction model for individualization of progression to fracture and its consequences, facilitating informed decision making about risk and thus treatment for individuals with different risk profiles. © 2020 American Society for Bone and Mineral Research.

KBG syndrome presenting with brachydactyly type E.

We report the case of a young woman who presented at age 10 years with height on the tenth centile, brachydactyly type E and mild developmental delay. Biochemistry and hormonal profiles were normal. Differential diagnoses considered included Albright hereditary osteodystrophy without hormone resistance (a.k.a pseudopseudohypoparathyroidism), 2q37 microdeletion syndrome and acrodysostosis. She had a normal karyotype and normal FISH of 2q37. Whole genome sequencing (WGS) identified a mutation in the ANKRD11 gene associated with KBG syndrome. We review the clinical features of the genetic syndromes considered, and suggest KBG syndrome be considered in patients presenting with syndromic brachydactyly type E, especially if short stature and developmental delay are also present.

A profiling analysis of contributions of cigarette smoking, dietary calcium intakes, and physical activity to fragility fracture in the elderly.

Fragility fracture and bone mineral density (BMD) are influenced by common and modifiable lifestyle factors. In this study, we sought to define the contribution of lifestyle factors to fracture risk by using a profiling approach. The study involved 1683 women and 1010 men (50+ years old, followed up for up to 20 years). The incidence of new fractures was ascertained by X-ray reports. A "lifestyle risk score" (LRS) was derived as the weighted sum of effects of dietary calcium intake, physical activity index, and cigarette smoking. Each individual had a unique LRS, with higher scores being associated with a healthier lifestyle. Baseline values of lifestyle factors were assessed. In either men or women, individuals with a fracture had a significantly lower age-adjusted LRS than those without a fracture. In men, each unit lower in LRS was associated with a 66% increase in the risk of total fracture (non-adjusted hazard ratio [HR] 1.66; 95% CI, 1.26 to 2.20) and still significant after adjusting for age, weight or BMD. However, in women, the association was uncertain (HR 1.30; 95% CI, 1.11 to 1.53). These data suggest that unhealthy lifestyle habits are associated with an increased risk of fracture in men, but not in women, and that the association is mediated by BMD.

Comorbidities Only Account for a Small Proportion of Excess Mortality After Fracture: A Record Linkage Study of Individual Fracture Types.

Nonhip, nonvertebral (NHNV) fractures constitute the majority of osteoporotic fractures, but few studies have examined the association between these fractures, comorbidity, and mortality. Our objective was to examine the relationship between individual nonhip, nonvertebral fractures, comorbidities, and mortality. The prospective population-based cohort of 267,043 subjects (45 and Up Study, Australia) had baseline questionnaires linked to hospital administrative and all-cause mortality data from 2006 to 2013. Associations between fracture and mortality were examined using multivariate, time-dependent Cox models, adjusted for age, prior fracture, body mass index, smoking, and comorbidities (cardiovascular disease, diabetes, stroke, thrombosis, and cancer), and survival function curves. Population attributable fraction was calculated for each level of risk exposure. During 1,490,651 person-years, women and men experienced 7571 and 4571 fractures and 7064 deaths and 11,078 deaths, respectively. In addition to hip and vertebral fractures, pelvis, humerus, clavicle, rib, proximal tibia/fibula, elbow and distal forearm fractures in both sexes, and ankle fractures in men were associated with increased multivariable-adjusted mortality hazard ratios ranging from 1.3 to 3.4. Comorbidity independently added to mortality such that a woman with a humeral fracture and 1 comorbidity had a similarly reduced 5-year survival as that of a woman with a hip fracture and no comorbidities. Population mortality attributable to any fracture without comorbidity was 9.2% in women and 5.3% in men. All proximal nonhip, nonvertebral fractures in women and men were associated with increased mortality risk. Coexistent comorbidities independently further increased mortality. Population attributable risk for mortality for fractures was similar to cardiovascular disease and diabetes, highlighting their importance and potential benefit for early intervention and treatment. © 2018 American Society for Bone and Mineral Research.

A Retrospective Review of Imaging and Operative Modalities Performed in Patients with Primary Hyperparathyroidism at a Mid-Volume Surgical Centre in Southeast Asia.

INTRODUCTION: A paradigm shift appears to have occurred worldwide in surgery for primary hyperparathyroidism with the advent of sensitive preoperative imaging techniques. Preoperative imaging for parathyroid adenoma localisation was not found to be useful in a study conducted in Singapore in the 1990s. This study aimed to explore what the change has been in preoperative localisation tools compared to the previous study and if the ability of these tools to correctly localise pathologic parathyroid glands has improved. MATERIALS AND METHODS: A retrospective review of patients who had surgery for primary hyperparathyroidism at our institution during the period 2005 to 2014 was carried out. Individuals with positive, as opposed to those with negative preoperative imaging, were compared with regard to whether they underwent limited focal or bilateral neck exploration. Length of hospital stay (LOHS) was also compared between patients who underwent limited versus bilateral exploration. RESULTS: Fifty-eight patients who had preoperative imaging and surgery were evaluated. True positive rates of sestamibi, ultrasound and 4-dimensional (4D) computed tomography (CT) scans were 63.8%, 72.4% and 90%, respectively. Eighty percent of patients who had positive localisation had limited exploration. LOHS was 2.8 days (1.6, 4.8) and 4.3 days (2.1, 9.0) for limited and bilateral exploration respectively, P = 0.011. CONCLUSION: Our study highlights the marked change in the surgical landscape for primary hyperparathyroidism in the last 2 decades in Singapore. Improved preoperative localisation has resulted in a swing from predominantly bilateral, to limited exploration in almost all cases of primary hyperparathyroidism due to solitary adenoma. LOHS was significantly shorter in patients who had limited as compared to those who had bilateral exploration.

Contribution of Quadriceps Weakness to Fragility Fracture: A Prospective Study.

The association between muscle weakness and fracture is not well understood. This study sought to examine the contribution of muscle strength at baseline and change in muscle strength to the observed risk of fragility fracture in older people. The study involved 595 men and 1066 women aged 60+ years (median 69 years) who had been followed for a median of 11 years (range, 4 to 22 years). Quadriceps isometric muscle strength (MS) measured at baseline and biennially was adjusted for height. Femoral neck bone mineral density (FNBMD) was measured by DXA. Low-trauma fracture was ascertained from X-ray reports and interview. The relationship between baseline MS and serial MS and fracture assessed by time-invariant and time-variant Cox's regression models was expressed as hazard ratio (HR) and 95% confidence interval (CI). During the follow-up period, 282 (26%) women and 89 (15%) men sustained a fragility fracture. From age 60 years, women lost 0.28 kg/m (1.6%) of MS per year, whereas men lost 0.39 kg/m (1.5%) of MS per year. In the time-variant model, using serial MS, each 1 SD (4.7 kg/m) lower MS was associated with a 27% increase in the risk of fracture in women (HR 1.27; 95% CI, 1.11 to 1.43); and 46% increase in men (HR 1.46; 95% CI, 1.22 to 1.75). After adjusting for FNBMD, age and prior fracture, history of fall and smoking, HR per SD of lower MS was 1.13 (95% CI, 0.99 to 1.28) for women and 1.35 (95% CI, 1.18 to 1.64) for men. These data indicate that muscle weakness is an independent determinant of fracture risk in men, but not in women. This sex difference suggests that apart from mechanical load effect of muscle on bone, there are other muscle-bone interactions that need to be investigated in future studies. The accuracy of fracture risk prediction for men may be improved by incorporating muscle strength.

Nutritional risk profile in a university hospital population.

BACKGROUND & AIMS: The prevalence of nutritional risk varies according to several factors. We aimed to determine the nutritional risk profile in a large Norwegian hospital population, specifically by age, disease category and hospital department. METHODS: Nutritional surveys are performed routinely at Haukeland University Hospital, Norway. During eight surveys in 2008-2009, 3279 patients were categorized according to the Nutritional Risk Screening tool (NRS 2002). RESULTS: The overall prevalence of nutritional risk was 29%, highest in patients with infections (51%), cancer (44%) and pulmonary diseases (42%), and in the departments of intensive care (74%), oncology (49%) and pulmonology (43%). Further, nutritional risk was identified in 40% of patients aged ≥80 years compared to 21% of age <40 years and 35% of patients with emergency admissions compared to 19% with elective admissions. Related to the tool components, nutritional risk was most common in patients with low BMI (<20.5 kg/m(2)) (95%) and/or high comorbidity (>7 diagnoses) (45%). However it was also high in patients with BMI ≥25 kg/m(2) (12%) and in those with fewer than 7 diagnoses (26%). CONCLUSIONS: Nutritional risk was most common among patients with high age, low BMI, more comorbidity, and with infections, cancer or pulmonary diseases, and patients who were discharged to nursing homes. However, the highest number of patients at nutritional risk had BMI in the normal or overweight range, were 60-80 years old, and were found in departments of general medicine or surgery. Importantly, younger patients and overweight patients were also affected. Thus, nutritional risk screening should be performed in the total patient population in order to identify, within this heterogeneous group of patients, those at nutritional risk.

Vitamin D: direct effects of vitamin D metabolites on bone: lessons from genetically modified mice.

The vitamin D endocrine system has clear beneficial effects on bone as demonstrated by prevention of rickets in children and by reducing the risk of osteomalacia or osteoporosis in adults or elderly subjects. Depending on the design of the study of genetically modified animals, however, 1,25(OH)2D and the vitamin D receptor (VDR) may have no effect, beneficial or even deleterious direct effects on bone. We present here a comprehensive model of the direct effects of vitamin D on bone. In case of sufficient calcium supply, vitamin D and its metabolites can improve the calcium balance and facilitate mineral deposition in bone matrix largely without direct effects on bone cells, although some beneficial effects may occur via mature osteoblasts, as demonstrated in mice with osteoblast-specific overexpression of VDR or 1α-hydroxylase. In case of calcium deficiency, however, 1,25(OH)2D enhances bone resorption, whereas simultaneously inhibiting bone mineralization, so as to defend serum calcium homeostasis at the expense of bone mass. This dual role probably provides a survival benefit for land vertebrates living in a calcium-poor environment.

Fracture liaison service: impact on subsequent nonvertebral fracture incidence and mortality.

BACKGROUND: A fracture liaison service model of care is widely recommended and applied, but data on its effectiveness are scarce. Therefore, the risk of subsequent nonvertebral fractures and mortality within two years after a nonvertebral fracture was analyzed in patients who presented to a hospital with a fracture liaison service and a hospital without a fracture liaison service. METHODS: In 2005 to 2006, all consecutive patients with an age of fifty years or older presenting with a nonvertebral fracture were included. In the group that presented to a hospital without a fracture liaison service (the no-FLS group), only standard fracture care procedures were followed to address proper fracture-healing. In the group that presented to a hospital with a fracture liaison service (the FLS group), dual x-ray absorptiometry scans and laboratory testing were performed, and if applicable, patients were treated according to the Dutch guideline for osteoporosis. The risk for subsequent nonvertebral fracture and mortality were analyzed using multivariable Cox regression models with adjustments for age, sex, and baseline fracture location. RESULTS: In total, 1412 patients presented to the fracture liaison service (73.2% were women, and the mean age was 71.1 years), and 1910 underwent standard fracture care (69.8% were women, and the mean age was 69.5 years). After adjustment for age, sex, and baseline fracture location, patients who attended the fracture liaison service had a significantly lower mortality risk (hazard ratio: 0.65; 95% confidence interval [CI]: 0.53 to 0.79) over two years of follow-up. The subsequent nonvertebral fracture risk was also significantly lower in the patients in the FLS group, but this effect was time-dependent, with a hazard ratio of 0.84 (95% CI: 0.64 to 1.10) at twelve months and 0.44 (95% CI: 0.25 to 0.79) at twenty-four months. CONCLUSIONS: Patients seen at the fracture liaison service had a significantly lower mortality and subsequently a lower risk of nonvertebral fracture than those not seen at the fracture liaison service, with a reduction of 35% and 56%, respectively, over two years of follow-up. A fracture liaison service appears to be a successful approach to reduce the number of subsequent fractures and premature mortality in this cohort of patients.

Multistage genome-wide association meta-analyses identified two new loci for bone mineral density.

Aiming to identify novel genetic variants and to confirm previously identified genetic variants associated with bone mineral density (BMD), we conducted a three-stage genome-wide association (GWA) meta-analysis in 27 061 study subjects. Stage 1 meta-analyzed seven GWA samples and 11 140 subjects for BMDs at the lumbar spine, hip and femoral neck, followed by a Stage 2 in silico replication of 33 SNPs in 9258 subjects, and by a Stage 3 de novo validation of three SNPs in 6663 subjects. Combining evidence from all the stages, we have identified two novel loci that have not been reported previously at the genome-wide significance (GWS; 5.0 × 10(-8)) level: 14q24.2 (rs227425, P-value 3.98 × 10(-13), SMOC1) in the combined sample of males and females and 21q22.13 (rs170183, P-value 4.15 × 10(-9), CLDN14) in the female-specific sample. The two newly identified SNPs were also significant in the GEnetic Factors for OSteoporosis consortium (GEFOS, n = 32 960) summary results. We have also independently confirmed 13 previously reported loci at the GWS level: 1p36.12 (ZBTB40), 1p31.3 (GPR177), 4p16.3 (FGFRL1), 4q22.1 (MEPE), 5q14.3 (MEF2C), 6q25.1 (C6orf97, ESR1), 7q21.3 (FLJ42280, SHFM1), 7q31.31 (FAM3C, WNT16), 8q24.12 (TNFRSF11B), 11p15.3 (SOX6), 11q13.4 (LRP5), 13q14.11 (AKAP11) and 16q24 (FOXL1). Gene expression analysis in osteogenic cells implied potential functional association of the two candidate genes (SMOC1 and CLDN14) in bone metabolism. Our findings independently confirm previously identified biological pathways underlying bone metabolism and contribute to the discovery of novel pathways, thus providing valuable insights into the intervention and treatment of osteoporosis.

Excess mortality attributable to hip-fracture: a relative survival analysis.

INTRODUCTION: Individuals with hip fracture are at substantially increased risk of mortality. The aim of this study was to estimate the excess mortality attributable to hip fracture in elderly men and women. METHODS: The Dubbo Osteoporosis Epidemiology Study was designed as a prospective epidemiologic investigation, in which more than 2000 men and women aged 60+ as of 1989 had been followed for 21 years. During the follow-up period, the incidence of atraumatic hip fractures was ascertained by X-ray reports, and mortality was ascertained by the New South Wales Birth, Death and Marriage Registry. Relative survival ratios were estimated by taking into account the age-and-sex specific expected survival in the general Australian population from 1989 to 2010. RESULTS: During the follow-up period 151 women and 55 men sustained a hip fracture. Death occurred in 86 (57%) women and 36 (66%) men. In women, the cumulative relative survival post hip-fracture at 1, 5 and 10 years was 0.83 (95% confidence interval (CI) 0.76-0.89), 0.59 (95% CI 0.48-0.68), and 0.31 (95% CI 0.20-0.43), respectively; in men, the corresponding estimates of relative survival were: 0.63 (95% CI 0.48-0.75), 0.48 (95% CI 0.32-0.63), and 0.36 (95% CI 0.18-0.56). On average post hip-fracture women died 4 years earlier (median: 4.1, inter-quartile range (IQR) 1.7-7.8) and men died 5 years earlier (median = 4.8, IQR 2.4-7.0) than expected. For every six women and for every three men with hip fracture one extra death occurred above that expected in the background population. CONCLUSION: Hip fracture is associated with reduced life expectancy, with men having a greater reduction than women, even after accounting for time-related changes in background mortality in the population. These data underscore that hip fracture is an independent clinical risk factor for mortality.

Nonsense mutation in the LGR4 gene is associated with several human diseases and other traits.

Low bone mineral density (BMD) is used as a parameter of osteoporosis. Genome-wide association studies of BMD have hitherto focused on BMD as a quantitative trait, yielding common variants of small effects that contribute to the population diversity in BMD. Here we use BMD as a dichotomous trait, searching for variants that may have a direct effect on the risk of pathologically low BMD rather than on the regulation of BMD in the healthy population. Through whole-genome sequencing of Icelandic individuals, we found a rare nonsense mutation within the leucine-rich-repeat-containing G-protein-coupled receptor 4 (LGR4) gene (c.376C>T) that is strongly associated with low BMD, and with osteoporotic fractures. This mutation leads to termination of LGR4 at position 126 and fully disrupts its function. The c.376C>T mutation is also associated with electrolyte imbalance, late onset of menarche and reduced testosterone levels, as well as an increased risk of squamous cell carcinoma of the skin and biliary tract cancer. Interestingly, the phenotype of carriers of the c.376C>T mutation overlaps that of Lgr4 mutant mice.

Serum level of under-carboxylated osteocalcin and bone mineral density in early menopausal Norwegian women.

PURPOSE: Serum level of under-carboxylated osteocalcin (ucOC) is considered a sensitive measure of vitamin K status, and ucOC levels are associated with bone mineral density (BMD) and fracture risk in elderly persons. The aim of this study was to assess the relationship between ucOC and BMD in early menopausal women. METHODS: The data reported here come from the enrollment in a double-blinded placebo-controlled randomized trial comprising 334 healthy Norwegian women between 50 and 60 years, 1-5 years after menopause, not using warfarin or medication known to affect bone metabolism. Total hip, femoral neck, lumbar spine, and total body BMD and serum level of ucOC and total osteocalcin were measured, and information of lifestyle was collected through questionnaires. The association between ucOC and BMD at all measurement sites was assessed by multiple regression analyses adjusting for possible confounding variables. RESULTS: The absolute serum level of ucOC was significantly and negatively associated with BMD at all measurements sites, both in univariate analyses (p < 0.01) and in multivariate analyses adjusting for years since menopause, smoking status and weight (p < 0.01). However, serum ucOC, expressed as percentage of the total osteocalcin level, was not associated with BMD at any site. CONCLUSIONS: Achievement of adequate vitamin K nutritional intake is important, but ucOC expressed as percentage of total osteocalcin levels as reflection of vitamin K status does not seem to play a central role in determining BMD levels in early menopausal women.

The endogenous opioid dynorphin is required for normal bone homeostasis in mice.

Chronic opiate usage, whether prescribed or illicit, has been associated with changes in bone mass and is a recognized risk factor for the development of osteoporosis; however, the mechanism behind this effect is unknown. Here we show that lack of dynorphin, an endogenous opioid, in mice (Dyn-/-), resulted in a significantly elevated cancellous bone volume associated with greater mineral apposition rate and increased resorption indices. A similar anabolic phenotype was evident in bone of mice lacking dynorphin's cognate receptor, the kappa opioid receptor. Lack of opioid receptor expression in primary osteoblastic cultures and no change in bone cell function after dynorphin agonist treatment in vitro indicates an indirect mode of action. Consistent with a hypothalamic action, central dynorphin signaling induces extracellular signal-regulated kinase (ERK) phosphorylation and c-fos activation of neurons in the arcuate nucleus of the hypothalamus (Arc). Importantly, this signaling also leads to an increase in Arc NPY mRNA expression, a change known to decrease bone formation. Further implicating NPY in the skeletal effects of dynorphin, Dyn-/-/NPY-/- double mutant mice showed comparable increases in bone formation to single mutant mice, suggesting that dynorphin acts upstream of NPY signaling to control bone formation. Thus the dynorphin system, acting via NPY, may represent a pathway by which higher processes including stress, reward/addiction and depression influence skeletal metabolism. Moreover, understanding of these unique interactions may enable modulation of the adverse effects of exogenous opioid treatment without directly affecting analgesic responses.