Use of proton pump inhibitors and mortality after hip fracture in a nationwide study.

We analyzed the association of proton pump inhibitors (PPIs) with mortality after osteoporosis-related hip fracture in Austria. PPIs were associated with reduced 90-day mortality but elevated mortality after half a year when initiated pre-fracture. Inpatients and discharged patients on PPIs showed lowered in-hospital and 90-day mortality, respectively. INTRODUCTION: We herein investigated use of proton pump inhibitors (PPIs) and mortality among hip fracture patients in a nationwide study in Austria. METHODS: In this retrospective cohort study, data on use of PPIs were obtained from 31,668 Austrian patients ≥50 years with a hip fracture between July 2008 and December 2010. All-cause mortality in patients without anti-osteoporotic drug treatment who had received their first recorded PPI prescription in the study period either before or after fracture was compared with hip fracture patients on neither PPIs nor anti-osteoporotic medication using logistic and Cox regression analysis. RESULTS: With PPI use, 90-day mortality was significantly reduced, both at initiation before (OR 0.66; p < 0.0001) and after hip fracture (OR 0.23; p < 0.0001). 90-day mortality was also reduced when PPIs were prescribed not until after discharge from the last recorded hip fracture-related hospital stay (OR 0.49; p < 0.0001) except for patients aged <70 years. In a sub-cohort of patients beginning PPIs during hospital stay, in-hospital mortality (0.2%) was substantially reduced relative to matched control patients (3.5%) (p < 0.0001). Longer-term mortality significantly increased after half a year post-fracture only among those who started PPI prescription before fracture. CONCLUSIONS: PPI use during and after hospital stay due to hip fracture is associated with a considerable decrease in mortality. These findings could have implications for hip fracture treatment.

Antiresorptive therapy and risk of mortality and refracture in osteoporosis-related hip fracture: a nationwide study.

UNLABELLED: We analyzed the association of bisphosphonate therapy with mortality and hip refracture incidence among osteoporosis-related hip fracture patients in Austria. Mortality was lower in primarily female bisphosphonate users, while hip refracture incidence was generally elevated relative to controls, indicating beneficial effects of bisphosphonates other than on bone. INTRODUCTION: The purpose of this study was to analyze mortality and hip refracture risk in osteoporotic hip fracture patients with and without antiosteoporotic medication. METHODS: We retrospectively analyzed data on 31,668 Austrian patients ≥50 years with a hip fracture between July 2008 and December 2010 for antiosteoporotic drug treatment with respect to outcome parameters all-cause mortality, hip refracture incidence, and hip refracture-free days. Outcomes when bisphosphonate (BP) treatment was begun before or after fracture were compared with an age- and sex-matched hip fracture control without antiosteoporotic medication. RESULTS: 27.69 % of patients (33.01 % of women, 13.13 % of men) were prescribed antiosteoporotic medication, primarily BPs. Females having initiated BP treatment before first fracture had lower odds for mortality 1 and 3 year(s) post-fracture, whereas hip refracture incidence under pre-fracture BP initiation was generally higher. Treatment that was started after fracture, however, entailed significantly lower mortality hazards for both genders (HR 0.43, 95 %CI 0.36-0.52, p < 0.0001 after 1 year) but significantly higher hip refracture incidence except for patients aged 50-69 years and more hip refracture free days for females. Hip refractures overall amounted to 29.22/1000 patient years differing significantly between women and men (31.03 vs. 23.89, respectively, p < 0.0001), and longer hip refracture free survival was observed for women than for men (499 vs. 466 median days, respectively, p < 0.0001). CONCLUSIONS: Although BP use is associated with reduced mortality after hip fracture, notably among women, hip refracture incidences are likewise elevated, which is most likely accounted for by a high probability of BP prescription to more comorbid patients suffering from more severe osteoporosis. Concomitantly, through possible effects other than on bone, BPs might be able to curtail mortality. Male hip fracture patients' low treatment frequency in particular reflects underdiagnosis and undertreatment of osteoporosis in Austria.

Osteoclasts on bone and dentin in vitro: mechanism of trail formation and comparison of resorption behavior.

The main function of osteoclasts in vivo is the resorption of bone matrix, leaving behind typical resorption traces consisting of pits and trails. The mechanism of pit formation is well described, but less is known about trail formation. Pit-forming osteoclasts possess round actin rings. In this study we show that trail-forming osteoclasts have crescent-shaped actin rings and provide a model that describes the detailed mechanism. To generate a trail, the actin ring of the resorption organelle attaches with one side outside the existing trail margin. The other side of the ring attaches to the wall inside the trail, thus sealing that narrow part to be resorbed next (3­21 lm). This 3D configuration allows vertical resorption layer-by-layer from the surface to a depth in combination with horizontal cell movement. Thus, trails are not just traces of a horizontal translation of osteoclasts during resorption. Additionally, we compared osteoclastic resorption on bone and dentin since the latter is the most frequently used in vitro model and data are extrapolated to bone. Histomorphometric analyses revealed a material-dependent effect reflected by an 11-fold higher resorption area and a sevenfold higher number of pits per square centimeter on dentin compared to bone. An important material-independent aspect was reflected by comparable mean pit area (µm²) and podosome patterns. Hence, dentin promotes the generation of resorbing osteoclasts, but once resorption has started, it proceeds independently of material properties. Thus, dentin is a suitable model substrate for data acquisition as long as osteoclast generation is not part of the analyses.

Epidemiology of proximal humeral fractures in Austria between 1989 and 2008.

UNLABELLED: Incidence rates of proximal humeral fractures in Austria over a period of twenty years (1989-2008) were estimated. Age standardized incidence rates increased until 2008, primarily driven by an increase in incidence rates in women. INTRODUCTION: The aim of the prevailing study was to estimate incidence rates of proximal humeral fractures and to assess changes in trend in the Austrian population aged 50 years and above, over a period of 20 years (1989-2008). METHODS: Number of proximal humeral fractures were obtained from the Austrian Hospital Discharge Register for the entire population >50 years of age. Adjustment factors were determined for multiple registrations of the same diagnosis, and for the fact that not all patients with proximal humeral fractures are treated in an inpatient setting. To analyze the overall change in this type of fracture for the period, average annual changes expressed as incidence rate ratios were calculated. RESULTS: The estimated age-standardized incidence (fractures per 100,000 individuals) of proximal humeral fractures among Austrians >50 years of age increased in men from 112 (95% CI, 99-124) to 141 (129-153) and in women from 222 (202-241) to 383 (360-406). The increase appeared to be linear with no leveling off towards the end of the study period. CONCLUSION: While some caution is necessary when interpreting the results given the use of adjustment factors, there appears to have been a rise in the incidence of proximal humeral fractures in Austria in both men and women, with no leveling off in recent years. The reasons for this are not clear, but in the light of previously reported leveling off in the increase in the incidence of hip fractures, a change in the patterns of falls cannot be ruled out.

Effects of 3 years treatment with once-yearly zoledronic acid on the kinetics of bone matrix maturation in osteoporotic patients.

UNLABELLED: Once-yearly administration of intravenous zoledronic acid for 3 years in humans affects the kinetics of matrix filling in by mineral, independent of bone turnover. INTRODUCTION: Yearly 5-mg infusions of zoledronic acid (ZOL) for 3 years have shown pronounced antifracture efficacy. The purpose of the present study was to test whether ZOL affects the kinetics of forming bone material properties maturation. METHODS: Iliac crest biopsies from the HORIZON-PFT clinical trial were analyzed by Raman microspectroscopy in actively bone-forming surfaces as a function of tissue age in trabecular and osteonal bone, to determine ZOL's effect on bone material quality indices maturation kinetics. RESULTS: Mineral/matrix ratio increased in both groups as a function of tissue age, at both osteonal- and trabecular-forming surfaces; ZOL exhibiting the greatest increase in the trabecular surfaces only. The proteoglycan content showed a dependency on tissue age in both trabecular and osteonal surfaces, with ZOL exhibiting lower values in the tissue age 8-22 days in the trabecular surfaces. Mineral crystallinity (crystallite length and thickness) showed a dependence on tissue age, with ZOL exhibiting lower crystallite length compared with placebo only in the 8- to 22-day-old tissue at trabecular surfaces, while crystal thickness was lower in the 1- to 5-day-old tissue at both osteonal and trabecular surfaces. CONCLUSIONS: The results of the present study suggest that once-yearly administration of intravenous ZOL for 3 years in humans does not exert any adverse effects on the evolution of bone material properties at actively forming osteonal and trabecular surfaces, while it may have a beneficial effect on the progression of the mineral-to-matrix ratio and mineral maturity bone quality indices.

Epidemiology of hip fractures in Austria: evidence for a change in the secular trend.

UNLABELLED: Hip fracture incidence rates in Austria over a period of 20 years (1989-2008) were assessed. Age-standardized incidence rates increased until 2005 but decreased thereafter. This change in the secular trend was primarily driven by a decrease in hip fracture incidence in women. INTRODUCTION: The aim of the prevailing study was to assess the incidence rates of hip fractures including changes in trend in the Austrian population over a period of 20 years (1989-2008). METHODS: The number of hip fractures was obtained from the Austrian Hospital Discharge Register for the entire population ≥ 50 years of age. A correction factor for multiple registrations of the same diagnosis was determined. Incidence rates (cases per 100,000) of hip fracture were calculated in 5-year age intervals. To analyze the overall change in hip fracture for the period, average annual change expressed as incidence rate ratios (IRRs) was calculated. RESULTS: The age-standardized incidence in women increased until 2005, from 493 to 642, and decreased thereafter. In men, it increased at a measured pace until 2006, from 192 to 280, and decreased thereafter with a slight rebound in 2008. The age-standardized incidence in the entire population increased until 2005, from 376 to 496, and decreased thereafter. The IRR for the last 3 years (2006-2008) was significantly below the IRR for the first 17 years (0.94, ρ < 0.01), driven by a lower IRR in women (0.91, ρ < 0.01) and to a lesser extent by a lower IRR (not statistically significant) in men (0.96, ρ < 0.15). CONCLUSION: The present study indicates that since 2006, age-standardized incidence of hip fractures has been declining in the Austrian population aged 50 years and above. This reversal in the secular trend has primarily been driven by a decrease in hip fracture incidence in women.

Effects of tumor-induced osteomalacia on the bone mineralization process.

Fibroblast growth factor 23 (FGF23) overexpression has been identified as a causative factor for tumor-induced osteomalacia (TIO) characterized by hypophosphatemia due to increased renal phosphate wasting, low 1,25(OH)(2)D(3) serum levels, and low bone density. The effects of long-lasting disturbed phosphate homeostasis on bone mineralization are still not well understood. We report on a patient with a 12-year history of TIO, treated with 1,25(OH)(2)D(3) and phosphate, who finally developed hyperparathyroidism with gland hyperplasia before the tumor could be localized in the scapula and removed. During surgery a transiliac bone biopsy was obtained. FGF23 expression in the tumor cells was confirmed by in situ hybridization. Serum FGF23 levels as measured by ELISA were found to be extremely elevated before and decreased after removal of the tumor. Bone histology/histomorphometry and measurement of bone mineralization density distribution using quantitative backscattered electron imaging were performed on the bone biopsy. The data showed important surface osteoidosis and a slightly increased osteoblast but markedly decreased osteoclast number. The mineralized bone volume (-11%) and mineralized trabecular thickness (-18%) were low. The mean degree of mineralization of the bone matrix (-7%), the most frequent calcium concentration (-4.1%), and the amounts of fully mineralized bone (-40.3%) were distinctly decreased, while the heterogeneity of mineralization (+44.5%) and the areas of primary mineralization (+131.6%) were dramatically increased. We suggest that the elevated levels of FGF23 and/or low phosphate concentrations disturb the mineralization kinetics in vivo without affecting matrix mineralization of pre-existing bone packets.