Interindividual differences contribute to variation in microbiota composition more than hormonal status: A prospective study.

Aims: Ovarian hormone deficiency is one of the main risk factors for osteoporosis and bone fractures in women, and these risks can be mitigated by menopausal hormone therapy. Recent evidence suggests that gut microbiota may link changes in estrogen levels and bone metabolism. This study was conducted to investigate the potential relationship between hormonal and bone changes induced by oophorectomy and subsequent hormonal therapy and shifts in gut microbiota composition. Methods: We collected 159 stool and blood samples in several intervals from 58 women, who underwent bilateral oophorectomy. Changes in fecal microbiota were assessed in paired samples collected from each woman before and after oophorectomy or the start of hormone therapy. Bacterial composition was determined by sequencing the 16S rRNA gene on Illumina MiSeq. Blood levels of estradiol, FSH, biomarkers of bone metabolism, and indices of low-grade inflammation were measured using laboratory analytical systems and commercial ELISA. Areal bone mineral density (BMD) of the lumbar spine, proximal femur, and femur neck was measured using dual-energy X-ray absorptiometry. Results: We found no significant changes in gut microbiota composition 6 months after oophorectomy, despite major changes in hormone levels, BMD, and bone metabolism. A small decrease in bacterial diversity was apparent 18 months after surgery in taxonomy-aware metrics. Hormonal therapy after oophorectomy prevented bone loss but only marginally affected gut microbiota. There were no significant differences in ß-diversity related to hormonal status, although several microbes (e.g., Lactococcus lactis) followed estrogen levels. Body mass index (BMI) was the most significantly associated with microbiota variance. Microbiota was not a suitable predictive factor for the state of bone metabolism. Conclusions: We conclude that neither the loss of estrogens due to oophorectomy nor their gain due to subsequent hormonal therapy is associated with a specific gut microbiota signature. Sources of variability in microbiota composition are more related to interindividual differences than hormonal status.

Menopausal Transition: Prospective Study of Estrogen Status, Circulating MicroRNAs, and Biomarkers of Bone Metabolism.

Objective: Osteoporosis is associated with an impaired balance between bone resorption and formation, which in turn leads to bone loss and fractures. Many recent studies have underlined the regulatory role of microRNAs (miRNAs) in bone remodeling processes and their potential as biomarkers of osteoporosis. The purpose of this study was to prospectively examine the association of circulating miRNAs and bone biomarkers with estrogen status in women before and after oophorectomy, as well as in oophorectomized women on estrogen therapy. Methods: In this prospective study, we included 11 women before oophorectomy and hysterectomy and at 201 ± 24 days after the surgery. Another 11 women were evaluated 508 ± 127 days after oophorectomy and hysterectomy and after an additional 203 ± 71 days of estradiol treatment. Serum miRNAs were profiled by sequencing. Estrogen status and biomarkers of bone metabolism were quantified. Bone mineral density was assessed in the lumbar spine. Results: Our analysis revealed 17 miRNAs associated with estrogen levels. Of those miRNAs that were upregulated with estrogen deficiency and downregulated after estrogen therapy, miR-422a correlated with serum beta-carboxy-terminal type I collagen crosslinks (ß-CTX) and procollagen 1 N-terminal propeptide (P1NP); and miR-1278 correlated with serum ß-CTX, P1NP, osteocalcin, sclerostin, and Dickkopf-1(Dkk1). In contrast, we found an inverse association of miR-24-1-5p with estrogen status and a negative correlation with serum ß-CTX, P1NP, osteoprotegerin, and sclerostin levels. Conclusion: The reported miRNAs associated with estrogen status and bone metabolism could be potential biomarkers of bone pathophysiology and would facilitate studies on the prevention of postmenopausal osteoporosis. Our findings require validation in an extended cohort.

Update on Menopausal Hormone Therapy for Fracture Prevention.

PURPOSE OF REVIEW: The goal of the review is to assess the appropriateness of menopausal hormone therapy (MHT) for the primary prevention of bone loss in women at elevated risk in the early years after menopause. RECENT FINDINGS: Estrogen alone or combined with progestin to protect the uterus from cancer significantly reduces the risk of osteoporosis-related fractures. MHT increases type 1 collagen production and osteoblast survival and maintains the equilibrium between bone resorption and bone formation by modulating osteoblast/osteocyte and T cell regulation of osteoclasts. Estrogens have positive effects on muscle and cartilage. Estrogen, but not antiresorptive therapies, can attenuate the inflammatory bone-microenvironment associated with estrogen deficiency. However, already on second year of administration, MHT is associated with excess breast cancer risk, increasing steadily with duration of use. MHT should be considered in women with premature estrogen deficiency and increased risk of bone loss and osteoporotic fractures. However, MHT use for the prevention of bone loss is hindered by increase in breast cancer risk even in women younger than 60 years old or who are within 10 years of menopause onset.

Serum 25-hydroxy-vitamin D and the risk of fractures in the teriparatide versus risedronate VERO clinical trial.

PURPOSE: Using data from the 2-year, randomized, double-dummy VERO trial, we examined the changes in 25-hydroxy-vitamin D (25[OH]D) concentrations over time, and whether the fracture risk reduction of teriparatide versus risedronate varies by baseline 25(OH)D sufficiency category. METHODS: Postmenopausal women with established osteoporosis received subcutaneous daily teriparatide 20 µg or oral weekly risedronate 35 mg, with concomitant 500-1000 mg of elemental calcium and 400-800 IU/day of vitamin D supplements. Fracture endpoints were analyzed by predefined subgroups of 25(OH)D insufficient and sufficient patients. Heterogeneity of the treatment effect on fractures was investigated by logistic and Cox proportional hazards regression models. RESULTS: At baseline, mean serum 25(OH)D was 31.9 ng/mL in the teriparatide group and 31.5 ng/mL in the risedronate group, and 16.8% and 17.9% of patients, respectively, were 25(OH)D insufficient. At month 6, the mean serum 25(OH)D concentration decreased in teriparatide-treated patients to 24.5 ng/mL (by approximately 23%) but remained relatively constant in risedronate-treated patients (32.2 ng/mL) (p < 0.001). Proportions of 25(OH)D insufficient patients at month 6 were 26.7% and 5.6%, respectively (p < 0.001). The risk reduction with teriparatide versus risedronate for any of the fracture endpoints did not significantly differ between subgroups by 25(OH)D sufficiency status at baseline, with nonsignificant (p > 0.1) treatment-by-25(OH)D interactions in all fracture analyses. CONCLUSIONS: Serum 25(OH)D concentration decreases during teriparatide treatment. Fracture risk reduction with teriparatide versus risedronate did not significantly differ between the two groups of patients defined by baseline 25(OH)D. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01709110 EudraCT Number: 2012-000123-41.

Teriparatide Treatment Increases Mineral Content and Volume in Cortical and Trabecular Bone of Iliac Crest: A Comparison of Infrared Imaging With X-Ray-Based Bone Assessment Techniques.

Teriparatide increases bone mass primarily through remodeling of older or damaged bone and abundant replacement with new mineralizing bone. This post hoc analysis investigated whether dual-energy X-ray absorptiometric (DXA) areal bone mineral density (aBMD) measurement adequately reflects changes of mineral and organic matrix content in cortical and trabecular bone. Paired biopsies and aBMD measurements were obtained before and at end of 2 years of teriparatide treatment from postmenopausal women with osteoporosis who were either alendronate pretreated (mean, 57.5 months) or osteoporosis-treatment naive. Biopsies were assessed by micro-computed tomography (µCT) to calculate mean cortical width (Ct.Wi), cortical area (Ct.Ar), and trabecular bone volume fraction (BV/TV). Fourier transformed infrared imaging (pixel size ∼6.3 × 6.3 µm2 ) was utilized to calculate mineral and organic matrix density (mean absorption/pixel), as well as total mineral and organic contents of cortical and cancellous compartments (sum of all pixels in the compartment). Effect of pretreatment over time was analyzed using mixed model repeated measures. µCT derived Ct.Wi and BV/TV increased, accompanied by similar increases in the overall mineral contents of their respective bone compartments. Mineral density did not change. Marked increases in the total content of both mineral and organic matrix associated with volumetric growth in both compartments consistently exceeded those of aBMD. Increases in organic matrix exceeded increases in mineral content in both cortical and trabecular compartments. For percent changes, only change in Ct.Wi correlated to change in femoral neck aBMD (r = .38, p = 0.043), whereas no other significant correlations of Ct.Wi or BV/TV with lumbar spine, total hip, or femoral neck aBMD were demonstrable. These data indicate that 2 years of teriparatide treatment leads to an increased bone organic matrix and mineral content in the iliac crest. The magnitude of these increases in the iliac crest were not detected with conventional aBMD measurements at other skeletal sites. © 2018 American Society for Bone and Mineral Research.

Effects of Teriparatide Compared with Risedronate on the Risk of Fractures in Subgroups of Postmenopausal Women with Severe Osteoporosis: The VERO Trial.

The 2-year, randomized, double-blind, active-controlled fracture endpoint VERO study included postmenopausal women with established osteoporosis, who had at least 2 moderate or 1 severe baseline vertebral fractures (VFx), and bone mineral density (BMD) T-score ≤-1.5. Patients were treated with either s.c. daily teriparatide 20 µg or oral weekly risedronate 35 mg. As previously reported, the risk of new VFx and clinical fractures (a composite of clinical VFx and nonvertebral fragility fractures [NVFFx]) was statistically significantly reduced with teriparatide compared with risedronate. Here we present the prospectively planned subgroup analyses of fracture data across subgroups, which were predefined by the following baseline characteristics: age, number and severity of prevalent VFx, prevalent nonvertebral fractures (NVFx), glucocorticoid use, prior osteoporosis drugs, recent bisphosphonate use, clinical VFx in the year before study entry, and baseline BMD. Heterogeneity of the treatment effect on the primary endpoint (new VFx), and the four key secondary endpoints (including clinical fractures and NVFFx) were investigated by logistic and Cox proportional hazards regression models. A total of 1360 women were randomized and treated (680 per group). Mean age was 72.1 years, mean (SD) number of prevalent VFx was 2.7 (2.1), 55.4% had a BMD T-score <-2.5, 36.5% had a recent clinical VFx, 28.3% had a prior major NVFx, 43.2% were osteoporosis drug-naïve, 39.3% were recent bisphosphonate users, and 9.3% were taking glucocorticoids at a prednisone-equivalent dose of >5 mg/d. For most fracture endpoints, the risk reduction of teriparatide versus risedronate did not significantly differ in any of the subgroups analyzed (treatment-by-subgroup interaction p > 0.1), with most subgroups mirroring results from the total study population. In conclusion, in postmenopausal women with severe osteoporosis, the antifracture efficacy of teriparatide compared with risedronate was consistent in a wide range of patient settings, including treatment-naïve and previously treated patients. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Secondary fracture prevention in hip fracture patients requires cooperation from general practitioners.

Despite individual recommendations on osteoporosis management in patients after hip fracture surgery, addressed by orthopedic surgeons to Czech general practitioners, the patients remained undiagnosed and untreated because of provider-level barriers to post-fracture secondary prevention. PURPOSE: The goal of the study was to assess whether an individual recommendation on osteoporosis treatment addressed to a hip fracture patient's GP would lead to better osteoporosis management. METHODS: Two groups of patients who suffered hip fractures and were treated at the Orthopedic Department were evaluated. In 111 patients, general recommendations on osteoporosis treatment and fracture prevention were provided in a discharge report addressed to the GP. In the second group, 96 patients were provided individually with a detailed written set of recommendations on osteoporosis examination, treatment, and fracture prevention, which was also provided in the discharge report. A questionnaire to assess the provided care was mailed to the patients 5.3 ± 1.2 months of discharge. Those patients who did not return the questionnaires were contacted by phone. RESULTS: The questionnaires were received from 44% and 49% of patients from the general and detailed recommendation groups, respectively. Along with the phone call, we were able to contact 78 (70.3%) and 68 (70.8%) patients from the general and detailed recommendation groups, respectively. GPs secured osteoporosis evaluation in 14.6% of the patients. Calcium supplementation and vitamin D supplementation were newly provided in 42.7 and 36.4% of the patients, respectively. Anti-resorptive therapy was newly provided in 8.3% of the patients. No significant differences between the groups were observed in osteoporosis evaluation, calcium and vitamin D supplementation, and anti-osteoporosis treatments. Out of 207 patients, further examination or treatment was requested by 45 patients (21.7%); 75 patients (36.2%) declared no interest in further care. CONCLUSION: Recommendations on osteoporosis management addressed to Czech GPs after surgical fracture management had little effect on treatment. As the anti-osteoporotic preparations can only be prescribed by specialists, the availability of necessary examinations and treatment is limited by the motivation of GPs. Consequently, the implementation of Fracture Liaison Services to help close the care gap may be limited in the absence of participation by Czech GPs.

Effect of Teriparatide or Risedronate in Elderly Patients With a Recent Pertrochanteric Hip Fracture: Final Results of a 78-Week Randomized Clinical Trial.

We present final results of a study comparing teriparatide 20 µg every day (QD) with risedronate 35 mg once per week (QW) started within 2 weeks after surgery for a pertrochanteric hip fracture. Patients with BMD T-score ≤ -2.0 and 25OHD ≥9.2 ng/mL were randomized to receive 26-week double-dummy treatment plus calcium and vitamin D, followed by 52-week open-label treatment with the same assigned active drug. Primary endpoint was change from baseline in lumbar spine (LS) BMD at 78 weeks. Secondary and exploratory endpoints were change in BMD at the proximal femur, function, hip pain (Charnley score and 100 mm Visual Analog Scale [VAS]), quality of life (Short Form-36), radiology outcomes, and safety. Data were analyzed with mixed models for repeated measures (MMRM) and logistic regression. Totally, 224 patients were randomized; 171 (teriparatide: 86) contributed to the efficacy analyses (mean ± SD age: 77 ± 7.7 years, 77% females). Mean baseline LS, femoral neck (FN), and total hip (TH) T-scores were -2.16, -2.63, and -2.51, respectively. At 78 weeks, BMD increased significantly more with teriparatide compared to risedronate at the LS (+11.08% versus +6.45%; p < 0.001) and FN (+1.96% versus -1.19%; p = 0.003), with no significant between-group difference in TH BMD. Timed up-and-go (TUG) test was significantly faster with teriparatide at 6, 12, 18, and 26 weeks (differences: -3.2 to -5.9 s; p = 0.045 for overall difference). Hip pain during TUG test by 100 mm VAS was significantly lower with teriparatide at 18 weeks (adjusted difference: -11.3 mm, p = 0.033; -10.0 and -9.3 mm at 12 and 26 weeks, respectively; p = 0.079 for overall difference). Other secondary and exploratory outcomes were not different. Teriparatide group showed two new hip fractures versus seven with risedronate (p = 0.171) and more frequent hypercalcemia and hyperuricemia. In conclusion, 78-week treatment with teriparatide showed significantly greater increases in LS and FN BMD, less pain, and a faster TUG test versus risedronate. © 2016 American Society for Bone and Mineral Research.

Focal osteoporosis defects play a key role in hip fracture.

BACKGROUND: Hip fractures are mainly caused by accidental falls and trips, which magnify forces in well-defined areas of the proximal femur. Unfortunately, the same areas are at risk of rapid bone loss with ageing, since they are relatively stress-shielded during walking and sitting. Focal osteoporosis in those areas may contribute to fracture, and targeted 3D measurements might enhance hip fracture prediction. In the FEMCO case-control clinical study, Cortical Bone Mapping (CBM) was applied to clinical computed tomography (CT) scans to define 3D cortical and trabecular bone defects in patients with acute hip fracture compared to controls. Direct measurements of trabecular bone volume were then made in biopsies of target regions removed at operation. METHODS: The sample consisted of CT scans from 313 female and 40 male volunteers (158 with proximal femoral fracture, 145 age-matched controls and 50 fallers without hip fracture). Detailed Cortical Bone Maps (c.5580 measurement points on the unfractured hip) were created before registering each hip to an average femur shape to facilitate statistical parametric mapping (SPM). Areas where cortical and trabecular bone differed from controls were visualised in 3D for location, magnitude and statistical significance. Measures from the novel regions created by the SPM process were then tested for their ability to classify fracture versus control by comparison with traditional CT measures of areal Bone Mineral Density (aBMD). In women we used the surgical classification of fracture location ('femoral neck' or 'trochanteric') to discover whether focal osteoporosis was specific to fracture type. To explore whether the focal areas were osteoporotic by histological criteria, we used micro CT to measure trabecular bone parameters in targeted biopsies taken from the femoral heads of 14 cases. RESULTS: Hip fracture patients had distinct patterns of focal osteoporosis that determined fracture type, and CBM measures classified fracture type better than aBMD parameters. CBM measures however improved only minimally on aBMD for predicting any hip fracture and depended on the inclusion of trabecular bone measures alongside cortical regions. Focal osteoporosis was confirmed on biopsy as reduced sub-cortical trabecular bone volume. CONCLUSION: Using 3D imaging methods and targeted bone biopsy, we discovered focal osteoporosis affecting trabecular and cortical bone of the proximal femur, among men and women with hip fracture.

Effects of Teriparatide Compared with Risedronate on Recovery After Pertrochanteric Hip Fracture: Results of a Randomized, Active-Controlled, Double-Blind Clinical Trial at 26 Weeks.

BACKGROUND: Osteoporosis drugs might affect fracture-healing. We therefore studied the effects of teriparatide in comparison with risedronate on recovery after pertrochanteric hip fractures. METHODS: The study was a randomized, multicenter, active-controlled, 78-week trial comparing teriparatide (20 µg/day) with risedronate (35 mg/week) initiated within 2 weeks after fixation of a low-trauma pertrochanteric hip fracture (AO/OTA 31-A1 or 31-A2). The main inclusion criteria were a bone mineral density T-score of ≤-2.0 and 25-OH-vitamin D of ≥9.2 ng/mL. During the first 26 weeks, patients received study medication with oral or injectable placebo plus calcium and vitamin D in a double-blinded fashion. Secondary (Timed Up-and-Go [TUG] test, hip pain, Short Form [SF]-36 health status, and safety) and exploratory (radiographic outcomes and ability to walk) 26-week end points are reported. RESULTS: Of the 224 patients who were randomized, 171 (86 teriparatide, 85 risedronate) were included in the analysis. The mean age was 77 ± 8 years, 77% were female, and 26% had a prior history of low-trauma fracture. The teriparatide group completed the TUG test in a shorter time at 6, 12, 18, and 26 weeks (differences of -5.7, -4.4, -3.1, and -3.1 seconds, respectively; p = 0.021 for the overall difference). They also reported less pain on a visual analog scale immediately after the TUG test at 12 and 18 weeks (adjusted absolute differences of 10.6 and 11.9 mm, respectively; p < 0.05). There were no significant between-group differences in the SF-36 score, Charnley hip pain score, ability to walk, or use of walking aids during follow-up. Radiographic healing at 6, 12, and 26 weeks, mechanical failure of the implant (teriparatide, 7; risedronate, 8), loss of reduction (teriparatide, 2; risedronate, 4), and nonunion (0 cases) were not significantly different. Mild hypercalcemia and hyperuricemia were more frequent with teriparatide. CONCLUSIONS: Teriparatide was associated with less pain and a shorter time to complete the TUG test between 6 and 26 weeks compared with risedronate. Other fracture-recovery outcomes were similar. The results should be interpreted with caution as these were secondary end points. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Serum and bone pentosidine in patients with low impact hip fractures and in patients with advanced osteoarthritis.

BACKGROUND: Femoral neck fractures are a common occurrence in patients suffering from osteoporosis, while intracapsular hip fracture is rare in cases of osteoarthritis of the hip. Previous histomorphometric studies have emphasized the association between bone microarchitecture and the risk of low-impact fractures in osteoarthritis and osteoporosis patients. However, the strength of bone material is also a function of composition of organic bone matrix. In order to compare tissue material properties in these two clinical conditions, serum and bone pentosidine, a non-enzymatic collagen crosslinking element, was measured in patients who suffered a low-impact fracture, and in patients with advanced osteoarthritis. METHODS: The patient population consisted of 70 patients who underwent hemiarthroplasty surgery for a femoral neck fracture, and 41 patients with advanced hip joint osteoarthritis without a history of low- impact fracture, who were indicated for total hip joint replacement. Pentosidine content was analyzed in bone samples and in serum obtained from fracture and osteoarthritis patients using high performance liquid chromatography. RESULTS: Serum and bone concentrations of pentosidine were higher in subjects with hip fractures compared with osteoarthritis after adjustment for age, sex, weight, serum creatinine, and diabetes. A significant positive correlation was found between bone and serum pentosidine in fractured cases. A comparable relationship was also demonstrated for pentosidine levels in serum and bone relative to differentiation of fracture and osteoarthritis cases. CONCLUSIONS: Serum pentosidine can be considered a potential biomarker for identification of subjects with impaired bone quality and bone strength.

Improvement of cancellous bone microstructure in patients on teriparatide following alendronate pretreatment.

An increase in procollagen type I amino-terminal propeptide (PINP) early after teriparatide initiation was shown to correlate with increased lumbar spine areal BMD and is a good predictor of the anabolic response to teriparatide. Few data exist correlating PINP and bone microstructure, and no data exist in patients on teriparatide following prior potent antiresorptive treatment. This exploratory analysis aimed to investigate the effects of teriparatide on cancellous bone microstructure and correlations of bone markers with microstructure in alendronate-pretreated patients. This was a post hoc analysis of changes in bone markers and three-dimensional indices of bone microstructure in paired iliac crest biopsies from a prospective teriparatide treatment study in postmenopausal women with osteoporosis who were either treatment-naïve (TN, n=16) or alendronate-pretreated (ALN, n=29) at teriparatide initiation. Teriparatide (20µg/day) was given for 24months; biopsies were taken at baseline and endpoint, and serum concentrations of PINP and type 1 collagen cross-linked C-telopeptide (ßCTX) were measured at intervals up to 24months. In the TN and ALN groups, respectively, mean (SD) increases in three-dimensional bone volume/tissue volume were 105 (356)% (P=0.039) and 55 (139)% (P<0.005) and trabecular thickness 30.4 (30)% (P<0.001) and 30.8 (53)% (P<0.001). No significant changes were observed in trabecular number or separation. In the ALN patients, 3-month change of neither PINP nor ßCTX correlated with indices of cancellous bone microstructure. However, 12-month changes in biochemical bone markers correlated significantly with improvements in bone volume/tissue volume, r=0.502 (P<0.01) and r=0.378 (P<0.05), trabecular number, r=0.559 (P<0.01) and r=0.515 (P<0.01), and reduction of trabecular separation, r=-0.432 (P<0.05) and r=-0.530 (P<0.01), for PINP and ßCTX, respectively. We conclude that cancellous bone microstructure improved with teriparatide therapy irrespective of prior antiresorptive use.

Serum sclerostin in high-activity adult patients with juvenile idiopathic arthritis.

INTRODUCTION: Juvenile idiopathic arthritis (JIA) is a disease associated with loss of bone mass, deterioration in bone mass quality and an increased risk of fractures. The objective of this study was to evaluate factors that predict bone mineral density (BMD) alterations in young adult patients with active JIA before and during therapy with tumour necrosis factor α (TNFα) inhibitors. METHODS: Thirty-one patients (twelve males and nineteen females; mean age =25.1 ± 6.1 years) with active JIA (mean Disease Activity Score in 28 joints (DAS28) =6.36 ± 0.64; mean high-sensitivity C-reactive protein (hsCRP) =18.36 ± 16.95 mg/L) were investigated. The control group consisted of 84 healthy individuals matched by sex and age. BMD, bone turnover markers and serum concentrations of soluble receptor activator of nuclear factor κB ligand, osteoprotegerin, dickkopf Wnt signalling pathway inhibitor 1 (Dkk1) and sclerostin were evaluated. RESULTS: Baseline BMD values in the lumbar spine, proximal femur, femoral neck and distal radius were significantly lower in patients with JIA compared to healthy control participants. Baseline sclerostin serum concentrations were significantly higher in patients with JIA compared to control participants. After 2 years of treatment with TNFα inhibitors, BMD was significantly increased in the lumbar spine. This increase correlated with a drop in DAS28 score. A statistically significant correlation between hsCRP and Dkk1 was found at baseline, as well as during the 2-year follow-up period. A significant reduction in serum sclerostin after 1 year of therapy was predictive of a drop in DAS28 score observed with a 1-year delay after reduction of serum sclerostin. CONCLUSION: A significant correlation between the sclerostin serum concentration and the number of tender and swollen joints, but not BMD, supports the hypothesis that chondrocytes and cells of the subchondral bone may contribute to circulating sclerostin in JIA.

The association between lean mass and bone mineral content in the high disease activity group of adult patients with juvenile idiopathic arthritis.

BACKGROUND: The study is aimed to evaluate body composition and bone status in adolescent and adult patients with active juvenile idiopathic arthritis (JIA) untreated with tumor necrosis factor alpha inhibitors. METHODS: Adult patients (12 male and 19 female) with active JIA and 84 healthy age- and gender- matched controls were enrolled into the study. Body composition (tissue mass in grams, lean mass, fat mass and bone mineral content as a fraction of tissue mass) and areal bone mineral density parameters (aBMD) at the lumbar spine, proximal femur, femoral neck, distal radius and total body were assessed using dual energy x-ray absorptiometry (DXA), and correlated with clinical characteristics of the disease and physical performance tests. Disease activity was assessed using high-sensitivity C-reactive protein (hsCRP) and disease activity score 28 (DAS 28). Differences between the groups were tested by t-test, and One-way ANOVA. Correlations were assessed using the Pearson correlation coefficients and multiple linear regression analysis. Significances were counted at the 0.05 level. RESULTS: In patients with clinically active JIA (DAS 28, 6.36 ± 0.64, hsCRP, 18.36 ± 16.95 mg/l), aBMD at all measured sites, bone mineral content (BMC) and lean mass were reduced, and fat mass was increased as compared with healthy controls. Significant negative correlations were observed between BMC and disease duration, use of glucocorticoids (GCs), and fat mass, respectively. A positive correlation was found between BMC and lean mass, and between the body fat fraction and the use of GCs. Using multiple linear regression analysis, lean mass was the only significant predictor of BMC of total body both in men and women, and of BMC of legs (only in men). Lean mass was also the only predicting factor of total proximal femur BMD and femoral neck BMD. No significant correlations have been determined among the body composition parameters and DAS 28 or hsCRP endpoints. CONCLUSIONS: In adult patients with long-term active JIA, lean mass was the main determining factor of total body and leg BMC, and total proximal femur and femoral neck aBMD.

Effects of teriparatide on cortical histomorphometric variables in postmenopausal women with or without prior alendronate treatment.

Cortical bone, the dominant component of the human skeleton by volume, plays a key role in protecting bones from fracture. We analyzed the cortical bone effects of teriparatide treatment in postmenopausal women with osteoporosis who had previously received long-term alendronate (ALN) therapy or were treatment naïve (TN). Tetracycline-labeled paired iliac crest biopsies obtained from 29 ALN-pretreated and 16 TN women were evaluated for dynamic histomorphometric parameters of bone formation at the periosteal, endocortical and intracortical bone compartments, before and after 24months of teriparatide treatment. At baseline, the frequency of specimens without any endocortical and periosteal tetracycline labeling, and the percentage of quiescent osteons, was higher in the ALN than the TN group. Endocortical and periosteal mineralizing surface (MS/BS%), periosteal bone formation rate (BFR/BS), mineral apposition rate (MAR) and the number of intracortical forming osteons were significantly lower in the ALN-pretreated patients than in the TN group. Following teriparatide treatment, the frequency of endocortical and periosteal unlabeled biopsies decreased; in the ALN-pretreated group the percentage of quiescent osteons decreased and, in contrast, forming and resorbing osteons were increased. Teriparatide treatment resulted in significant increases of MAR in the endocortical, and MS/BS% in the periosteal compartment in the ALN-pretreated group. Most indices of bone formation remained lower in the ALN-pretreated group compared with the TN group at study end. Endocortical wall width was increased in both ALN-pretreated and TN groups. Cortical porosity and cortical thickness were significantly increased in the ALN-pretreated group after teriparatide treatment. Our results suggest that 24months of teriparatide treatment increases cortical bone formation and cortical turnover in patients who were either TN or had previous ALN therapy.

Strontium ranelate: in search for the mechanism of action.

Strontium ranelate is a medicine with evidenced effects on the risk of fractures. The heterogeneity of strontium distribution in bone, quality of bone mineral crystals in young bone packets on bone surfaces formed during strontium ranelate administration, and activation of the calcium sensing receptor may, at least partially, explain the beneficial effects of SrR on reducing the risk of fractures. In this review, the concept of the dual action of strontium ranelate is also discussed. However, sufficient evidence for the bone anabolic effect of SrR does not exist in humans. The knowledge of the mechanism of action of SrR is important not only for the explanation of the effects of SrR upon the skeleton, but also for the safety of treatment for other tissues.

Bone status in adults with early-onset juvenile idiopathic arthritis following 1-year anti-TNFα therapy and discontinuation of glucocorticoids.

Juvenile idiopathic arthritis (JIA) is an inflammatory disease associated with bone loss and low bone mineral density (BMD). The treatment involves disease-modifying antirheumatic drugs, glucocorticoids (GCs) and biological agents. The aim of this study was to evaluate effects of 12-month therapy with the anti-tumor necrosis factor alpha (anti-TNFα) preparations on bone mineral density (BMD) and biochemical turnover markers (BTM) in adult patients with JIA who were previously either treated or not treated with glucocorticoids (GC) and to assess effects of the discontinuation of GCs on their bone status. Nineteen adult patients (12 women, 7 men) aged 18-33 years with active JIA were prospectively enrolled to receive the anti-TNFα therapy (infliximab, etanercept or adalimumab). BMD and BTMs were determined at baseline and 1-year follow-up. The anti-TNFα therapy resulted in a significant reduction in disease activity score 28 (DAS28) and C-reactive protein (CRP) and a significant increase in BMD at the lumbar spine and total body and in serum N-terminal propeptide of type I procollagen (PINP, marker of bone formation). No significant changes in serum beta C-terminal telopeptide of type I collagen (ßCTX, marker of osteoclastic bone resorption) and osteocalcin (marker of bone remodeling) were found. A significant negative correlation was observed between the change in the DAS28, CRP and serum PINP. The change in serum PINP concentrations positively correlated with the change in lumbar spine BMD. A significant increase in serum PINP was observed only in patients discontinuing GCs during the anti-TNFα treatment. After the initiation of the anti-TNFα therapy in young adults with JIA, the increase in new bone formation can be explained by discontinuation of GCs administration as the patients with the largest reduction in DAS28 and CRP probably are the ones most likely to stop GC.

Acute effects of glucocorticoids on serum markers of osteoclasts, osteoblasts, and osteocytes.

The aim of this study was to investigate the acute effects of oral glucocorticoids in doses used in clinical practice on biochemical indices of the function of osteoclasts, osteoblasts, and osteocytes. In 17 adult patients suffering from various medical pathologies requiring systemic steroid therapy that were never before treated with glucocorticoids, glucocorticoid treatment was initiated (mean prednisolone equivalent dose of 23.1 ± 12.7 mg/day, range 10-50). Fasting morning serum concentrations of osteocalcin (OC), amino-terminal propeptide of type I procollagen (PINP), type 1 collagen cross-linked C-telopeptide (ßCTX), soluble receptor activator of nuclear factor kappaB ligand (sRANKL), osteoprotegerin (OPG), sclerostin, Dickkopf-1 (Dkk-1), and high-sensitivity C-reactive protein (hsCRP) were measured at baseline and on three consecutive days. Significant reductions in serum OC, PINP, OPG, sclerostin, and hsCRP were observed during 96 h of glucocorticoid administration, while serum ßCTX showed a significant percentual increase. A significant positive correlation was found between serum concentrations of Dkk-1 and ßCTX after 96 h of treatment with glucocorticoids. A significant drop in serum sclerostin, OPG, and OC observed in this study may reflect the rapid glucocorticoid-induced apoptosis of osteocytes.

Cortical thickness mapping to identify focal osteoporosis in patients with hip fracture.

BACKGROUND: Individuals with osteoporosis are predisposed to hip fracture during trips, stumbles or falls, but half of all hip fractures occur in those without generalised osteoporosis. By analysing ordinary clinical CT scans using a novel cortical thickness mapping technique, we discovered patches of markedly thinner bone at fracture-prone regions in the femurs of women with acute hip fracture compared with controls. METHODS: We analysed CT scans from 75 female volunteers with acute fracture and 75 age- and sex-matched controls. We classified the fracture location as femoral neck or trochanteric before creating bone thickness maps of the outer 'cortical' shell of the intact contra-lateral hip. After registration of each bone to an average femur shape and statistical parametric mapping, we were able to visualise and quantify statistically significant foci of thinner cortical bone associated with each fracture type, assuming good symmetry of bone structure between the intact and fractured hip. The technique allowed us to pinpoint systematic differences and display the results on a 3D average femur shape model. FINDINGS: The cortex was generally thinner in femoral neck fracture cases than controls. More striking were several discrete patches of statistically significant thinner bone of up to 30%, which coincided with common sites of fracture initiation (femoral neck or trochanteric). INTERPRETATION: Femoral neck fracture patients had a thumbnail-sized patch of focal osteoporosis at the upper head-neck junction. This region coincided with a weak part of the femur, prone to both spontaneous 'tensile' fractures of the femoral neck, and as a site of crack initiation when falling sideways. Current hip fracture prevention strategies are based on case finding: they involve clinical risk factor estimation to determine the need for single-plane bone density measurement within a standard region of interest (ROI) of the femoral neck. The precise sites of focal osteoporosis that we have identified are overlooked by current 2D bone densitometry methods.