Serum tryptophan metabolites are associated with erosive hand osteoarthritis and pain: results from the DIGICOD cohort.

OBJECTIVE: To investigate host and gut-microbiota related Tryptophan metabolism in hand osteoarthritis (HOA). METHODS: The baseline serum concentration of 20 Tryptophan metabolites was measured in 416 HOA patients in a cross-sectional analysis of the DIGICOD cohort. Tryptophan metabolites levels, metabolite-ratios and metabolism pathway activation were compared between erosive (N = 141) and non-erosive HOA (N = 275) by multiple logistic regressions adjusted on age, BMI and sex. The association between Tryptophan metabolite levels and HOA symptoms was investigated by a Spearman's rank correlation analysis. RESULTS: Four serum Tryptophan metabolites, eight metabolite ratios and one metabolism pathway were associated with erosive HOA. Erosive HOA was negatively associated with Tryptophan (odds ratio (OR) = 0.41, 95% confidence interval [0.24-0.70]), indole-3-aldehyde (OR = 0.67 [0.51-0.90]) and 3-OH-anthranilic acid (OR = 1.32 [1.13-1.54]) and positively with 5-OH-Tryptophan levels (OR = 1.41 [1.13-1.77]). The pro-inflammatory kynurenine-indoleamine 2,3-dioxygenase pathway was upregulated in erosive HOA (OR = 1.60 [1.11-2.29]). Eleven metabolites were correlated with HOA symptoms and were mostly pain-related. Serotonin and N-acetyl serotonin levels were negatively correlated with number of tender joints. Indole-3-aldehyde level was negatively correlated and 3-OH-anthranilic acid, 3-OH-kynurenine and 5-OH-Tryptophan levels were positively correlated with number of patients-reported painful joints. Quinolinic acid and 3-OH-kynurenine levels correlated positively with AUSCAN pain. CONCLUSIONS: Tryptophan metabolites disturbance is associated with erosive HOA and pain and emphasize the role of low-grade inflammation and gut dysbiosis in HOA.

Inhibition of sphingosine 1-phosphate protects mice against chondrocyte catabolism and osteoarthritis.

OBJECTIVE: Cartilage loss observed in osteoarthritis (OA) is prevented when osteoclasts in the subchondral bone are inhibited in mice. Here, we investigated the role of the osteoclast secretome and of the lipid mediator sphingosine 1-phosphate (S1P) in chondrocyte metabolism and OA. MATERIALS AND METHODS: We used SphK1LysMCre and wild type mice to assess the effect of murine osteoclast secretome in chondrocyte metabolism. Gene and protein expressions of matrix metalloproteinase (Mmp) were quantified in chondrocytes and explants by RT-qPCR and Western blots. SphK1LysMCre mice or wild type mice treated with S1P2 receptor inhibitor JTE013 or anti-S1P neutralizing antibody sphingomab are analyzed by OA score and immunohistochemistry. RESULTS: The osteoclast secretome increased the expression of Mmp3 and Mmp13 in murine chondrocytes and cartilage explants and activated the JNK signaling pathway, which led to matrix degradation. JTE013 reversed the osteoclast-mediated chondrocyte catabolism and protected mice against OA, suggesting that osteoclastic S1P contributes to cartilage damage in OA via S1P/S1P2 signaling. The activity of sphingosine kinase 1 (SphK1) increased with osteoclast differentiation, and its expression was enhanced in subchondral bone of mice with OA. The expression of Mmp3 and Mmp13 in chondrocytes was low upon stimulation with the secretome of Sphk1-lacking osteoclasts. Cartilage damage was significantly reduced in SphK1LysMCre mice, but not the synovial inflammation. Finally, intra-articular administration of sphingomab inhibited the cartilage damage and synovial inflammation. CONCLUSIONS: Lack of S1P in myeloid cells and local S1P neutralization alleviates from osteoarthritis in mice. These data identify S1P as a therapeutic target in OA.

Results of a global, patient-based survey assessing the impact of psoriatic arthritis discussed in the context of the Psoriatic Arthritis Impact of Disease (PsAID) questionnaire.

BACKGROUND: Psoriatic arthritis (PsA) is a chronic immune-mediated inflammatory musculoskeletal disease, manifesting as peripheral arthritis, enthesitis, dactylitis, spondylitis, and skin and nail psoriasis. A core set of domains for measuring the impact of PsA has been developed, including pain, patient global assessment, physical function, health-related quality of life (HRQoL), and fatigue. To understand the impact of PsA on health domains from a patient's perspective, a global survey was developed and results reported in the context of the 12-item Psoriatic Arthritis Impact of Disease (PsAID-12) questionnaire. METHODS: An online patient-based global survey was conducted by The Harris Poll in Australia, Brazil, Canada, France, Spain, Taiwan, the UK, and the US between November 2, 2017 and March 12, 2018. Eligible patients were ≥ 18 years old with a diagnosis of PsA for > 1 year, had visited a rheumatologist/dermatologist in the past 12 months and reported using ≥ 1 synthetic/biologic disease-modifying antirheumatic drug for PsA. Patients reported on PsA severity and symptoms, and the impact of PsA on HRQoL. After survey completion, responses were aligned with PsAID health domains. Descriptive statistics and chi-square tests were conducted. RESULTS: This analysis included 1286 patients from eight countries. Most patients (97%) reported musculoskeletal symptoms relating to PsA in the past year. Common moderate/major impacts of PsA were on physical activity (78%), ability to perform certain activities (76%), work productivity (62%), and career path (57%). Skin/nail symptoms occurred in 80% of patients. Overall, 69% of patients reported that PsA had a moderate/major impact on emotional/mental wellbeing, 56% on romantic relationships/intimacy, and 44% on relationships with family and friends. Social impacts included emotional distress (58%), social shame or disapproval (32%), and ceased participation in social activities (45%). Over half of all patients experienced unusual fatigue over the past 12 months (52%). The health domains that patients reported as being impacted by PsA aligned with life impact domains of the patient-derived PsAID health domains. CONCLUSION: These results highlight the impact of PsA on multiple health domains from a patient perspective that should be considered during shared decision-making processes between healthcare providers and patients.

2016 updated EULAR evidence-based recommendations for the management of gout.

BACKGROUND: New drugs and new evidence concerning the use of established treatments have become available since the publication of the first European League Against Rheumatism (EULAR) recommendations for the management of gout, in 2006. This situation has prompted a systematic review and update of the 2006 recommendations. METHODS: The EULAR task force consisted of 15 rheumatologists, 1 radiologist, 2 general practitioners, 1 research fellow, 2 patients and 3 experts in epidemiology/methodology from 12 European countries. A systematic review of the literature concerning all aspects of gout treatments was performed. Subsequently, recommendations were formulated by use of a Delphi consensus approach. RESULTS: Three overarching principles and 11 key recommendations were generated. For the treatment of flare, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), oral or intra-articular steroids or a combination are recommended. In patients with frequent flare and contraindications to colchicine, NSAIDs and corticosteroids, an interleukin-1 blocker should be considered. In addition to education and a non-pharmacological management approach, urate-lowering therapy (ULT) should be considered from the first presentation of the disease, and serum uric acid (SUA) levels should be maintained at<6 mg/dL (360 µmol/L) and <5 mg/dL (300 µmol/L) in those with severe gout. Allopurinol is recommended as first-line ULT and its dosage should be adjusted according to renal function. If the SUA target cannot be achieved with allopurinol, then febuxostat, a uricosuric or combining a xanthine oxidase inhibitor with a uricosuric should be considered. For patients with refractory gout, pegloticase is recommended. CONCLUSIONS: These recommendations aim to inform physicians and patients about the non-pharmacological and pharmacological treatments for gout and to provide the best strategies to achieve the predefined urate target to cure the disease.

Cost utility modeling of early vs late total knee replacement in osteoarthritis patients.

Given the dramatic increase in the number of total knee replacement (TKR) surgeries in developed countries, the issue of the best time for surgery needs to be addressed from an economic perspective. OBJECTIVE: To assess, from the perspective of the healthcare payer, the cost-utility of two surgical strategies in which knee replacement is performed at the early or late stage of the disease in patients with knee osteoarthritis (OA). DESIGN: Patient data and evidence from published literature on economic costs and outcomes in OA, including utilities, non-pharmacological, pharmacological and surgical options, combined with population life tables were entered in a Markov model of OA. The model represented the lifetime experience of a cohort of patients following their therapeutic management, discounting costs (euros) and utilities (quality-adjusted life-years) at 4% annually. RESULTS: In the base-case scenario, early TKR cost €6,624 more than late TKR (€76,223 vs €69,599) with a 0.15 gain in QALYs (18.675 vs 18.524). This yielded an incremental cost-utility ratio (ICUR) of 43,631 €/QALY. Sensitivity analyses of the most influential uncertain parameters were performed and did not modify the direction of the conclusions: early TKR cost between €3,655 and €7,194 more than late TKR with a gain in QALYs between 0.15 and 0.39. The ICUR ranged from 17,131 €/QALY to 48,241 €/QALY. CONCLUSION: Our data do not support the early TKR strategy over the late TKR strategy in knee OA patients from a medico-economic perspective.

Iron overload in a murine model of hereditary hemochromatosis is associated with accelerated progression of osteoarthritis under mechanical stress.

OBJECTIVE: Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress. DESIGN: OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice. OA progression was assessed using histology, micro CT, gene expression and immunohistochemistry at 8 weeks after surgery. RESULTS: Hfe-KO mice showed a systemic iron overload and an increased iron accumulation in the knee synovial membrane following surgery. The histological OA score was significantly higher in the Hfe-KO mice at 8 weeks after surgery. Micro CT study of the proximal tibia revealed increased subchondral bone volume and increased trabecular thickness. Gene expression and immunohistochemical analysis showed a significant increase in the expression of matrix metallopeptidase 3 (MMP-3) in the joints of Hfe-KO mice compared with control mice at 8 weeks after surgery. CONCLUSIONS: HH was associated with an accelerated development of OA in mice. Our findings suggest that synovial iron overload has a definite role in the progression of HH-related OA.

Impact of allopurinol on risk of myocardial infarction.

BACKGROUND: Gout therapy includes xanthine oxidase inhibitors (XOI) and colchicine, which have both been associated with decreased cardiovascular risk. However, their effects on major cardiac events, such as myocardial infarction (MI), need to be investigated further. OBJECTIVES: To investigate whether XOIs and colchicine are associated with decreased risk of MI. METHODS: This case-control study compared patients with first-ever MI and matched controls. Cases were recruited from the Pharmacoepidemiological General Research on MI registry. Controls were selected from a referent population (n=8444) from general practice settings. RESULTS: The study sample consisted of 2277 MI patients and 4849 matched controls. Use of allopurinol was reported by 3.1% of cases and 3.8 of controls, and 1.1% of cases and controls used colchicine. The adjusted OR (95% CI) for MI with allopurinol use was 0.80 (0.59 to 1.09). When using less stringent matching criteria that allowed for inclusion of 2593 cases and 5185 controls, the adjusted OR was 0.73 (0.54 to 0.99). Similar results were found on analysis by sex and hypertension status. Colchicine used was not associated with a decreased risk of MI (aOR=1.17 (0.70 to 1.93)). CONCLUSIONS: Allopurinol may be associated with a reduced risk of MI. No decreased risk of MI was found in colchicine users. Besides its urate-lowering property, allopurinol might have a cardioprotective effect.

Identification of patients with gout: elaboration of a questionnaire for epidemiological studies.

OBJECTIVES: In France, the prevalence of gout is currently unknown. We aimed to design a questionnaire to detect gout that would be suitable for use in a telephone survey by non-physicians and assessed its performance. METHODS: We designed a 62-item questionnaire covering comorbidities, clinical features and treatment of gout. In a case-control study, we enrolled patients with a history of arthritis who had undergone arthrocentesis for synovial fluid analysis and crystal detection. Cases were patients with crystal-proven gout and controls were patients who had arthritis and effusion with no monosodium urate crystals in synovial fluid. The questionnaire was administered by phone to cases and controls by non-physicians who were unaware of the patient diagnosis. Logistic regression analysis and classification and regression trees were used to select items discriminating cases and controls. RESULTS: We interviewed 246 patients (102 cases and 142 controls). Two logistic regression models (sensitivity 88.0% and 87.5%; specificity 93.0% and 89.8%, respectively) and one classification and regression tree model (sensitivity 81.4%, specificity 93.7%) revealed 11 informative items that allowed for classifying 90.0%, 88.8% and 88.5% of patients, respectively. CONCLUSIONS: We developed a questionnaire to detect gout containing 11 items that is fast and suitable for use in a telephone survey by non-physicians. The questionnaire demonstrated good properties for discriminating patients with and without gout. It will be administered in a large sample of the general population to estimate the prevalence of gout in France.

Adalimumab in patients with hand osteoarthritis refractory to analgesics and NSAIDs: a randomised, multicentre, double-blind, placebo-controlled trial.

AIM: To test the efficiency of tumour necrosis factor blockers (adalimumab) in patients with painful refractory (non-responders to analgesics and non-steroidal anti-inflammatory drugs (NSAIDs)) hand osteoarthritis (OA). METHODS: We performed a randomised, double-blind, placebo-controlled, parallel group, multicentre study. Patients were randomised to: 1/1 adalimumab 40 mg for two subcutaneous injections at a 15-day interval or placebo and monitored for 6 months. The primary outcome was the percentage of patients with an improvement of more than 50% in global pain (Visual Analogue Scale) between week 0 (W0) and week 6 (W6). Secondary outcomes included the number of painful joints, swollen joints, morning stiffness duration, patient and practitioner global assessments, functional indexes for hand OA, and consumption of analgesics. Analysis on the mean primary outcome measure was done on patients who received at least one injection. RESULTS: 99 patients were recruited and 85 patients were randomised. Among them, 37 patients in the placebo group and 41 in the adalimumab group received at least one injection and were evaluated at W6 (n=78) on the main efficacy outcome. Mean age was 62 years, 85% were women, and mean level of pain was 62 mm at W0. At W6, 35.1% in the adalimumab group versus 27.3% in the placebo group had a pain reduction ≥50% (RR 1.12 (95% CI 0.82 to 1.54; p=0.48). There were no statistical differences for all secondary end points. The rate of adverse events was similar in the two groups. CONCLUSIONS: Adalimumab was not superior to placebo to alleviate pain in patients with hand OA not responding to analgesics and NSAIDs. TRIALS REGISTRATION NUMBER: NCT00597623.

Diabetes is a risk factor for knee osteoarthritis progression.

PURPOSE: Recent studies have suggested that metabolic factors (obesity, diabetes, hypertension and dyslipidemia) and their clustering in metabolic syndrome (MetS) might be involved in the pathophysiology of knee osteoarthritis (OA). We investigated their impact on radiographic progression by an annualised measure of the joint space narrowing (JSN) of the medial tibiofemoral compartment. METHODS: 559 patients older than 50 years with symptomatic knee OA were recruited for the placebo arm of the SEKOIA trial. The presence of diabetes, hypertension and dyslipidemia was determined at baseline interview. Body mass index (BMI) was calculated, obesity was considered >30 kg/m(2). MetS was defined by the sum of metabolic factors ≥ 3. Minimal medial tibiofemoral joint space on plain radiographs was measured by an automated method at baseline and then annually for up to 3 years. RESULTS: The mean age of patients was 62.8 [62.2-63.4] years; 392 were women. A total of 43.8% was obese, 6.6% had type 2 diabetes, 45.1% hypertension, 27.6% dyslipidemia and 13.6% MetS. Mean annualised JSN was greater for patients with type 2 diabetes than without diabetes (0.26 [-0.35 to -0.17] vs 0.14 [-0.16 to -0.12] mm; P = 0.001). This association remained significant after adjustment for sex, age, BMI, hypertension and dyslipidemia (P = 0.018). In subgroup analysis, type 2 diabetes was a significant predictor of JSN in males but not females. The other metabolic factors and MetS were not associated with annualised JSN. CONCLUSION: Type 2 diabetes was a predictor of joint space reduction in men with established knee OA. No relationships were found between MetS or other metabolic factors and radiographic progression.

Recommendations for an update of the 2010 European regulatory guideline on clinical investigation of medicinal products used in the treatment of osteoarthritis and reflections about related clinically relevant outcomes: expert consensus statement.

OBJECTIVE: The European Society on Clinical and Economic aspects of Osteoporosis and Osteoarthritis (ESCEO) organised a working group to evaluate the need for updating the current European guideline on clinical investigation of drugs used in the treatment of osteoarthritis (OA). DESIGN: Areas of potential attention were identified and the need for modifications, update or clarification was examined. Proposals were then developed based on literature reviews and through a consensus process. RESULTS: It was agreed that the current guideline overall still reflects the current knowledge in OA, although two possible modifications were identified. The first relates to the number and timing of measurements required as primary endpoints during clinical trials of symptom-relieving drugs, either drugs with rapid onset of action or slow acting drugs. The suggested modifications are intended to take into consideration the time related clinical need and expected time response to these drugs - i.e., a more early effect for the first category in addition to the maintenance of effect, a more continuous benefit over the long-term for the latter - in the timing of assessments. Secondly, values above which a benefit over placebo should be considered clinically relevant were considered. Based on literature reviews, the most consensual values were determined for primary endpoints of both symptom-relieving drugs (i.e., pain intensity on a visual analogue scale (VAS)) and disease-modifying drugs (i.e., radiographic joint-space narrowing). CONCLUSIONS: This working document might be considered by the European regulatory authorities in a future update of the guideline for the registration of drugs in OA.

Impact of treatments for osteoporosis on cartilage biomarkers in humans.

The rationale to target bone for treating osteoarthritis (OA) relies on the known cross-talk between subchondral bone and cartilage and the demonstration that subchondral bone resorption occurs at an early stage in the development of OA. Therefore, the possible OA disease-modifying effects of bone antiresorptive agents are of interest. This paper aims to review the published data on the effect of estrogens, selective estrogen receptor modulators, calcitonin, strontium ranelate, and bisphosphonates on cartilage biomarkers levels used as surrogate endpoints in clinical trials. Except for findings for tibolone, most observations indicated that these antiresorptive therapies decreased the urinary levels of CTX-II, a biomarker of type II collagen degradation. These data, which should be cautiously interpreted, suggest that these drugs might favorably affect cartilage homeostasis.

Impact of treatments for osteoporosis on osteoarthritis progression.

Subchondral bone is involved in the development of osteoarthritis, with an excess in bone resorption at an early stage and increased bone formation thereafter. Experimental and observational studies suggest that acting on bone can change progression of osteoarthritis. Clinical prospective controlled studies failed to confirm this result. Appropriate identification of patients at high risk of developing cartilage deterioration is a key issue for the analysis of impact of treatments for osteoporosis on osteoarthritis progression.

[Gout: an overview of available urate lowering therapies]. / Les traitements hypo-uricémiants disponibles dans la goutte.

The aim of urate-lowering therapy is to maintain urate concentration below the saturation point for monosodium urate. This therapy dissolves crystal deposits and cures gout while it is maintained. EULAR guidelines recommend that plasma urate should be maintained at a concentration less than 360µM, and the British Guidelines less than 300µM. Urate-lowering therapy is indicated for patients with recurrent gout attacks, chronic arthropathy, tophi, and gout with uric acid stones. Allopurinol lowers uricemia through inhibition of xanthine oxidase activity. The maximum allowed dose is reduced in case of renal failure, which is relatively frequent in gouty patients. Febuxostat has been approved for the treatment of chronic hyperuricemia in conditions where urate deposition has already occurred. Febuxostat is a novel non-purine, selective inhibitor of xanthine oxidase, metabolized and excreted by the liver, so no dose adjustment appears to be necessary in patients with mild-to-moderate renal impairment. Another powerful hypo-uricemic drug is the PEG-uricase (pegloticase). Pegloticase is a uric acid-specific PEGylated recombinant mammalian uricase recently approved by the FDA for treatment of patients with refractory chronic gout.

European League Against Rheumatism recommendations for calcium pyrophosphate deposition. Part I: terminology and diagnosis.

OBJECTIVES: To agree terminology and to develop recommendations for the diagnosis of calcium pyrophosphate deposition (CPPD). METHODS: The European League Against Rheumatism (EULAR) CPPD Task Force, comprising 15 experts from 10 countries, agreed the terms and recommendations for diagnosis of CPPD using a Delphi consensus approach. Evidence was systematically reviewed and presented in terms of sensitivity, specificity and positive likelihood ratio (LR) to support diagnosis; ORs were used for association. Strength of recommendation (SOR) was assessed by the EULAR visual analogue scale. RESULTS: It was agreed that 'CPPD' should be the umbrella term that includes acute calcium pyrophosphate (CPP) crystal arthritis, osteoarthritis (OA) with CPPD and chronic CPP crystal inflammatory arthritis. Chondrocalcinosis (CC) defines cartilage calcification, most commonly due to CPPD and detected by imaging or histological examination. A total of 11 key recommendations were generated on the topics of clinical features, synovial fluid (SF) examination, imaging, comorbidities and risk factors. Definitive diagnosis of CPPD relies on identification of SF CPP crystals. Rapid onset inflammatory symptoms and signs are suggestive but not definitive for acute CPP crystal arthritis. Radiographic CC is not highly sensitive or specific, whereas ultrasonography appears more useful (LR=24.2, 95% CI 3.51 to 168.01) for peripheral joints. Recognised risk factors for CPPD include ageing, OA and metabolic conditions such as primary hyperparathyroidism, haemochromatosis and hypomagnesaemia; familial forms are rare. SORs varied from 53 to 99 (maximum 100). CONCLUSION: New terms for CPPD were agreed and 11 key recommendations for diagnosis of CPPD were developed using research evidence and expert consensus.

EULAR recommendations for calcium pyrophosphate deposition. Part II: management.

OBJECTIVES: To develop evidence-based recommendations for management of calcium pyrophosphate deposition (CPPD). METHODS: A multidisciplinary guideline development group of 15 experts, representing 10 European countries, generated key propositions for management of CPPD using a Delphi consensus approach. For each recommendation research evidence was searched systematically. Whenever possible, the effect size and number needed to treat for efficacy and RR or OR for side effects were calculated for individual treatment modalities. Strength of recommendation was assessed by the European League Against Rheumatism visual analogue scale. RESULTS: Nine key recommendations were generated, including topics for general management, treatment of acute attacks, prophylaxis against recurrent acute attacks and management of chronic symptoms. It was recommended that optimal treatment requires both non-pharmacological and pharmacological treatments. For acute CPP crystal arthritis, cool packs, temporary rest and joint aspiration combined with steroid injection are often sufficient. For prophylaxis or chronic inflammatory arthritis with CPPD, oral non-steroidal anti-inflammatory drugs with gastroprotective treatment and/or low-dose colchicine 0.5-1.0 mg daily may be used. Other recommendations included parenteral or oral corticosteroid for acute CPP arthritis in those unresponsive or unsuited to other measures, and low-dose corticosteroid, methotrexate or hydroxychloroquine for chronic inflammatory arthritis with CPPD. Asymptomatic CPPD requires no treatment. Strength of recommendations varies from 79% to 95%. CONCLUSION: Nine key recommendations for management of CPP crystal associated arthritis were developed using both research evidence and expert consensus. Strength of recommendations was provided to assist the application of these recommendations.

Bone mineral density in patients with rapidly destructive or common hip osteoarthritis.

BACKGROUND: Recent findings that subchondral insufficiency fracture in the femoral head may precede rapid chondrolysis suggest a role for systemic low bone mass in the genesis of rapidly destructive hip osteoarthritis (RDHOA). OBJECTIVE: To compare bone mineral density (BMD) in females with RDHOA and those with common hip osteoarth-ritis (OA). METHODS: This prospective case-control study involved 26 females with RDHOA recruited from our institution between March 2000 and November 2006. BMD was measured at the femoral neck and lumbar spine (L1-L4) by dual-energy x-ray absorptiometry. For comparison, BMD was measured in 33 women with common hip OA who were scheduled for primary total hip arthroplasty. RESULTS: Patients with RDHOA and those with common hip OA were similar in age (74.9+/-9.9 vs. 74.7+/-8.8 years) and BMI (26.3+/-4.3 vs. 26.3+/-5 g/m2) and did not differ in mean BMD at the lumbar spine (1.0+/-0.2 vs. 1.1+/-0.2 g/cm2; mean T-score: -0.6+/-1.3 vs. -0.8+/-1.5) or at the femoral neck (0.7+/-0.1 vs. 0.8+/-0.2 g/cm2; mean T-score: -1.5+/-1.1 vs. -1.4+/-1.4). CONCLUSION: The results of this study do not suggest a role for systemic low bone mass in the pathophysiology of RDHOA.