Are Bone Mineral Density and Fractures Related to the Incidence and Progression of Radiographic Osteoarthritis of the Knee, Hip, and Hand in Elderly Men and Women? The Rotterdam Study

Endophenotypes of Primary Osteoarthritis of the Hip Joint in the Bulgarian Population over 60 Years Old

Aim. To identify subgroups of patients with primary osteoarthritis of the hip joint (pHOA) with similar imaging and laboratory findings, disease evolution, and response to conventional therapies. Methods. We performed further statistical analyses on patient data from two published, double-blind, randomized, and placebo-controlled studies (DB-RCTs), which examined the effects of intra-articular corticosteroids (ia-CSs), hyaluronic acid (ia-HA)-KИ-109-3-0008/14.01.2014, and intravenous bisphosphonates (iv-BPs) -KИ- 109-3-0009/14.01.2014 compared to the country's standard pHOA therapy. The data span an 8-year follow-up of 700 patients with pHOA, including: 1. Clinical parameters (WOMAC-A, B, C, and T; PtGA). 2. Laboratory markers (serum calcium and phosphate levels; 25-OH-D and PTH, markers for bone sCTX-I and cartilage uCTX-II turnover). 3. Radiological indicators: X-ray stage (Kellgren-Lawrence (K/L) and model (Bombelli/OOARSI), width (mJSW), speed (JSN mm/year), and zone of maximum narrowing of the joint space (max-JSN)-determining the type of femoral head migration (FHM). 4. DXA indicators: bone geometry (HAL; NSA; and MNW); changes in regional and total bone mineral density (TH-BMD, LS-BMD, and TB-BMD). 5. Therapeutic responses (OARSI/MCII; mJSW; JSNmm/yearly) to different drug regimens (iv-BP -zoledronic acid (ZA/-5 mg/yearly for 3 years)); ia-CS 40 mg methylprednisolone acetate, twice every 6 months; and ia-HA with intermediate molecular weight (20 mg/2 mL × 3 weekly applications, two courses every 6 months) were compared to standard of care therapy (Standard of Care/SC/), namely D3-supplementation according to serum levels (20-120 ng/mL; target level of 60 ng/mL), simple analgesics (paracetamol, up to 2.0 g/24 h), and physical exercises. The abovementioned data were integrated into a non-supervised hierarchical agglomerative clustering analysis (NHACA) using Ward's linkage method and the squared Euclidean distance to identify different endophenotypes (EFs). Univariate and multivariate multinomial logistic regression analyses were performed to determine the impact of sex and FHM on clinical and radiographic regression of pHOA. Results. A baseline cluster analysis using incoming (M0) patient data identified three EFs: hypertrophic H-HOA, atrophic A-HOA, and intermediate I-HOA. These EFs had characteristics that were similar to those of patients grouped by radiographic stage and pattern ('H'-RPs, 'I'-RPs, and 'A'-RPs), p < 0.05). The repeated cluster analysis of M36 data identified four EF pHOAs: 1. Hypertrophic (slow progressors, the influence of the type of femoral head migration (FHM) outweighing the influence of sex on progression), progressing to planned total hip replacement (THR) within 5 (K/LIII) to 10 (K/LII) years. 2. Intermediate (sex is more important than the FHM type for progression) with two subgroups: 2#: male-associated (slow progressors), THR within 4 (K/LIII) to 8 years. (K/LII). 2* Female-associated (rapid progressors), THR within 3 (K/LIII) to 5 (K/LII) years. 3. Atrophic (rapid progressors; the influence of FHM type outweighs that of sex), THR within 2 (K/LIII) to 4 (K/LII) years. Each EF, in addition to the patient's individual progression rate, was also associated with a different response to the aforementioned therapies. Conclusions. Clinical endophenotyping provides guidance for a personalized approach in patients with pHOA, simultaneously assisting the creation of homogeneous patient groups necessary for conducting modern genetic and therapeutic scientific studies.

Osteoporosis, Osteoarthritis, and Subchondral Insufficiency Fracture: Recent Insights

The increased incidence of osteoarthritis (OA), particularly knee and hip OA, and osteoporosis (OP), owing to population aging, have escalated the medical expense burden. Osteoarthritis is more prevalent in older women, and the involvement of subchondral bone fragility spotlights its association with OP. Notably, subchondral insufficiency fracture (SIF) may represent a more pronounced condition of OA pathophysiology. This review summarizes the relationship between OA and OP, incorporating recent insights into SIF. Progressive SIF leads to joint collapse and secondary OA and is associated with OP. Furthermore, the thinning and fragility of subchondral bone in early-stage OA suggest that SIF may be a subtype of OA (osteoporosis-related OA, OPOA) characterized by significant subchondral bone damage. The high bone mineral density observed in OA may be overestimated due to osteophytes and sclerosis and can potentially contribute to OPOA. The incidence of OPOA is expected to increase along with population aging. Therefore, prioritizing OP screening, early interventions for patients with early-stage OA, and fracture prevention measures such as rehabilitation, fracture liaison services, nutritional management, and medication guidance are essential.

Vertebral bone quality different in magnetic resonance imaging parameters

OBJECTIVE

This was a single-center retrospective study that aimed to measure the vertebral bone quality (VBQ) in people of all ages and compare changes in VBQ across ages. Differences in VBQ under various MRI parameters were compared.

METHODS

We first screened patients without underlying disease and no history of fractures who underwent lumbar MRI in our center in the past four years. Over the span of 10 years, 200 patients (100 males and 100 females) were randomly recruited into each cohort to undergo 1.5 T and 3.0 T MRI scans. Subsequently, we tabulated the number of patients admitted to our hospital with OVCF over the past four years. There were 30 healthy adults under 4 times of MRI scans in different parameters to determine the differentiation of VBQ. The 30 healthy adults were recruited to validate the differentiation of VBQ under various parameters.

RESULTS

A total of 2400 patients without OVCF and 405 patients with OVCF were enrolled. The VBQ value of 1.5 T was significantly higher compared with that of 3.0 T (2.769 ± 0.494 > 2.199 ± 0.432, P < 0.0001). VBQ of 43.31 kHz in 1.5 T was significantly lower than that of 35.36 kHz (2.447 ± 0.350 < 2.632 ± 0.280, P < 0.05). The differentiation of VBQ in 1.5 T and 3.0 T was validated using results of healthy adults.

CONCLUSIONS

VBQ is an effective tool for differentiating patients with OVCF and can be used as a primary screening tool for osteoporosis. However, VBQ is significantly affected by magnetic field intensity and bandwidth and cannot achieve its universality as it originally proposed.

Association of knee and hip osteoarthritis with the risk of falls and fractures: a systematic review and meta-analysis

OBJECTIVE

Studies evaluating the association of knee and hip osteoarthritis (OA) with falls and fractures have inconsistent findings. We aimed to investigate associations of symptomatic and radiographic knee and hip OA with risk of falls, recurrent falls, and fractures.

METHODS

We conducted an electronic search of databases from inception to February 2023. Two authors independently screened studies, extracted data, and assessed the risk of bias using the Newcastle-Ottawa Scale tool in eligible studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Of 17 studies included (n = 862849), 2 had a high risk of bias. Among studies that evaluated falls or fractures as outcomes, 7/8 (87.5%) and 5/11 (45.5%) were self-reported, respectively. Both symptomatic knee and hip OA were associated with increased risk of recurrent falls (knee: OR = 1.55, 95% CI 1.10 to 2.18; hip: OR = 1.50, 95% CI 1.28 to 1.75) but not falls or fractures. Radiographic knee OA increased risk of falls (OR = 1.28, 95% CI 1.03 to 1.59) and did not significantly increase risk of recurrent falls (OR = 1.39, 95% CI 0.97 to 1.97) or fractures (OR = 1.22, 95% CI 0.99 to 1.52). Radiographic hip OA decreased the risk of recurrent falls (OR = 0.70, 95% CI 0.51 to 0.96) but had no statistically significant association with fractures (OR = 1.16, 95% CI 0.79 to 1.71).

CONCLUSION

Symptomatic knee and hip OA were both associated with an increased risk of recurrent falls, and radiographic knee OA was associated with an increased risk of falls. No statistically significant associations of radiographic and symptomatic knee or hip OA with fractures were found.

Lower bone mineral density can be a risk for an enlarging bone marrow lesion: A longitudinal cohort study of Japanese women without radiographic knee osteoarthritis

OBJECTIVES

The aim is to elucidate the relationship between bone mineral density (BMD) at baseline and the change of bone marrow lesion (BML) during a 2-year follow-up (2YFU) period.

METHODS

Seventy-eight female participants (mean age: 54.9 ± 9.6 years) without radiographic knee osteoarthritis were eligible. Based on right-knee magnetic resonance imaging, maximum BML area (BMLa) was calculated by tracing the BML border. The change in BMLa was defined using the following formula: [2YFU] - [Baseline] = ΔBMLa. Positive ΔBMLa was defined as enlarged; negative ΔBMLa was defined as regressed. Dual-energy X-ray absorptiometry was performed to measure the BMD of distal radius. Young adult mean [YAM (%)] of the BMD was used for statistical analysis. Linear regression analysis was conducted with ΔBMLa as the dependent variable and YAM as the independent variable. Receiver operating characteristic curve and logistic regression analyses were conducted for YAM to predict the prevalence of BML enlargement or regression.

RESULTS

Twenty-six (33.3%) patients had enlarged BMLa, 12 (15.4%) participants showed regressing BMLa, and 40 (51.3%) patients remained stable. YAM was negatively associated with ΔBMLa (β: - 0.375, P = 0.046). The best predictor of BML enlargement risk was 85% (odds ratio: 8.383, P = 0.025).

CONCLUSIONS

Lower BMD could predict BML enlargement during a 2YFU period.

Correlation between Bone Mineral Density and Progression of Hip Osteoarthritis in Adult Men and Women in Bulgaria-Results from a 7-Year Study

Changes in clinical presentation, radiographic progression (RP), bone mineral density (BMD), bone turnover (BT), and cartilage turnover (CT) markers were compared in two groups of patients with hip osteoarthritis (HOA) over a period of 7 years. Each group consisted of 150 patients, including a control group on standard-of-care therapy (SC) with simple analgesics and physical exercises, and a study group (SG) on standard-of-care therapy supplemented by vitamin D3 and intravenous administration of zoledronic acid (5 mg) yearly for 3 consecutive years. Patient groups were homogenized regarding the following: (1) radiographic grade (RG), including 75 patients with hip OA RG II according to the Kellgren-Lawrence grading system (K/L), and 75 with RG III on K/L; (2) radiographic model (RM), as each of the K/L grades was subdivided into three subgroups consisting of 25 patients of different RMs: atrophic ('A'), intermediate ('I'), and hypertrophic ('H'); (3) gender-equal ratio of men and women in each subgroup (Female/Male = 15/10). The following parameters were assessed: (1) clinical parameters (CP), pain at walking (WP-VAS 100 mm), functional ability (WOMAC-C), and time to total hip replacement (tTHR); (2) radiographic indicators(RI)-joint space width (JSW) and speed of joint space narrowing (JSN), changes in BMD (DXA), including proximal femur (PF-BMD), lumbar spine (LS-BMD), and total body (TB-BMD); (3) laboratory parameters (LP)-vitamin D3 levels and levels of BT/CT markers. RV were assessed every 12 months, whereas CV/LV were assessed every 6 months. Results: Cross-sectional analysis (CsA) at baseline showed statistically significant differences (SSD) at p < 0.05 in CP (WP, WOMAC-C); BMD of all sites and levels of CT/BT markers between the 'A' and 'H' RM groups in all patients. Longitudinal analysis (LtA) showed SSD (p < 0.05) between CG and SG in all CP (WP, WOMAC-C, tTHR) parameters of RP (mJSW, JSN), BMD of all sites, and levels of CT/BT markers for all 'A' models and in 30% of 'I'-RMs (those with elevated markers for BT/CT at baseline and during the observation period). Conclusion: The presence of SSD at baseline ('A' vs. 'H') supported the thesis that at least two different subgroups of HOA exist: one associated with 'A' and the other with 'H' models. D3 supplementation and the intravenous administration of bisphosphonate were the treatment strategies that slowed down RP and postponed tTHR by over 12 months in the 'A' and 'I' RM with elevated BT/CT markers.

Induced inactivation of Wnt16 in young adult mice has no impact on osteoarthritis development

Osteoarthritis (OA) is a common disorder and a major cause of disability in the elderly population. WNT16 has been suggested to play important roles in joint formation, bone homeostasis and OA development, but the mechanism of action is not clear. Transgenic mice lacking Wnt16 expression (Wnt16-/-) have a more severe experimental OA than control mice. In addition, Wnt16-/- mice have a reduced cortical thickness and develop spontaneous fractures. Herein, we have used Cre-Wnt16flox/flox mice in which Wnt16 can be conditionally ablated at any age through tamoxifen-inducible Cre-mediated recombination. Wnt16 deletion was induced in 7-week-old mice to study if the Cre-Wnt16flox/flox mice have a more severe OA phenotype after destabilizing the medial meniscus (DMM surgery) than littermate controls with normal Wnt16 expression (Wnt16flox/flox). WNT16 deletion was confirmed in articular cartilage and cortical bone in Cre-Wnt16flox/flox mice, shown by immunohistochemistry and reduced cortical bone area compared to Wnt16flox/flox mice. After DMM surgery, there was no difference in OA severity in the articular cartilage in the knee joint between the Cre-Wnt16flox/flox and Wnt16flox/flox mice in neither female nor male mice. In addition, there was no difference in osteophyte size in the DMM-operated tibia between the genotypes. In conclusion, inactivation of Wnt16 in adult mice do not result in a more severe OA phenotype after DMM surgery. Thus, presence of WNT16 in adult mice does not have an impact on experimental OA development. Taken together, our results from Cre-Wnt16flox/flox mice and previous results from Wnt16-/- mice suggest that WNT16 is crucial during synovial joint establishment leading to limited joint degradation also later in life, after onset of OA. This may be important when developing new therapeutics for OA treatment.

Is Osteoarthritis Always Associated with Low Bone Mineral Density in Elderly Patients?

Background and Objectives: The relationship between osteoarthritis (OA) and osteoporosis (OP) has been analysed for over four decades. However, this relationship has remained controversial. Numerous observational and longitudinal studies have shown an inverse association between the two diseases and a protective effect of one against the other. On the other hand, some studies show that patients with OA have impaired bone strength and are more prone to fractures. The study’s main objective was to determine the bone mineral density (BMD) of the spine and hip (femoral neck) of postmenopausal women of different ages, with radiologically determined OA of the hip and knee, as well as to determine the correlation between BMD values and age in the experimental group. Materials and Methods: The retrospective cohort study included 7018 patients with osteoarthritis of peripheral joints and the spine, examined by a rheumatologist in an outpatient rheumatology clinic at the Institute for Treatment and Rehabilitation, Niška Banja from July 2019 to March 2021. A nested anamnestic study was conducted within the cohort study of patients, and it included two groups: an experimental group composed of 60 postmenopausal women, and a control group composed of the same number of women. Out of 120 patients, 24 did not meet the criteria for the continuation of the study (due to technical errors—radiographic and/or densitometry artefacts). Fifty-six postmenopausal women (aged 45−77 years) with hip and knee radiological OA were examined as an experimental group. The participants were divided into two subgroups according to age (45−60 years and over 61 years). The control group included 40 healthy postmenopausal women of the same age range, without radiological OA, with normal BMD of the hip and spine. All patients with OA met the American College of Radiology (ACR) criteria. OA of the hip and knee was determined radiologically according to Kellgren and Lawrence (K&L) classification, and patients were included in the study if a K&L grade of at least ≥ 2 was present. Hip and spine BMD was measured by dual-energy X-ray absorptiometry (DXA). Results: Compared to the control group, we found statistically significantly lower BMD and T-scores of the spine in older postmenopausal women: BMD (g/cm2), p = 0.014; T-score, p = 0.007, as well as of the hip: BMD (g/cm2), p = 0.024; T-score p < 0.001. The values of BMD and T-score of the spine and hip are lower in more severe forms of OA (X-ray stage 3 and 4, according to K&L), p < 0.001. We found negative correlation between BMD and T-score and age only for the hip: BMD (g/cm2), ρ = 0.378, p = 0.005; T-score ρ = −0.349, p = 0.010. Conclusions: Older postmenopausal women with radiographic hip and knee OA had significantly lower BMD of the hip and spine as compared to the control group without OA, pointing to the need for the prevention and treatment of OA, as well as early diagnosis, monitoring, and treatment of low bone mineral density.

High bone mass and cam morphology are independently related to hip osteoarthritis: findings from the High Bone Mass cohort

BACKGROUND

High bone mass (HBM, BMD Z-score ≥  + 3.2) and cam morphology (bulging of lateral femoral head) are associated with greater odds of prevalent radiographic hip osteoarthritis (rHOA). As cam morphology is itself a manifestation of increased bone deposition around the femoral head, it is conceivable that cam morphology may mediate the relationship between HBM and rHOA. We therefore aimed to determine if individuals with HBM have increased odds of prevalent cam morphology. In addition, we investigated whether the relationship between cam and prevalent and incident osteoarthritis was preserved in a HBM population.

METHODS

In the HBM study, a UK based cohort of adults with unexplained HBM and their relatives and spouses (controls), we determined the presence of cam morphology using semi-automatic methods of alpha angle derivation from pelvic radiographs. Associations between HBM status and presence of cam morphology, and between cam morphology and presence of rHOA (or its subphenotypes: osteophytes, joint space narrowing, cysts, and subchondral sclerosis) were determined using multivariable logistic regression, adjusting for age, sex, height, weight, and adolescent physical activity levels. The association between cam at baseline and incidence of rHOA after an average of 8 years was determined. Generalised estimating equations accounted for individual-level clustering.

RESULTS

The study included 352 individuals, of whom 235 (66.7%) were female and 234 (66.5%) had HBM. Included individuals contributed 694 hips, of which 143 had a cam deformity (20.6%). There was no evidence of an association between HBM and cam morphology (OR = 0.97 [95% CI: 0.63-1.51], p = 0.90) but a strong relationship was observed between cam morphology and rHOA (OR = 3.96 [2.63-5.98], p = 5.46 × 10-11) and rHOA subphenotypes joint space narrowing (OR = 3.70 [2.48-5.54], p = 1.76 × 10-10), subchondral sclerosis (OR = 3.28 [1.60-6.60], p = 9.57 × 10-4) and osteophytes (OR = 3.01 [1.87-4.87], p = 6.37 × 10-6). Cam morphology was not associated with incident osteoarthritis (OR = 0.76 [0.16-3.49], p = 0.72).

CONCLUSIONS

The relationship between cam morphology and rHOA seen in other studies is preserved in a HBM population. This study suggests that the risk of OA conferred by high BMD and by cam morphology are mediated via distinct pathways.

Epidemiology of osteoarthritis

OBJECTIVE

To summarize the current state of the evidence regarding osteoarthritis (OA) prevalence, incidence and risk factors at the person-level and joint-level.

DESIGN

This was a narrative review that took a comprehensive approach regarding inclusion of potential risk factors. The review complements prior reviews of OA epidemiology, with a focus on new research and emerging topics since 2017, as well as seminal studies.

RESULTS

Studies continue to illustrate the high prevalence of OA worldwide, with a greater burden among older individuals, women, some racial and ethnic groups, and individuals with lower socioeconomic status. Modifiable risk factors for OA with the strongest evidence are obesity and joint injury. Topics of high interest or emerging evidence for a potential association with OA risk or progression include specific vitamins and diets, high blood pressure, genetic factors, metformin use, bone mineral density, abnormal joint shape and malalignment, and lower muscle strength/quality. Studies also continue to highlight the heterogenous nature of OA, with strong interest in understanding and defining OA phenotypes.

CONCLUSIONS

OA is an increasingly prevalent condition with worldwide impacts on many health outcomes. The strong evidence for obesity and joint injury as OA risk factors calls for heightened efforts to mitigate these risks at clinical and public health levels. There is also a need for continued research regarding how potential person- and joint-level risk factors may interact to influence the development and progression of OA.

Hip, vertebral, and wrist fracture risks and schizophrenia: a nationwide longitudinal study

BACKGROUND

Fractures are a great health issue associated with morbidity, quality of life, life span, and health care expenditure. Fractures are correlated with cardiovascular disease, type 2 diabetes mellitus, cerebrovascular disease, and some psychiatric disorders. However, representative national data are few, and longitudinal cohort studies on the association between schizophrenia and the subsequent fracture risk are scant. We designed a nationwide population-based cohort study to investigate the association of schizophrenia with hip, vertebral, and wrist fractures over a 10-year follow-up.

METHODS

Data of patients with schizophrenia (International Classification of Diseases, Ninth Revision, Clinical Modification code 295) and matched over January 2000-December 2009) were extracted from Taiwan National Health Insurance Research Database. A Cox proportional-hazards regression model was constructed to calculate hazard ratios (HRs) for fractures between the schizophrenia and control cohorts.

RESULTS

Of 2028 people with schizophrenia (mean age: 36.3 years, 49.4% female), 89 (4.4%) reported newly diagnosed fractures-significantly higher than the proportion in the control population (257, 3.2%; P = 0.007). The incidences of hip (1.2%, P = 0.009) and vertebral (2.6%, P = 0.011) fractures were significantly higher in the schizophrenia cohort than in the control cohort. In Cox regression analysis, hip (adjusted HR: 1.78, 95% confidence interval [CI]: 1.08-2.93) and vertebral (adjusted HR: 1.40, 95% CI: 1.01-1.95) fracture risks were significantly higher in patients with schizophrenia. Furthermore, a sex-based subgroup analysis revealed that the risk of hip fracture remained significantly higher in female patients with schizophrenia (HR: 2.68, 95% CI: 1.32-5.44) than in female controls. On the other hand, there was no significant interaction between effects of sex and schizophrenia on the risk of fractures.

CONCLUSIONS

Over a 10-year follow-up, hip and vertebral fracture risks were higher in the people with schizophrenia than in the controls. The risk of fractures in patients with schizophrenia does not differ between female and male.

The causal association between bone mineral density and risk of osteoarthritis: A Mendelian randomization study

OBJECTIVES

The causal direction and magnitude of the association between total body bone mineral density (TB-BMD) and osteoarthritis (OA) risk is uncertain owing to the susceptibility of observational studies to confounding and reverse causation. The study aimed to explore the relationships between TB-BMD concentration and OA using Mendelian randomization (MR).

METHODS

In this study, we used two-sample MR to obtain unconfounded estimates of the effect of TB-BMD on hip and knee OA. Single nucleotide polymorphisms (SNPs) strongly associated with TB-BMD in a large genome-wide association study (GWAS) were identified and selected as instrumental variables (IVs). In addition to the main analysis using inverse-variance weighted (IVW) method, we applied 2 additional methods to control for pleiotropy(MR-Egger regression, weighted median estimator) and compared the respective MR estimates.

RESULTS

MR analyses suggested that genetically predicted higher TB-BMD is associated with risks of hip OA (For IVW: OR=1.199, 95%CI: 1.02-1.42, P=0.032; for WM: OR=1.257, 95%CI: 1.09-1.45, P=0.002). There was no evidence that the observed causal effect between TB-BMD and the risk of hip OA was affected by genetic pleiotropy(P=0.618). Additionally, our study didn't support causal effects of a genetically increased TB-BMD risk on knee OA risk(OR=1.121, 95%CI: 0.99-1.28, P=0.084 using IVW; OR=1.132, 95%CI: 0.99-1.29, P=0.068 using WM; OR=1.274, 95%CI: 0.88-1.85, P=0.217 using MR-Egger).

CONCLUSIONS

Our findings support a causal effect that a genetic predisposition to systematically higher TB-BMD was associated with the risk of OA. And, TB-BMD likely exerts an effect on the risk of hip OA not knee OA.

Mendelian randomization study on vitamin D levels and osteoarthritis risk: a concise report

OBJECTIVE

The role of vitamin D in OA is unclear and previous epidemiological studies have provided inconsistent results. We conducted a two-sample Mendelian randomization (MR) study to investigate the causal relationship between genetically determined serum vitamin D levels and hip/knee OA.

METHODS

Six single-nucleotide polymorphisms (SNPs) associated with vitamin D levels in the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits Consortium were selected as instrumental variables. Summary statistics of the SNPs effects on OA were derived from the Iceland and UK Biobank, comprising 23 877 knee OA cases, 17 151 hip OA cases and >562 000 controls. The control samples match the OA cases in age, sex and county of origin.

RESULTS

The MR analyses showed no causal association between genetically determined vitamin D levels and knee OA [odds ratio (OR) 1.03 (95% CI 0.84, 1.26)] or hip OA [OR 1.06 (95% CI 0.83, 1.35)].

CONCLUSION

Genetic variations associated with low vitamin D serum levels are not associated with increased risk of hip or knee OA in community-dwelling older adults, suggesting that vitamin D levels are not causally linked to OA. It is therefore unlikely that vitamin D supplementation protects against hip or knee OA.

Correlation of osteoarthritis or rheumatoid arthritis with bone mineral density in adults aged 20-59 years

Background

It is reported that osteoporosis commonly occurs among patients with rheumatoid arthritis (RA), whereas the association between osteoporosis and osteoarthritis (OA) remains controversial. Our aim in this study was to investigate the association between BMD, as a marker of osteoporosis, and OA and RA among adults 20−59 years of age, using a population-based sample from the National Health and Nutrition Examination Survey (NHANES).

Methods

Our analysis was based on the NHANES data collected between 2011 and 2018. Data regarding arthritis status and the type of arthritis (OA or RA) were obtained from questionnaires. Lumbar BMD was measured by dual-energy X-ray absorptiometry. The association between OA, RA, and lumbar BMD was evaluated using logistic regression models. Subgroup analyses, stratified by gender and race, were performed. The association between duration of arthritis and lumbar BMD was also investigated.

Results

A total of 11,094 adults were included in our study. Compared to the non-arthritis group, participants with OA had a higher lumbar BMD (β = 0.023, 95% CI 0.011–0.035), with no significant association between lumbar BMD and RA (β = 0.014, 95% CI − 0.003 to 0.031). On subgroup analyses stratified by gender, males with OA had a higher lumbar BMD compared to those without OA (β = 0.047, 95% CI 0.028–0.066). In females, OA was not associated with lumbar BMD (β = 0.007, 95% CI − 0.008 to 0.021). There was no association between lumbar BMD and RA in both males (β = 0.023, 95% CI − 0.003 to 0.048) and females (β = 0.008, 95% CI − 0.015 to 0.031). Duration of arthritis was not associated with lumbar BMD for both OA (β = − 0.0001, 95% CI − 0.0017 to 0.0015) and RA (β = 0.0006, 95% CI − 0.0012 to 0.0025).

Conclusions

Lumbar BMD was associated with OA but not with RA. While a higher lumbar BMD was associated with OA in males, but not in females. Our findings may improve our understanding between OA, RA, and bone health.

ROS-Sensitive Nanoparticles Co-delivering Dexamethasone and CDMP-1 for the Treatment of Osteoarthritis Through Chondrogenic Differentiation Induction and Inflammation Inhibition

Objective: Osteoarthritis (OA) is a common subtype of arthritis. To date, treatment of OA focuses primarily on alleviating pain and improving joint function. The lack of a vascular system within synovial joints and the rapid removal of agents due to synovial exchange hinder continuous delivery of OA drugs. However, these obstacles are being addressed by promising nanoscale drugs.

Methods: We synthesize and assemble a hydrogen peroxide [H₂O₂, belongs to the category of active oxygen species (ROS)]-sensitive nanomicelle, which is loaded with the anti-inflammation drug dexamethasone and chondrogenic differentiation factor cartilage-derivedmor-phogeneticprotein-1. The micelle can induce bone marrow mesenchymal stem cells to repair cartilage while inhibiting joint inflammation.

Results: The prepared nanoparticles were of uniform size and displayed an obvious core-shell structure. Under H₂O₂ stimulation, the shell layer could be removed gradually. The drug-loaded micelle effectively inhibited proliferation of activated macrophages, induced macrophage apoptosis with an anti-inflammatory effect, and caused the BMSCs to differentiate into chondrocytes.

Conclusion: This work provides an experimental and theoretical basis for further development of a drug-loaded micelle in the healing of osteoarthritis.

Increased development of radiographic hip osteoarthritis in individuals with high bone mass: a prospective cohort study

BACKGROUND

Individuals with high bone mass (HBM) have a greater odds of prevalent radiographic hip osteoarthritis (OA), reflecting an association with bone-forming OA sub-phenotypes (e.g. osteophytosis, subchondral sclerosis). As the role of bone mineral density (BMD) in hip OA progression is unclear, we aimed to determine if individuals with HBM have increased incidence and/or progression of bone-forming OA sub-phenotypes.

METHODS

We analysed an adult cohort with and without HBM (L1 and/or total hip BMD Z-score > + 3.2) with pelvic radiographs collected at baseline and 8-year follow-up. Sub-phenotypes were graded using the OARSI atlas. Superior/inferior acetabular/femoral osteophyte and medial/superior joint space narrowing (JSN) grades were summed and Δosteophyte and ΔJSN derived. Pain and functional limitations were quantified using the WOMAC questionnaire. Associations between HBM status and change in OA sub-phenotypes were determined using multivariable linear/logistic regression, adjusting for age, sex, height, total body fat mass, follow-up time and baseline sub-phenotype grade. Generalised estimating equations accounted for individual-level clustering.

RESULTS

Of 136 individuals, 62% had HBM at baseline, 72% were female and mean (SD) age was 59 (10) years. HBM was positively associated with both Δosteophytes and ΔJSN (adjusted mean grade differences between individuals with and without HBM β_osteophyte = 0.30 [0.01, 0.58], p = 0.019 and β_JSN = 0.10 [0.01, 0.18], p = 0.019). Incident subchondral sclerosis was rare. HBM individuals had higher WOMAC hip functional limitation scores (β = 8.3 [0.7, 15.98], p = 0.032).

CONCLUSIONS

HBM is associated with the worsening of hip osteophytes and JSN over an average of 8 years, as well as increased hip pain and functional limitation.

Defining disease progression in Chinese mainland people: Association between bone mineral density and knee osteoarthritis

Objective

To evaluate change in bone mineral density (BMD) during development of knee osteoarthritis (OA) in elderly Chinese community residents. Further, to monitor disease progression by recording speed of sound (SOS), one parameter of BMD provided by quantitative ultrasound measurement.

Methods

A total of 4173 community residents of the Chinese mainland were organized to complete questionnaires and relevant measurements, including anthropometry, radiology and quantitative ultrasound (QUS). SOS measurements of the distal radius were acquired using QUS measurements. The Kellgren-Lawrence (KL) grade of knee OA was evaluated by two experienced radiographers using X-rays. Finally, a general linear models analysis was performed to determine potential relationships. Further, the area under the receiver operating characteristic curve (ROC AUC) was applied to assess the distinction model.

Results

The SOS score in the OA group was significantly lower than that in the control group (p ​< ​0.001). However, after adjustment for age and body mass index (BMI), no significant difference was observed in the male population (p ​＝ ​0.841), while a significantly lower SOS score presented in knee OA participants in the female population (p ​＝ ​0.033). A turning point in SOS scores, from increasing to decreasing trends, occurred around KL grade 2; the SOS score gradually increased with progression in participants from KL grades 0 to 2, whereas the SOS score presented a significant decrease in participants with KL grades 3 and 4. The AUC for the model to distinguish OA progression was 0.891.

Conclusion

There was a non-linear and stage-specific association between SOS score and knee OA, which presented a positive relationship in early stages, but a negative relationship in advanced stages. A decline of SOS score in knee OA patients in early stages should alert clinicians to the possibility of disease progression.

The Translational potential of this article

In the present study, the relationship between OA and BMD had established by SOS. The results suggested that close monitoring of SOS in elderly Chinese communities residents with knee OA could alert disease progression involvement by an easily accessible method, and help early referral to orthopedist consultation for further examination and treatment.

An in-depth study of the associations between osteoarthritis- and osteoporosis-related phenotypes at different skeletal locations

The relationship between OA and osteoporosis characteristics remains controversial. This study revealed that age-adjusted hand OA is associated with lower hand/arm BMD levels. Wrist fracture occurrence is associated with increased OA hand scores and low arm BMD. Conversely, age-adjusted knee and spine OA is associated with high spine, hip, and total BMDs.

INTRODUCTION

Osteoarthritis (OA) and osteoporosis are two common musculoskeletal diseases which contribute a high burden of disability, yet assessments of their relationship remains controversial. The aim of this study was to clarify the association between bone mineral densities (BMD) of the hand, arm, spine, hip, and total body, and OA of the hand and knee and lumbar disc degeneration in two different ethnic groups.

METHODS

Radiographic assessments of the hand, knee, and spine were collected and coded for joint space narrowing, osteophytes, and the Kellgren-Lawrence score from Chuvashian (n = 1504) and British (n = 2280) individuals. BMD measurements of standard skeletal sites were estimated by dual X-ray absorptiometry. Age- and familial-adjusted regression analyses were conducted to determine associations.

RESULTS

Knee OA affection was positively associated with elevated hip, spine, and total body BMD levels (p < 0.001). Additionally, disc degeneration phenotypes showed significant positive associations with the hip, spine, and total BMD (p < 0.001). However, increased hand OA scores was significantly negatively correlated with arm and hand BMD measurements in males and females in both samples (p < 0.001). Additionally, higher hand OA scores were significantly associated with wrist fracture.

CONCLUSIONS

We discovered a clear pattern of association between hand OA and low hand and arm BMD, with increased risk of wrist fracture, as well as reproducing previous associations between knee and spine OA and elevated spine, hip, and total body BMD. It appears that hand OA manifests differently in comparison to hip and knee OA.

Association of bone mineral density with the development of knee osteoarthritis in men and women: a cross-sectional study using the fourth and fifth Korea National Health and Nutrition Examination Surveys

Bone mineral density (BMD) and osteoarthritis (OA) were correlated but the relationship was varied according to sex. An association between lumbar spine and femur neck BMDs and OA showed a positive relation in women, while lumbar spine and pelvis BMDs in men were associated with OA with a negative relation.

PURPOSE

The purpose of this study was to evaluate the association of BMD in various body parts in conjunction with the presence or severity of radiographic knee osteoarthritis (KOA) in relation to sex.

METHODS

This study was a cross-sectional analysis using Korea National Health and Nutrition Examination Surveys. KOA was graded using the Kellgren-Lawrence (KL) grading system. Radiographic KOA was defined as a KL grade 2 or higher. The associations between KOA and BMD in certain body parts (femur, pelvis, lumbar, lower leg, and whole-body) were assessed. BMD was measured using dual-energy X-ray absorptiometry. The BMD of each body part was divided into quartiles and the relationship between KOA and BMD was examined according to sex.

RESULTS

BMD did not show a significant tendency according to KL grade in either sex. In men, the severity of KL grade have a statistically significant relationship with total femur (R² = 0.303, p < 0.05), femur neck (R² = 0.257, p < 0.05), lumbar (R² = 0.137, p < 0.05), and pelvis BMD (R² = 0.185, p < 0.05). In women, total femur (R² = 0.466, p < 0.05), lumbar (R² = 0.316, p < 0.05), pelvis (R² = 0.343, p < 0.05), and lower leg BMD (R² = 0.133, p < 0.05) were associated with the severity of KL grade. When the BMD was divided into quartiles, lumbar (p < 0.05) and pelvis BMD (p < 0.05) in men had statistically significant association with knee OA as BMD decreased. In women, femur neck (p < 0.05) and lumbar BMD (p < 0.05) were significantly associated with knee OA as BMD increased.

CONCLUSION

The relationship between BMD and OA severity varied according to sex. In women, there was a positive association between femur neck and lumbar BMD and OA, while BMD of the lumbar and pelvis in men was negatively correlated with OA.

LEVEL OF EVIDENCE

Cohort study, III.

Wnt16 Overexpression in Osteoblasts Increases the Subchondral Bone Mass but has no Impact on Osteoarthritis in Young Adult Female Mice

Epidemiological studies have shown that high bone mineral density (BMD) is associated with an increased risk of osteoarthritis (OA), but the causality of this relationship remains unclear. Both bone mass and OA have been associated with the WNT signaling pathway in genetic studies, there is thus an interest in studying molecular partners of the WNT signaling pathway and OA. Female mice overexpressing WNT16 in osteoblasts (Obl-Wnt16 mice) have an increased bone mass. We aimed to evaluate if the high bone mass in Obl-Wnt16 mice leads to a more severe experimental OA development than in WT control mice. We induced experimental OA in female Obl-Wnt16 and WT control mice by destabilizing the medial meniscus (DMM). The Obl-Wnt16 mice displayed thicker medial and lateral subchondral bone plates as well as increased subchondral trabecular bone volume/tissue volume (BV/TV) but un-altered thickness of articular cartilage compared to WT mice. After DMM surgery, there was no difference in OA severity in the articular cartilage in the knee joint between the Obl-Wnt16 and WT mice. Both the Obl-Wnt16 and WT mice developed osteophytes in the DMM-operated tibia to a similar extent. We conclude that although the Obl-Wnt16 female mice have a high subchondral bone mass due to increased WNT signaling, they do not exhibit a more severe OA phenotype than their WT controls. This demonstrates that high bone mass does not result in an increased risk of OA per se.

The association of subchondral and systemic bone mineral density with osteoarthritis-related joint replacements in older adults

OBJECTIVE

To describe the association of subchondral and systemic bone mineral density (BMD) with knee and hip replacements (KR and HR, respectively) due to osteoarthritis.

DESIGN

1,095 participants (mean age 63 years, 51% female) were included. At baseline, subchondral BMD of the medial and lateral tibia in three regions of interest (ROI) for the right knee, and systemic BMD of the lumbar spine, femoral neck, total hip and whole-body, were measured using dual-energy X-ray absorptiometry. Subchondral BMD of the hip was not measured. Competing risk regression models were used to estimate sub-distribution hazard ratios (SHRs) of KR/HR per one standard deviation (SD) higher in BMD measures, with adjustment of potential confounders.

RESULTS

Over 12.2 years, 79 (7.2%) participants underwent a KR and 56 (5.1%) an HR due to osteoarthritis. For the right side, medial subchondral BMD in ROI-3 was associated with an increased risk of KR (SHR 1.95 per SD; 95% Confidence Interval [CI], 1.57 to 2.43). In contrast, systemic BMD was not associated with the risk of KR, but higher BMD at the lumbar spine (1.42, 1.07 to 1.88) and whole-body (1.29, 1.00 to 1.66) were associated with an increased risk of HR at both sides.

CONCLUSIONS

Subchondral BMD is positively associated with an increased risk of KR and systemic BMD with an increased risk of HR, suggesting a role of BMD in the progression of osteoarthritis.