No clear association between female hormonal aspects and osteoarthritis of the hand, hip and knee: a systematic review

Sexual dimorphism in articular tissue anatomy - Key to understanding sex differences in osteoarthritis?

OBJECTIVE

Osteoarthritis (OA) prevalence and incidence varies between women and men, but it is unknown whether this follows sex-specific differences in systemic factors (e.g. hormones) and/or differences in pre-morbid joint anatomy. We recognize that classifications of sex within humans cannot be reduced to female/male, but given the lack of literature on non-binary individuals, this review is limited to the sexual dimorphism of articular morphotypes.

METHODS

Based on a Pubmed search using relevant terms, and input from experts, we selected articles based on the authors' judgment of their relevance, interest, originality, and scientific quality; no "hard" bibliometric measures were used to evaluate their quality or importance. Focus was on clinical rather than pre-clinical studies, with most (imaging) data being available for the knee joint.

RESULTS

After introducing "sexual dimorphism", the specific literature on articular morphotypes is reviewed, structured by: radiographic joint space width (JSW), meniscus, ligaments, articular cartilage morphology, articular cartilage composition and deformation, and articular tissue response to treatment.

CONCLUSIONS

Sex-specific differences were clearly observed for JSW, meniscus damage, ligament size, and cartilage morphometry (volume, thickness, and surface areas) but not for cartilage composition. Ligament and cartilage measures were smaller in women even after matching for confounders. Taken together, the findings indicate that female (knee) joints may be structurally more vulnerable and at greater risk of OA. The "one size/sex fits all" approach must be abandoned in OA research, and all observational and interventional studies should report their results for sex-specific strata, at least in pre-specified secondary or post-hoc analyses.

Lost in research translation: Female athletes are not male athletes, especially at the hip

Altered shape of the proximal femur (cam morphology) or acetabulum (pincer morphology) is indicative of femoroacetabular impingement, which can result in hip pain and osteoarthritis of the hip. As mechanical load during growth affects the resulting bone shape, there is strong evidence in males that cam morphology develops during skeletal growth while physes are open, rather than as an adaptation after growth plates are closed (skeletal maturity). This adaptation is particularly evident in athletes who participate at elite levels prior to skeletal maturity. The research providing this evidence, however, has primarily focused on male athletes. Despite the lack of inclusion in the research, females consistently comprise two thirds of the clinical and surgical populations with structural hip pain or pathology. Knowledge gained from male-dominated cohorts may not appropriately transfer to female athletes, especially at the hip. This perspectives article briefly reviews differences between females and males in femoral and acetabular structure, hormones, timing of puberty/maturation, hypermobility, activity level and movement control-factors which affect hip structure development and loading. Without female-focused research, the application of research findings from male athletes to female athletes may lead to ineffective or even inappropriate recommendations and treatments. Thus, there is a critical need for investment in research to promote life-long hip health for females.

Multimorbidity patterns in the working age population with the top 10% medical cost from exhaustive insurance claims data of Japan Health Insurance Association

Although the economic burden of multimorbidity is a growing global challenge, the contribution of multimorbidity in patients with high medical expenses remains unclear. We aimed to clarify multimorbidity patterns that have a large impact on medical costs in the Japanese population. We conducted a cross-sectional study using health insurance claims data provided by the Japan Health Insurance Association. Latent class analysis (LCA) was used to identify multimorbidity patterns in 1,698,902 patients who had the top 10% of total medical costs in 2015. The present parameters of the LCA model included 68 disease labels that were frequent among this population. Moreover, subgroup analysis was performed using a generalized linear model (GLM) to assess the factors influencing annual medical cost and 5-year mortality. As a result of obtaining 30 latent classes, the kidney disease class required the most expensive cost per capita, while the highest portion (28.6%) of the total medical cost was spent on metabolic syndrome (MetS) classes, which were characterized by hypertension, dyslipidemia, and type 2 diabetes. GLM applied to patients with MetS classes showed that cardiovascular diseases or complex conditions, including malignancies, were powerful determinants of medical cost and mortality. MetS was classified into 7 classes based on real-world data and accounts for a large portion of the total medical costs. MetS classes with cardiovascular diseases or complex conditions, including malignancies, have a significant impact on medical costs and mortality.

Reasons for the Sex Bias in Osteoarthritis Research: A Review of Preclinical Studies

Osteoarthritis (OA) is one of the most common degenerative diseases of articular cartilage. During OA, all the elements that contribute to the joint undergo physiological and structural changes that impair the joint function and cause joint pain and stiffness. OA can arise naturally, with the aging population witnessing an increase in diagnoses of this pathology, but the root causes of OA have yet to be identified, and increasing interest is arising towards investigating biological sex as a risk factor. Clinical studies show increased prevalence and worse clinical outcomes for female patients, yet most clinical and preclinical studies have disproportionately focused on male subjects. This review provides a critical overview of preclinical practices in the context of OA, highlighting the underlying need for taking biological sex as both a risk factor and an important component affecting treatment outcome. A unique insight into the possible reasons for female underrepresentation in preclinical studies is offered, including factors such as lack of specific guidelines requiring the analysis of sex as a biological variable (SABV), research-associated costs and animal handling, and wrongful application of the reduction principle. Additionally, a thorough investigation of sex-related variables is provided, stressing how each of them could add valuable information for the understanding of OA pathophysiology, as well as sex-dependent treatment strategies.

The burden of osteoarthritis: Is it a rising problem?

The objective of this review is to provide an overview of the current status of osteoarthritis (OA) as one of the most common joint disorders worldwide. Despite being the 11th cause of disability globally, there has been an increase in the prevalence, annual incidence, and years lived with disability of OA, particularly in developed and developing countries. Erosive hand OA, which affects approximately 10% of the general population, has been associated with a higher clinical burden compared to non-erosive hand OA. Patients with knee and hip OA, but not hand OA, are also at an increased risk of cardiovascular disease and all-cause mortality. Furthermore, OA has a significant contribution to healthcare costs in most countries. The recent COVID-19 pandemic has further exacerbated the disease burden of OA patients due to limited access to medical and surgical treatment. With increasing life expectancy and the aging of the global population, the burden of OA is expected to worsen. Therefore, this review highlights the importance of improving population and policymaker awareness of risk factors, such as obesity and injury, as well as early intervention and management of OA to control the future burden of the disease.

Correlation between the Signal Intensity Alteration of Infrapatellar Fat Pad and Knee Osteoarthritis: A Retrospective, Cross-Sectional Study

Infrapatellar fat pad (IPFP) inflammation is a common pathological manifestation in knee osteoarthritis (OA). However, the significance of IPFP signal intensity alteration for clinical diagnosis and treatment of knee OA needs further research. We assessed IPFP signal intensity alteration (0-3), IPFP maximum cross-sectional area (CSA) and IPFP depth, meniscus injury, bone marrow edema, and cartilage injury from magnetic-resonance imaging (MRI) in 41 non-KOA patients (K-L grade 0 and grade I) and 68 KOA patients (K-L grade 2,3 and 4). We found that IPFP signaling was altered in all patients with KOA whose alteration was closely related to the K-L grading. We found that the IPFP signal intensity was increased in most OA patients, especially the ones in the late stage. There were significant differences in IPFP maximum CSA and IPFP depth between groups in KOA and non-KOA patients. Moreover, Spearman correlation analysis showed that IPFP signal intensity was moderately positively correlated with age, meniscal injury, cartilage injury, and bone marrow edema, and negatively correlated with height, while not correlated with visual analogue scale (VAS) scoring and body mass index (BMI). In addition, women have higher IPFP inflammation scores on MRI than men. In conclusion, IPFP signal intensity alteration is associated with joint damage in knee OA, which may have clinical significance for diagnosing and treating KOA.

The Regional Burden and Disability-Adjusted Life Years of Knee Osteoarthritis in Kazakhstan 2014-2020

A Global Burden of Disease (GBD) study reported that 9.6 million years lived with disability (YLDs) were lost due to hip and knee osteoarthritis (KOA) in 2017. Although the GBD study presents the disease burden at the global level, there is no information on any Central Asian country. This study aims to investigate the epidemiology of knee osteoarthritis in Kazakhstan. The data of 56,895 people with KOA between 2014-2020 was derived from the Unified National Electronic Health System of Kazakhstan and retrospectively analyzed. The majority of the cohort (76%) were women, of Kazakh ethnicity (66%), and older than 50 years of age (87%). The risk of gonarthrosis escalated for women after 50 years and peaked at 75 years with a rate of 3062 females admitted to hospital per 100,000 women in the population. This observation is approximately three times higher than for men of the same age group. A geographical analysis showed that the Jambyl oblast, West Kazakhstan, North Kazakhstan, and the Akmola oblast have the highest burden of disease. During the observation period, 127,077 age-adjusted YLDs were lost due to knee osteoarthritis. This is the first study in Kazakhstan to investigate the burden of knee osteoarthritis. This research recognizes age and sex-based differences, and regional disparities in the incidence of knee osteoarthritis. This knowledge can lead to the development of more specific diagnostic approaches and gender-personalized therapy protocols for patients.

Inhibition of anandamide breakdown reduces pain and restores LTP and monoamine levels in the rat hippocampus via the CB1 receptor following osteoarthritis

Chronic pain is a persistent, complex condition that contributes to impaired mood, anxiety and emotional problems. Osteoarthritis (OA) is one of the major causes of chronic pain in adults and elderly people. A substantial body of evidence demonstrate that hippocampal neural circuits, especially monoamine dopamine and serotonin levels, contributes to negative affect and avoidance motivation experienced during pain. Current pharmacological strategies for OA patients are unsatisfying and the endocannabinoid system modulation might represent an alternative for the treatment of OA-related pain. In the present study, we used a rat model of osteoarthritis induced by intra-articular injection of sodium monoiodoacetate to assess, 28 days post-induction, the contribution of endocannabinoid system on the possible alteration in pain perception and affective behavior, in LTP and monoamine levels in the lateral entorhinal cortex-dentate gyrus pathway. The results show that OA-related chronic pain induces working memory impairment and depressive-like behavior appearance, diminishes LTP, decreases dopamine levels and increases serotonin levels in the rat dentate gyrus. URB597 administration (i.p., 1 mg/kg) reduces hyperalgesia and mechanical allodynia, improves recognition memory and depressive-live behavior, restores LTP and normalizes monoamine levels in the hippocampus. The effect was observed 60-120 min post-treatment and was blocked by AM251, which proves the action of URB597 via the CB₁ receptor. Therefore, our study confirms the role of anandamide in OA-related chronic pain management at the behavioral and hippocampal levels. This article is part of the Special Issue on 'Advances in mechanisms and therapeutic targets relevant to pain'.

Accelerated menopausal changes as human disease model 'FOCUM' for the development of osteoarthritis and other degenerative disorders: protocol for a prospective cohort study

INTRODUCTION

The incidence of degenerative disorders, including osteoarthritis (OA), increases rapidly in women after menopause. However, the influence of the menopause is still insufficiently investigated due to the slowness of menopausal transition. In this study, a novel human model is used in which it is expected that menopausal-related changes will occur faster. This is the Females discontinuing Oral Contraceptives Use at Menopausal age model. The ultimate aim is to link these changes to OA and other degenerative disorders, including cardiovascular diseases, diabetes, osteoporosis and tendinopathies.

METHODS AND ANALYSIS

This is a pilot observational prospective cohort study with 2 years of follow-up. Fifty women aged 50-60 who use oral contraceptive (OC) and have the intention to stop are included. Measurements are performed once before stopping OC, and four times thereafter at 6 weeks, 6 months, 1 year and 2 years. At every time point, a questionnaire is filled in and a sample of blood is drawn. At the first and final time points, a physical examination, hand radiographs and a MRI scan of one knee are performed. The primary OA outcome is progression of the MRI Osteoarthritis Knee Score. Secondary OA outcomes are the development of clinical knee and hand OA, development of knee OA according to the MRI definition, and progression of radiographic features for hand OA. Principal component analysis will be used to assess which changes occur after stopping OC. Univariate and multivariate generalised estimating equation models will be used to test for associations between these components and OA.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Ethics Committee of the Erasmus MC University Medical Center Rotterdam (MEC-2019-0592). All participants must give informed consent before data collection. Results will be disseminated in national and international journals.

TRIAL REGISTRATION NUMBER

NL70796.078.19.

Osteoarthritis: The importance of hormonal status in midlife women

Osteoarthritis (OA) is the commonest joint condition globally, affecting 18 % of women over the age of 60 years, although the prevalence varies according to the definition used. Although it may develop in any joint, it most commonly affects joints of the knee, hip, hand, spine and foot. Because OA often emerges in women in midlife, there has been longstanding interest in the association between hormonal status and the development and progression of OA. Researchers have variably suggested that estrogen exposure may be a risk factor for OA development, or that, conversely, it may be used as a therapy to treat OA. This review considers the historical development of this question, first described in the literature in 1805, and highlights the need for future research in this area.

Physiological levels of estradiol limit murine osteoarthritis progression

Among patients with knee osteoarthritis (OA), postmenopausal women are over-represented. The purpose of this study was to determine whether deficiency of female sex steroids affects OA progression and to evaluate the protective effect of treatment with a physiological dose of 17β-estradiol (E2) on OA progression using a murine model. Ovariectomy (OVX) of female mice was used to mimic a postmenopausal state. OVX or sham-operated mice underwent surgery for destabilization of the medial meniscus (DMM) to induce OA. E2 was administered in a pulsed manner for 2 and 8 weeks. OVX of OA mice did not influence the cartilage phenotype or synovial thickness, while both cortical and trabecular subchondral bone mineral density (BMD) decreased after OVX compared with sham-operated mice at 8 weeks post-DMM surgery. Additionally, OVX mice displayed decreased motor activity, reduced threshold of pain sensitivity, and increased number of T cells in the inguinal lymph nodes compared to sham-operated mice 2 weeks after OA induction. Eight weeks of treatment with E2 prevented cartilage damage and thickening of the synovium in OVX OA mice. The motor activity was improved after E2 replacement at the 2 weeks time point, which was also associated with lower pain sensitivity in the OA paw. E2 treatment protected against OVX-induced loss of subchondral trabecular bone. The number of T cells in the inguinal lymph nodes was reduced by E2 treatment after 8 weeks. This study demonstrates that treatment with a physiological dose of E2 exerts a protective role by reducing OA symptoms.

Decrease in Glycosaminoglycan with Aging in Normal Rat Articular Cartilage Is Greater in Females than in Males

OBJECTIVE

Osteoarthritis (OA) is more prevalent in females. We hypothesized that changes in articular cartilage (AC) constituents with aging may cause differences. Herein, we aimed to compare the changes in AC constituents with aging in male and female normal rats.

DESIGN

The glycosaminoglycan (GAG) and collagen (COL) contents of the AC in knee, hip, and shoulder joints of male and female rats were quantified and compared between age groups and sexes.

RESULTS

The amount of GAG was decreased in multiple joints in both males and females with aging. In females, it had a significant decrease in all joints measured. The decrease in GAG with aging was more severe in females than in males. Even in young rats, the amount of knee joint GAG was significantly less in females than in males. The amount of COL in the AC was unchanged with aging in both sexes.

CONCLUSIONS

The drastic GAG decrease with aging in female normal rats may explain the higher prevalence and more severe OA in females.

Estrogen alleviates post-traumatic osteoarthritis progression and decreases p-EGFR levels in female mouse cartilage

Objective

To investigate the effect of estrogen on the progression of post-traumatic osteoarthritis (PTOA) in mice and its possible mechanism.

Methods

Twelve-week-old ICR mice were divided into Group A (female control group), group B (ovariectomized(OVX) group), group C (OVX group supplemented with estrogen), and group D (male group) by destabilization of the medial meniscus (DMM)or sham operation. Safranin O staining was performed at 8 weeks and 12 weeks after operation, and the degree of articular cartilage lesion was evaluated using Mankin score. Twelve weeks after the operation, tissue sections were stained to analyze the matrix metalloproteinase 13(MMP13), phosphorylated epidermal growth factor receptor (p-EGFR) expression and apoptosis of chondrocytes.

Results

Decreased estrogen can significantly increase the weight of mice in female mice. The degree of cartilage damage in the knee joint on the DMM side of female mice was significantly severer than that on the Sham side. The DMM side also showed higher MMP13 expression and increased apoptotic chondrocytes. The degree of cartilage damage in the knee joint on the DMM side of female mice was significantly reduced after estrogen supplementation, and cartilage damage in the knee joint on the DMM side of female mice was less serious than that of male mice. As estrogen levels decreased, the severity of cartilage erosion in the knee joint on the DMM side was aggravated, and p-EGFR expression in the cartilage surface was also higher in female mice contrast to that in male mice. However, minimal changes in p-EGFR expression in the cartilage surface of bilateral knee joints of male mice were observe.

Conclusion

Estrogen has a regulatory effect on PTOA and its inhibits the expression of p-EGFR in cartilage on the knee joint surface and has a protective effect on articular cartilage in female mice.

Gender and Sex Are Key Determinants in Osteoarthritis Not Only Confounding Variables. A Systematic Review of Clinical Data

Many risk factors for osteoarthritis (OA) have been noted, while gender/sex differences have been understated. The work aimed to systematically review literature investigating as primary aim the relationship between gender/sex related discriminants and OA. The search was performed in PubMed, Science Direct and Web of Knowledge in the last 10 years. Inclusion criteria were limited to clinical studies of patients affected by OA in any joints, analyzing as primary aim gender/sex differences. Exclusion criteria were review articles, in vitro, in vivo and ex vivo studies, case series studies and papers in which gender/sex differences were adjusted as confounding variable. Of the 120 records screened, 42 studies were included. Different clinical outcomes were analyzed: morphometric differences, followed by kinematics, pain, functional outcomes after arthroplasty and health care needs of patients. Women appear to use more health care, have higher OA prevalence, clinical pain and inflammation, decreased cartilage volume, physical difficulty, and smaller joint parameters and dimensions, as compared to men. No in-depth studies or mechanistic studies analyzing biomarker differential expressions, molecular pathways and omic profiles were found that might drive preclinical and clinical research towards sex-/gender-oriented protocols.

Current Epidemiology and Risk Factors for the Development of Hand Osteoarthritis

PURPOSE OF REVIEW

Hand osteoarthritis (hand OA), the most common peripheral arthritis in the world, is less studied than osteoarthritis (OA) of the knee and hip. However, it is uniquely situated to offer novel insight into OA as a disease process by removing weight-bearing as a confounder of systemic disease mechanisms. Here we review the epidemiology of hand OA and key risk factors for its development.

RECENT FINDINGS

Mounting evidence points to obesity as an important risk factor for hand OA development, with new evidence implicating a role for leptin and serum fatty acids. Disease progression in hand OA and specifically the erosive OA subtype may be associated with diabetes. New evidence supports an association between cardiovascular disease progression and symptomatic hand OA. Alcohol use may be associated with increased synovitis and erosive hand OA. Differences in ethnical distributions of hand OA have become more apparent, with a lower prevalence in Black patients compared to White patients. Novel genetic insights implicating the WNT gene pathway and IL-1β have led to novel potential targets in hand OA pathogenesis. Hand OA is a heterogeneous disease with many modifiable and non-modifiable risk factors that can determine disease severity and shed light on disease pathogenesis.

The prevalence of radiographic thumb base osteoarthritis: a meta-analysis

INTRODUCTION

Osteoarthritis (OA) affects millions of people worldwide. In hand OA, the thumb base is the most affected single joint. The reported radiographic prevalence ranges from 0 to 100%, making the true radiographic prevalence unclear. Hence, we conducted a meta-analysis on the age and sex-specific prevalence of radiographic thumb base OA.

METHODS

We performed a search in Embase, Medline Ovid, Web of Science Core Collection, Cochrane Central Register of Trials, and Google Scholar. We included studies of the general population that reported thumb base OA for males and females separately based on a hand radiograph and reported the age of these groups. Using meta-regression, we estimated the odds ratio (OR) of having radiographic thumb base OA for age and sex, while adjusting for within-study correlation.

RESULTS

The initial search yielded 4,278 articles; we finally included 16 studies that reported the age- and sex-stratified prevalence. Taken together, there were 104 age and gender specific-prevalence rates that could be derived from the 16 studies. The prevalence of radiographic OA for the 50-year-old male and female participants was 5.8% and 7.3%, respectively, while the respective prevalence for 80-year-old male and female participants was 33.1% and 39.0%. We found an OR for having radiographic OA of 1.06 (95%CI [1.055-1.065], p < 0.001) per increasing year of age, and 1.30 (95%CI: 1.05-1.61], p = 0.014) for females.

CONCLUSION

In the general population, radiographic thumb base OA is more prevalent in females and is strongly associated with age.

Reduced serum levels of anti-Mullerian hormone is a putative biomarker of early knee osteoarthritis in middle-aged females at menopausal transition

A recent epidemiological study revealed that the highest prevalence of early knee osteoarthritis (OA) was observed in females aged ≥ 50 years. The major causal factor of early knee OA was sex. Despite the relevance of estrogen in evaluating chondral and bone metabolism in OA, it is not easily clinically monitored because irregular menstrual cycles induce unstable female hormone patterns during menopausal transitions. Anti-Mullerian hormone (AMH) has been found to be a new stable biomarker to predict menopause. This study aimed to investigate the association between menopausal transition and early knee OA by using serum biomarkers, with special focus on AMH. A total of 518 female volunteers who participated in the Iwaki cohort study were enrolled and divided into pre-menopause and post-menopause groups. Weight-bearing anterior–posterior knee radiographs were classified by Kellgren–Lawrence (KL) grade, and grade ≥ 2 was defined as radiographic knee OA. In participants with KL grades 0 and 1, early knee OA was defined by Luyten’s criteria. AMH, luteinizing hormone, follicle-stimulating hormone, estradiol (pg/ml), prolactin, and testosterone were measured on the female hormones. Bone mineral density at a distal radius was measured. The predictive power of female hormones for early knee OA was estimated by ROC analysis (comparison of area under curve, AUC) and regression analysis. Fifty-two participants (10.0%) were diagnosed with early knee OA and 204 (39.4%) with radiographic knee OA. In 393 (75.9%) females, menopause began. From the ROC analysis in pre-menopausal females, cutoff value of AMH for detecting early knee OA was 0.08 ng/ml (area under curve (AUC), 0.712; 95% CI, 0.527–0.897; p value, 0.025; odds ratio, 8.28). AUCs of other female hormones did not reach the level of AMH (range, 0.513 of prolactine to 0.636 of estradiol). Logistic regression analysis focusing on AMH reduction at menopausal transition showed that the related AMH below 0.08 ng/ml was significantly related to the presence of early knee OA (p = 0.035; odds ratio, 5.55). Reduced serum levels of AMH in middle-aged females were correlated with the presence of early knee OA, which might be a useful serum biomarker.

Abortion is associated with knee osteoarthritis among older women in China: A STROBE-compliant article

The current studies revealed inconsistent relationship between reproductive factors and osteoarthritis. Community-based research has not been conducted in China. The study was to examine the association of reproductive factors with the prevalence of knee osteoarthritis (OA).Through a multistage stratified random sampling method, 10 streets or villages from 5 cities in Hunan province were randomly selected, a total 2746 eligible women aged 50 to 83 were recruited in this cross-sectional study. A structured questionnaire including demographic factors, socio-economic status, reproductive factors, and knee OA was used. According to the criteria of American College of Rheumatology, clinical knee OA was assessed by doctors in community or village health clinics for knee pain, age, morning stiffness, crepitus on active motion or for knee pain, morning stiffness, crepitus on active motion, and tenderness of the bony navigation of the joint. Self-reported age of menarche, parity, abortion history, and menopausal status were collected.The prevalence of knee OA was 13.44%. Abortion is associated with knee OA (odds ratio [OR] = 1.271, 95% confidence interval [CI] = 1.007, 1.606), but age at menarche, parity, and menopausal status were not the factors. Furthermore, age (OR = 1.040, 95% CI = 1.020, 1.060), weight (OR = 1.019, 95% CI = 1.004, 1.035), higher education level (OR = 1.530, 95% CI = 1.121, 2.088), higher monthly household income (OR = .583, 95% CI = 0.441, 0.770 for 3000-4999 ¥ and OR = 0.599, 95% CI = 0.431, 0.833 for 5000 ¥ or more), and chronic gastritis (OR = 3.364, 95% CI = 2.548, 4.442) were associated with knee OA.Abortion may increase the risk of knee OA. Special attention should be paid to women with a history of abortion, and women who are planning to abort should be informed of the risk of knee OA later in life. The relationship between abortion and knee OA should be interpreted with caution and further confirmed.

Reproductive history and osteoarthritis in the Women's Health Initiative

Objective: To investigate the relationship between self-reported osteoarthritis (OA) and reproductive factors in the Women's Health Initiative (WHI). Method: We used multivariable logistic regression to study the association of self-reported OA and reproductive factors in the WHI Observational Study and Clinical Trial cohorts of 145 965 postmenopausal women, in a retrospective cross-sectional format. Results: In our cohort, we observed no clinically significant associations between reproductive factors and OA given small effect sizes. The following factors were associated with statistically significant increased likelihood of developing OA: younger age at menarche (p < 0.001), history of hysterectomy [adjusted odds ratio (aOR) 1.013, 95% confidence interval (CI) 1.004-1.022, p = 0.04 vs no hysterectomy], history of unilateral oophorectomy (aOR 1.015, 95% CI 1.004-1.026, p < 0.01 vs no oophorectomy), parity (aOR 1.017, 95% CI 1.009-1.026, p < 0.001), ever use of oral contraceptives (aOR 1.008, 95% CI 1.001-1.016, p < 0.01 vs never use), and current use of hormonal therapy (reference current users, aOR 0.951, 95% CI 0.943-0.959 for never users; aOR 0.981, 95% CI 0.972-0.989 for past users; global p < 0.001). Age at menopause, first birth, and pregnancy were not associated with OA. Among parous women, no clear pattern was observed with number of pregnancies, births, or duration of breastfeeding in relation to OA. Conclusion: Our study showed that reproductive factors did not have significant clinical associations with OA after controlling for confounders. This may be due to complex hormonal effects. Additional investigation is warranted in prospective cohort studies. The Women's Health Initiative is registered under ClinicalTrials.gov. Trial registration ID: NCT00000611.

Development and validation of a prediction model for incident hand osteoarthritis in the HUNT study

OBJECTIVE

To develop and externally validate prediction models for incident hand osteoarthritis (OA) in a large population-based cohort of middle aged and older men and women.

DESIGN

We included 17,153 men and 18,682 women from a population-based cohort, aged 35-70 years at baseline (1995-1997). Incident hand OA were obtained from diagnostic codes in the Norwegian National Patient Register (1995-2018). We studied whether a range of self-reported and clinically measured predictors could predict hand OA, using the Area Under the receiver-operating Curve (AUC) from logistic regression. External validation of an existing prediction model for male hand OA was tested on discrimination in a sample of men. Bootstrapping was used to avoid overfitting.

RESULTS

The model for men showed modest discriminatory ability (AUC = 0.67, 95% CI 0.62-0.71). Adding a genetic risk score did not improve prediction. Similar discrimination was observed in the model for women (AUC = 0.62, 95% CI 0.59-0.64). Prediction was not improved by adding a genetic risk score or hormonal and reproductive factors. Applying external validation, similar results were observed among men in HUNT (The Nord-Trøndelag Health Study) as in the developmental sample (AUC = 0.62, 95% CI 0.57-0.65).

CONCLUSION

We developed prediction models for incident hand OA in men and women. For women, the model included body mass index (BMI), heavy physical work, high physical activity and perceived poor health. The model showed moderate discrimination. For men, we have shown that a prediction model including BMI, education and information on sleep can predict incident hand OA in several populations with moderate discriminative ability.

Sex Specific Determinants in Osteoarthritis: A Systematic Review of Preclinical Studies

Osteoarthritis (OA) is a highly prevalent joint disease that primarily affects about 10% of the world's population over 60 years old. The purpose of this study is to systematically review the preclinical studies regarding sex differences in OA, with particular attention to the molecular aspect and gene expression, but also to the histopathological aspects. Three databases (PubMed, Scopus, and Web of Knowledge) were screened for eligible studies. In vitro and in vivo papers written in English, published in the last 11 years (2009-2020) were eligible. Participants were preclinical studies, including cell cultures and animal models of OA, evaluating sex differences. Independent extraction of articles and quality assessments were performed by two authors using predefined data fields and specific tools (Animals in Research Reporting In Vivo Experiments (ARRIVE) guideline and Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) tool). Twenty-three studies were included in the review: 4 in vitro studies, 18 in vivo studies, and 1 both in vitro and in vivo study. From in vitro works, sex differences were found in the gene expression of inflammatory molecules, hormonal receptors, and in responsiveness to hormonal stimulation. In vivo research showed a great heterogeneity of animal models mainly focused on the histopathological aspects rather than on the analysis of sex-related molecular mechanisms. This review highlights that many gaps in knowledge still exist; improvementsin the selection and reporting of animal models, the use of advanced in vitro models, and multiomics analyses might contribute to developing a personalized gender-based medicine.

Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: the Japan Nurses' Health Study

OBJECTIVES

To investigate whether body mass index (BMI) trajectory, lifestyle and reproductive factors are associated with knee pain risk among middle-aged women.

DESIGN

Prospective study of the Japan Nurses' Health Study (JNHS).

SETTING

The JNHS investigates the health of female nurses in Japan. Biennial follow-up questionnaires are mailed to the participants.

PARTICIPANTS

The 7434 women aged over 40 years who responded to the 10-year self-administered follow-up questionnaire.

PRIMARY OUTCOME MEASURE

Self-reported knee pain at the 10-year follow-up was the primary outcome. We analysed BMI (normal or overweight) trajectory data from a baseline survey to the 10-year follow-up survey using group-based trajectory modelling. Exposure measurements were BMI trajectory, BMI at age 18 years, lifestyle variables and reproductive history.

RESULTS

BMI trajectories from baseline to the 10-year follow-up were divided into four groups: remained normal, remained overweight, gained weight or lost weight. At the 10-year follow-up, 1281 women (17.2%) reported knee pain. Multivariable logistic regression analysis revealed that compared with the remained normal group, multivariable-adjusted ORs (95% CI) of knee pain were 1.93 (1.60 to 2.33) for the remained overweight group, 1.60 (1.23 to 2.08) for the gained weight group and 1.40 (0.88 to 2.21) for the lost weight group. The attributable risk percent (95% CI) of the remained overweight group was 48.1% (37.3% to 57.0%) compared with the reference group of remained normal. Alcohol intake at baseline was significantly associated with knee pain.

CONCLUSIONS

The lost weight group had a lower risk than the remained overweight group and the gained weight group and did not carry statistically significant risks for knee pain. Weight reduction and maintaining a normal BMI in middle age was important for preventing knee pain in women.

A Deep Neural Network-Based Method for Early Detection of Osteoarthritis Using Statistical Data

A large number of people suffer from certain types of osteoarthritis, such as knee, hip, and spine osteoarthritis. A correct prediction of osteoarthritis is an essential step to effectively diagnose and prevent severe osteoarthritis. Osteoarthritis is commonly diagnosed by experts through manual inspection of patients’ medical images, which are usually collected in hospitals. Checking the occurrence of osteoarthritis is somewhat time-consuming for patients. In addition, the current studies are focused on automatically detecting osteoarthritis through image-based deep learning algorithms. This needs patients’ medical images, which requires patients to visit the hospital. However, medical utilization and health behavior information as statistical data are easier to collect and access than medical images. Using indirect statistical data without any medical images to predict the occurrence of diverse forms of OA can have significant impacts on pro-active and preventive medical care. In this study, we used a deep neural network for detecting the occurrence of osteoarthritis using patient’s statistical data of medical utilization and health behavior information. The study was based on 5749 subjects. Principal component analysis with quantile transformer scaling was employed to generate features from the patients’ simple background medical records and identify the occurrence of osteoarthritis. Our experiments showed that the proposed method using deep neural network with scaled PCA resulted in 76.8% of area under the curve (AUC) and minimized the effort to generate features. Hence, this methos can be a promising tool for patients and doctors to prescreen for possible osteoarthritis to reduce health costs and patients’ time in hospitals.

Correlates and predictors of pain intensity and physical function among individuals with chronic knee osteoarthritis in Nigeria

BACKGROUND

Little is known about the correlates between pain intensity (PI) and physical function (PF) and psychosocial factors {kinesiophobia (K), Pain Catastrophizing (PC) and Self-efficacy (SE)} among patients diagnosed with knee osteoarthritis in developing countries like Nigeria.

OBJECTIVE

To investigate the correlates of PI and PF and psychosocial factors in patients with knee osteoarthritis in Nigeria.

DESIGN

Eighty-nine consecutively sampled patients diagnosed with knee osteoarthritis from three selected public hospitals in Enugu, South-East Nigeria, participated in this cross-sectional survey.

METHOD

Brief Fear of Movement Scale for Osteoarthritis, Pain Catastrophizing Scale and Arthritis Self-Efficacy Scale-8 item were used to assess kinesiophobia, pain catastrophizing and Self-efficacy respectively. Visual Analogue Scale and Ibadan Knee or Hip Osteoarthritis Measure were used to assess PI and PF respectively. Data were analysed using Pearson's correlation coefficient and multiple regression at p = 0.05.

RESULTS/FINDINGS

Participants were aged 59.11 ± 12.46years involving male (17.9%) and female (82.1%) participants. There were no significant gender differences in the scores of kinesiophobia, PI, PF, PC and self-efficacy. Pain intensity was significantly proportional to kinesiophobia (r = 0.38), and PC(r = 0.39). Better physical function was associated with high self-efficacy (r = 0.35), low kinesiophobia (r = -0.43) and low PC(r = -0.28). Significant predictive markers of PI included kinesiophobia (β = 0.24) and PC(β = 0.11) while that of PF, included kinesiophobia (β = -0.41) and SE(β = 2.39).

CONCLUSIONS

Kinesiophobia and pain catastrophizing correlate and predict PI significantly. Kinesiophobia and SE are significant correlates and predictors of PF among patients with knee osteoarthritis in Nigeria.

Prevalence of osteoarthritis and association between smoking patterns and osteoarthritis in China: a cross-sectional study

Objective

The aims of this study were to estimate the prevalence of radiographic osteoarthritis (OA) and to assess the association between smoking patterns and OA prevalence in adults aged 50 years or older belonging to the Shanxi province of China.

Methods

A cross-sectional study in the rural regions of the Shanxi province was conducted among 2638 Chinese adults (aged ≥50 years). Demographic characteristics and behavioral information were collected through epidemiological surveys. All participants with joint pain underwent plain radiographic examination and were diagnosed by a professional orthopedist. Associations between smoking patterns and the prevalence of OA were assessed using binary logistic regression modeling.

Results

Among 2638 individuals (men, 50.3% and women, 49.7%; mean age, 61.5 years) included in the analysis, 49.8% had radiographic OA and 27.5% had knee OA. The prevalence of radiographic OA was higher in women than in men (P<0.001). After adjusting for potential confounding factors, there was a nonsignificant correlation between smoking and OA prevalence in the multivariate model. Odds ratios (ORs) for all types of OA and knee OA were higher in active and passive smokers than in nonsmoking individuals after adjustments (OR 1.374; 95% confidence interval [CI] 1.049–1.802; OR 1.440; 95% CI 1.059–1.958, respectively).

Conclusions

This study showed that smoking may not be an independent risk factor for OA; however, there was a positive correlation between active and passive smoking and OA.

Potential Effect Modifiers of the Association Between Physical Activity Patterns and Joint Symptoms in Middle-Aged Women

OBJECTIVE

To examine whether body mass index (BMI), menopausal status, and hormone therapy (HT) use modify the association between physical activity (PA) patterns throughout middle age and the incidence and prevalence of joint symptoms in women in later middle age.

METHODS

Data were from 6,661 participants (born 1946-1951) in the Australian Longitudinal Study on Women's Health. Surveys, with questions on joint pain and stiffness, PA, height and weight, menopausal symptoms, and HT use, were completed every 3 years from 1998 to 2010. PA patterns were defined as none or low, low or meeting guidelines, fluctuating, or meeting guidelines at all times (reference pattern). Logistic regression was used to examine the association between PA patterns and prevalent (in 2010) and cumulative incident (1998-2010) joint symptoms and effect modification by patterns in BMI, menopausal status, and HT.

RESULTS

The groups representing fluctuating PA (odds ratio [OR] 1.34 [99% confidence interval (99% CI) 1.04-1.72]) and no or low PA (OR 1.60 [99% CI 1.08-2.35]) had higher odds of incident joint symptoms than those described as meeting guidelines at all times. Stratification by BMI showed that this association was statistically significant in the obese group only. No evidence for effect modification by menopausal status or HT use was found. The findings were similar for prevalent joint symptoms.

CONCLUSION

Maintaining at least low levels of PA throughout middle age was associated with a lower prevalence and incidence of joint symptoms later in life. This apparent protective effect of PA on joint symptoms was stronger in obese women than in under- or normal-weight women, and not related to menopause or HT status.

Lower Quadriceps Rate of Force Development Is Associated With Worsening Physical Function in Adults With or at Risk for Knee Osteoarthritis: 36-Month Follow-Up Data From the Osteoarthritis Initiative

OBJECTIVE

To determine the association between quadriceps rate of force development (RFD) and decline in self-reported physical function and objective measures of physical performance.

DESIGN

Longitudinal cohort study.

SETTING

Community-based sample from 4 urban areas.

PARTICIPANTS

Osteoarthritis Initiative participants with or at risk for knee osteoarthritis, who had no history of knee/hip replacement, knee injury, or rheumatoid arthritis (N=2630).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Quadriceps RFD (N/s) was measured during isometric strength testing. Worsening physical function was defined as the minimal clinically important difference for worsening self-reported Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale score, 20-m walk time, and repeated chair stand time over 36 months.

RESULTS

Compared with the slowest tertile of RFD, the fastest tertile had a lower risk for worsening of WOMAC physical function subscale score at 36-month follow-up, with an odds ratio (OR) of .68 (95% confidence interval [CI], .51-.92) after adjustment for age, sex, body mass index, depression, history of chronic diseases, and knee pain. In women, in comparison with the slowest tertile of RFD, the fastest tertile had a lower risk for worsening of WOMAC physical function subscale score at 36-month follow-up, with an adjusted OR of .57 (95% CI, .38-.86). This decreased risk did not reach statistical significance in men (OR, 0.81; 95% CI, 0.52-1.27). No statistically significant associations were detected between baseline RFD and walk or chair stand times.

CONCLUSIONS

Our results indicate that higher RFD is associated with decreased risk for worsening self-reported physical function but not with decreased risk for worsening of physical performance.

Estradiol and proinflammatory cytokines stimulate ISG20 expression in synovial fibroblasts of patients with osteoarthritis

Interferon stimulated gene 20-kDa (ISG20) has been implicated in the pathology of osteoarthritis (OA) and it has been separately found to be responsive to estrogen stimulation. OA disproportionately affects women, and especially older women, suggesting some role of reproductive hormones in its pathology. The current study characterized the expression of ISG20 following stimulation with estradiol (E2) and proinflammatory cytokines in OA synovial fibroblasts (OASFs). E2 and the proinflammatory cytokines interleukin-6 (IL-6), lipopolysaccharide (LPS), and tumor necrosis factor α (TNF-α) were used to stimulate OASFs in vitro. The expression of ISG20 before and after stimulation was detected using quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting. E2 and proinflammatory cytokine (IL-6, LPS and TNF-α) stimulation significantly induced the expression of ISG20 both at the messenger RNA (mRNA) and protein level. Moreover, the induction was time- and dose-dependent. Small interfering RNA (siRNA) was transfected into OASFs, and expression of the inflammatory factors interleukin-1α (IL-1α), IL-6, and interleukin-10 (IL-10) was detected using RT-qPCR. Silencing ISG20 with siRNA inhibited the expression of IL-1α, IL-6, and IL-10. Thus, expression of ISG20 was regulated by estradiol and proinflammatory factors, while ISG20 in turn regulated the expression of other inflammatory factors. These data support the contention that ISG20 plays a role in the inflammatory process of OA.

Age of menarche is associated with knee joint replacement due to primary osteoarthritis (The HUNT Study and the Norwegian Arthroplasty Register)

OBJECTIVE

To investigate whether parity, age at menarche, menopausal status, age at menopause, use of oral contraceptives (OC) or use of hormone replacement therapy (HRT) were associated with total knee replacement (TKR) or total hip replacement (THR) due to primary osteoarthritis.

METHOD

In a prospective cohort study of 30,289 women from the second and third surveys of the Nord-Trøndelag Health Study, data were linked to the Norwegian Arthroplasty Register (NAR) in order to identify TKR or THR due to primary osteoarthritis. Cox proportional hazards models were used to estimate the hazard ratios (HRs).

RESULTS

We observed 430 TKRs and 675 THRs during a mean follow-up time of 8.3 years. Increasing age at menarche was inversely associated with the risk of TKR (P-trend < 0.001). Past users and users of systemic HRT were at higher risk of TKR compared to never users (HR 1.42 (95% confidence interval (CI) 1.06-1.90) and HR 1.40 (95% CI 1.03-1.90), respectively). No association was found between parity, age at menarche, menopausal status, age at menopause, oral contraceptive use or HRT use and THR.

CONCLUSION

We found that increasing age at menarche reduced the risk of TKR. Past users and users of systemic HRT were at higher risk of TKR compared to never users. Parity did not increase the risk of THR or TKR.

Plasminogen activator inhibitor-1 deficiency enhances subchondral osteopenia after induction of osteoarthritis in mice

BACKGROUND

Subchondral osteopenia is important for the pathophysiology of osteoarthritis (OA). Although previous studies suggest that plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis, is related to bone metabolism, its role in OA remains unknown. We therefore investigated the roles of PAI-1 in the subchondral bone in OA model mice.

METHODS

Wild type (WT) and PAI-1-deficient (KO) mice were ovariectomized (OVX), and then destabilization of the medial meniscus (DMM) surgery was performed.

RESULTS

DMM and OVX significantly decreased the trabecular bone mineral density of the subchondral bone evaluated by quantitative computed tomography in PAI-1 KO mice. The effects of OVX and/or PAI-1 deficiency on the OARSI score for the evaluation of the progression of knee degeneration were not significant. PAI-1 deficiency significantly augmented receptor activator nuclear factor κB ligand mRNA levels enhanced by IL-1β in mouse primary osteoblasts, although it did not affect osteoblast differentiation. Moreover, PAI-1 deficiency significantly increased osteoclast formation from mouse bone marrow cells.

CONCLUSION

We showed that PAI-1 deficiency accelerates the subchondral osteopenia after induction of OA in mice. PAI-1 might suppress an enhancement of bone resorption and subsequent subchondral osteopenia after induction of OA in mice.

Relationship between circulating sex steroid hormone concentrations and incidence of total knee and hip arthroplasty due to osteoarthritis in men

OBJECTIVE

Few studies have examined the association between circulating sex steroid concentrations and risk of osteoarthritis (OA) in men with inconsistent results. Our aim was to examine whether concentrations of circulating sex steroid hormones were associated with the incidence of primary knee and hip arthroplasty for OA in a prospective cohort study.

DESIGN

Two thousand four hundred and ninety four men from the Melbourne Collaborative Cohort Study (MCCS) had circulating sex steroid concentrations measured in blood samples drawn at recruitment (1990-1994) and stored in liquid nitrogen. The plasma concentrations of sex hormones, including dehydroepiandrosterone sulphate, androstenedione, testosterone, estradiol, androstanediol glucuronide, and sex hormone binding globulin, were measured. The incidence of total knee and hip arthroplasty for OA during 2001-2013 was determined by linking MCCS records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

One hundred and four men had knee and 80 had hip arthroplasty for OA over 10.7 (SD 3.8) years. Higher concentrations of androstenedione were associated with a decreased risk of total knee (hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.77-0.98) and hip (HR 0.84 95% CI 0.71-1.00) arthroplasty for OA in overweight and obese men. No significant association was observed for the other measured hormones.

CONCLUSION

Low plasma androstenedione concentration is associated with an increased risk of both knee and hip arthroplasty for OA for overweight and obese men. While the findings need to be confirmed in other cohort studies, they suggest that circulating sex steroids may play a role in the pathogenesis of OA in men.

Association of Body Composition and Hormonal and Inflammatory Factors With Tibial Cartilage Volume and Sex Difference in Cartilage Volume in Young Adults

OBJECTIVE

To describe the associations between body composition and hormonal and inflammatory factors measured 5 years prior and tibial cartilage volume in young adults, and to explore if these factors contribute to the sex difference in tibial cartilage volume.

METHODS

Subjects broadly representative of the young adult Australian population (n = 328, ages 31-41 years, 47.3% women) were selected. They underwent T1-weighted fat-suppressed magnetic resonance imaging (MRI) of their knees. Tibial cartilage volume was measured from MRI. Sex hormone binding globulin (SHBG) and testosterone in a subset of women and C-reactive protein (CRP) level and fibrinogen in both sexes were measured 5 years prior. Body mass index (BMI), fat mass, and lean mass were calculated from height, weight, and skinfolds.

RESULTS

In multivariable analyses, correlates of tibial cartilage volume included lean body mass (β = 26.4 mm(3) ; 95% confidence interval [95% CI] 13.6, 39.1), fat mass (β = -11.8 mm(3) ; 95% CI -22.2, -1.4), and fibrinogen (β = -146.4 mm(3) ; 95% CI -276.4, -16.4), but not BMI, testosterone, or CRP level. In women, SHBG was positively associated with tibial cartilage volume (β = 0.67 mm(3) ; 95% CI 0.14, 1.20) and Free Androgen Index was negatively associated with lateral tibial cartilage volume (β = -0.04 mm(3) ; 95% CI -0.07, 0.00). Men had 13% more tibial cartilage volume (500 mm(3) ) than women. The magnitude of this association decreased by 38%, 20%, and 37% after adjustment for lean body mass, fat mass, and fibrinogen, respectively.

CONCLUSION

Body composition, sex hormones, and fibrinogen correlate with knee cartilage volume in young adult life. Sex difference in knee cartilage volume is contributed largely by variations in body composition and/or fibrinogen.

Quantitative Ultrasound Assessment of Cartilage Degeneration in Ovariectomized Rats with Low Estrogen Levels

The aim of this study was to assess quantitatively the site-specific degeneration of articular cartilage in ovariectomized rats with low estrogen levels using a high-frequency ultrasound system. Fourteen female Sprague-Dawley rats were randomly divided into two groups (n = 7 per group): a sham group in which only the peri-ovarian fatty tissue was exteriorized and an ovariectomized group that underwent bilateral ovariectomy to create a menopause model with low estrogen levels. All animals were sacrificed at the end of the third week after ovariectomy. Hindlimbs were harvested. The articular cartilage from five anatomic sites (i.e., femoral caput [FC], medial femoral condyle [MFC], lateral femoral condyle [LFC], medial tibial plateau [MTP] and lateral tibial plateau [LTP]) was examined with ultrasound. Four parameters were extracted from the ultrasound radiofrequency data: reflection coefficient of the cartilage surface (RC1), reflection coefficient of the cartilage-bone interface (RC2), ultrasound roughness index (URI) and thickness of the cartilage tissue. The results indicated significant (p < 0.05) site dependence for cartilage thickness, URI and RC1 in the sham group. The 3-wk post-menopause ovariectomized rats exhibited significant increases (p < 0.05) in the URI at the LFC, MTP and LTP; significant decreases (p < 0.05) in RC1 at the FC, LFC and MTP; and significant decreases (p < 0.05) in cartilage thickness at the MFC, LFC, MTP and LTP. These results of this study suggest that post-menopausal estrogen reduction induces morphologic and acoustic alterations in the articular cartilage of the hip and knee joints in ovariectomized rats.

Early menarche and chronic widespread musculoskeletal complaints--Results from the HUNT study

BACKGROUND

There is a predominance of chronic widespread musculoskeletal complaints (WMSC) among women. Previous studies suggest an association between hormonal factors and pain. However, it is not known whether earlier age at menarche is associated with higher prevalence of chronic WMSC. The aim of this study was to investigate the association between age at menarche and chronic WMSC.

METHODS

Data from a cross-sectional study of inhabitants ≥20 years in Nord-Trøndelag County (Helseundersøkelsen i Nord-Trøndelag -HUNT), conducted in 1995-1997 (HUNT 2) were used. The study population comprised 32,673 women with valid information of age at menarche (exposure) and chronic WMSC (outcome data).

RESULTS

In total, 8986 (27.5%) women reported WMSC. The overall prevalence of WMSC was 29.7% among those with menarche ≤12 years and 26.7% among those with menarche >12 years. The prevalence of chronic WMSC was consistently higher for those with early age at menarche in all age groups. The crude odds ratio for chronic WMSC, when comparing women with age at menarche ≤12 years to women with age at menarche >12 years, was 1.16 (95% CI: 1.10-1.22). The corresponding odds ratio was 1.26 (95% CI: 1.19-1.34) when adjusted for age, education, body mass index (BMI), smoking, alcohol consumption, depression, systolic blood pressure (SBP) and parity.

CONCLUSION

In this cross-sectional study, there was an association between early age at menarche and chronic WMSC later in life, but the difference in absolute risk was low (3%).

Incidence of total knee and hip replacement for osteoarthritis in relation to circulating sex steroid hormone concentrations in women

OBJECTIVE

The increased prevalence of osteoarthritis (OA) in postmenopausal women suggests that changes in either circulating sex steroid concentrations or the tissue response to sex steroids may have a role in the pathogenesis of OA. The aim of this study was to examine whether circulating sex steroid concentrations are associated with the incidence of total knee and total hip replacement for OA.

METHODS

Study subjects (n = 2,621; all women) were recruited in 1990-1994 from the Melbourne Collaborative Cohort Study (MCCS). Circulating sex steroid concentrations were measured in blood samples obtained from the women at the time of recruitment. The incidence of total knee and total hip replacement for OA during 2001-2011 was determined by linking the MCCS records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

During the followup period, 115 women had undergone total knee replacement and 99 had undergone total hip replacement for OA. Greater log-transformed concentrations of estradiol were associated with a lower incidence of knee replacement (hazard ratio [HR] 0.70, 95% confidence interval [95% CI] 0.50-0.96), and greater log-transformed concentrations of androstenedione were associated with a lower incidence of hip replacement (HR 0.70, 95% CI 0.52-0.93). In contrast, greater log-transformed concentrations of sex hormone binding globulin (SHBG) were associated with a higher incidence of hip replacement (HR 1.70, 95% CI 1.05-2.77).

CONCLUSION

A lower estradiol concentration is a risk factor for knee OA, while a lower androstenedione concentration and higher SHBG concentration are risk factors for hip OA in women. These findings suggest that circulating sex steroids have a role in the pathogenesis of OA, and that modifying these steroid concentrations may provide a potential strategy for the prevention and treatment of knee and hip OA.

Experimental osteoarthritis models in mice

Osteoarthritis (OA) is a slowly progressing, degenerative disorder of synovial joints culminating in the irreversible destruction of articular cartilage and subchondral bone. It affects almost everyone over the age of 65 and influences life quality of affected individuals with enormous costs to the health care system. Current therapeutic strategies seek to ameliorate pain and increase mobility; however, to date none of them halts disease progression or regenerates damaged cartilage or bone. Thus, there is an ultimate need for the development of new, noninvasive treatments that could substitute joint replacement for late- or end-stage patients. Therefore, osteoarthritis animal models for mimicking of all OA features are important. Mice develop an OA pathology that is comparable to humans, rapidly develop OA due to the short lifetime and show reproducible OA symptoms. They provide a versatile and widely used animal model for analyzing molecular mechanisms of OA pathology. One major advantage over large animal models is the availability of knockout or transgenic mice strains to examine genetic predispositions/contributions to OA.In this chapter, we describe three widely used instability-inducing murine osteoarthritis models. The most common two methods for surgical induction are: (1) destabilization of the medial meniscus (DMM) and (2) anterior cruciate ligament transection (ACLT). In the DMM model, the medial meniscotibial ligament is transected while in the ACLT model the anterior cruciate ligament is destroyed. In the third, chemical induced instability method, intraarticular collagenase is injected into the knee joint. Intraarticular collagenase weakens articular ligaments which cause instability of the joint, and full-blown OA develops within 6 weeks. For morphological evaluation, we correspond mainly to the recommendations of OARSI for histological assessment of osteoarthritis in mouse. For statistical evaluation summed or mean scores of all four knee areas (medial tibial plateau (MTP), medial tibial condyle (MFC), lateral tibial plateau (LTP) or lateral femoral condyle (LFC)), medial and/or lateral regions are used.In future, not only large animal models like guinea pigs, sheep, goats, or horses will be important for a better understanding of osteoarthritis, but especially the mouse model with its rapid development of osteoarthritis and its numerous advantages by providing knockout or transgenic strains will become more and more relevant for drug development and determination of genetic predispositions of osteoarthritis pathology.

Estrogen alone and joint symptoms in the Women's Health Initiative randomized trial

OBJECTIVE

Although joint symptoms are commonly reported after menopause, observational studies examining exogenous estrogen's influence on joint symptoms provide mixed results. Against this background, estrogen-alone effects on joint symptoms were examined in post hoc analyses in the Women's Health Initiative randomized, placebo-controlled, clinical trial.

METHODS

A total of 10,739 postmenopausal women who have had a hysterectomy were randomized to receive daily oral conjugated equine estrogens (0.625 mg/d) or a matching placebo. The frequency and severity of joint pain and joint swelling were assessed by questionnaire in all participants at entry and on year 1, and in a 9.9% random subsample (n = 1,062) after years 3 and 6. Logistic regression models were used to compare the frequency and severity of symptoms by randomization group. Sensitivity analyses evaluated adherence influence on symptoms.

RESULTS

At baseline, joint pain and joint swelling were closely comparable in the randomization groups (about 77% with joint pain and 40% with joint swelling). After 1 year, joint pain frequency was significantly lower in the estrogen-alone group compared with the placebo group (76.3% vs 79.2%, P = 0.001), as was joint pain severity, and the difference in pain between randomization groups persisted through year 3. However, joint swelling frequency was higher in the estrogen-alone group (42.1% vs 39.7%, P = 0.02). Adherence-adjusted analyses strengthen estrogen's association with reduced joint pain but attenuate estrogen's association with increased joint swelling.

CONCLUSIONS

The current findings suggest that estrogen-alone use in postmenopausal women results in a modest but sustained reduction in the frequency of joint pain.

Epidemiology and burden of osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease involving the cartilage and many of its surrounding tissues. Disease progression is usually slow but can ultimately lead to joint failure with pain and disability. OA of the hips and knees tends to cause the greatest burden to the population as pain and stiffness in these large weight-bearing joints often leads to significant disability requiring surgical intervention.

SOURCES OF DATA

The article reviews the existing data on epidemiology of osteoarthritis and the burden of the disease.

AREAS OF AGREEMENT

Symptoms and radiographic changes are poorly correlated in OA. Established risk factors include obesity, local trauma and occupation. The burden of OA is physical, psychological and socioeconomic.

AREAS OF CONTROVERSY

Available data does not allow definite conclusion regarding the roles of nutrition, smoking and sarcopenia as risk factors for developing OA.

GROWING POINTS

Variable methods of diagnosing osteoarthritis have significantly influenced the comparability of the available literature.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further research is required to fully understand how OA affects an individual physically and psychologically, and to determine their healthcare need.

Role of sex hormones in the development of osteoarthritis

Women older than 50 years have a considerably higher prevalence of osteoarthritis than men of the same age group. Although several factors have been proposed, there is some evidence that sex hormones influence the development of osteoarthritis. This article will focus on the basic science and clinical evidence that describe the current state of knowledge regarding the relationship between sex hormones and the development of osteoarthritis.

Hand osteoarthritis--a heterogeneous disorder

Hand osteoarthritis (OA) is a prevalent disorder. Hand OA is not one single disease, but a heterogeneous group of disorders. Radiographic signs of hand OA, such as osteophytes or joint space narrowing, can be found in up to 81% of the elderly population. Several hand OA subsets--such as nodal interphalangeal OA, thumb base OA and erosive OA--can be discriminated. Furthermore, the experience of symptoms and the course of the disease differ between patients. Studies that used well-defined study populations with longitudinal follow-up have shown that similarities and differences can be observed in the pathogenesis, epidemiology and risk factors of the various hand OA subsets. Erosive OA in particular, characterized by erosive lesions on radiographical images, has a higher clinical burden and worse outcome than nonerosive hand OA. Imaging modalities (such as ultrasonography) have increased our knowledge of the role of inflammation of the disease. Our understanding of the heterogeneous nature of hand OA can eventually lead to increased knowledge of the pathogenesis of, and ultimately new treatment modalities for, this complex disease.

Estrogen receptor-related receptor α regulation by interleukin-1β in prostaglandin E(2)- and cAMP-dependent pathways in osteoarthritic chondrocytes

OBJECTIVE

We reported previously that the orphan nuclear receptor, estrogen receptor-related receptor α (ERRα), is expressed in articular chondrocytes and is dysregulated in a mouse model of inflammatory arthritis. The aim of this study, therefore, was to determine whether ERRα is also dysregulated in patients with osteoarthritis (OA).

METHODS

ERRα messenger RNA (mRNA) and protein were quantified in normal and OA cartilage samples and in OA chondrocytes in vitro, with and without short-term treatment with a variety of OA-associated factors and signaling pathway agonists and inhibitors.

RESULTS

ERRα expression was lower in OA than in normal articular cartilage. Interleukin-1β (IL-1β) markedly up-regulated ERRα expression in OA chondrocytes in vitro, and agonist or inhibitor treatment indicated that the up-regulation was dependent on cyclooxygenase 2 (COX-2; NS398), prostaglandin E(2), cAMP (8-bromo-cAMP), and protein kinase A (PKA; KT5720). Treatment with the ERRα inverse agonist XCT790 decreased the expression of SOX9 and the up-regulation of ERRα by IL-1β, suggesting autoregulation of ERRα in the IL-1β pathway. Matrix metalloproteinase 13 (MMP-13) expression was also decreased by treatment with XCT790 plus IL-1β versus IL-1β alone, and the down-regulation of MMP-13 mRNA and protein observed with XCT790 alone suggests that the up-regulation of MMP-13 by IL-1β is ERRα-dependent.

CONCLUSION

We report the first evidence that ERRα expression is regulated by IL-1β in COX-2-, cAMP-, and PKA-dependent pathways in OA chondrocytes. We confirmed that SOX9 is an ERRα target gene in human, as in rodent, chondrocytes and identified MMP-13 as a potential new target gene, which suggests that ERRα may both respond to the healing signal and contribute to extracellular degradation in OA cartilage.

Osteoarthritis subpopulations and implications for clinical trial design

Treatment guidelines for osteoarthritis have stressed the need for research on clinical predictors of response to different treatments. However, identifying such clinical predictors of response is less easy than it seems, and there is not a given classification of osteoarthritis subpopulations. This review article highlights the key methodical issues when analyzing and designing clinical studies to detect important subgroups with respect to treatment effect. In addition, we discuss the main osteoarthritis subpopulations and give examples of how specific treatment effects in these subpopulations have been assessed.

Proximal interphalangeal joint arthritis

Proximal interphalangeal joint function is critical for proper finger and hand function and arthritis of this joint can lead to considerable hand impairment. Proximal interphalangeal joint arthritides are broadly categorized into nonerosive and erosive osteoarthritis (OA), posttraumatic arthritis, and inflammatory arthritis. The nonerosive type is considered idiopathic or primary OA, whereas the erosive form exhibits an inflammatory component. Idiopathic or primary OA occurs as a consequence of abnormal mechanical stress that leads to damage of cartilage and subchondral bone, with subsequent cytokine and growth factor activation. Individual genetics then mediate the cellular responses. Although erosive OA is described as a separate entity, this remains controversial, with many suggesting that it is merely a more aggressive form of nonerosive, primary OA. Inflammatory OA occurs when connective tissues are diseased, allowing for normal use to incite arthritic damage. Treatment modalities for proximal interphalangeal joint arthritis are currently limited.