Associations of Osteoarthritis with Prevalence and Incidence of Cardiovascular Disease over 10 Years in Community-Dwelling Older Adults: The Sydney Memory and Ageing Study

INTRODUCTION

The data are limited for the association between osteoarthritis (OA) and cardiovascular disease (CVD) in community-based older populations and whether there is sex difference. This study aimed to examine the relationship between OA and prevalence and incidence of CVD over 10 years in community-dwelling older adults.

METHODS

Data on self-reported OA, high cholesterol, hypertension, and type 2 diabetes were collected from 1,025 community-dwelling participants aged 70-90 years in the Sydney Memory and Ageing Study. The presence of CVD at baseline was defined as self-reported presence of stroke, heart attack, transient ischaemic attack, angina, aortic aneurysm, or claudication. The incidence of CVD was defined by a combination of incident self-reported CVD or CVD mortality at different follow-up timepoints over 10 years.

RESULTS

At baseline, 395 (38.5%) participants self-reported OA (252 [44.6%] women, 143 [31.1%] men). Self-reported OA was associated with increased prevalence of CVD in women (OR 1.67, 95% CI 1.12-2.47) but not men (1.26, 0.80-1.98). In the total population, self-reported OA at baseline was associated with increased incidence of CVD at 4 years (OR 1.77, 95% CI 1.10-2.83), 6 years (1.59, 1.03-2.46), 8 years (1.56, 1.02-2.38), and 10 years (1.66, 1.10-2.50), but not at 2 years (1.43, 0.79-2.57). Significant associations were observed in female participants at 4, 8, and 10 years, with no significant associations seen in male participants.

CONCLUSION

OA was associated with increased prevalence at baseline and incidence of CVD over 10 years in community-based older adults, especially women. Identifying those with OA to target their cardiovascular risk factors while managing their OA has the potential to reduce the burden of CVD in older people, particularly women.

Metformin for knee osteoarthritis with obesity: study protocol for a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Over half of the populations with knee osteoarthritis (OA) have obesity. These individuals have many other shared metabolic risk factors. Metformin is a safe, inexpensive, well-tolerated drug that has pleiotropic effects, including structural protection, anti-inflammatory and analgesic effects in OA, specifically the knee. The aim of this randomised, double-blind, placebo-controlled trial is to determine whether metformin reduces knee pain over 6 months in individuals with symptomatic knee OA who are overweight or obese.

METHODS AND ANALYSIS

One hundred and two participants with symptomatic knee OA and overweight or obesity will be recruited from the community in Melbourne, Australia, and randomly allocated in a 1:1 ratio to receive either metformin 2 g or identical placebo daily for 6 months. The primary outcome is reduction of knee pain [assessed by 100 mm Visual Analogue Scale (VAS)] at 6 months. The secondary outcomes are OMERACT-OARSI (Outcome Measures in Rheumatology-Osteoarthritis Research Society International) responder criteria [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, function and participant's global assessment (VAS)] at 6 months; change in knee pain, stiffness, function using WOMAC at 6 months and quality of life at 6 months. Adverse events will be recorded. The primary analysis will be by intention to treat, including all participants in their randomised groups.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Alfred Hospital Ethics Committee (708/20) and Monash University Human Research Ethics Committee (28498). Written informed consent will be obtained from all the participants. The findings will be disseminated through peer-review publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12621000710820 .

Patterns and natural history of hand pain in individuals with symptomatic hand osteoarthritis in a prospective cohort study: A post-hoc analysis of a randomised controlled trial

Objective

To investigate the variation in the distribution and the natural history of hand pain over 6 weeks in individuals with symptomatic hand osteoarthritis.

Design

Patient-reported outcome data were collected at baseline and weekly for 6 weeks from community-based participants enrolled in a randomised controlled trial. Participants were grouped based on location of significant pain (Visual Analogue Scale, VAS≥40/100 ​mm) (both carpometacarpal (CMC) and interphalangeal (IP), CMC only, and IP only).

Results

At baseline, of the 106 participants, 55(51.9 %) had pain in both CMC and IP joints, 28(26.4 %) in IP joints only, and 16(15.1 %) in CMC joint only. Those with CMC and IP pain had significantly higher VAS pain [68.1 (2.6) vs 59.3 (3.5) vs 51.2 (4.7)]; Australian Canadian Osteoarthritis Hand Index, (AUSCAN) pain [290.1 (15.7) vs 225.3 (21.2) vs 237.9 (28.4)], stiffness [57.1 (3.7) vs 44.6 (5.0) vs 32.2 (6.7)] and functional limitation [527.5 (30.9) vs 356.0 (41.7) vs 433.3 (55.7)]; and pain sensitization [PainDETECT score 11.1 (1.1) vs 8.1 (1.8) vs 5.8 (1.9)] compared to those with IP or CMC only pain, respectively. All groups showed improvement in outcomes over 6 weeks without significant inter-group differences.

Conclusion

In a population with significant hand pain, pain in both CMC and IP joints was most common and identified a more severe phenotype than pain in IP or CMC only with higher pain, more functional limitation and pain sensitization. These data have the potential to inform clinical management of patients with hand pain and patient selection in clinical trials.

Our biology working against us in obesity: A narrative review on implications for management of osteoarthritis

Obesity is the major modifiable risk factor for osteoarthritis (OA). A major focus of management in OA is weight loss. Although we live in an obesogenic environment, obesity has a predominantly genetic and epigenetic basis. This explains a person's weight set point which is defended by biological mechanisms making weight loss difficult to achieve and maintain long term, regardless of the methods used. Significant weight regain occurs after weight loss, with weight tending to return to pre-treatment levels after cessation of interventions including the glucagon-like peptide-1 (GLP-1) agonists. An area that has received little attention is the slow, insidious weight creep of 0.5-1 kg/year over adulthood that sees individuals relentlessly increase weight. There is evidence that low intensity, personalised lifestyle interventions can prevent this weight creep, providing patients with achievable goals. In this narrative review, we examine the evidence for weight loss in OA, the biological mechanisms that make weight loss difficult to achieve and maintain and the potential negative impacts on patients. We review the evidence for preventing weight gain, the improvement in patient outcomes and the potential for significant healthcare savings through reduced knee replacements. We propose a combined approach of weight loss when indicated, together with targeting weight creep across adult years and the potential role of metformin. Implementing these combined approaches is likely to be more effective in improving patient related outcomes, reducing joint damage and healthcare costs, than our current focus on achieving weight loss in OA.

Effect of 6-week treatment with topical betamethasone dipropionate in patients with symptomatic hand osteoarthritis: A randomized double-blind, placebo-controlled trial

Objective

To examine the efficacy and safety of topical corticosteroid over 6 weeks in patients with symptomatic hand osteoarthritis.

Design

In a randomized, double-blind, placebo-controlled trial, community-based participants with hand osteoarthritis were randomly assigned (1:1) to topical Diprosone OV (betamethasone dipropionate 0.5 ​mg/g in optimised vehicle, n=54) or placebo (plain paraffin, n=52) ointment to painful joints 3 times daily for 6 weeks. Primary outcome was pain reduction [assessed by 100 ​mm visual analogue scale (VAS)] at 6 weeks. Secondary outcomes included changes in pain and function using the Australian Canadian Osteoarthritis Hand Index (AUSCAN), Functional Index for Hand Osteoarthritis (FIHOA), and Michigan Hand Outcomes Questionnaire (MHQ) at 6 weeks. Adverse events were recorded.

Results

Of 106 participants (mean age 64.2 years, 85.9% female), 103 (97.2%) completed the study. Change in VAS at 6 weeks was similar in the Diprosone OV and placebo groups (-19.9 vs. -20.9, adjusted difference 0.6, 95% CI -8.9 to 10.2). There were no significant between-group differences in change in AUSCAN pain [adjusted difference 25.8 (-16.0 to 67.5)], AUSCAN function [21.2 (-55.0 to 97.4)], FIHOA [-0.1 (-1.7 to 1.5)], or MHQ [-1.2 (-6.0 to 3.6)]. Incidence of adverse events was 16.7% in Diprosone OV and 19.2% in placebo group.

Conclusions

Topical Diprosone OV ointment, although well-tolerated, was no better than placebo in improving pain or function over 6 weeks in patient with symptomatic hand osteoarthritis. Future studies should consider examining joints with synovitis and whether delivery approaches enhancing transdermal penetration of corticosteroids into joints are effective in hand osteoarthritis.

Trial registration

ACTRN 12620000599976. Registered May 22, 2020.

A TaqMan minor groove binder probe-based quantitative reverse transcription polymerase chain reaction for detection and quantification of chikungunya virus

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus with widespread distribution across the globe. Since 2016, CHIKV re-emerged in several countries including Indian subcontinent and Southeast Asia. A proper diagnostic tool for early diagnosis of CHIKV infection is crucial to facilitate patient management and control virus transmission at the earliest stage of outbreak. Therefore, a TaqMan minor groove binder (MGB) probe-based quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay was developed to detect and quantify the CHIKV. The primers and probe were designed based on a conserved genomic region of 730 global CHIKV sequences that is located between nsP1 and nsP2 genes. The nucleotide mismatches of primers and probe with 730 global CHIKV sequences and 13 alphaviruses were then analysed in silico. In this study, the last 5 nucleotides at 3' end of primers and 5' end of probe were considered to be the critical regions for priming. In silico analysis revealed that the critical regions of primers and probe were at least 99.6% matched with the 730 global CHIKV sequences. Besides, the primers and probe showed at least 5/20 (25.0%) and 4/17 (23.5%) nucleotide mismatches with 13 alphaviruses respectively. The amplification efficiency of qRT-PCR assay was 100.59% (95% CI= 93.06, 109.33) with a R2 score of 0.957. Its limit of detection (LOD) at 95% probability level was 16.6 CHIKV RNA copies (95% CI= 12.9, 28.9). The qRT-PCR assay was specific to CHIKV without cross-reacting with all dengue virus serotypes, Getah virus, Tembusu virus and Zika virus. The diagnostic results of qRT-PCR assay were perfectly agreed (k=1.000, p=0.003) with a commercial trioplex assay, with sensitivity of 100% (95% CI= 61, 100) and specificity of 100% (95% CI= 44, 100). Overall, the developed qRT-PCR assay is ideal for rapid, sensitive and specific detection as well as quantification of CHIKV.

Metformin as a potential disease-modifying drug in osteoarthritis: a systematic review of pre-clinical and human studies

OBJECTIVE

Osteoarthritis causes significant pain and disability with no approved disease-modifying drugs. We systematically reviewed the evidence from both pre-clinical and human studies for the potential disease-modifying effect of metformin in osteoarthritis.

METHODS

Ovid Medline, Embase and CINAHL were searched between inception and June 2021 using MeSH terms and key words to identify studies examining the association between metformin use and outcome measures related to osteoarthritis. Two reviewers performed the risk of bias assessment and 3 reviewers extracted data independently. Qualitative evidence synthesis was performed. This systematic review is registered on PROSPERO (CRD42021261052 and CRD42021261060).

RESULTS

Fifteen (10 pre-clinical and 5 human) studies were included. Most studies (10 pre-clinical and 3 human) assessed the effect of metformin using knee osteoarthritis models. In pre-clinical studies, metformin was assessed for the effect on structural outcomes (n = 10); immunomodulation (n = 5); pain (n = 4); and molecular pathways of its effect in osteoarthritis (n = 7). For human studies, metformin was evaluated for the effect on structural progression (n = 3); pain (n = 1); and immunomodulation (n = 1). Overall, pre-clinical studies consistently showed metformin having a chondroprotective, immunomodulatory and analgesic effect in osteoarthritis, predominantly mediated by adenosine monophosphate-activated protein kinase activation. Evidence from human studies, although limited, was consistent with findings in pre-clinical studies.

CONCLUSION

We found consistent evidence across pre-clinical and human studies to support a favourable effect of metformin on chondroprotection, immunomodulation and pain reduction in knee osteoarthritis. Further high-quality clinical trials are needed to confirm these findings as metformin could be a novel therapeutic drug for the treatment of osteoarthritis.

Effect of atorvastatin on skeletal muscles of patients with knee osteoarthritis: Post-hoc analysis of a randomised controlled trial

Objective

Populations with knee osteoarthritis (KOA) are at increased risk of cardiovascular disease, due to higher prevalence of risk factors including dyslipidaemia, where statins are commonly prescribed. However, the effect of statins on muscles and symptoms in this population is unknown. Thus, this study examined the effect of atorvastatin on muscle properties in patients with symptomatic KOA.

Design

Post-hoc analysis of a 2-year multicentre randomised, double-blind, placebo-controlled trial.

Setting

Australian community.

Participants

Participants aged 40–70 years (mean age 55.7 years, 55.6% female) with KOA who met the American College of Rheumatology clinical criteria received atorvastatin 40 mg daily (n = 151) or placebo (n = 153).

Main outcome measures

Levels of creatinine kinase (CK), aspartate transaminase (AST), and alanine transaminase (ALT) at 1, 6, 12, and 24 months; muscle strength (by dynamometry) at 12 and 24 months; vastus medialis cross-sectional area (CSA) on magnetic resonance imaging at 24 months; and self-reported myalgia.

Results

There were no significant between-group differences in CK and AST at all timespoints. The atorvastatin group had higher ALT than placebo group at 1 (median 26 vs. 21, p = 0.004) and 6 (25 vs. 22, p = 0.007) months without significant between-group differences at 12 and 24 months. Muscle strength increased in both groups at 24 months without between-group differences [mean 8.2 (95% CI 3.5, 12.9) vs. 5.9 (1.3, 10.4), p = 0.49]. Change in vastus medialis CSA at 24 months favoured the atorvastatin group [0.11 (−0.10, 0.31) vs. −0.23 (−0.43, −0.03), p = 0.02] but of uncertain clinical significance. There was a trend for more myalgia in the atorvastatin group (8/151 vs. 2/153, p = 0.06) over 2 years, mostly occurring within 6 months (7/151 vs. 1/153, p = 0.04).

Conclusions

In those with symptomatic KOA, despite a trend for more myalgia, there was no clear evidence of an adverse effect of atorvastatin on muscles, including those most relevant to knee joint health.

Association between popliteal artery wall thickness and structural progression in patients with symptomatic knee osteoarthritis

OBJECTIVE

There is increasing evidence for the involvement of vascular disease in the pathogenesis of knee osteoarthritis. Popliteal artery wall thickness can be used as a surrogate marker of atherosclerosis. We examined the association between popliteal artery wall thickness and knee cartilage volume in individuals with symptomatic knee osteoarthritis.

METHODS

This prospective cohort study analysed 176 participants from a randomised placebo-controlled trial examining the effect of atorvastatin on structural progression in knee osteoarthritis. The participants underwent magnetic resonance imaging (MRI) of the study knee at baseline and two-year follow-up. Popliteal artery wall thickness and tibial cartilage volume were measured from MRI using validated methods. The top quartile of the rate of tibial cartilage volume loss was defined as rapid progression.

RESULTS

At baseline, every 10% increase in popliteal artery wall thickness was associated with 120.8 mm3 (95% CI 5.4-236.2, p= 0.04) lower of medial tibial cartilage volume and 151.9 mm3 (95% CI 12.1-291.7, p= 0.03) lower of lateral tibial cartilage volume. Longitudinally, for every 10% increase in popliteal artery wall thickness, the annual rate of medial tibial cartilage volume loss was increased by 1.14% (95% CI 0.09%-2.20%, p= 0.03) and there was a 2.28-fold (95% CI 1.07-4.83, p= 0.03) risk of rapid progression of medial tibial cartilage loss, adjusted for age, sex, body mass index, tibial bone area, smoking, vigorous physical activity, and intervention group allocation.

CONCLUSION

The findings support a role for vascular pathology in the progression of knee osteoarthritis. Targeting atherosclerosis has the potential to improve outcomes in knee osteoarthritis.

Association between arthritis and cardiovascular risk factors in community-based adults: an opportunity to target cardiovascular risk

Background

Undertreated risk factors are major contributors to the burden of cardiovascular disease (CVD). Those with arthritis have an increased prevalence of CVD risk factors. CVD risk factors are often asymptomatic, which may be a barrier their treatment. Arthritis causes pain and immobility, and is a common reason for individuals to seek healthcare. Our aims were to (1) examine the relationship between arthritis and CVD risk factors in Australian adults, and (2) calculate the proportion of CVD risk factors that could be reduced if individuals with arthritis were targeted.

Methods

This cross-sectional study uses data from the 2017–18 Australian National Health Survey which included 13,776 participants, categorised into young (18–39 years), middle aged (40–64 years) and older (≥ 65 years) adults. Hypertension, height and weight were measured. Arthritis, dyslipidemia and diabetes were self-reported. The associations between arthritis and CVD risk factors were examined using logistic regression, and the population attributable fraction (PAF) of arthritis for each CVD risk factor was calculated.

Results

Arthritis was reported by 4.0% of young adults, 28.8% of middle-aged adults and 54.5% of older adults. Those with arthritis were at increased odds of obesity (2.07 fold in young, 1.75 fold in middle-aged and 1.89 fold in older adults), increased odds of diabetes (5.70 fold in young, 1.64 fold in middle-aged and 1.37 fold in older adults), increased odds of hypertension (2.72 fold in young, 1.78 fold in middle-aged and 1.48 fold in older adults) and an increased odds of dyslipidaemia (4.64 fold in young, 2.14 fold in middle-aged and 1.22 fold in older adults) compared to those without arthritis. This elevated chance remained significant even after adjusting for obesity, with the exception of diabetes in the older population. This elevated chance remained significant even after adjusting for obesity, with the exception of diabetes in the older population. The PAF of the presence of arthritis for having at least one CVD risk factor was 30.7% in middle-aged adults and 70.4% in older adults.

Conclusion

Australian adults of all ages with arthritis are at increased odds of having CVD risk factors. For young and middle-aged adults, this increased odds remains significant even when adjusted for obesity. Presentation to healthcare practitioners with arthritis is an opportunity to screen for asymptomatic CVD risk factors with the potential of improving outcomes for both diseases. By adopting an approach of managing arthritis and CVD risk factors in parallel, rather than in silos, we could reduce the burden of CVD risk factors by 20–30%.

Topical corticosteroid for treatment of hand osteoarthritis: study protocol for a randomised controlled trial

Background

Hand osteoarthritis is a common and disabling chronic joint disease with a lack of effective therapies. Emerging evidence suggests the role of local inflammation in causing pain in hand osteoarthritis. Corticosteroids are potent anti-inflammatory drugs used in many rheumatic diseases. The aim of this randomised, double-blind, placebo-controlled trial is to determine whether topical corticosteroid reduces pain over 6 weeks in patients with hand osteoarthritis.

Methods

One hundred participants with hand osteoarthritis will be recruited from the community in Melbourne, Australia, and randomly allocated in a 1:1 ratio to receive either topical Diprosone OV or placebo ointment administered 3 times daily on the painful hand joints for 6 weeks. The primary outcome is pain reduction (assessed by 100 mm visual analogue scale) at 6 weeks. The secondary outcomes include changes in pain and function assessed using Functional Index for Hand Osteoarthritis, Australian Canadian Osteoarthritis Hand Index, Michigan Hand Outcomes Questionnaire, and tender and swollen joint count at 6 weeks. Adverse events will be recorded. The primary analysis will be by intention to treat, including all participants in their randomised groups.

Discussion

This study will provide high-quality evidence to determine whether topical corticosteroid reduces pain over 6 weeks in patients with hand osteoarthritis, with major clinical and public health importance by informing clinical practice guidelines for the management of hand osteoarthritis and reducing the burden of the disabling disease.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12620000599976. Registered 22 May 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04921-2.

Rates, costs and determinants of lumbar spine imaging in population-based women born in 1973-1978: Data from the Australian Longitudinal Study on Women's Health

Objective

There are concerns that lumbar spine imaging represents low value care. Our aim was to examine the use of lumbar spine imaging [radiography, computed tomography (CT), magnetic resonance imaging (MRI)] over 20 years, and costs and person-level characteristics of imaging in a large cohort of Australian women.

Methods

The Australian Longitudinal Study on Women’s Health (ALSWH) is a longitudinal population-based survey of women randomly selected from national health insurance scheme (Medicare) database. This study examined 13458 women born in 1973–1978 who consented to link their ALSWH and Medical Benefits Scheme records. Self-reported data on demographics, body mass index, depression, physical and mental health, and back pain were collected in each survey performed in 1996, 2000, 2003, 2006, 2009, 2012, and 2015. Data on lumbar spine imaging from 1996 to 2015 were obtained from the Medical Benefits Scheme database.

Results

38.9% of women underwent some form of lumbar spine imaging over 20 years. While radiography increased from 1996 to 2011 and decreased thereafter, CT and MRI continued to increase from 1996 to 2015. In women with self-reported back pain, depression and poorer physical health were associated with imaging, with no significant differences in types of imaging. Based on imaging rates in ALSWH, the estimated costs for Australian women aged 30–39 years were AU$51,735,649 over 2011–2015.

Conclusions

Lumbar spine imaging was common in population-based Australian women, with rates increasing over 20 years. Depression and poor physical health were associated with lumbar spine imaging. Raising awareness of this in clinicians is likely to result in significant cost savings if clinical guidelines are followed, with the potential of freeing resources for high value care and health outcomes.

Association between metformin use and disease progression in obese people with knee osteoarthritis: data from the Osteoarthritis Initiative-a prospective cohort study

OBJECTIVE

To examine whether metformin use was associated with knee cartilage volume loss over 4 years and risk of total knee replacement over 6 years in obese individuals with knee osteoarthritis.

METHODS

This study analysed the Osteoarthritis Initiative participants with radiographic knee osteoarthritis (Kellgren-Lawrence grade ≥ 2) who were obese (body mass index [BMI] ≥ 30 kg/m²). Participants were classified as metformin users if they self-reported regular metformin use at baseline, 1-year and 2-year follow-up (n = 56). Non-users of metformin were defined as participants who did not report the use of metformin at any visit from baseline to 4-year follow-up (n = 762). Medial and lateral cartilage volume (femoral condyle and tibial plateau) were assessed using magnetic resonance imaging at baseline and 4 years. Total knee replacement over 6 years was assessed. General linear model and binary logistic regression were used for statistical analyses.

RESULTS

The rate of medial cartilage volume loss was lower in metformin users compared with non-users (0.71% vs. 1.57% per annum), with a difference of - 0.86% per annum (95% CI - 1.58% to - 0.15%, p = 0.02), after adjustment for age, gender, BMI, pain score, Kellgren-Lawrence grade, self-reported diabetes, and weight change over 4 years. Metformin use was associated with a trend towards a significant reduction in risk of total knee replacement over 6 years (odds ratio 0.30, 95% CI 0.07-1.30, p = 0.11), after adjustment for age, gender, BMI, Kellgren-Lawrence grade, pain score, and self-reported diabetes.

CONCLUSIONS

These data suggest that metformin use may have a beneficial effect on long-term knee joint outcomes in those with knee osteoarthritis and obesity. Randomised controlled trials are needed to confirm these findings and determine whether metformin would be a potential disease-modifying drug for knee osteoarthritis with the obese phenotype.

Are biomechanical factors, meniscal pathology, and physical activity risk factors for bone marrow lesions at the knee? A systematic review

OBJECTIVE

To systematically review the literature to determine whether biomechanical factors, meniscal pathology, and physical activity are risk factors for bone marrow lesions (BMLs) at the knee identified from magnetic resonance imaging in pre-osteoarthritis and osteoarthritis populations.

METHODS

Electronic searches of MEDLINE and EMBASE were performed from January 1, 1996 to October 31, 2012 using the keywords of bone marrow lesion(s), bone marrow (o)edema, osteoarthritis, and knee. Studies examining biomechanical factors, meniscal pathology, or physical activity in relation to the presence, incidence, or change in BMLs at the knee were included. Two independent reviewers extracted the data and assessed the methodological quality of selected studies. Due to the heterogeneity of the studies, we performed a best evidence synthesis.

RESULTS

Fifteen studies were included in this review, of which 9 were considered high quality. The study populations were heterogeneous in terms of the symptoms and radiographic knee osteoarthritis. There was strong evidence for relationships of mechanical knee alignment and meniscal pathology with BMLs in osteoarthritis populations. There was a paucity of evidence for a relationship between physical activity and BMLs.

CONCLUSION

Despite the heterogeneity of included studies, these data suggest that mechanical knee alignment and meniscal pathology are risk factors for BMLs in knee osteoarthritis. It suggests that BMLs in individuals with osteoarthritis are more susceptible to mechanical knee alignment. Given the role of BMLs in the pathogenesis of knee osteoarthritis, identifying strategies to modify these risk factors will be important in slowing the progression and reducing the burden of knee osteoarthritis.

Association of obesity and systemic factors with bone marrow lesions at the knee: a systematic review

OBJECTIVE

The objective of this study was to systematically review the literature to determine whether obesity and systemic factors, including age, gender, heritability, dietary factors, smoking, serum and urine biomarkers of cartilage or bone metabolism, bone-related factors, and medication, are associated with knee bone marrow lesions (BMLs) identified on magnetic resonance imaging in asymptomatic pre-osteoarthritis and osteoarthritis populations.

METHODS

Electronic searches of MEDLINE and EMBASE were performed from January 1, 1996 to September 30, 2012 using the following keywords: bone marrow lesion(s), bone marrow (o)edema, osteoarthritis, and knee. Studies examining obesity and non-biomechanical factors in relation to the presence, incidence, or change in BMLs were included. Two independent reviewers extracted data and assessed methodological quality of selected studies. Due to the heterogeneity of the studies, we performed a best evidence synthesis.

RESULTS

Among 30 studies, 17 were considered high quality. The study populations were heterogeneous in terms of symptoms and radiographic knee osteoarthritis. There was strong evidence for an association between serum lipids and BMLs and no association between age and BMLs. There was moderate evidence for a relationship between obesity and BMLs. There was limited evidence for gender, smoking, C-telopeptide of type I collagen, anti-bone-resorptive treatments, licofelone, and chondroitin sulfate. There was a paucity of evidence for heritability and conflicting evidence for dietary fatty acids.

CONCLUSION

There is strong evidence for serum lipids and moderate evidence for obesity as risk factors for knee BMLs. Given the role of BMLs in the pathogenesis of knee osteoarthritis, identification of modifiable risk factors of BMLs and therapeutic interventions targeting BMLs has the potential to reduce the burden of knee osteoarthritis.