Association between statin use and incidence or progression of osteoarthritis: meta-analysis of observational studies

Causal impact of statins on susceptibility to osteoarthritis: insights from a two-sample Mendelian randomization analysis

BACKGROUND

Osteoarthritis is a widely prevalent cause of pain and disability among older adults. It is an incurable condition, and most treatments are aimed at alleviating symptoms.

AIM

This study aimed to investigate the impact of statins on osteoarthritis by using a two-sample Mendelian randomization approach, using genetic variants associated with statin use as instrumental variables.

METHOD

Information on single nucleotide polymorphisms associated with statin medication was obtained from the FinnGen study, and data on osteoarthritis were sourced from the UK Biobank. The inverse variance weighted method was used as the primary analytical approach for the Mendelian randomization analysis. Sensitivity analyses were conducted to evaluate horizontal pleiotropy and heterogeneity. To examine the genetic relationship between statins and osteoarthritis, linkage disequilibrium score regression-based estimates were used.

RESULTS

Mendelian randomization analysis indicated a positive effect of statin use on the treatment of osteoarthritis (odds ratio 0.951, 95% confidence interval 0.914-0.99, p < 0.05). This conclusion was supported by various Mendelian randomization methods. Sensitivity analyses revealed no significant directional pleiotropy or influential single nucleotide polymorphisms that could compromise the overall causal inference. Linkage disequilibrium score regression-based estimates suggested a modest genetic correlation between statin use and osteoarthritis (Rg = 0.098, Se = 0.034, p < 0.05), thus reinforcing the robustness of the Mendelian randomization analysis.

CONCLUSION

Statins reduce the risk of osteoarthritis, aligning with the results of observational studies. Further research is essential to validate these results and explore the underlying mechanisms in detail.

Enhancement of Intracellular Cholesterol Efflux in Chondrocytes Leading to Alleviation of Osteoarthritis Progression

OBJECTIVE

Osteoarthritis (OA) is the most common degenerative disease worldwide, with no practical means of prevention and limited treatment options. Recently, our group unveiled a novel mechanism contributing to OA pathogenesis in association with abnormal cholesterol metabolism in chondrocytes. In this study, we aimed to establish a clinical link between lipid profiles and OA in humans, assess the effectiveness of cholesterol-lowering drugs in suppressing OA development in mice, and uncover the cholesterol-lowering mechanisms that effectively impede OA progression.

METHODS

Five clinically approved cholesterol-lowering drugs (fenofibrate, atorvastatin, ezetimibe, niacin, and lomitapide) were injected into the knee joints or administered with diet to mice with OA who underwent destabilization of the medial meniscus induction and were fed a 2% high-cholesterol diet. Gene expression linked to cholesterol metabolism was determined using microarray analysis. Furthermore, the in vivo functions of these genes were explored through intra-articular injection of either its inhibitor or adenovirus.

RESULTS

Logistic regression analysis confirmed a close relationship between the diagnostic criteria of hyperlipidemia based on serum lipid levels and OA incidence. Among the cholesterol-lowering drugs examined, fenofibrate exerted the most significant protective effect against cartilage destruction, which was attributed to elevated levels of high-density lipoprotein cholesterol that are crucial for cholesterol efflux. Notably, cholesterol efflux was suppressed during OA progression via down-regulation of apolipoprotein A1-binding protein (AIBP) expression. Overexpression of AIBP effectively inhibits OA progression.

CONCLUSION

Our results suggest that restoration of cholesterol homeostasis to a normal state through administration of fenofibrate or AIBP overexpression, both of which induce cholesterol efflux, offers an effective therapeutic option for patients with OA.

Exploring the causal link among statin drugs and the osteoarthritis risk based on Mendelian randomization research

Purpose

Statins may have a protective effect against osteoarthritis (including knee osteoarthritis and hip osteoarthritis); however, the link between statins and osteoarthritis risk is incompletely established. The aim of this study was to explore the relationship between statins and osteoarthritis risk through Mendelian randomization analysis using pooled information from a large population-wide genome-wide association study (GWAS).

Methods

Statin-related single-nucleotide polymorphisms (SNPs) were obtained from FinnGen's latest 9th edition database, and data on osteoarthritis, knee osteoarthritis, and hip osteoarthritis were acquired from the IEU OpenGWAS, the UK Biobank, and Arthritis Research UK Osteoarthritis Genetics (ArcOGEN) database, respectively. The inverse-variance weighting method is an important analysis method to estimate the causal effect. Weighted median method, simple median method, weighted median estimator method, and MR-Egger regression were employed to supplement the explanation. Odds ratio and 95%CI were used to evaluate the causal relationship among statins and the osteoarthritis risk, osteoarthritis in the knee, and osteoarthritis in the hip. Second, sensitivity analysis was carried out to validate the reliability of the results. Cochran's Q test was employed to test heterogeneity, MR-Egger intercept was employed to test whether horizontal pleiotropy existed, and single-nucleotide polymorphisms with potential influence were determined by the one-method analysis.

Results

(1) The results of the inverse variance weighting method showed Gene prediction indicated that statins were associated with osteoarthritis (OR = 0.998, 95% CI: 0.996-0.999, P = 0.01) and knee osteoarthritis (OR = 0.964, 95% CI: knee (0.940-0.989, P = 0.005) and hip osteoarthritis risk were associated (OR = 0.928, 95% CI: 0.901-0.955, P = 4.28 × 10-7). (2) MR-Egger intercept analysis did not detect potential horizontal pleiotropy (osteoarthritis: P = 0.658; knee osteoarthritis: P = 0.600; and hip osteoarthritis: P = 0.141). (3) The findings provide evidence that statins reduce osteoarthritis risk, osteoarthritis in the knee, and osteoarthritis in the hip, as described in observational studies, and the specific mechanisms by which statins treat osteoarthritis require further investigation.

Conclusion

The results of this study, at the genetic level, reveal a negative causal relationship between statins and osteoarthritis, and this causal relationship is also present in knee and hip osteoarthritis. This study provides evidence against the potential of statins in the treatment of osteoarthritis, prompting the clinical treatment of osteoarthritis to consider improving the start and compliance of statins in the future.

Lovastatin impairs cellular proliferation and enhances hyaluronic acid production in fibroblast-like synoviocytes

INTRODUCTION

Statins have demonstrated chondroprotective effects by reducing inflammation and mitigating extracellular matrix degradation. However, statins are also reported to be cytotoxic to several types of cells. Early-onset osteoarthritis (OA) is characterized by synovial inflammation, which adversely affects hyaluronan (HA) production in fibroblast-like synoviocytes (FLSs). Nevertheless, the precise effects of statins on the synovium remain unclear.

METHODS

This study investigated the impact of lovastatin on human FLSs, and HA secretion-related genes, signaling pathways, and production were evaluated.

RESULTS

The findings revealed that high doses of lovastatin (20 or 40 μM) decreased FLS viability and increased cell death. FLS proliferation ceased when cultured in a medium containing 5 or 10 μM lovastatin. mRNA expression analysis demonstrated that lovastatin (5 and 10 μM) upregulated the gene level of hyaluronan synthase 1 (HAS1), HAS2, and proteoglycan 4 (PRG4), but not HAS3. While the expression of multidrug resistance-associated protein 5 transporter gene remained unaffected, both inward-rectifying potassium channel and acid-sensing ion channel 3 were upregulated. Western blot further confirmed that lovastatin increased the production of HAS1 and PRG4, and activated the PKC-α, ERK1/2, and p38-MAPK signaling pathways. Additionally, lovastatin elevated intracellular cAMP levels and HA production in FLSs.

CONCLUSION

Lovastatin impairs cellular proliferation but enhances HA production in human FLSs.

Assessing the causal associations of different types of statins use and knee/hip osteoarthritis: A Mendelian randomization study

OBJECTIVE

This study comprehensively evaluated the causal relationship between different types of statins use and knee/hip osteoarthritis (OA) using a two-sample and multivariate Mendelian randomization (MR) method.

METHODS

MR analysis was conducted using publicly available summary statistics data from genome-wide association studies (GWAS) to assess the causal associations between total statins use (including specific types) and knee/hip OA. The primary analysis utilized the inverse variance-weighted (IVW) method, with sensitivity analysis conducted to assess robustness. Multivariable MR (MVMR) analysis adjusted for low-density lipoprotein cholesterol (LDL-C), intermediate-density lipoprotein cholesterol (IDL-C), high-density lipoprotein cholesterol (HDL-C), and body mass index (BMI).

RESULTS

The MR analysis revealed a significant inverse association between genetically predicted total statins use and the risk of knee OA (OR = 0.950, 95%CI: 0.920-0.982, p = 0.002) as well as hip OA (OR = 0.932, 95%CI: 0.899-0.966, p <0.001). Furthermore, this study highlighted a reduced risk of knee/hip OA with the use of atorvastatin and simvastatin. Rosuvastatin use was associated with a decreased risk of hip OA but showed no association with knee OA. MVMR results indicated no correlation between exposure factors and outcomes after adjusting for LDL-C or IDL-C. HDL-C may not significantly contribute to statin-induced osteoarthritis, while BMI may play an important role.

CONCLUSION

This study provides compelling evidence of the close relationship between statin use and a reduced risk of knee/hip OA, particularly with atorvastatin and simvastatin. LDL-C and IDL-C may mediate these effects. These findings have important implications for the clinical prevention and treatment of knee/hip OA.

Possible link between statin and iron deficiency anemia: A South Korean nationwide population-based cohort study

An extensive evaluation of disease occurrence after statin use based on a "hypothesis-free" approach remains scarce. To examine the effect of statin use on the potential risk of developing diseases, a propensity score-matched cohort study was executed using data from the National Sample Cohort in South Korea. A total of 7847 statin users and 39,235 nonstatin users were included in the final analysis. The period of statin use was defined as our main time-dependent exposure and was divided into three periods: current, recent, and past. The main outcomes were defined as new-onset diseases with ≥100 events based on the International Statistical Classification of Diseases, 10th Revision. We calculated the adjusted hazard ratios and 95% confidence intervals (CIs) using Cox regression. We found that statin use significantly increased the risk of developing iron deficiency anemia up to 5.04 times (95% CI, 2.11 to 12.03). Therefore, the iron levels of patients using statins should be monitored carefully.

Uncovering the Relationship Between Statins and Muscle Problems in the ELSA-Brasil MSK Cohort

PURPOSE

To investigate the association between statins and muscle problems in a highly diverse sample of Brazilian civil servants.

METHODS

We conducted a cross-sectional data analysis at baseline of the ELSA-Brasil MSK cohort. Pain was identified through self-reported symptoms in large muscle groups (lower back and/or hips/thighs). Muscle strength was assessed using the five-times-sit-to-stand (FTSTS) and handgrip tests, with weakness defined as the lowest and highest quintiles of age- and sex-stratified handgrip strength and FTSTS performance time, respectively. Multivariable logistic regression analyses were conducted to investigate the association between statin use and muscle pain and weakness. Secondary analyses explored the impact of different types of statins and their duration of use on the response variables.

RESULTS

A total of 2156 participants (mean age 55.6 ± SD 8.9, 52.8% women) were included, of whom 21.1% were taking statins and 25.1% reported muscle pain. We found no significant association between statin use and muscle problems. Secondary analysis on different types of statins revealed an association between atorvastatin and muscle weakness, as measured by the five-times-sit-to-stand test (OR 1.94, 95% CI 1.12-3.37), but not by the handgrip test (OR 0.75, 95% CI 0.29-1.42). No evidence was found to support a link between the duration of statin treatment and muscle problems.

CONCLUSIONS

This study challenges previous claims of an efficacy-effectiveness gap between experimental and observational literature on statins. The findings indicate that statin use does not contribute to muscular problems.

Intensive cholesterol-lowering treatment reduces synovial inflammation during early collagenase-induced osteoarthritis, but not pathology at end-stage disease in female dyslipidemic E3L.CETP mice

INTRODUCTION

The association between metabolic syndrome (MetS) and osteoarthritis (OA) development has become increasingly recognized. In this context, the exact role of cholesterol and cholesterol-lowering therapies in OA development has remained elusive. Recently, we did not observe beneficial effects of intensive cholesterol-lowering treatments on spontaneous OA development in E3L.CETP mice. We postulated that in the presence of local inflammation caused by a joint lesion, cholesterol-lowering therapies may ameliorate OA pathology.

MATERIALS AND METHODS

Female ApoE3∗Leiden.CETP mice were fed a cholesterol-supplemented Western type diet. After 3 weeks, half of the mice received intensive cholesterol-lowering treatment consisting of atorvastatin and the anti-PCSK9 antibody alirocumab. Three weeks after the start of the treatment, OA was induced via intra-articular injections of collagenase. Serum levels of cholesterol and triglycerides were monitored throughout the study. Knee joints were analyzed for synovial inflammation, cartilage degeneration, subchondral bone sclerosis and ectopic bone formation using histology. Inflammatory cytokines were determined in serum and synovial washouts.

RESULTS

Cholesterol-lowering treatment strongly reduced serum cholesterol and triglyceride levels. Mice receiving cholesterol-lowering treatment showed a significant reduction in synovial inflammation (P = 0.008, WTD: 95% CI: 1.4- 2.3; WTD + AA: 95% CI: 0.8- 1.5) and synovial lining thickness (WTD: 95% CI: 3.0-4.6, WTD + AA: 95% CI: 2.1-3.2) during early-stage collagenase-induced OA. Serum levels of S100A8/A9, MCP-1 and KC were significantly reduced after cholesterol-lowering treatment (P = 0.0005, 95% CI: -46.0 to -12.0; P = 2.8 × 10^-10, 95% CI: -398.3 to -152.1; P = 2.1 × 10^-9, -66.8 to -30.4, respectively). However, this reduction did not reduce OA pathology, determined by ectopic bone formation, subchondral bone sclerosis and cartilage damage at end-stage disease.

CONCLUSION

This study shows that intensive cholesterol-lowering treatment reduces joint inflammation after induction of collagenase-induced OA, but this did not reduce end stage pathology in female mice.

The association between statin use and osteoarthritis-related outcomes: An updated systematic review and meta-analysis

Objective: Findings among studies evaluating the effect of statin use and OA development in a 2020 meta-analysis of data from 11 observational studies of statin use and osteoarthritis (OA) revealed controversial results. We aimed to determine the associations between statin use and OA-related outcomes in an updated meta-analysis. Methods: The protocol was registered with PROSPERO (CRD42020163983). A systematic literature retrieval was performed in the online databases, including PubMed, Cochrane Library, Embase, Web of Science, and Scopus, from inception to 1 June 2022, for clinical studies that compared the effects of statin users vs. nonusers on OA-related outcomes risks. Systematic reviews and meta-analyses were performed to estimate the correlations between statin use and OA-related outcomes. Tendency analysis was also used to estimate dose-response effects. The risk of bias was evaluated with the Newcastle-Ottawa scale. Results: We included 23 studies involving more than 6,000,000 participants. Statin use was associated with increased OA risk (OR 1.099 [95%CI 1.002-1.206, p = 0.045]). Higher statin doses had higher OA risk (simvastatin equivalent daily of >40 mg). OA and related surgery risks were significantly reduced in statin users using antihypertensive drugs (AHDs). No significant differences were seen in other outcomes. Conclusion: This meta-analysis inferred that statin use might be associated with increased OA development, especially at higher doses. The present study highlights the importance of recognizing potential OA risk in the population with long-term and/or high-dose statin use, especially in older populations. In addition, AHDs are associated with lower OA risk and fewer surgeries in hypertensive statin users. Due to limitations of heterogeneity and confounders, more rigorous studies are needed to define the correlations between statin use and OA-related outcomes.

Therapeutic effects of statins on osteoarthritis: A review

Osteoarthritis (OA) is a progressive joint disease. The etiology of OA is considered to be multifactorial. Currently, there is no definitive treatment for OA, and the existing treatments are not very effective. Hypercholesterolemia is considered a novel risk factor for the development of OA. Statins act as a competitive inhibitor of the β-hydroxy β-methylglutaryl-CoA (HMG-CoA) reductase and are widely used to manage hypercholesterolemia. Inhibition of HMG-CoA reductase results in reduced synthesis of a metabolite named mevalonate, thereby reducing cholesterol biosynthesis in subsequent steps. By this mechanism, statins such as atorvastatin and simvastatin could potentially have a preventive impact on joint cartilage experiencing osteoarthritic deterioration by reducing serum cholesterol levels. Atorvastatin can protect cartilage degradation following interleukin-1β-stimulation. Atorvastatin stimulates the STAT1-caspase-3 signaling pathway that was shown to be responsible for its anti-inflammatory effects on the knee joint. Simvastatin had chondroprotective effects on OA in vitro by reducing matrix metalloproteinases expression patterns. In this study, we tried to review the therapeutic effects of statins on OA.

Statin use and MRI subchondral bone marrow lesion worsening in generalized osteoarthritis: longitudinal analysis from Osteoarthritis Initiative data

OBJECTIVES

To determine the association between statin therapy and knee MRI-detected subchondral bone marrow lesion (BML) longitudinal worsening in patients with Heberden's nodes (HNs) as the hallmark of generalized osteoarthritis (OA) phenotype.

METHODS

All participants gave informed consent, and IRB approved HIPAA-compliant protocol. We assessed the worsening in BML volume and number of affected subregions in the Osteoarthritis Initiative (OAI) participants with HNs at baseline clinical examination (HN⁺), using the semi-quantitative MRI Osteoarthritis Knee Scores at baseline and 24 months. Participants were classified according to baseline BML involvement as "no/minimal" (≤ 2/14 knee subregions affected and maximum BML score ≤ 1) or "moderate/severe." Statin users and non-users were selected using 1:1 propensity-score (PS) matching for OA and cardiovascular disease (CVD)-related potential confounding variables. We assessed the association between statin use and increasing BML score and affected subregions using adjusted mixed-effect regression models.

RESULTS

The PS-matched HN⁺ participants (63% female, aged 63.5 ± 8.5-year-old) with no/minimal and moderate/severe BML cohorts consisted of 332 (166:166, statin users: non-users) and 380 (190:190) knees, respectively. In the HN⁺ participants with no/minimal BML, statin use was associated with lower odds of both BML score worsening (odds ratio, 95% confidence interval: 0.62, 0.39-0.98) and increased number of affected subregions (0.54, 0.33-0.88). There was no such association in HN^- participants or those HN⁺ participants with baseline moderate/severe BML.

CONCLUSION

In patients with CVD indications for statin therapy and generalized OA phenotype (HN⁺), statin use may be protective against the OA-related subchondral bone damage only in the subgroup of participants with no/minimal baseline BML.

KEY POINTS

• Statin use may reduce the risk of subchondral bone damage in specific osteoarthritis patients with a generalized phenotype, minimal subchondral bone damage, and cardiovascular statin indications.

Epidemiology of osteoarthritis

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Effect of blood lipids and lipid-lowering therapies on osteoarthritis risk: A Mendelian randomization study

Background

We aimed to investigate the effects of blood lipids and lipid-lowering agents on osteoarthritis (OA) risk.

Materials and methods

We performed Mendelian randomization (MR) analyses to estimate the causal effect of blood low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels on knee and hip OA. Single nucleotide polymorphisms (SNPs) were selected from large genome-wide association studies (GWASs) of individuals of European ancestry as genetic instruments for blood lipid levels. The associations of selected genetic instruments with knee and hip OA were estimated in a recent GWAS of the UK Biobank and arcOGEN datasets. Univariate and multivariate MR analyses were performed to detect and adjust for potential pleiotropy. Furthermore, genetic instruments in HMGCR, NPC1L1, and PCSK9 regions were used to mimic LDL-C-lowering effects of statin, ezetimibe, and evolocumab, respectively.

Results

Genetically determined LDL-C increments led to reduced risks of both knee OA (OR = 0.91 per 1-SD increment, 95% CI: 0.86-0.95, P = 6.3 × 10^-5) and hip OA (OR = 0.92, 95% CI: 0.85-0.99, P = 0.027). Multivariate MR analysis proved that the effect was independent of HDL-C, TG, and body mass index. TG increment was associated with reduced risks of hip OA in the univariate MR analysis; however, this was not supported by the multivariate MR analysis. Genetically proxied LDL-C-lowering effects of statins are related to increased risks of knee OA but not hip OA.

Conclusions

The findings suggested that LDL-C increments have independent protective effects on both knee and hip OA. LDL-C-lowering effects of statins may increase the risk of knee OA.

Prevention of Osteoarthritis Progression by Statins, Targeting Metabolic and Inflammatory Aspects: A Review

Background and purpose:

Several traditional risk factors of atherosclerosis such as age, obesity, and altered lipid metabolism are shared with osteoarthritis (OA). Metabolic abnormalities and atheromatous vascular disease are linked with systemic inflammation and progression of OA. Hence, treatment of OA with statins is expected to improve metabolic abnormalities and prevent OA progression. Many studies which have addressed this issue found inconsistent results. This review aims to elucidate the effect of statins in OA by summarizing the existing data.

Methods:

Potential studies in English language published in Medline/PubMed, Scopus and Google Scholar since 2000 were searched by using keywords such as osteoarthritis, statins, progression, treatment, prevalence, synovitis, pain. Fourteen papers were found to be relevant and were summarised.

Results:

Data regarding symptomatic effect of statins in OA are scarce and the results varied from no effect to a small improvement or even increased risk of pain in knee OA. However, most studies on the incidence and progression of OA found a significant decreased risk of incident OA, as well as reduced risk of radiographic progression in statin users vs. non-users. Factors such as patient adherence, duration of treatment, and higher cumulative statin doses were associated with greater efficacy.

Conclusion:

Existing data indicate a preventing effect of statin therapy on OA progression. However, unless a formal meta-analysis with weight analysis is made, a conclusion cannot be drawn.

Cholesterol metabolism related genes in osteoarthritis

Cholesterol homeostasis plays a significant role in skeletal development and the dysregulation of cholesterol-related mechanism has been shown to be involved in the development of cartilage diseases including osteoarthritis (OA). Epidemiological studies have shown an association between elevated serum cholesterol levels and OA. Furthermore, abnormal lipid accumulation in chondrocytes as a result of abnormal regulation of cholesterol homeostasis has been demonstrated to be involved in the development of OA. Although, many in vivo and in vitro studies support the connection between cholesterol and cartilage degradation, the mechanisms underlying the complex interactions between lipid metabolism, especially HDL cholesterol metabolism, and OA remain unclear. The current review aims to address this problem and focuses on key molecular players of the HDL metabolism pathway and their role in ΟΑ pathogenesis. Understanding the complexity of biological processes implicated in OA pathogenesis, such as cholesterol metabolism, may lead to new targets for drug therapy of OA patients.

Implications on the Therapeutic Potential of Statins via Modulation of Autophagy

Statins, which are functionally known as 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) inhibitors, are lipid-lowering compounds widely prescribed in patients with cardiovascular diseases (CVD). Several biological and therapeutic functions have been attributed to statins, including neuroprotection, antioxidation, anti-inflammation, and anticancer effects. Pharmacological characteristics of statins have been attributed to their involvement in the modulation of several cellular signaling pathways. Over the past few years, the therapeutic role of statins has partially been attributed to the induction of autophagy, which is critical in maintaining cellular homeostasis and accounts for the removal of unfavorable cells or specific organelles within cells. Dysregulated mechanisms of the autophagy pathway have been attributed to the etiopathogenesis of various disorders, including neurodegenerative disorders, malignancies, infections, and even aging. Autophagy functions as a double-edged sword during tumor metastasis. On the one hand, it plays a role in inhibiting metastasis through restricting necrosis of tumor cells, suppressing the infiltration of the inflammatory cell to the tumor niche, and generating the release of mediators that induce potent immune responses against tumor cells. On the other hand, autophagy has also been associated with promoting tumor metastasis. Several anticancer medications which are aimed at inducing autophagy in the tumor cells are related to statins. This review article discusses the implications of statins in the induction of autophagy and, hence, the treatment of various disorders.

Effect of atorvastatin on knee cartilage volume in patients with symptomatic knee osteoarthritis: results from a randomised placebo-controlled trial

OBJECTIVE

To determine whether atorvastatin compared to placebo slows tibial cartilage volume loss in patients with symptomatic knee osteoarthritis in a multicentre, randomised, double-blind, placebo-controlled trial.

METHODS

Participants aged 40-70 years were randomised to oral atorvastatin 40 mg (n=151) or matching placebo (n=153) once daily. Primary endpoint: annual percentage change in tibial cartilage volume assessed using magnetic resonance imaging (MRI) over two years. Pre-specified secondary endpoints: progression of cartilage defects and bone marrow lesions assessed using MRI, and change in Western Ontario and McMaster Universities Osteoarthritis Index pain, stiffness and function over two years.

RESULTS

Of 304 participants (mean age 55.7 years, 55.6% female), 248 (81.6%) completed the trial. Annual change in tibial cartilage volume differed minimally between the atorvastatin and placebo groups (-1.66% vs. -2.17%, difference 0.50%, 95%CI -0.17% to 1.17%). There were no significant differences in progression of cartilage defects (odds ratio 0.86, 95%CI 0.52-1.41) or bone marrow lesions (odds ratio 1.00, 95%CI 0.62-1.63), change in pain [-36.0 vs. -29.5, adjusted difference -2.7, 95%CI -27.1 to 21.7), stiffness (-14.2 vs. -11.8, adjusted difference -0.2, 95%CI -12.2 to 11.8), or function [-89.4 vs. -87.5, adjusted difference 0.3, 95%CI -83.1 to 83.6). Incidence of adverse events was similar in atorvastatin (n=57, 37.7%) and placebo (n=52, 34.0%) groups.

CONCLUSION

Oral atorvastatin 40 mg once daily, compared with placebo, did not significantly reduce cartilage volume loss over two years in patients with symptomatic knee osteoarthritis. These findings do not support use of atorvastatin in the treatment of knee osteoarthritis.