Does statin use have a disease modifying effect in symptomatic knee osteoarthritis? Study protocol for a randomised controlled trial

Application of Injectable Hydrogels as Delivery Systems in Osteoarthritis and Rheumatoid Arthritis

Osteoarthritis and rheumatoid arthritis, though etiologically distinct, are both inflammatory joint diseases that cause progressive joint injury, chronic pain, and loss of function. Therefore, long-term treatment with a focus on relieving symptoms is needed. At present, the primary treatment for arthritis is drug therapy, both oral and intravenous. Although significant progress has been achieved for these treatment methods in alleviating symptoms, certain prominent drawbacks such as the substantial side effects and limited absorption of medications call for an urgent need for improved drug delivery methods. Injected hydrogels can be used as a delivery system to deliver drugs to the joint cavity in a controlled manner and continuously release them, thereby enhancing drug retention in the joint cavity to improve therapeutic effectiveness, which is attributed to the desirable attributes of the delivery system such as low immunogenicity, good biodegradability and biocompatibility. This review summarizes the types of injectable hydrogels and analyzes their applications as delivery systems in arthritis treatment. We also explored how hydrogels counteract inflammation, bone and cartilage degradation, and oxidative stress, while promoting joint cartilage regeneration in the treatment of osteoarthritis (OA) and rheumatoid arthritis (RA). This review also highlights new approaches to developing injectable hydrogels as delivery systems for OA and RA.

Effects of Simvastatin on Cartilage Homeostasis in Steroid-Induced Osteonecrosis of Femoral Head by Inhibiting Glucocorticoid Receptor

Steroid-induced osteonecrosis of femoral head (SONFH) is one of the most common bone disorders in humans. Statin treatment is beneficial in preventing the development of SONFH through anti-inflammation effects and inhibition of the glucocorticoid receptor (GR). However, potential mechanisms of statin action remain to be determined. In this study, pulse methylprednisolone (MP) treatment was used to induce SONFH in broilers, and then MP-treated birds were administrated with simvastatin simultaneously to investigate the changes in cartilage homeostasis. Meanwhile, chondrocytes were isolated, cultured, and treated with MP, simvastatin, or GR inhibitor in vitro. The changes in serum homeostasis factors, cell viability, and expression of GR were analyzed. The results showed that the morbidity of SONFH in the MP-treated group increased significantly compared with the simvastatin-treated and control group. Furthermore, MP treatment induced apoptosis and high-level catabolism and low-level anabolism in vitro and vivo, while simvastatin significantly decreased catabolism and slightly recovered anabolism via inhibiting GR and the hypoxia-inducible factor (HIF) pathway. The GR inhibitor or its siRNA mainly affected the catabolism of cartilage homeostasis in vitro. In conclusion, the occurrence of SONFH in broilers was related to the activation of GR and HIF pathway, and imbalance of cartilage homeostasis. Simvastatin and GR inhibitor maintained cartilage homeostasis via GR and the HIF pathway.

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.

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.

The in vitro and in vivo study of novel formulation of andrographolide PLGA nanoparticle embedded into gelatin-based hydrogel to prolong delivery and extend residence time in joint

Andrographolide (AG), a well-known traditional medicinal plant in Southeast Asia, is widely used for treatment of many chronic diseases. Interestingly, AG has been reported to have inhibitory effects on osteoclast function and anti-inflammatory properties. Because of these therapeutic properties, this study aimed to develop and optimize the formulation of AG using PLGA nanocarriers and gelatin-based hydrogel to prolong the retention time in the joint. We investigated the in vitro release pattern of the AG nanoparticles formulation which prepared by emulsion solvent evaporation method and embedded into gelatin-based hydrogel. The result showed that the AG loaded ester terminated end group PLGA polymer gradually released AG from the PLGA nanoparticles when compared with AG solution. Importantly, the combined use of gelatin-based hydrogel with AG from the PLGA nanoparticles significantly delayed the AG release more than 1 month. Furthermore, we selected the DiR fluorescence dye to represents AG and monitored the retention time by IVIS imaging. The optimal formulation was administered as intra-articular drug delivery systems in in vivo study. The results successfully displayed a long-term sustained release for implantation (≈2 months) and injection (≥2 months) providing a novel strategy for the local management of osteoarthritis disease.

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.

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

OBJECTIVE

The objective of the study was to determine whether statin use could reduce the risk of the incidence or progression of osteoarthritis (OA).

METHODS

The PubMed, Embase, and Cochrane databases were systematically searched for observational studies on the association between statin use and OA. ORs and 95% CIs were directly retrieved or calculated. The Newcastle-Ottawa quality assessment scale was used for study quality assessment. Subgroup analysis, sensitivity analysis, and publication bias were conducted using Stata software.

RESULTS

A total of 11 studies (679807 participants) were identified from the systematic literature search. No significant association between statin use and incidence (OR = 1.010; 95% CI: 0.968 to 1.055; P = 0.638) or progression (OR = 1.076; 95% CI: 0.824 to 1.405; P = 0.589) of OA was found in our meta-analysis. The meta-analysis according to the symptomatic or radiological OA also found no significant association between statin use and OA. The subgroup analysis showed that atorvastatin (OR = 0.953; 95% CI: 0.911 to 0.998; P = 0.041) and rosuvastatin (OR = 1.180; 95% CI: 1.122 to 1.241; P < 0.0001) had opposite effects on OA. The results of the analysis according to the joint site, interval, and statin dose were all not significant.

CONCLUSIONS

Statin use may not be associated with a lower risk of incidence and progression of OA, regardless of joint site. The opposite effects of atorvastatin and rosuvastatin were detected in OA.

Protective effects of atorvastatin on high glucose-induced oxidative stress and mitochondrial apoptotic signaling pathways in cultured chondrocytes

The high glucose concentration is able to disturb chondrocyte homeostasis and contribute to OA pathogenesis. This study was designed to investigate the protective effects of atorvastatin (ATO) on high glucose (HG)-mediated oxidative stress and mitochondrial apoptosis in C28I2 human chondrocytes. The protective effect of ATO (0.01 and 0.1 μM) on HG (75 mM)-induced oxidative stress and apoptosis was evaluated in C28I2 cells. The effects of ATO on HG-induced intracellular ROS production and lipid peroxidation were detected and the protein expression levels of Bax, Bcl-2, caspase-3, total and phosphorylated JNK and P38 MAPKs were analyzed by Western blotting. The mRNA expression levels of antioxidant enzymes including heme oxygenase-1, NAD(P)H quinine oxidoreductase, glutathione S-transferase-P1, catalase, superoxide dismutase-1, glutathione peroxidase-1, -3, -4 were evaluated by reverse transcription-polymerase chain reaction. Pretreatment with ATO remarkably increased the gene expression levels of antioxidant enzymes and reduced HG-induced elevation of ROS, lipid peroxidation, Bax/Bcl-2 ratio, caspase-3 activation, and JNK and P38 phosphorylation. Atorvastatin could considerably reduce HG-induced oxidative stress and mitochondrial apoptosis through increasing the expression of antioxidant enzymes. Atorvastatin may be considered as a promising agent to prevent high glucose-induced cartilage degradation in OA patients.

Association of Statin Use with Increased Risk of Musculoskeletal Conditions: A Retrospective Cohort Study

INTRODUCTION

Musculoskeletal conditions, including osteoarthritis (OA), result in tremendous disability and cost. Statins are among the most commonly prescribed medications and their use for primary prevention in many otherwise healthy individuals, including those who are physically active, is increasing. There is conflicting evidence regarding the relationship of statin use and musculoskeletal conditions. Given the rising disability associated with musculoskeletal conditions, understanding predisposing factors, including medication-related exposures, deserves further attention.

OBJECTIVES

We examined the association between statin use and the risk of being diagnosed with non-traumatic arthropathies, use-related injury, and undergoing rehabilitation in a cohort with longitudinal follow-up.

METHODS

Patients enrolled in a regional military healthcare system between 2003 and 2012 were evaluated in this retrospective cohort study. A propensity score was generated to match statin-users and nonusers using 115 baseline characteristics. Outcomes included ICD-9 diagnoses codes for Agency for Healthcare Research and Quality disease categories of: non-traumatic arthropathies, use-related injury and undergoing rehabilitation. Primary analysis examined the outcomes in statin-users and nonusers after propensity score matching using conditional logistic regression analysis.

RESULTS

Initially, 60,455 patients were identified. We propensity score-matched 6728 statin users with 6728 nonusers (52 years of age, ~ 47% women). In the propensity score-matched cohort, non-traumatic arthropathies occurred in 59.8% of statin users and 56.0% of nonusers [odds ratio (OR) 1.17, 95% confidence interval (95% CI) 1.09-1.25] and use related injury occurred in 31.9% of statin users and 29.8% of nonusers (OR 1.11, 95% CI 1.03-1.19). There was no difference between statin users and nonusers undergoing rehabilitation (22.6% among statin users, 21.9% among nonusers, OR 1.04, 95% CI 0.96-1.13).

CONCLUSION

Statin use was associated with a significant increased risk of non-traumatic arthropathies and use-related injury. Our results provide additional data that can inform patient and clinician conversations about the benefits and risks of statin use.

Association between the severity of symptomatic knee osteoarthritis and cumulative metabolic factors

BACKGROUND

The association between cumulative metabolic syndrome (MS) factors and knee osteoarthritis (KOA) has been highlighted over the past two decades.

AIMS

To clarify the relationship between cumulative MS factors and symptomatic KOA.

METHODS

A cross-sectional survey involving 119 women aged 45-88 years who were scheduled to undergo knee surgery was conducted. They were stratified into tertiles of symptoms as assessed by the Japanese Orthopedic Association score for KOA. Multinomial logistic regressions were performed using the severity of symptomatic KOA as the dependent variable and each MS factor or the cumulative MS factors as the independent variables.

RESULTS

Logistic regression analyses were performed with the upper tertile of stratified symptoms of subjects used as the reference group. After adjustment for confounders, KOA patients who had two (p = 0.004) or three or more (p < 0.0001) MS factors were significantly more likely to have severe symptoms compared to those who had no MS factors. MS factors excluding obesity were similarly analyzed. Even after additional adjustment for body mass index (BMI), KOA patients who had two or more (p = 0.005) MS factors were significantly more likely to have severe symptoms.

CONCLUSION

Among KOA female patients diagnosed using radiographic definition, the severity of symptomatic KOA was significantly associated with hypertension, dyslipidemia, and the number of MS factors after adjustment for age, BMI, strength of the knee extensor, and Kellgren-Lawrence grade. The severity of radiographic KOA was not associated with any MS factor or cumulative MS factors.

Association between statin use and consultation or surgery for osteoarthritis of the hip or knee: a pooled analysis of four cohort studies

OBJECTIVE

Experimental findings and previous observational data have suggested lower risk of osteoarthritis (OA) with statin use but results are inconsistent. Large-scale studies with a clinically important outcome are needed. Thus, we aimed to determine whether statin use is associated with a reduced risk of developing clinically-defined hip or knee OA.

DESIGN

Pooled analysis based on time-to-event analysis of four population-based large cohorts, encompassing in total 132,607 persons aged 57-91 years resident in southern and central Sweden. We studied the association between statin use and time to consultation or surgery for OA of the hip or knee by time-dependent exposure analysis and Cox regression.

RESULTS

During 7.5 years of follow-up, we identified 7468 out- or inpatient treated cases of hip or knee OA. Compared with never use, current use of statins conferred no overall reduction in the risk of OA with an adjusted pooled hazard ratio (HR) of 1.04 (95% confidence intervals [95% CI] 0.99-1.10). We found no dose-response relation between duration of current statin use and the risk of OA, with similar HRs among patients with less than 1 year of use (HR 1.09; 95% CI 0.92-1.32) as in patients with use for 3 years or more (HR 1.05; 0.93-1.16). Results were comparable in those with low, medium and high dose of current statin use, without indications of heterogeneity of study results.

CONCLUSION

Statin use is not associated with reduced risk of consultation or surgery for OA of the hip or knee.

Statin use and knee osteoarthritis progression: Results from a post-hoc analysis of the SEKOIA trial

OBJECTIVE

Epidemiological and experimental studies have suggested that lipid disorders might be involved in the pathophysiology of knee osteoarthritis (OA). Studies assessing the effect of statins on knee OA progression have shown conflicting results. We investigated the impact of statin use on radiological progression in patients with radiological and symptomatic knee OA.

METHODS

In total, 336 patients from the placebo arm of SEKOIA trial completed the 3-year follow-up and were included in this post-hoc analysis. Statin use was recorded at baseline interview. Minimal medial tibiofemoral joint space was measured on plain radiographs by an automated method at baseline and then annually. Radiologic progression was defined as joint space narrowing≥0.5mm over 3 years.

RESULTS

Overall, 71 patients were statin users (21.1%). They had a higher BMI (31.1±5.3 vs. 29.3±5.2kg/m², P=0.008), a higher sum of metabolic factors (≥3 factors: 43.7% vs 7.2%; P for trend<0.001) and a higher rate of radiological progression (49.3% vs. 32.1%, P=0.007) as compared to statin non-users. The significant association between radiological progression and statin use was independent of age, gender, WOMAC global score, disease duration, baseline joint space width, hypertension, type 2 diabetes, obesity (BMI>30kg/m²) and cardiovascular diseases [relative risk 1.49 (95% CI: 1.10-2.02), P=0.010].

CONCLUSION

Among patients with knee OA, statin use was associated with radiological worsening over 3 years, regardless of other potential confounding factors (obesity, type 2 diabetes, hypertension, disease duration, symptom intensity and radiological severity).

The cross-sectional and longitudinal effect of hyperlipidemia on knee osteoarthritis: Results from the Dongfeng-Tongji cohort in China

To quantify the cross-sectional and longitudinal effects of hyperlipidemia on knee osteoarthritis (KOA), we studied 13,906 middle-aged or older participants from the Dongfeng-Tongji cohort. Physical examinations were performed at baseline and follow-up. Knee pain was diagnosed by self-reported pain or stiffness. Clinical KOA was diagnosed from knee pain complains and clinical X-ray radiographs. The prevalence of knee pain and clinical KOA was 39.0% and 6.7% at baseline, respectively. Hyperlipidemia was associated with knee pain (OR 1.34, 1.23–1.45) and clinical KOA (1.34, 1.15–1.55). Compared with the participants without hyperlipidemia or use of lipid-lowering drugs, those with hyperlipidemia but no use of lipid-lowering drugs had higher risks of knee pain (1.28, 1.15–1.43) and clinical KOA (1.20, 0.97–1.48), those with hyperlipidemia and use of lipid-lowering drugs had the highest risks of knee pain (1.40, 1.26–1.56) and clinical KOA (1.45, 1.21–1.75). The risks were not elevated among participants without hyperlipidemia but using lipid-lowering drugs for prevention of other diseases. Furthermore, each 1-unit increase in triglyceride was associated with 9% and 5% increases in the risk of clinical KOA prevalence and clinical KOA onset, respectively. In conclusion, hyperlipidemia is associated with elevated risks of knee pain and clinical KOA among middle-aged or older adults.

Association between MRI-detected osteophytes and changes in knee structures and pain in older adults: a cohort study

OBJECTIVE

To describe cross-sectional and longitudinal associations between magnetic resonance imaging (MRI)-detected osteophytes (OPs) and knee structural abnormalities and knee pain in older adults.

METHOD

A prospective population-based cohort study of 895 participants aged 50-80 years (mean age 62 years, 50% female) was performed. T1-or T2-weighted fat suppressed MRI was used to assess knee OPs, cartilage volume, cartilage defects and bone marrow lesions (BMLs) at baseline and after 2.6 years. Radiographically-detected OPs were scored according to the Osteoarthritis Research Society International (OARSI) atlas. Knee pain was assessed using a self-administered questionnaire at baseline, 2.6 and 5 years later.

RESULTS

85% of participants had MRI-detected OPs at baseline, while 10% of participants had radiographically-detected OPs. Cross-sectionally, higher gardes of MRI-detected OPs in all compartments were significantly, independently and site-specifically associated with higher prevalences of cartilage defects and BMLs, lower cartilage volume and higher prevalence of knee pain. Longitudinally, higher gardes of baseline MRI-detected OPs site-specifically predicted greater risks of any increase in cartilage defects or BMLs, and loss of cartilage volume in medial and lateral tibiofemoral (LTF) and total compartments over 2.6 years in multivariable analyses. These significant associations were similar in those without radiographically-detected OPs. MTF and total OP scores were significantly associated with change in total knee pain over 2.6 and 5 years but these became non-significant after adjustment for cartilage defects and BMLs.

CONCLUSION

MRI-detected knee OPs are common and appear to be clinically relevant to knee structural changes in older adults.

An overview of hydrogel-based intra-articular drug delivery for the treatment of osteoarthritis

Drug administration by intra-articular injection is an emerging popular treatment for knee osteoarthritis (OA). This method of drug administration minimizes the toxic effects of the drugs administered systemically, and maximizes local effects. However, traditional oral drugs delivered via intra-articular injection are limited by the lack of sustained release. Injectable materials such as hydrogels or hydrogel microspheres have been extensively studied for their applications as intra-articular injection for the treatment of OA, which is attribute to their minimally invasive manner, extended drug retention time and high loading efficiency. In this review, we summarized hydrogel types and hydrogel characteristics for intra-articular injection, and the drugs, proteins and cells used in the injectable delivery systems. Through this review, we hope to inspire researchers to construct novel hydrogel-based delivery system for the intra-articular injection treatment of knee OA.