Dietary intake of fibre and risk of knee osteoarthritis in two US prospective cohorts

Evaluation of the Concentration of Selected Elements in the Serum of Patients with Degenerative Stenosis of the Lumbosacral Spine

In humans, 23 elements have been shown to have biological activity. The purpose of this study was to evaluate the concentrations of iron (Fe), zinc (Zn), sodium (Na), potassium (K), magnesium (Mg), phosphorus (P), and calcium (Ca) in the serum of patients diagnosed with lumbar degenerative stenosis when compared to the concentrations of those elements in the serum of healthy volunteers. The study group consisted of 60 patients who were diagnosed with degenerative stenosis of the lumbosacral spine and who qualified for hemilaminectomy. The control group included 60 healthy volunteers without degenerative spinal stenosis. The clinical specimens studied had sera collected from both groups. The quantitative analysis of the selected elements revealed statistically significant (p < 0.05) lower concentrations of Zn (740 ± 110 µg/L vs. 880 ± 160 µg/L) and Mg (22,091 ± 4256 µg/L vs. 24,100 ± 4210 µg/L) in the serum of the patients from the study group when compared to the controls. By contrast, K (16,230 µg/L ± 1210 µg/L vs. 13,210 µg/L ± 1060 µg/L) and Fe (141.87 µg/L ± 11.22 µg/L vs. 109.1 µg/L ± 26.43 µg/L) levels were significantly higher in the study group compared to the controls (p < 0.05). No statistically significant changes were detected in the concentrations of the assessed micronutrients and macronutrients in both sexes in either the study group, the control group, or those based on body mass index (p > 0.05). In the serum samples from the study group, the strongest correlations were noted between the concentrations. In the study group, we showed a significant relationship between the levels of Fe/Zn (r = 0.41), Fe/Na (r = 0.41), Fe/P (r = 0.55), Zn/P (r = 0.68), Zn/K (r = 0.48), Zn/Ca (r = 0.94), Mg/Ca (r = 0.79), and Na/K (r = 0.67). We showed that only Mg concentration varied statistically significantly with the severity of pain (p < 0.05). These findings suggest that the assessment of Fe, Zn, Mg, and K concentrations can be helpful in predicting the onset of degenerative changes in the spine.

Causal relationship between modifiable risk factors and knee osteoarthritis: a Mendelian randomization study

Background

While several risk factors for knee osteoarthritis (KOA) have been recognized, the pathogenesis of KOA and the causal relationship between modifiable risk factors and KOA in genetic epidemiology remain unclear. This study aimed to determine the causal relationship between KOA and its risk factors.

Methods

Data were obtained from published Genome-Wide Association study (GWAS) databases. A two-sample Mendelian randomization (MR) analysis was performed with genetic variants associated with risk factors as instrumental variables and KOA as outcome. First, inverse variance weighting was used as the main MR analysis method, and then a series of sensitivity analyses were conducted to comprehensively evaluate the causal relationship between them.

Results

Univariate forward MR analysis revealed that genetically predicted hypothyroidism, hyperthyroidism/thyrotoxicosis, educational level, income level, metabolic syndrome (MS), essential hypertension, height, hot drink temperature, diet (abstaining from sugar-sweetened or wheat products), and psychological and psychiatric disorders (stress, depression, and anxiety) were causally associated with KOA. Reverse MR exhibits a causal association between KOA and educational attainment. Multivariate MR analysis adjusted for the inclusion of potential mediators, such as body mass index (BMI), smoking, alcohol consumption, and sex, exhibited some variation in causal effects. However, hyperthyroidism/thyrotoxicosis had a significant causal effect on KOA, and there was good evidence that height, hypothyroidism, educational level, psychological and psychiatric disorders (stress, depression, and anxiety), and abstaining from wheat products had an independent causal relationship. The mediating effect of BMI as a mediator was also identified.

Conclusion

This study used MR to validate the causal relationship between KOA and its risk factors, providing new insights for preventing and treating KOA in clinical practice and for developing public health policies.

Association between folate intake and radiographic progression, pain function scores in subjects with radiographic knee osteoarthritis: Data from the osteoarthritis initiative

BACKGROUND

Folate has an important role in the functioning of the musculoskeletal system, including modulation of inflammation, immunity, cartilage regeneration, prevention of osteoporosis, and maintenance of muscle strength, but evidence on the association between folate intake and knee pain, functional scores, and radiographic progression in patients with knee osteoarthritis (OA) is still limited.

METHODOLOGY

Our population-based cohort was extracted from the osteoarthritis initiative (OAI), focusing on individuals with prevalent radiographic knee OA (with a Kellgren-Lawrence score ≥2). Folate consumption was determined using the food frequency questionnaire. Data regarding the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and radiographic readings were collected over 48 months. We analyzed the compiled data using generalized additive mixed models.

RESULTS

Our cohort consisted of 1472 OA patients (626 men and 846 women, mean [SD] age 62.35 [8.92]). At the 48-month follow-up, we observed a significant correlation between higher folate intake and a slower progression of knee pain and functional scores, as evidenced by a statistically significant decrease in the WOMAC total score, WOMAC pain subscale score, and WOMAC function/disability subscale score (p < .05). The fully adjusted models estimated a reduction of -0.028 points per 50 μg/1000 kcal of daily folate intake on the WOMAC pain subscale, -0.117 points on the WOMAC function subscale, and -0.160 points on the total WOMAC scale. Furthermore, our nonparametric fit analysis suggested that a higher intake of folate might decelerate the radiographic progression of OA. Stratified analyses indicated that an increase in folate consumption might particularly benefit men, older adults, overweight and obese individuals, and those with a higher dietary fiber intake.

CONCLUSION

Higher folate intake is correlated with improved knee function and reduced pain in patients with knee OA and might deter the radiographic progression of OA. The benefits appear to be more pronounced in men, older adults, overweight and obese individuals, and those with a higher dietary fiber intake.

Effect of prebiotic fiber on physical function and gut microbiota in adults, mostly women, with knee osteoarthritis and obesity: a randomized controlled trial

PURPOSE

Obesity is a primary risk factor for knee osteoarthritis (OA). Prebiotics enhance beneficial gut microbes and can reduce body fat and inflammation. Our objective was to examine if a 6-month prebiotic intervention improved physical function in adults with knee osteoarthritis and obesity. We also measured knee pain, body composition, quality of life, gut microbiota, inflammatory markers, and serum metabolomics.

METHODS

Adults (n = 54, mostly women) with co-morbid obesity (BMI > 30 kg/m2) and unilateral/bilateral knee OA were randomly assigned to prebiotic (oligofructose-enriched inulin; 16 g/day; n = 31) or isocaloric placebo (maltodextrin; n = 21) for 6 months. Performance based-tests, knee pain, quality of life, serum metabolomics and inflammatory markers, and fecal microbiota and short-chain fatty acids were assessed.

RESULTS

Significant between group differences were detected for the change in timed-up-and-go test, 40 m fast paced walk test, and hand grip strength test from baseline that favored prebiotic over placebo. Prebiotic also reduced trunk fat mass (kg) at 6 months and trunk fat (%) at 3 months compared to placebo. There was a trend (p = 0.059) for reduced knee pain at 6 months with prebiotic versus placebo. In gut microbiota analysis, a total of 37 amplicon sequence variants differed between groups. Bifidobacterium abundance was positively correlated with distance walked in the 6-min walk test and hand grip strength. At 6 months, there was a significant separation of serum metabolites between groups with upregulation of phenylalanine and tyrosine metabolism with prebiotic.

CONCLUSION

Prebiotics may hold promise for conservative management of knee osteoarthritis in adults with obesity and larger trials are warranted.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov/study/NCT04172688.

Association between Dietary total antioxidant capacity and knee osteoarthritis: a case-control study in the Iranian Population

AIM

Knee osteoarthritis (KOA) is a prevalent chronic condition associated with significant pain, disability, and healthcare costs, particularly among the elderly population. Despite the considerable burden of KOA, effective treatment options for managing the condition's underlying causes remain limited. This case-control study aims to investigate the relationship between dietary total antioxidant capacity (DTAC) and knee osteoarthritis.

METHODS

This case-control study was conducted on 105 patients with confirmed KOA and 210 controls. KOA was diagnosed based on the American College of Rheumatology criteria. Dietary total antioxidant capacity (DTAC) was calculated based on the ferric-reducing antioxidant power method.

RESULTS

The mean age and BMI of the participants were 53.6 ± 8.8 years old and 27.3 ± 2.7 kg/m2, respectively. The study participant's DTAC score ranged from 3.56 to 25.32 with a mean and SD of 12.46 ± 5.12. In the crude model, individuals in the highest quartile of DTAC score had 71% lower odds of having knee osteoarthritis compared to those in the first quartile (OR: 0.29, 95%CI: 0.15 to 0.58, P-trend < 0.001). These associations remained significant after adjustment for potential confounders including age, sex, energy intake, family history of osteoarthritis, vitamin D and calcium use, physical activity level, cigarette smoking and BMI. Although the odds of having knee osteoarthritis decreased with increasing quartiles of DTAC in both sexes, this relationship was stronger among males than females.

CONCLUSION

The results of this study showed that there was an inverse correlation between DTAC and KOA among the Iranian patients with KOA.

Flavan-3-ol monomers intake is associated with osteoarthritis risk in Americans over 40 years of age: results from the National Health and Nutritional Examination Survey database

Objectives: Osteoarthritis (OA) stands as the prevailing progressive musculoskeletal disease, serving as the primary cause of chronic pain and activity limitations among adults over 40. Flavan-3-ols, common polyphenolic compounds, are believed to harbor anti-inflammatory and anti-aging properties. This study explores the relationship between flavan-3-ol intake and osteoarthritis risk in individuals over the age of 40 in the US. Methods: This study included 7452 participants over the age of 40 from three cycles (2007-2008, 2009-2010, and 2017-2018) of the National Health and Nutrition Examination Survey. Information on OA history was obtained via home surveys. Information on flavan-3-ol monomers intake was obtained using a survey from the Food and Nutrient Database for Dietary Studies. We used a logistic regression model and restricted cubic spline to analyze the relationships between flavan-3-ol monomers and OA. Stratified analyses were also conducted in this study. Results: There were 1056 participants with OA and 6396 without OA. Compared to the first tertile (T1) group, the adjusted odds ratio with a 95% confidence interval (CI) of logistic regression model 2 for the flavan-3-ol T2 group was 1.296 (0.979-1.715) (p = 0.068), the OR for (-)-epigallocatechin was 1.292 (1.025-1.629) (p = 0.032), and the OR for (-)-epicatechin 3-gallate was 1.348 (1.013, 1.793) (p = 0.042). A dose-response curve indicated a non-linear association (p for non-linearity <0.05) between OA and total flavan-3-ol monomers (nadir point: 483.29 mg, 95% CI: 0.61-0.90). No interaction effects were found in the subgroup analysis. Conclusions: In individuals over 40 in the US, the average daily dietary intake of flavan-3-ol monomers manifests a J-shaped relationship with OA risk.

Role of Nutrition in the Management of Patients with Chronic Musculoskeletal Pain

Chronic musculoskeletal pain (CMP), defined as persistent discomfort in musculoskeletal tissues persisting for over 3 months, afflicts an estimated 1.71 billion people globally, leading to significant functional impairments and psychological distress, thereby detrimentally affecting individuals' quality of life. The objective of this narrative review is to elucidate the complex relationship among dietary habits, sarcopenia, and gut microbiota composition, with an eye toward enhancing patient management and outcomes. Given the burgeoning interest in the influence of diet on CMP, a detailed examination of the current literature is warranted. Nutritional intake is a critical determinant of the gut microbiota profile, which, in turn, is linked to musculature integrity and performance, potentially leading to sarcopenia. The development of sarcopenia can aggravate CMP owing to diminished muscular strength and functionality. Additionally, disruptions in the gut microbiota may directly modulate nociception, intensifying CMP manifestations. Thus, nutritional optimization emerges as a viable approach to CMP management. Emphasizing a diet conducive to a healthy gut microbiome could forestall or mitigate sarcopenia, thereby attenuating CMP intensity. Nevertheless, the domain calls for further empirical exploration to unravel the nuances of these interactions and to forge efficacious dietary strategies for individuals with CMP. Beyond mere analgesia, comprehensive patient care for CMP requires acknowledgment of the complex and multifactorial nature of pain and its foundational elements. Embracing an integrative treatment model allows healthcare practitioners to promise better patient prognoses, enriched life quality, and a decrease in the sustained healthcare costs associated with CMP.

Ultra-processed food consumption, genetic susceptibility, and the risk of hip/knee osteoarthritis

BACKGROUND

The associations between ultra-processed food (UPF) consumption, genetic susceptibility, and the risk of osteoarthritis (OA) remain unknown. This study was to examine the effect of UPF consumption, genetic susceptibility, and their interactions on hip/knee OA.

METHODS

Cohort analyses included 163,987 participants from the UK Biobank. Participants' UPF consumption was derived from their 24-h dietary recall using a questionnaire. Genetic risk scores (GRSs) of 70 and 83 single nucleotide polymorphisms (SNPs) for hip and knee OA were constructed.

FINDINGS

After 1,461,447 person-years of follow-up, 11,540 patients developed OA. After adjustments, compared to participants in the low quartile of UPF consumption, those in the high quartile had a 10 % (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.03-1.18) increased risk of knee OA. No significant association was found between UPF consumption and hip OA. Replacing 20% of UPF diet weight with an equivalent proportion of unprocessed or minimally processed food caused a 6% (HR, 0.94; 95% CI, 0.89-0.98) decreased risk of knee OA, respectively. A significant interaction was found between UPF consumption, genetic predisposition, and the risk of knee OA (P = 0.01). Participants with lower OA-GRS scores experienced higher knee OA risks due to UPF consumption.

INTERPRETATION

UPF consumption was associated with a higher risk of knee OA but not hip OA, particularly in those with lower genetic susceptibility. These results highlight the importance of reducing UPF consumption to prevent knee OA.

The role of dietary preferences in osteoarthritis: a Mendelian randomization study using genome-wide association analysis data from the UK Biobank

Background

To understand the impact of individual preferences for specific dietary items on OA, and to help inform the development of effective and targeted OA prevention and management strategies, we performed a Mendelian randomization analysis between dietary preferences and osteoarthritis.

Methods

This study utilized genetic data from the UK Biobank to investigate the association between OA and 21 different common dietary items. Instrumental variables representing European populations were carefully selected based on their genetic significance and linkage disequilibrium. In cases where a dietary item had few relevant genetic markers, a more lenient selection threshold was applied. To prevent bias, the analysis excluded single nucleotide polymorphisms (SNPs) associated with factors such as body mass index (BMI) and cholesterol. Using inverse-variance weighting (IVW) and Mendelian randomization, significant associations were detected between certain dietary items and OA.

Results

Using Mendelian randomization to examine the relationship between 21 different dietary items and OA, significant associations were found for coffee, peas, watercress, and cheese, where the first two had a promoting effect and the last two an inhibiting effect on OA. Due to heterogeneity in the test results for cheese, a random IVW representation was used. The results of sensitivity analysis showed no significant heterogeneity or horizontal pleiotropy in the selected SNPS, demonstrating the reliability of Mendelian randomization analysis.

Conclusion

This study identified coffee, peas, watercress, and cheese as food items that may have significant dietary effects on osteoarthritis. This information may be useful to consider in the development of OA management strategies.

Association between traditional Chinese Medicine and osteoarthritis outcome: A 5-year matched cohort study

Objective

The aim of this study was to investigate the relationship between Traditional Chinese medicine (TCM) and pain reduction, hospital readmission, and joint replacement in patients with osteoarthritis (OA). Chinese herbal medicine (CHM) prescription patterns were further analyzed to confirm the association with prognosis and quality of life in OA patients.

Methods

We retrospectively followed 3,850 hospitalized patients with osteoarthritis between January 2018 and December 2022 using the hospital's HIS system. Propensity score matching (PSM) was used for data matching. Cox's proportional risk model was used to assess the impact of various factors on the outcomes of patients with OA, including pain worsening, readmission, and joint replacement. The Kaplan-Meier survival curve was applied to determine the impact of TCM intervention time on patient outcomes. Data mining methods including association rules, cluster analysis, and random walks have been used to assess the efficacy of TCM.

Results

The utilization rate of TCM in OA patients was 67.01% (2,511/3,747). After PSM matching, 1,228 TCM non-user patients and 1,228 TCM user patients were eventually included. The outcomes of pain worsening, re-admission rate, and joint replacement rate of the TCM non-user group were observably higher than those of the TCM user group with OA (p < 0.05). Based on the Cox proportional risk model, TCM is an independent protective factor. Compared with non-TCM users, TCM users had 58.4% lower rates of pain, 51.1% lower rates of re-admission, and 42% lower rates of joint replacement. In addition, patients in the high-exposure subgroup (TCM＞24 months) had a markedly lower risk of outcome events than those in the low-exposure subgroup (TCM ≤24 months). Data mining methods have shown that TCM therapy can significantly improve immune-inflammatory indices, VAS scores, and SF-36 scale scores in OA patients.

Conclusion

s TCM acts as a protective factor to improve the prognosis of patients with OA, and the benefits of long-term use of herbal medicines are even greater.

Bioactives and their roles in bone metabolism of osteoarthritis: evidence and mechanisms on gut-bone axis

Bioactives significantly modify and maintain human health. Available data suggest that Bioactives might play a beneficial role in chronic inflammatory diseases. Although promised, defining their mechanisms and opting to weigh their benefits and limitations is imperative. Detailed mechanisms by which critical Bioactives, including probiotics and prebiotics such as dietary lipids (DHA, EPA, alpha LA), vitamin D, polysaccharides (fructooligosaccharide), polyphenols (curcumin, resveratrol, and capsaicin) potentially modulate inflammation and bone metabolism is limited. Certain dietary bioactive significantly impact the gut microbiota, immune system, and pain response via the gut-immune-bone axis. This narrative review highlights a recent update on mechanistic evidence that bioactive is demonstrated demonstrated to reduce osteoarthritis pathophysiology.

Is diet related to osteoarthritis? A univariable and multivariable Mendelian randomization study that investigates 45 dietary habits and osteoarthritis

Background

Diet is a safe intervention for many chronic diseases as a modifiable lifestyle. However, the potential causal effect of many dietary intake habits on the risk of osteoarthritis has not been fully understood. The purpose of this study was to reveal the potential causal relationship of 45 genetically predicted dietary intakes with osteoarthritis and its subtypes.

Methods

Data on 45 dietary intakes were obtained from the UK Biobank study of approximately 500,000 participants, and data on six osteoarthritis-related phenotypes were obtained from the Genetics of Osteoarthritis Consortium study of 826,690 participants. We performed univariable Mendelian randomization (MR), multivariable MR and linkage disequilibrium score regression (LDSC) analyses.

Results

In univariate analyses, 59 potential associations between diet and osteoarthritis were found. After false discovery rate (FDR) correction and sensitivity analyses, 23 reliable causal evidence were identified. In multivariate analyses, controlling separately for the effects of body mass index, total body bone mineral density, and smoking status, eight robust causal relationships remained: Muesli intake was negatively associated with knee osteoarthritis, spine osteoarthritis and total knee replacement. Dried fruit intake had a negative association with osteoarthritis of knee and total knee replacement. Eating cheese may reduce the risk of osteoarthritis in the knee and spine. And alcohol usually taken with meals was associated with a reduced risk of total knee replacement. LDSC analyses showed significant genetic correlations between all exposures and their corresponding outcomes, respectively, in these eight causal relationships.

Conclusion

Evidence of dietary effects on osteoarthritis is provided in our study, which has important implications for the prevention, management, and intervention of osteoarthritis in common sites through rational dietary modification.

Whole grain consumption and risk of radiographic knee osteoarthritis: a prospective study from the Osteoarthritis Initiative

OBJECTIVES

To assess the association of whole grain consumption with the risk of incident knee OA.

MATERIAL AND METHODS

We followed 2846 participants in the Osteoarthritis Initiative ages 45-79 years. Participants were free from radiographic knee OA (Kellgren-Lawrence grade <2) in at least one knee at baseline. Dietary data from baseline were obtained using the Block Brief Food Frequency Questionnaire. We defined radiographic knee OA incidence as a Kellgren-Lawrence grade ≥2 during the subsequent 96 months. Cox proportional hazards models were used to assess the association between whole grain food intake and the risk of incident knee OA.

RESULTS

During the 96 month follow-up, 518 participants (691 knees) developed incident radiographic knee OA. Higher total whole grain consumption was significantly associated with a lower knee OA risk [hazard ratio (HR)quartile 4vs1 = 0.66 (95% CI 0.52, 0.84), P for trend < 0.01] after adjusting for demographic and socio-economic factors, clinical factors and other dietary factors related to OA. Consistently, a significant inverse association of dark bread consumption with knee OA risk was observed [HRquartile 4vs1 = 0.68 (95% CI 0.53, 0.87), P for trend < 0.01). In addition, we observed a significant inverse association between higher cereal fibre intake and reduced knee OA risk [HRquartile 4vs1 = 0.61 (95% CI 0.46, 0.81), P for trend < 0.01).

CONCLUSIONS

Our findings revealed a significant inverse association of whole grain consumption with knee OA risk. These findings provide evidence that eating a diet rich in whole grains may be a potential nutritional strategy to prevent knee OA.

Dietary fiber intake associated with risk of rheumatoid arthritis among U.S. adults: NHANES 2010-2020

Rheumatoid arthritis (RA) is a prevalent inflammatory joint disease that imposes a significant medical burden and morbidity. Recent scientific evidence suggests that dietary components and patterns could be associated with RA risk. In this study, we aim to investigate the possible relationship between dietary fiber intake and RA risk. We included 15,114 participants from the 2010 to 2020 National Health and Nutrition Examination Survey database in our study. Participants aged 20 or above were categorized into those with and without RA. Univariate logistic regression analysis and multivariate regression models were used to test the association between dietary fiber intake, high-sensitivity C-reactive protein, and RA. Out of all the participants, 1053 were diagnosed with RA (6.97%). Multivariate logistic regression analysis indicated that fiber intake was negatively associated with high-sensitivity c-reactive protein (-0.09 [-0.18, -0.02]) and RA risk (0.99 [0.98, 0.99]). Furthermore, our sensitivity analysis suggested that individuals with higher fiber intake (>19.1 g/day) had a 25% lower risk of developing RA than those with lower fiber intake [0.75 (0.63, 0.88)]. Our findings suggest that higher dietary fiber intake is associated with a reduced risk of RA and may help reduce systemic inflammation, thereby potentially slowing down RA progression.

The effects of dietary patterns and food groups on symptomatic osteoarthritis: A systematic review

AIM

To systematically review current literature to determine the association between symptomatic osteoarthritis and dietary patterns, diet quality and food groups in adults aged ≥45 years.

METHODS

The review was registered on PROSPERO (CRD42021270891). Cochrane Central Library, Cumulative Index of Nursing and Allied Health Literature, Embase, Medline and Web of Science databases were searched. A total of 3816 records were identified. Eligible articles involved populations aged ≥45 years with symptomatic osteoarthritis, assessing dietary patterns, diet quality or food groups, with pain in joints as outcomes. The Joanna Briggs Institute Critical Appraisal Checklists were used for quality assessment. Grading of Recommendations, Assessment, Development and Evaluation was used to assess the certainty of evidence.

RESULTS

Six cohort studies were included. The Prudent dietary pattern and the Mediterranean dietary pattern reduced the progression of osteoarthritis symptoms. The Western dietary pattern increased symptomatic osteoarthritis progression. Increased total fibre consumption reduced symptomatic osteoarthritis progression and pain worsening, but the effects of fibre from each food group were inconclusive. Diet with high inflammatory potential increased risk of new onset symptomatic osteoarthritis, but the effects of overall diet quality were inconclusive.

CONCLUSIONS

The Prudent dietary pattern showed the highest protection on symptomatic osteoarthritis in adults aged 45 years and over. The body of evidence is limited, suggesting that further research is needed to corroborate the estimated effect at a high certainty of evidence, and to incorporate previously unstudied dietary patterns and food groups. Identifying the most beneficial dietary pattern may inform future guidelines for reducing symptomatic osteoarthritis in middle aged and older adults.

Association of macronutrients intake distribution with osteoarthritis risk among adults in NHANES, 2013-2016

The association between dietary macronutrient distribution and the risk of OA remains unknown. We aimed to evaluate how dietary macronutrient distribution was correlated with the risk of OA in US adults. We performed a cross-sectional study consisting of 7,725 participants from National Health and Nutrition Examination Survey (NHANES) 2013-2016. Dietary macronutrient intake and OA status were assessed by using dietary recall method and self-reported questionnaire, respectively. We evaluated the association between dietary macronutrient distribution and the risk of OA using multivariate regression models. We conducted the isocaloric substitution analysis using the multivariate nutrient density method. Higher percentage of energy intake from fat was associated with higher risk of OA [OR = 1.05 (95% CI, 1.00, 1.09); P = 0.034]. No significant correlation was observed between the percentage of energy intake from carbohydrate or protein and risk of OA. Isocaloric substitution analysis revealed that only the substitution between fat and carbohydrate was significantly associated with the risk of OA [OR = 1.05 (95% CI, 1.003 to 1.09); P = 0.037]. Our findings suggested that a diet with low percentage of energy intake from fat may be beneficial in the prevention of OA. Further prospective cohort studies are needed to assess our results.

Alkylresorcinol, a biomarker for whole grain intake, and its association with osteoarthritis: the MOST study

INTRODUCTION

Higher intake of fiber has been associated with lower risk of incident symptomatic osteoarthritis (OA). We examined whether levels of alkylresorcinol (AR), a marker of whole grain intake, were associated with OA in subjects in The Multicenter Osteoarthritis (MOST) Study.

METHOD

Knee x-rays and knee pain were assessed at baseline and through 60-months. Stored baseline fasting plasma samples were analyzed for AR homologues (C17:0, C19:0, C21:0, C23:0, C25:0) and total AR levels (AR sum). Two nested case-control studies, one for incident radiographic OA and one for incident symptomatic OA were performed with participants re-assessed at 15, 30 and 60 months. Multivariable conditional logistic regression with baseline covariates including age, sex, BMI, physical activity, quadriceps strength, race, smoking, depressive symptoms, diabetes and knee injury tested the association of log transformed AR levels with OA outcomes.

RESULTS

Seven hundred seventy-seven subjects were, on average, in their 60's, and most were women. For 60-month cumulative incidence, there was no significant association between quartiles of AR concentration and incident radiographic (e.g., for incident radiographic OA, highest vs lowest quartile of AR sum showed RR = 0.93 (95% CI 0.59, 1.47), and for symptomatic OA RR was 1.22 (95% CI 0.76, 1.94). In secondary analyses examining 30-month incidence, high AR levels were associated with a reduced risk of X-ray OA (RR = 0.31 (95% CI 0.15, 0.64).

CONCLUSION

In primary analyses, AR levels were not associated with risk of OA, but secondary analyses left open the possibility that high AR levels may protect against OA.

Association of dietary fiber and risk of hip fracture in men from the Framingham Osteoporosis Study and the Concord Health and Ageing in Men Project

BACKGROUND

Data in the Offspring Framingham Osteoporosis Study (FOS) suggested that higher intake of dietary fiber was modestly protective against loss of bone mineral density at the femoral neck in men but not in women.

AIM

To examine the relationship of fiber intake with risk of hip fractures in men.

METHODS

We included 367 men from the FOS Original cohort, 1730 men from the FOS Offspring cohort, and 782 men from the Concord Health and Ageing in Men Project (CHAMP) in the analysis. Incident fractures were defined as medically confirmed first occurrence of osteoporotic fractures at the proximal femur. Fiber intake was estimated via a validated food frequency questionnaire (FFQ) or diet history. Cox proportional hazards models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). A random-effects model was used to estimate the pooled relative risk in meta-analysis.

RESULTS

Seventy-two incident hip fractures were identified, of which 24 occurred in the FOS Original cohort [mean (SD): age 75.3 (5.1) years; follow-up time: 8.5 (6.2) years; dietary fiber: 19 (8) (g/d)], 19 in the FOS Offspring cohort [58.8 (9.8) years; 11.0 (5.9) years; 19 (8) (g/d)], and 29 in CHAMP [81.4 (4.5) years; 5.2 (1.5) years; 28 (10) (g/d)]. We did not find significant associations within each cohort between fiber intake and risk of hip fractures. The pooled HR (95% CI) was 0.80 (0.39, 1.66) comparing energy-adjusted dietary fiber at tertile 3 vs. tertile 1 (I2 = 0, p = 0.56).

CONCLUSION

These data suggested that dietary fiber was not associated with risk of incident hip fractures in men.

Excessive alcohol consumption and the risk of knee osteoarthritis: a prospective study from the Osteoarthritis Initiative

OBJECTIVE

To examine the association of alcohol consumption with risk of incident knee osteoarthritis (OA) in a large prospective cohort study.

DESIGN

In the Osteoarthritis Initiative, 2,846 participants aged 45-79 years and free from radiographic knee OA in at least one knee at baseline were followed up to 96 months. Information on baseline alcohol consumption was obtained from the Block Brief Food Frequency Questionnaire. Incident cases of radiographic knee OA (ROA) were defined as Kellgren-Lawrence grade changing from zero or one to ≥ two during the follow-up time. Incident symptomatic OA (SxOA) was defined as ROA with knee pain worsening. The Cox proportional hazards models were used to assess the independent association between alcohol consumption and risk of knee.

RESULTS

During 96 months' follow-up, we identified 691 knees with incident ROA, and 496 knees with incident SxOA among 2,846 subjects. Compared to non-drinkers, excessive alcohol consumption was significantly associated with increased risk of ROA (HR _{≥ 30  g/d vs none} = 1.93, 95% CI: 1.28-2.89) and SxOA (HR _{≥ 30 g/d vs none} = 1.61, 95% CI: 1.04-2.48). Similar association was observed for liquor consumption (HR _{liquor≥15 g/d vs none} = 1.71, 95% CI: 1.16-2.52 for ROA; HR _{liquor≥15 g/d vs none} = 1.59, 95% CI: 1.04-2.39 for SxOA). Light to moderate alcohol consumption was not associated with knee OA risk.

CONCLUSION

Our results suggest that excessive alcohol drinking was associated with an increased risk of knee OA. Further studies are needed in other populations.

Association between Iron Intake and Progression of Knee Osteoarthritis

Background: Iron overload is drawing attention in the development of knee osteoarthritis (OA). To identify the modifiable risk factors for iron-related pathological conditions, we examined the association between iron intake and the risk of knee OA progression. Methods: A total of 1912 participants in the Osteoarthritis Initiative (OAI), aged 45−79 years and with at least one knee radiographic OA at baseline, were identified and were followed up to 6 years. The iron and other nutrient intake was measured by the validated Block Brief 2000 Food Frequency Questionnaire. The outcome measures were by radiographic progression on the basis of the Kellgren−Lawrence (KL) grade and the joint-space-narrowing (JSN) score. The association between the iron intake and the knee OA progression was examined by Cox proportional hazards models and restricted cubic spline (RCS) regression. Results: Among the study participants, 409 participants experienced KL-grade progression, and 684 participants experienced JSN-score progression within 6 years. Overall, the association between iron intake and the risk of KL-grade progression followed a U shape (p for nonlinearity < 0.001). The risk of KL-grade progression was significantly lower in participants with iron intakes of <16.5 mg/day (per mg/day: adjusted hazard ratio (HR), 0.75; 95% CI (confidence interval), 0.64−0.89), and it was higher in those with iron intakes ≥16.5 mg/day (per mg/day: HR, 1.20; 95% CI, 1.04−1.38). Consistently, when the iron intake was assessed as deciles, compared to those in Deciles 3−5 (10.9−23.3 mg/day), the risk of KL-grade progression was higher for Deciles 1−2 (≤10.9 mg/day: HR, 1.57; 95% CI, 1.17−2.10) and for Deciles 6−10 (>23.3 mg/day: adjusted HR, 1.60; 95% CI, 1.19−2.16). Similar U-shaped relations were found for iron intake with the risk of JSN-score progression (p for nonlinearity = 0.035). Conclusions: There was a U-shaped association between the iron intake and the progression of knee OA, with an inflection point at about 16.5 mg/day, and minimal risk from 10.9 to 23.3 mg/day of iron intake. An appropriate iron intake was advisable for knee OA, whereas excessive or deficient iron intake increased the risk of knee OA progression.

High Estimated 24-Hour Urinary Sodium Excretion Is Related to Symptomatic Knee Osteoarthritis: A Nationwide Cross-Sectional Population-Based Study

OBJECTIVES

High salt intake results in various harmful effects on human health including hypertension, cardiovascular disease, and reduced bone density. Despite this, there are very few studies in the literature that have investigated the association between sodium intake and osteoarthritis (OA). Therefore, we aimed to explore these associations in a Korean population.

METHODS

This study used cross-sectional data from adult subjects aged 50-75 years from two consecutive periods of the Korean National Health and Nutrition Examination Survey V-VII (2010-2011 and 2014-2016). The estimated 24-hour urinary sodium excretion (24HUNa) was used as a surrogate marker of salt intake. In the 2010-2011 dataset, knee OA (KOA) was defined as the presence of the radiographic features of OA and knee pain. The association between KOA and salt intake was analysed using univariable and multivariable logistic regression methods. For the sensitivity analysis, the same procedures were conducted on subjects with self-reported OA (SR-OA) with knee pain in the 2010-2011 dataset and any site SR-OA in the 2014-2016 dataset.

RESULTS

Subjects with KOA had significantly lower energy intake, but higher 24HUNa than those without KOA. The restricted cubic spline plots demonstrated a J-shaped distribution between 24HUNa and prevalent KOA. When 24HUNa was stratified into five groups (<2, 2-3, 3-4, 4-5 and ≥5 g/day), subjects with high sodium intake (≥5 g/day) had a higher risk of KOA (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.03-2.62) compared to the reference group (3-4 g/day) after adjusting for covariates. The sensitivity analysis based on SR-OA with knee pain showed that high sodium intake was also significantly associated with increased prevalence of OA (OR = 1.84, 95% CI 1.10-3.10) compared with the reference group. Regarding SR-OA at any site in the 2014-2016 dataset, estimated 24HUNa showed a significantly positive association with the presence of SR-OA after adjusting for potential confounders.

CONCLUSIONS

This nationwide Korean representative study showed a significant association between symptomatic KOA and high sodium intake (≥5 g/day). Avoidance of a diet high in salt might be beneficial as a non-pharmacologic therapy for OA.

Prebiotic and Exercise Do Not Alter Knee Osteoarthritis in a Rat Model of Established Obesity

OBJECTIVE

Metabolic disturbance is a known risk factor for cardiovascular disease and has been identified as a risk factor for the development of knee osteoarthritis. In this study, we sought to determine the effects of prebiotic fiber supplementation, aerobic exercise, and the combination of the 2 interventions, on the progression of knee osteoarthritis in a high-fat/high-sucrose diet-induced rat model of metabolic disturbance.

DESIGN

Twelve-week-old male CD-Sprague-Dawley rats were either fed a standard chow diet, or a high-fat/high-sucrose diet. After 12 weeks on diets, rats consuming the high-fat/high-sucrose diet were randomized into 4 subgroups: a sedentary, an aerobic exercise, a prebiotic fiber supplementation, and an aerobic exercise combined with prebiotic fiber supplementation group. The aerobic exercise intervention consisted of a progressive treadmill training program for 12 weeks, while the prebiotic fiber was added to the high-fat/high-sucrose diet at a dose of 10% by weight for 12 weeks. Outcome measures included knee joint damage, body mass, percent body fat, bone mineral density, insulin sensitivity, and serum lipid profile.

RESULTS

Aerobic exercise, or the combination of prebiotic fiber and aerobic exercise, improved select markers of metabolic disturbance, but not knee joint damage. However, these results need to be considered in view of the fact that the chow-fed rats had similar knee OA-like damage as the high-fat/high-sucrose-fed rats.

CONCLUSION

Exercise or prebiotics did not increase joint damage and might be good strategies for populations with metabolic knee osteoarthritis to alleviate other health-related problems, such as diabetes or cardiovascular disorders.

Osteoarthritis complications and the recent therapeutic approaches

The accelerated prevalence of osteoarthritis (OA) disease worldwide and the lack of convenient management led to the frequent search for unprecedented and specific treatment approaches. OA patients usually suffer from many annoying complications that negatively influence their quality of life, especially in the elderly. Articular erosions may lead eventually to the loss of joint function as a whole which occurs over time according to the risk factors presented in each case and the grade of the disease. Conventional therapies are advancing, showing most appropriate results but still greatly associated with many adverse effects and have restricted curative actions as well. Hence, novel management tools are usually required. In this review, we summarized the recent approaches in OA treatment and the role of natural products, dietary supplements and nanogold application in OA treatment to provide new research tracks for more therapeutic opportunities to those who are in care in this field.

Role of dietary patterns and factors in determining the risk of knee osteoarthritis: A meta-analysis

OBJECTIVES

To evaluates the role of diet in determining knee osteoarthritis risk.

METHODS

Literature search was conducted in Ovid, PubMed, Science Direct, and Springer. To estimate knee osteoarthritis risk with high use of vegetarian, prudent, and omnivorous diets, dairy products, vitamin C/E, and carotenoids, the odds ratios (ORs) or relative risks (RRs) reported by included studies were pooled.

RESULTS

Fifteen studies (97,157 individuals) were included. High use of vegetarian diet {OR 0.71 [95% confidence interval (CI): 0.45, 0.97]}, prudent diet [OR 0.87 (95% CI: 0.76, 0.98)/RR 0.89 (95% CI: 0.82, 0.97)], and dairy [OR 0.66 (95% CI: -0.08, 1.39)/RR 0.58 (95% CI: 0.41, 0.75)] were associated with lower risk of knee osteoarthritis but risk was relatively higher with high use of omnivorous diet [OR 1.13 (95% CI: 0.95, 1.30)/RR 1.06 (95% CI: 0.84, 1.29) and 1.05 (0.78, 1.33)]. High intake of vitamin C [OR 0.92 (0.29, 1.56)] or E [OR 0.93 (0.64, 1.21)] did not reduce knee osteoarthritis risk, but high use of carotenoids was associated with the lower risk [OR 0.66 (0.37, 0.96)].

CONCLUSIONS

Knee osteoarthritis risk is low with high use of vegetarian diet, prudent diet, and dairy, but cannt be reduced by high intakes of vitamin C/E.

Food sources of dietary fibre and risk of total knee replacement related to severe osteoarthritis, the Singapore Chinese Health Study

Objectives

We aimed to evaluate the association between fibre intake and its food sources, and the risk of total knee replacement (TKR) due to severe knee osteoarthritis (KOA).

Methods

We used data from the Singapore Chinese Health Study, a prospective cohort study that recruited 63 257 participants aged 45–74 years from 1993 to 1998. At baseline, we assessed diet using a validated 165-item semiquantitative food frequency questionnaire, together with body mass index (BMI) and lifestyle factors. Incident TKR cases were identified via record linkage with nationwide hospital discharge database through 2017.

Results

There were 2816 cases of incident TKR due to severe KOA. The total fibre intake at baseline was not associated with the risk of TKR after adjustment for confounders. Among the food sources of fibre, higher intake of legumes was associated with a lower risk of TKR in a dose-dependent manner; compared with those having the lowest quartile intake, HR (95% CI) was 0.86 (0.76, 0.96) for those having the highest quartile intake (p for trend=0.004). This association was consistent after including BMI in the model and homogeneous across BMI categories. The consumption of other fibre sources, namely grain products, nuts and seeds, soy food, fruits and vegetables, was not associated with the risk of TKR.

Conclusion

Intake of legumes, but not total fibre, was associated with a reduced risk of TKR. Further research is needed to replicate our findings and to evaluate possible biological mechanisms that could explain the effect of dietary legumes on pathogenesis or progression of KOA.

Dietary patterns and risk of developing knee osteoarthritis: data from the osteoarthritis initiative

OBJECTIVE

Some studies have examined the association between dietary factors and risk of knee osteoarthritis (OA). We aimed to examine the prospective association of major dietary patterns with the risk of developing knee OA.

METHOD

We followed 2,842 participants in Osteoarthritis Initiative (OAI) aged 45-79 years and with at least one knee free from radiographic knee OA at baseline for up to 72 months. We defined knee OA incidence as Kellgren and Lawrence grade ≥2 during follow-up visits. Using principal component analysis, Western and prudent dietary patterns were derived. Cox proportional hazards models were used to assess the association between dietary patterns and incident knee OA.

RESULTS

Among study participants, 385 (418 knees) developed knee OA within 72 months. Following a Western dietary pattern was associated with an increased risk of knee OA (HR _{quartile 4 vs 1} = 1.69, 95% CI: 1.13 to 2.52, p trend: 0.03), while adherence to the prudent pattern was associated with a reduced risk of knee OA (HR _{quartile 4 vs 1} = 0.70, 95% CI: 0.50 to 0.98, p trend: 0.05). The observed associations attenuated after additionally adjusting for body mass index (BMI). The observed associations were mediated through BMI by approximately 30%.

CONCLUSION

Following a Western diet was associated with increased risk of knee OA, whereas following a prudent pattern was associated with a reduced risk of knee OA. The associations were partially mediated through BMI.

Nutrition in Physical Therapist Practice: Setting the Stage for Taking Action

Diet and nutrition are critical components of health, recovery from disease and illness, performance, and normal growth across the lifespan. Thus, it is important for physical therapists to be knowledgeable about nutrition and to have competency in providing information and guidance to patients/clients. Yet, there is an overwhelming amount of diet and nutrition information available from numerous sources, which makes it difficult to reach conclusions and determine the importance and relevance to patient care. The purpose of this perspective paper is to increase the knowledge and skills of physical therapists by providing guidelines for healthy eating and outlining diet and nutrition information most relevant for physical therapist practice and to clarify professional scope of practice related to diet and nutrition, including boundaries created by law, and the connection between healthy eating and health outcomes, muscle strength, bone health, and wound healing.

Magnesium in joint health and osteoarthritis

Osteoarthritis (OA) is a prevalent debilitating age-related skeletal disease. The hallmark of OA is the degradation of articular cartilage that cushions the joint during movement. It is characterized by chronic pain and disability. Magnesium, a critical trace element in the human body, plays a pivotal role in metabolism homeostasis and the energy balance. Humans obtain magnesium mainly from the diet. However, inadequate magnesium intake is not uncommon. Moreover, the magnesium status deteriorates with ageing. There has been a growing body of clinical studies pointing to an intimate relationship between dietary magnesium and OA although the conclusion remains controversial. As reported, the magnesium ion concentration is essential to determine cell fate. Firstly, the low-concentration magnesium ions induced human fibroblasts senescence. Magnesium supplementation was also able to mitigate chondrocyte apoptosis, and to facilitate chondrocyte proliferation and differentiation. In this literature review, we will outline the existing evidence in animals and humans. We will also discuss the controversies on plasma or intracellular level of magnesium as the indicator of magnesium status. In addition, we put forward the interplay between dietary magnesium intake and intestinal microbiome to modulate the inflammatory milieu in the conjecture of OA pathogenesis. This leads to an emerging hypothesis that the synergistic effect of magnesium and probiotics may open a new avenue for the prevention and treatment of OA.

Poor diet quality is associated with self-reported knee pain in community-dwelling women aged 50 years and older

In the current study, we aimed to examine the association between knee pain and diet quality in women aged ≥ 50 years using data from the Korea National Health and Nutrition Examination Survey. This was a population-based, cross-sectional study. Diet quality was assessed using the Diet Quality Index-International (DQI-I), and knee pain and osteoarthritis were self-reported. A multivariate logistic regression model was used to adjust for age, body mass index, household income, marital status, education, occupation, smoking status, hazardous alcohol use, regular physical activity, menopause, and chronic diseases, including hypertension, diabetes, dyslipidemia, osteoarthritis, and depression. A total of 3,881 women were included in this study, and the prevalence of knee pain was 25.4%. The intakes of total energy, protein, and fat were lower in women with knee pain than in those without (all P < 0.01), while the carbohydrate intake was higher (P = 0.01). No significant differences were noted in the scores for variety, overall balance, and moderation components, except for the item of total fat intake, between the DQI-I scores for women with and without knee pain, after adjusting for age. Women without knee pain showed higher scores in several items of the adequacy component (P < 0.05) than did women with knee pain. The total DQI-I scores were lower in women with knee pain than in women without knee pain, after adjusting for covariates, including osteoarthritis (OR = 0.985, 95% CI = 0.973–0.997, P = 0.01). Knee pain independent of osteoarthritis was associated with poor diet quality in community-dwelling women aged ≥ 50 years.

Inflammatory potential of diet and risk of incident knee osteoarthritis: a prospective cohort study

Background

To examine the relation between inflammatory potential of diet and incident knee osteoarthritis (OA) and the role of BMI in the association of interest.

Methods

In the Osteoarthritis Initiative, the energy-adjusted dietary inflammatory index (E-DII™) scores were calculated based on the Block Brief 2000 Food Frequency Questionnaire and categorized into sex-specific quartiles. Outcomes were incident (1) radiographic knee OA (ROA) (i.e., a KL grade ≥ 2) and (2) symptomatic knee OA (SxOA) (i.e., a combination of frequent knee pain and ROA). We fitted generalized estimating equation models to examine the association between E-DII scores and incident knee OA. We performed mediation analyses to assess the potential mediation by BMI in the DII-OA relation.

Results

Over a 48-month follow-up period, 232 and 978 knees developed ROA and SxOA, respectively. Compared with the lowest (most anti-inflammatory) E-DII quartile, the odds ratio (OR) of incident ROA for the highest (most pro-inflammatory) E-DII quartile was 1.73 (95% confidence interval (CI) 1.15 to 2.62, P_trend = 0.007). The corresponding OR for SxOA was 1.43 (95% CI 1.16 to 1.76, P_trend = 0.001). The DII-OA association was significantly mediated via BMI with an indirect effect of 1.08 (95% CI 1.04, 1.13) for ROA and 1.13 (95% CI 1.09, 1.16) for SxOA, accounting for 20.4% and 44.5% of the total effect, respectively.

Conclusions

A higher inflammatory potential of diet increased the risk of knee OA. The association was significantly mediated via BMI. Targeting the inflammatory potential of diet may be beneficial to reduce the risk of knee OA.

Gut microbiota and obesity: Impact of antibiotics and prebiotics and potential for musculoskeletal health

Obesity is a complex disease with multiple contributing factors. One of the most intensely studied factors during the past decade has been the gut microbiota, which is the community of all microbes in the intestinal tract. The gut microbiota, via energy extraction, inflammation, and other actions, is now recognized as an important player in the pathogenesis of obesity. Dysbiosis, or an imbalance in the microbial community, can initiate a cascade of metabolic disturbances in the host. Early life is a particularly important period for the development of the gut microbiota, and perturbations such as with antibiotic exposure can have long-lasting consequences for host health. In early life and throughout the life span, diet is one of the most important factors that shape the gut microbiota. Although diets high in fat and sugar have been shown to contribute to dysbiosis and disease, dietary fiber is recognized as an important fermentative fuel for the gut microbiota and results in the production of short-chain fatty acids that can act as signaling molecules in the host. One particular type of fiber, prebiotic fiber, contributes to changes in the gut microbiota, the most notable of which is an increase in the abundance of Bifidobacterium. This review highlights our current understanding of the role of gut microbiota in obesity development and the ways in which manipulating the microbiota through dietary means, specifically prebiotics, could contribute to improved health in the host, including musculoskeletal health.

Gut microbiota and osteoarthritis management: An expert consensus of the European society for clinical and economic aspects of osteoporosis, osteoarthritis and musculoskeletal diseases (ESCEO)

The prevalence of osteoarthritis (OA) increases not only because of longer life expectancy but also because of the modern lifestyle, in particular physical inactivity and diets low in fiber and rich in sugar and saturated fats, which promote chronic low-grade inflammation and obesity. Adverse alterations of the gut microbiota (GMB) composition, called microbial dysbiosis, may favor metabolic syndrome and inflammaging, two important components of OA onset and evolution. Considering the burden of OA and the need to define preventive and therapeutic interventions targeting the modifiable components of OA, an expert working group was convened by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) to review the potential contribution of GMB to OA. Such a contribution is supported by observational or dietary intervention studies in animal models of OA and in humans. In addition, several well-recognized risk factors of OA interact with GMB. Lastly, GMB is a critical determinant of drug metabolism and bioavailability and may influence the response to OA medications. Further research targeting GMB or its metabolites is needed to move the field of OA from symptomatic management to individualized interventions targeting its pathogenesis.

Gut microbiota and obesity-associated osteoarthritis

Obesity is a well-known primary risk factor for osteoarthritis (OA). In recent decades, the biomechanics-based theoretical paradigm for the pathogenesis of obesity-associated OA has been gradually but fundamentally modified. This modification is a result of accumulating evidence that biological factors also contribute to the etiology of the disease. The gut microbiota is a complicated ecosystem that profoundly influences the health of the host and can be modulated by the combined effects of environmental stimuli and genetic factors. Recently, enteric dysbacteriosis has been identified as a causal factor in the initiation and propagation of obesity-associated OA in animal models. Gut microbes and their components, microbe-associated lipid metabolites, and OA interact at both systemic and local levels through mechanisms that involve interplay with the innate immune system. However, the demonstration of causality in humans will require further studies. Nonetheless, probiotics, prebiotics, dietary habits and exercise, which aid the restoration of a healthy microbial community, are potential therapeutic approaches in the treatment of obesity-associated OA.

Statin Use and Knee Osteoarthritis Outcomes: A Longitudinal Cohort Study

OBJECTIVE

Statins have several pleiotropic effects, but the literature regarding the possible relationship between use of statins and outcomes in knee osteoarthritis (OA) is limited. The aim of this study was to investigate whether statin use is associated with a lower risk of radiographic OA (ROA), radiographic symptomatic knee OA, and pain in North American individuals.

METHODS

A total of 4,448 community-dwelling adults from the Osteoarthritis Initiative were followed for 4 years. Statin use (including the time from baseline and the type of statin) was defined through self-report information and confirmed by a trained interviewer. Knee OA outcomes included incident ROA, symptomatic knee OA (new onset of a combination of a painful knee and ROA), and knee pain worsening (i.e., a Western Ontario and McMaster Universities Osteoarthritis Index difference between baseline and each annual examination ≥14%).

RESULTS

At baseline, 1,127 participants (25.3% of the total population) used statins. Based on a multivariable Poisson regression analysis with robust variance estimators, any use of statins was not associated with a lower risk of pain worsening (relative risk [RR] 0.97, 95% confidence interval [95% CI] 0.93-1.02), incident ROA, or symptomatic knee OA. However, statin use for more than 5 years (RR 0.91, 95% CI 0.83-0.997) and use of atorvastatin (RR 0.95, 95% CI 0.91-0.996) were associated with a reduced risk of developing pain, while rosuvastatin use was associated with a higher risk (RR 1.18, 95% CI 1.12-1.24). Analysis with adjustment for the propensity score confirmed these findings.

CONCLUSION

The effect of statin use on knee OA outcomes remains unclear, although in our study, a significantly lower risk of developing knee pain was observed in individuals using statins for >5 years and those using atorvastatin.

Establishing outcome measures in early knee osteoarthritis

The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and quality of life), features of clinical examination (such as joint line tenderness and crepitus), objective measures of physical function, levels of physical activity, features of imaging modalities (such as of magnetic resonance imaging) and biochemical markers in body fluid. Patient characteristics such as adiposity and biomechanics of the knee could also have relevance to the assessment of early OA. Importantly, research is needed to enable the selection of outcome measures that are feasible, reliable and validated in individuals at risk of knee OA or with early knee OA. In this Perspectives article, potential outcome measures for early symptomatic knee OA are discussed, including those measures that could be of use in clinical practice and/or the research setting.

Osteoarthritis year in review 2018: clinical

Osteoarthritis (OA) is the most common joint disease in the world, with an age-associated increase in both incidence and prevalence. Clinical and epidemiologic research is crucial to better understand risk factors for disease, find the best treatments for symptoms, and identify therapies to slow down or even prevent disease progression. This paper is based on a systematic review of the osteoarthritis literature published in English between 2017/05/01 and 2018/04/25, with a focus on papers which have the potential to improve patient care, or which suggest novel areas for future research.

Mediterranean diet and knee osteoarthritis outcomes: A longitudinal cohort study

OBJECTIVES

Mediterranean diet has several beneficial effects on health, but data regarding the association between Mediterranean diet and knee osteoarthritis (OA) are limited mainly to cross-sectional studies. We investigated whether higher Mediterranean diet adherence is prospectively associated with lower risk of radiographic OA (ROA), radiographic symptomatic knee OA (SxOA) and pain worsening in North American people at high risk or having knee OA.

METHODS

Adherence to the Mediterranean diet was evaluated using a validated Mediterranean diet score (aMED), categorized in five categories (Q1 to Q5, higher values reflecting higher adherence to Mediterranean diet). Knee OA outcomes included incident (1) ROA, (2) SxOA, as the new onset of a combination of a painful knee and ROA, (3) knee pain worsening, i.e. a Western Ontario and McMaster Universities Osteoarthritis Index difference between baseline and each annual exam of ≥14%.

RESULTS

4330 subjects (mean age: 61.1 years; 58.0% females) were included. Based on a multivariable Poisson regression analysis, during a mean follow-up period of 4 years, participants who were more highly adherent to a Mediterranean diet (Q5) reported lower risk of pain worsening (relative risk, RR = 0.96; 95% CI: 0.91-0.999) compared to those in Q1. In 2994 people free from SxOA at baseline, higher adherence to a Mediterranean diet was associated with a lower risk for SxOA during follow-up by 9% (Q5 vs. Q1; RR = 0.91; 95% CI: 0.82-0.998). No significant associations emerged between aMED and incident ROA.

CONCLUSION

Higher adherence to Mediterranean diet is associated with a lower risk of pain worsening and symptomatic forms of knee OA.

Body Mass Index Mediates the Association between Dietary Fiber and Symptomatic Knee Osteoarthritis in the Osteoarthritis Initiative and the Framingham Osteoarthritis Study

Background

Dietary fiber reduces body weight and inflammation in clinical trials. It is unclear whether body mass index (BMI) and inflammation might explain the observed association between higher fiber intake and the lower risk of symptomatic knee osteoarthritis (SXKOA).

Objectives

We quantified the extent to which BMI and inflammation influenced the relation between dietary fiber and SXKOA.

Methods

We used longitudinal data from the Osteoarthritis Initiative (OAI) and the Framingham Offspring Osteoarthritis Study. At baseline of each study, men and women (mean age: 61 y) with or at risk of knee osteoarthritis were followed for 48 mo in the OAI. Adults (mean age: 53 y) were followed for 9.5 y in the Framingham study. Dietary fiber intake was estimated using a validated food-frequency questionnaire. Measured weight and height were used to calculate BMI. Serum high-sensitivity C-reactive protein (CRP) was measured in the Framingham study only. Incident SXKOA was defined as new onset of a combination of knee pain and radiographic osteoarthritis. We applied marginal structural models to quantify the mediation through BMI in the OAI and the sequential mediation through BMI and CRP in the Framingham study.

Results

Incident SXKOA occurred in 861 knees among 2876 persons in the OAI and in 143 knees among 971 persons in the Framingham study. In persons whose fiber intake was ≥21 g/d compared with those with intakes <21 g/d, the OR (95% CI) was 0.70 (0.53, 0.91) for the overall association with SXKOA and was 0.93 (0.92, 0.95) for the mediation via BMI (per kg/m2) in the OAI. In the Framingham study, the overall association was 0.57 (0.30, 1.09), the mediation through BMI (via BMI and the influence of BMI on CRP) was 0.94 (0.85, 1.02), and the mediation through CRP (per milligram per liter) was 0.99 (0.84, 1.19).

Conclusion

Our findings suggest that the inverse association of fiber intake and the risk of incident symptomatic knee osteoarthritis is partially mediated by BMI.

Low magnesium intake is associated with increased knee pain in subjects with radiographic knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

As magnesium mediates bone and muscle metabolism, inflammation, and pain signaling, we aimed to evaluate whether magnesium intake is associated with knee pain and function in radiographic knee osteoarthritis (OA).

METHODS

We investigated the associations between knee pain/function metrics and magnesium intake from food and supplements in 2548 Osteoarthritis Initiative cohort participants with prevalent radiographic knee OA (Kellgren-Lawrence score ≥2). Magnesium intake was assessed by Food Frequency Questionnaire (FFQ) at baseline. WOMAC and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores were reported annually with total follow up of 48 months. Analyses used linear mixed models.

RESULTS

Among participants with baseline radiographic knee OA the mean total magnesium intake was 309.9 mg/day (SD 132.6) for men, and 287.9 mg/day (SD 118.1) for women, with 68% of men and 44% of women below the estimated average requirement. Subjects with lower magnesium intake had worse knee OA pain and function scores, throughout the 48 months (P < 0.001). After adjustment for age, sex, race, body mass index (BMI), calorie intake, fiber intake, pain medication use, physical activity, renal insufficiency, smoking, and alcohol use, lower magnesium intake remained associated with worse pain and function outcomes (1.4 points higher WOMAC and 1.5 points lower KOOS scores for every 50 mg of daily magnesium intake, P < 0.05). Fiber intake was an effect modifier (P for interaction <0.05). The association between magnesium intake and knee pain and function scores was strongest among subjects with low fiber intake.

CONCLUSION

Lower magnesium intake was associated with worse pain and function in knee OA, especially among individuals with low fiber intake.

Epidemiology of osteoarthritis: literature update

PURPOSE OF REVIEW

The purpose of this review is to highlight recent studies of osteoarthritis epidemiology, including research on prevalence, disease impact, and potential risk factors.

RECENT FINDINGS

Osteoarthritis is highly prevalent in the United States and around the globe. It is a leading cause of disability and can negatively impact people's physical and mental well being. Healthcare resources and costs associated with managing the disease can be substantial. There is increasing evidence that there are different osteoarthritis phenotypes that reflect different mechanisms of the disease. Various person-level risk factors are recognized, including sociodemographic characteristics (e.g. female sex, African-American race), genetic predispositions, obesity, diet-related factors, and high bone density/mass. Joint-level risk factors include specific bone/joint shapes, thigh flexor muscle weakness, joint malalignment, participation in certain occupational/sports activities, and joint injury. Recent studies have enhanced our understanding of preradiographic lesions associated with osteoarthritis.

SUMMARY

Application of these new findings may allow us to develop innovative strategies and novel therapies with the purpose of preventing new disease onset and minimizing disease progression.