Association of weight gain with incident knee pain, stiffness, and functional difficulties: A longitudinal study

Musculoskeletal pain among Chinese women during the menopausal transition: findings from a longitudinal cohort study

ABSTRACT

The profiles of muscle and joint pain throughout the menopausal transition and the factors associated with these symptoms have not been determined. A total of 609 participants from a longitudinal cohort study conducted in an urban Chinese community were enrolled in this study. We assessed the prevalence of musculoskeletal symptoms at different menopausal stages and explored the factors associated with these symptoms. The prevalence and severity of muscle and joint pain increase as menopausal stages progress, and late menopausal transition may be a crucial timepoint that triggers the onset of musculoskeletal pain. The results of the multivariate analysis revealed that poor health status (OR = 2.245, 95% CI = 1.714-2.94, P < 0.001), body mass index (BMI) (OR = 1.046, 95% CI = 1.01-1.084, P = 0.011), the presence of anxiety (OR = 1.601, 95% CI = 1.211-2.117, P < 0.001), and depression (OR = 1.368, 95% CI = 1.143-1.639, P < 0.001) were independently associated with muscle and joint pain. In addition, the severity of musculoskeletal pain was related to poor health status (OR = 2.738, 95% CI = 1.91-3.924, P < 0.001) and depression (OR = 1.371, 95% CI = 1.095-1.718, P = 0.006). Musculoskeletal symptoms are frequent somatic symptoms experienced by Chinese middle-aged women. Women with poor health status, high BMI, anxiety, and depression were at heightened risk of experiencing musculoskeletal pain. The severity of pain increased over time.

Obesity and the risk of multiple or severe frequent knee pain episodes: a 4-year follow-up of the ELSA-Brasil MSK cohort

BACKGROUND/OBJECTIVE

Knee pain is an important health problem due to its high prevalence, negative impact on daily activities and quality of life, and societal burden. While the link between excess weight and knee pain has been well-documented in the literature, many studies are limited to patients with osteoarthritis or use cross-sectional data. This longitudinal study investigated whether overweight and obesity were associated with the frequency and severity of frequent knee pain (FKP) episodes over 4 years in civil servants enrolled in the ELSA-Brasil MSK cohort.

METHODS

Knee pain was assessed during baseline face-to-face interviews (2012-2014) and four yearly telephone follow-ups (2015-2019). Disabling FKP episodes or those of moderate to very severe intensity were classified as severe. Multinomial logistic regression models adjusted for confounders were used to test for associations in two participant groups: those with knee pain at baseline (prognosis cohort) and those without knee pain (incidence cohort).

RESULTS

A total of 2644 participants were included: 54.2% female, mean age 55.8 (SD 8.8) years. In the incidence cohort (n = 1896), obesity increased the risk of one (OR: 1.63; 95% CI 1.13-2.37) and multiple FKP episodes (OR: 2.61; 95% CI 1.71-3.97), as well as the risk of non-severe (OR: 1.72; 95% CI 1.04-2.84) and severe FKP episodes (OR: 2.10; 95% CI 1.50-2.95). In the prognosis cohort (n = 748), obesity increased the risk of multiple (OR: 2.54; 95% CI 1.60-4.05) and severe FKP episodes (OR: 2.31; 95% CI 1.49-3.59). Overweight presented the same trends but fell short of significance.

CONCLUSIONS

These results provide further support that overweight and obesity are important contributors to the incidence and worsening of FKP, and that weight management must be prioritized in multidisciplinary knee pain prevention and treatment programs to reduce the burden of musculoskeletal disorders.

Associations between weight change, knee subcutaneous fat and cartilage thickness in overweight and obese individuals: 4-Year data from the osteoarthritis initiative

OBJECTIVE

To assess (i) the impact of changes in body weight on changes in joint-adjacent subcutaneous fat (SCF) and cartilage thickness over 4 years and (ii) the relation between changes in joint-adjacent SCF and knee cartilage thickness.

DESIGN

Individuals from the Osteoarthritis Initiative (total=399) with > 10% weight gain (n=100) and > 10% weight loss (n=100) over 4 years were compared to a matched control cohort with less than 3% change in weight (n=199). 3.0T Magnetic Resonance Imaging (MRI) of the right knee was performed at baseline and after 4 years to quantify joint-adjacent SCF and cartilage thickness. Linear regression models were used to evaluate the associations between the (i) weight change group and 4-year changes in both knee SCF and cartilage thickness, and (ii) 4-year changes in knee SCF and in cartilage thickness. Analyses were adjusted for age, sex, baseline body mass index (BMI), tibial diameter (and weight change group in analysis (ii)).

RESULTS

Individuals who lost weight over 4-years had significantly less joint-adjacent SCF (beta range, medial/lateral joint sides: 2.2-4.2 mm, p < 0.001) than controls; individuals who gained weight had significantly greater joint-adjacent SCF than controls (beta range: -1.4 to -3.9 mm, p < 0.001). No statistically significant associations were found between weight change and cartilage thickness change. However, increases in joint-adjacent SCF over 4 years were significantly associated with decreases in cartilage thickness (p = 0.04).

CONCLUSIONS

Weight change was associated with joint-adjacent SCF, but not with change in cartilage thickness. However, 4-year increases in joint-adjacent SCF were associated with decreases in cartilage thickness independent of baseline BMI and weight change group.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

Rheumatology researchers often categorize continuous predictor variables. We aimed to show how this practice may alter results from observational studies in rheumatology.

METHODS

We conducted and compared the results of two analyses of the association between our predictor variable (percentage change in body mass index [BMI] from baseline to four years) and two outcome variable domains of structure and pain in knee and hip osteoarthritis. These two outcome variable domains covered 26 different outcomes for knee and hip combined. In the first analysis (categorical analysis), percentage change in BMI was categorized as ≥ 5% decrease in BMI, < 5% change in BMI, and ≥ 5% increase in BMI, while in the second analysis (continuous analysis), it was left as a continuous variable. In both analyses (categorical and continuous), we used generalized estimating equations with a logistic link function to investigate the association between the percentage change in BMI and the outcomes.

RESULTS

For eight of the 26 investigated outcomes (31%), the results from the categorical analyses were different from the results from the continuous analyses. These differences were of three types: 1) for six of these eight outcomes, while the continuous analyses revealed associations in both directions (i.e., a decrease in BMI had one effect, while an increase in BMI had the opposite effect), the categorical analyses showed associations only in one direction of BMI change, not both; 2) for another one of these eight outcomes, the categorical analyses suggested an association with change in BMI, while this association was not shown in the continuous analyses (this is potentially a false positive association); 3) for the last of the eight outcomes, the continuous analyses suggested an association of change in BMI, while this association was not shown in the categorical analyses (this is potentially a false negative association).

CONCLUSIONS

Categorization of continuous predictor variables alters the results of analyses and could lead to different conclusions; therefore, researchers in rheumatology should avoid it.

Effects of Weight Change on Knee and Hip Radiographic Measurements and Pain Over Four Years: Data From the Osteoarthritis Initiative

OBJECTIVE

To assess the effects of weight loss and weight gain on hip and knee radiographic changes, pain, and joint replacement over 4 years.

METHODS

Participants (n = 2,752) from the Osteoarthritis Initiative were classified as those with weight gain (more than 5% gain), weight loss (more than -5% loss), or as controls (-3% to 3% change) over 4 years. Generalized estimating equations (adjusted for age, sex, and body mass index) were used to assess the relationship between the weight-change group and 4-year changes in knee radiographic osteoarthritis (OA) (Kellgren/Lawrence [K/L] grade), hip OA (Croft summary grade), joint space narrowing (JSN), and joint pain.

RESULTS

For radiographic knee OA, weight loss was associated with significantly lower odds of K/L grade worsening over 4 years (odds ratio [OR] 0.69 [95% confidence interval (95% CI) 0.53-0.91], P = 0.009), and weight gain was significantly associated with higher odds of medial knee JSN (OR 1.29 [95% CI 1.01-1.64], P = 0.038) compared to controls. For knee pain, weight loss was significantly associated with knee pain resolution over 4 years (OR 1.40 [95% CI 1.06-1.86], P = 0.019) while weight gain was associated with knee pain development (OR 1.34 [95% CI 1.08-1.67], P = 0.009) compared to controls. For all hip outcomes, no significant associations (P > 0.05) were found with weight-change groups. The associations between the weight-change group and total hip or total knee replacement were not significant (P > 0.05).

CONCLUSION

This large, longitudinal study (n = 2,752 with 4-year follow-up) suggests that weight loss may protect against, and weight gain may exacerbate, radiographic and symptomatic knee OA, while weight change (at a 5% threshold) does not have significant effects on hip OA.

Association between weight gain and knee osteoarthritis: a systematic review

OBJECTIVE

Although weight loss is recommended to manage knee osteoarthritis (KOA), adults tend to gain weight with age which may affect KOA symptoms and progression. We conducted a systematic review and data synthesis to investigate the association between weight gain and KOA, defined by clinical features, structural progression, and total knee replacement (TKR).

DESIGN

MEDLINE and EMBASE were systematically searched for controlled trials and cohort studies of participants with (or at risk of) KOA examining the relationship between weight gain and KOA clinical features (pain, function, quality of life), structural progression, and TKR. Risk of bias was assessed using the ROBINS-I tool. Results were organised by outcome, with meta-analyses performed where appropriate.

RESULTS

Twenty-three studies were included. Results showed significant detrimental effects of weight gain on pain (4 of 7 studies), stiffness (2 of 2 studies), function (5 of 6 studies), and the single studies examining quality of life, and clinical and radiographic KOA. Weight gain adversely affected cartilage (6 of 9 studies), bone marrow lesions (1 of 4 studies), meniscal damage (1 of 3 studies) and effusion/synovitis (1 of 1 study). Weight gain significantly increased TKR (3 of 6 studies): meta-analysis of 2 with available data demonstrated significant increases in TKR/5 kg weight gain in women, HR 1.34 (95% CI 1.18-1.51), and in men, HR 1.25 (95% CI 1.16-1.34).

CONCLUSIONS

Weight gain in adults is associated with increased clinical and structural KOA and TKR. Prevention of weight gain should be considered to improve outcomes in KOA.

Physiological Changes and Pathological Pain Associated with Sedentary Lifestyle-Induced Body Systems Fat Accumulation and Their Modulation by Physical Exercise

A sedentary lifestyle is associated with overweight/obesity, which involves excessive fat body accumulation, triggering structural and functional changes in tissues, organs, and body systems. Research shows that this fat accumulation is responsible for several comorbidities, including cardiovascular, gastrointestinal, and metabolic dysfunctions, as well as pathological pain behaviors. These health concerns are related to the crosstalk between adipose tissue and body systems, leading to pathophysiological changes to the latter. To deal with these health issues, it has been suggested that physical exercise may reverse part of these obesity-related pathologies by modulating the cross talk between the adipose tissue and body systems. In this context, this review was carried out to provide knowledge about (i) the structural and functional changes in tissues, organs, and body systems from accumulation of fat in obesity, emphasizing the crosstalk between fat and body tissues; (ii) the crosstalk between fat and body tissues triggering pain; and (iii) the effects of physical exercise on body tissues and organs in obese and non-obese subjects, and their impact on pathological pain. This information may help one to better understand this crosstalk and the factors involved, and it could be useful in designing more specific training interventions (according to the nature of the comorbidity).

Nationwide Cross-Sectional Study of the Association between Knee Pain and Weight Change: Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES 2013-2015)

The knee is a hinge joint that provides stability and control, which are essential in daily life. Obesity is a major cause of knee pain and its incidence continues to increase worldwide. In this study, we analyzed Korea National Health and Nutrition Examination Survey data on the general population, and showed an association between weight change and knee pain. A total of 22,948 participants were enrolled; those under the age of 50 and those who did not answer the questions about knee pain or weight change were excluded. In all, 8480 patients were analyzed, 7001 (82.56%) of whom indicated that they did not have knee pain, versus 1479 (17.44%) who did experience knee pain. Multivariate regression analysis was performed to analyze the association between knee pain and weight change. With full adjustment for covariates, weight gain per se (OR 1.37; p = 0.002), and gains of 3–6 kg (OR 1.28; p = 0.029) and ≥6 kg (OR 1.62; p = 0.012), showed significant associations with knee pain. This cross-sectional study confirmed a significant association between knee pain and weight change. Therefore, when evaluating patients with knee pain, it is necessary to evaluate weight gain.

Knee pain trajectories over 18 months in non-Hispanic Black and non-Hispanic White adults with or at risk for knee osteoarthritis

BACKGROUND

Pain is the hallmark symptom of knee osteoarthritis (OA), and varies widely across individuals. Previous research has demonstrated both fluctuating and stable pain trajectories in knee OA using various time periods. Changes in pain assessed quarterly (i.e. 3-month intervals) in knee OA are relatively unknown. The current study aimed to investigate temporal variations in pain over a one and a half year period (18 months) based on quarterly characteristic pain assessments, and to examine differences in pain patterns by sociodemographic and baseline pain characteristics.

METHODS

The sample included a prospective cohort of 188 participants (mean age 58 years; 63% female; 52% non-Hispanic Black) with or at risk for knee OA from an ongoing multisite investigation of ethnic/race group differences. Knee pain intensity was self-reported at baseline and quarterly over an18-month period. Baseline pain assessment also included frequency, duration, and total number of pain sites. Group-based trajectory modeling was used to identify distinct pain trajectories. Multinomial logistic regression was used to examine associations between sociodemographic characteristics, risk factors, and pain trajectory groups.

RESULTS

Pain trajectories were relatively stable among a sample of adults with knee pain. Four distinct pain trajectories emerged in the overall sample, with the largest proportion of participants (35.1%) classified in the moderate-high pain group. There were significant relationships between age, education, income, ethnicity/race and trajectory group; with younger, less educated, lower income, and non-Hispanic Black participants had a greater representation in the highest pain trajectory group.

CONCLUSIONS

Pain remained stable across a one and a half-year period in adults with or at risk for knee osteoarthritis, based on quarterly assessments. Certain sociodemographic variables (e.g. ethnicity/race, education, income, age) may contribute to an increased risk of experiencing greater pain.

Body Mass Index and Musculoskeletal Pain: A Cross-Sectional Study

Introduction

With obesity reaching pandemic proportions, its detrimental influence on many health-related conditions has recently become a focus of research. Musculoskeletal (MSK) pain is one of several disorders associated with obesity.

Materials and methods

This study was designed to identify MSK pain in individuals with severe obesity, recruited from a specialized obesity clinic, and to evaluate the correlation between the MSK symptoms and some individual criteria.

Results

In 466 patients (342 females and 124 males), with a mean BMI of 42,77 ± 5.64 kg/m², 90,3% reported MSK pain. Severe pain was reported by 57,8% of female vs 26,6% of male patients. Female patients showed higher mean pain level when compared with males. Body sites with a higher prevalence of pain were: knee (63.5%), lumbar region (46.8%), hip (29%) and ankle (23%), with a predominance of severe pain. BMI have shown a positive correlation to numeric rating scale score in female participants in three body regions: shoulder (P = 0.010), knee (P = 0.042) and ankle (P = 0.024). Body sites with higher pain prevalence were especially in areas of increased mechanical load.

Conclusions

Understanding the relationship between obesity and pain may provide insights into preventive measures and therapeutic strategies for MSK pain. Persistent MSK pain is a significant problem in obese patients that can have a negative relationship with quality of life and function. This fact highlights the importance that patients with obesity may have access to interdisciplinary care, for the prevention and rehabilitation of MSK disorders. To further understand this association, more robust studies are needed.

The Influence of Tobacco Use, Alcohol Consumption, and Weight Gain on Development of Secondary Musculoskeletal Injury After Lower Limb Amputation

OBJECTIVES

To evaluate whether tobacco use, alcohol consumption, and weight gain are associated with the diagnosis of overuse musculoskeletal injuries within the first 12 months after lower limb amputation.

DESIGN

Retrospective cohort study.

SETTING

Military treatment facilities.

PARTICIPANTS

Service members (N=681) with a deployment-related lower limb amputation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Clinical diagnosis codes associated with musculoskeletal overuse injuries of the lower limb, upper limb, and low back regions.

RESULTS

In the first three months after amputation, tobacco use and alcohol consumption were reported in 55.7% and 72.0%, respectively, of the retrospective sample. The overall mean weight change was 22.9±23.6 pounds. The prevalence of reporting at least 1 overuse injury within 4 to 12 months after amputation was 57.0% in the sample, with prevalence rates of lower limb, upper limb and low back pain diagnoses at 28.3%, 21.7%, and 21.1%, respectively. Service members reporting tobacco use in the first 3 months after amputation were nearly twice as likely to be diagnosed with a lower limb musculoskeletal injury 4 to 12 months after amputation. Similarly, service members reporting alcohol consumption within the first 3 months after amputation were more than twice as likely to be diagnosed with at least 1 overuse musculoskeletal injury 4 to 12 months after amputation. However, weight change or maximum weight after amputation were not associated with the diagnosis of an overuse musculoskeletal injury.

CONCLUSIONS

Development of secondary overuse musculoskeletal injury appears to be related to tobacco use and alcohol consumption, but not to weight gain. These findings warrant focused research efforts toward developing preventive interventions.

Weight Gain Trajectory and Pain Interference in Young Adulthood: Evidence from a Longitudinal Birth Cohort Study

OBJECTIVE

Obesity is associated with chronic pain, but the contribution of body mass index (BMI) trajectories over the life course to the onset of pain problems remains unclear. We retrospectively analyzed how BMI trajectories during the transition to adulthood were associated with a measure of pain interference obtained at age 29 in a longitudinal birth cohort study.

METHODS

Data from the National Longitudinal Survey of Youth, 1997 Cohort (follow-up from 1997 to 2015), were used to determine BMI trajectories from age 14 to 29 via group trajectory modeling. At age 29, respondents described whether pain interfered with their work inside and outside the home over the past four weeks (not at all, a little, or a lot). Multivariable ordinal logistic regression was used to evaluate pain interference according to BMI trajectory and study covariates.

RESULTS

Among 7,875 respondents, 11% reported "a little" and 4% reported "a lot" of pain interference at age 29. Four BMI trajectory groups were identified, varying in starting BMI and rate of weight gain. The "obese" group (8% of respondents) had a starting BMI of 30 kg/m2 and gained an average of 0.7 kg/m2/y. On multivariable analysis, this group was the most likely to have greater pain interference, compared with "high normal weight" (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.14-1.88), "low normal weight" (OR = 1.45, 95% CI = 1.13-1.87), and "overweight" trajectories (OR = 1.33, 95% CI = 1.02-1.73).

CONCLUSIONS

Obesity and rapid weight gain during the transition to adulthood were associated with higher risk of pain interference among young adults.

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

OBJECTIVES

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

DESIGN

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

SETTING

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

PARTICIPANTS

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

PRIMARY OUTCOME MEASURE

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

RESULTS

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

CONCLUSIONS

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

Comparison of weight bearing functional exercise and non-weight bearing quadriceps strengthening exercise on pain and function for people with knee osteoarthritis and obesity: protocol for the TARGET randomised controlled trial

Background

Clinical guidelines recommend exercise as a core treatment for individuals with knee osteoarthritis (OA). However, the best type of exercise for clinical benefits is not clear, particularly in different OA subgroups. Obesity is a common co-morbidity in people with knee OA. There is some evidence suggesting that non-weight bearing exercise may be more effective than weight bearing exercise in patients with medial knee OA and obesity.

Methods

To compare the efficacy of two different exercise programs (weight bearing functional exercise and non-weight bearing quadriceps strengthening) on pain and physical function for people ≥50 years with painful medial knee OA and obesity (body mass index ≥30 kg/m²) 128 people in Melbourne, Australia will be recruited for a two group parallel-design, assessor- and participant-blinded randomised controlled trial. Participants will be randomly allocated to undertake a program of either weight bearing functional exercise or non-weight bearing quadriceps strengthening exercise. Both groups will attend five individual sessions with a physiotherapist who will teach, monitor and progress the exercise program. Participants will be asked to perform the exercises at home four times per week for 12 weeks. Outcomes will be measured at baseline and 12 weeks. Primary outcomes are self-reported knee pain and physical function. Secondary outcomes include other measures of knee pain, physical function, quality-of-life, participant-perceived global change, physical performance, and lower limb muscle strength.

Discussion

This study will compare the efficacy of two different 12-week physiotherapist-prescribed, home-based exercise programs for people with medial knee OA and obesity. Findings will provide valuable information to help inform exercise prescription in this common OA patient subgroup.

Trial registration

Australian New Zealand Clinical Trials Registry reference: ACTRN12617001013358, 14/7/2017

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2662-5) contains supplementary material, which is available to authorized users.

Contributions of birthweight, annualised weight gain and BMI to back pain in adults: a population-based co-twin control study of 2754 Australian twins

PURPOSE

To investigate associations between anthropometric measures (birthweight, weight gain and current BMI) and back pain; and to determine whether these associations differ between those born with low or full birthweight.

METHODS

The cross-sectional associations between the lifetime prevalence of back pain and anthropometric measures (birthweight, weight gain and current BMI) among 2754 adult twins were investigated in three stages: total sample; within-pair case-control for monozygotic and dizygotic twins together; and within-pair case-control analysis separated by dizygotic and monozygotic. Results were expressed as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Birthweight was not associated with back pain (OR 0.99; 95% CI 0.99-1.00), but a weak association was found between weight gain (OR 1.01; CI 1.00-1.01) or current BMI (OR 1.02; 95% CI 1.00-1.05) and back pain in the total sample analysis. These associations did not remain significant after adjusting for genetics. The associations did not differ between those whose were born with low or full birthweight.

CONCLUSION

Birthweight was not associated with prevalence of back pain in adulthood. Weight gain and current BMI were weakly associated with back pain prevalence in the total sample analysis but did not differ between those born with low or full birthweight. However, the small-magnitude association only just achieved significance and appeared to be confounded by genetics and the early shared environment. Our results suggest that a direct link between these predictors and back pain in adults is unlikely. These slides can be retrieved under Electronic Supplementary Material.

Is muscle strength in a painful limb affected by knee pain status of the contralateral limb? - Data from the Osteoarthritis Initiative

Contralateral knee pain has been suggested to be associated with muscle weakness in a pain-free knee, potentially through a mechanism of central nervous inhibition. Whether contralateral knee pain also affects muscle strength in a painful knee, however, is unknown. Here we study the extent to which isometric muscle strength differs between matched painful limbs of people with unilateral knee pain vs. matched painful limbs people with bilateral knee pain. To that end, 163 participants with unilateral knee pain were identified from the Osteoarthritis Initiative. Unilaterally painful (UP) limbs were defined as having numerical rating scale (NRS) ≥4/10, infrequent/frequent pain in the painful limb, while contralateral pain-free limbs were defined by NRS=0-1, no/infrequent pain and Western Ontario and McMaster Universities Arthritis Index (WOMAC) ≤1. The comparator group were matched bilaterally painful (BP) limbs. Maximum isometric muscle strength (N) was compared between 1:1 matched BP and UP limbs. Extensor strength was found to be lower in BP limbs than in UP limbs, (-2.9%; p=0.39) but this difference was not statistically significant. Extensor strength was significantly lower in the UP vs. contralateral pain-free limbs (-6.2%; p<0.001). No differences were observed between BP and contralateral painful limbs (0.6%; p=0.87). In conclusion, the current results identify a slight reduction of maximum knee extensor strength in a painful limb, when the contralateral knee is also painful. In contrast to pain-free limbs, this effect did not reach statistical significance, but the overall findings support the concept of central nervous inhibition of muscle strength by contralateral knee pain.

Relationship of weight and obesity with the risk of knee and hip arthroplasty for osteoarthritis across different levels of physical performance: a prospective cohort study

OBJECTIVE

To examine the association between obesity and knee and hip arthroplasty for osteoarthritis across a range of physical performance.

METHOD

The body mass index and physical performance (on the 36-item Short Form Health Survey) of 9135 Australian Diabetes, Obesity and Lifestyle Study participants were measured in 1999-2000. The incidence of knee and hip arthroplasty during 2002-2011 was determined by linking the cohort records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

Over 9.1 ± 2.3 years (mean ± sd)) of follow-up, 317 participants had knee and 202 had hip arthroplasty for osteoarthritis. Using those with neither obesity nor significantly impaired physical performance as the reference group, participants with both obesity and significantly impaired physical performance had a higher knee arthroplasty risk [hazard ratio (HR) = 5.25, 95% confidence interval (CI) 3.85-7.14] than those with obesity alone (HR = 2.49, 95% CI 1.81-3.44) or impaired physical performance alone (HR = 2.19, 95% CI 1.59-3.02). Similar results were observed for hip arthroplasty (obesity and impaired physical performance: HR = 2.67, 95% CI 1.72-4.15; obesity alone: HR = 1.65, 95% CI 1.08-2.51; impaired physical performance alone: HR = 1.83, 95% CI 1.26-2.66). Among overweight/obese patients, 5 kg greater baseline weight increased the knee arthroplasty risk across all levels of physical performance, and hip arthroplasty risk in those with the highest level of physical performance.

CONCLUSION

Although impaired physical performance is an independent risk factor for knee and hip arthroplasty, greater weight increased knee arthroplasty for overweight/obese participants at all levels of physical performance, but hip arthroplasty only in those with good physical performance. Targeting weight loss has the potential to reduce the risk of knee arthroplasty and improve patient outcomes, even in those with poor physical performance.

Effect of a low-intensity, self-management lifestyle intervention on knee pain in community-based young to middle-aged rural women: a cluster randomised controlled trial

Background

Knee pain is common with obesity and weight gain being important risk factors. Previous clinical trials have focused on overweight or obese adults with knee pain and osteoarthritis and demonstrated modest effects of intense weight loss programs on reducing knee pain despite very significant weight loss. There has been no lifestyle intervention that targets community-based adults to test its effect on prevention of knee pain. We aimed to determine the effect of a simple low-intensity self-management lifestyle intervention (HeLP-her), proven in randomised controlled trials to improve lifestyle and prevent weight gain, on knee pain in community-based young to middle-aged rural women.

Methods

A 1-year pragmatic, cluster randomised controlled trial was conducted in 649 community-based women (aged 18–50 years) to receive either the HeLP-her program (consisting of one group session, monthly SMS text messages, one phone coaching session, and a program manual) or one general women’s health education session. Secondary analyses were performed in 390 women who had knee pain measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and 12-month follow-up. “Any knee pain” was defined as a WOMAC pain score ≥ 1. Knee pain worsening was defined as an increase in WOMAC pain score over 12 months.

Results

Thirty-five percent of women had “any knee pain” at baseline. The risk of knee pain worsening did not differ between the intervention and control groups over 12 months. For women with any knee pain at baseline, those in the intervention arm had a lower risk of knee pain worsening compared with those in the control arm (OR 0.37, 95% CI 0.14–1.01, p = 0.05), with a stronger effect observed in women with body mass index ≥ 25 kg/m² (OR 0.28, 95% CI 0.09–0.87, p = 0.03).

Conclusions

In community-based young to middle-aged women, a simple low-intensity lifestyle program reduced the risk of knee pain worsening in those with any knee pain at baseline, particularly in those overweight or obese. Pragmatic lifestyle programs such as HeLP-her may represent a feasible lifestyle intervention to reduce the burden of knee pain in the community.

Trial registration

ACTRN12612000115831, registered 24 January 2012.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1572-5) contains supplementary material, which is available to authorized users.

Incidence and risk factors of exercise-related knee disorders in young adult men

Background

Musculoskeletal disorders and injuries are common causes of morbidity and loss of active, physically demanding training days in military populations. We evaluated the incidence, diagnosis, and risk factors of knee disorders and injuries in male Finnish military conscripts.

Methods

The study population comprised 5 cohorts of 1000 men performing their military service, classified according to birth year (1969, 1974, 1979, 1984, and 1989). Follow-up time for each conscript was the individual conscript’s full, completed military service period. Data for each man were collected from a standard pre-information questionnaire used by defense force healthcare officials and from all original medical reports of the garrison healthcare centers. Background variables for risk factor analysis included the conscripts’ service data, i.e., service class (A, B), length of military service, age, height, weight, body mass index (BMI), underweight, overweight, obesity, smoking habit, education, diseases, injuries, and subjective symptoms.

Results

Of the 4029 conscripts, 853 visited healthcare professionals for knee symptoms during their military service, and 103 of these had suffered a knee injury. Independent risk factors for the incidence of knee symptoms were: older age; service class A; overweight (BMI 25.0–29.9 kg/m²); smoking habit; comprehensive school education only; and self-reported previous symptoms of the musculoskeletal, respiratory, and gastrointestinal system. The majority of visits to garrison healthcare services due to knee symptoms occurred during the first few months of military service. Knee symptoms were negatively correlated with self-reported mental and behavioral disorders.

Conclusions

The present study highlights the frequency of knee disorders and injuries in young men during physically demanding military training. One-fifth of the male conscripts visited defense force healthcare professionals due to knee symptoms during their service period. Independent risk factors for the incidence of knee symptoms during military service were age at military service; military service class A; overweight; smoking habit; comprehensive school education only; and self-reported previous symptoms of the musculoskeletal system, respiratory system, or gastrointestinal system. These risk factors should be considered when planning and implementing procedures to reduce knee disorders and injuries during compulsory military service.

Prevalence of musculoskeletal symptoms in obese patients candidates for bariatric surgery and its impact on health related quality of life

OBJECTIVE

This study was designed to identify the major musculoskeletal symptoms of individuals with obesity, to assess their health-related quality of life, and to evaluate the correlation between the musculoskeletal symptoms and the individuals' health-related quality of life.

MATERIALS AND METHODS

Cross-sectional study.

INSTRUMENTS USED

"Nordic Musculoskeletal Questionnaire" and "The Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36)".

RESULTS

In total, 41 subjects were evaluated, of which 90.15% were female. The mean age of the subjects was 40.78 ± 9.85 years and their mean body-mass index was 46.87 ± 8.08. All subjects reported musculoskeletal pain in at least one anatomical region and 80.49% had pain in three or more regions. The activity limitations due to pain were reported by 75.61% of them. The most affected regions by pain were the ankles and/or feet, lower back, knees and wrists/hands/fingers. The most associated regions with activity limitations due to pain were the ankles and/or feet, knees and lower back. The presence of pain showed a negative correlation with the domains physical functioning (PF), role-physical (RP) and body pain (BP). The activity limitations showed a negative correlation with the domains PF, BP, social functioning (SF) and role-emotional (RE).

CONCLUSION

Our data showed a high prevalence of musculoskeletal pain and limitation in activities due to pain in obese subjects. The musculoskeletal symptoms had negative correlations with physical and mental components of the health-related quality of life, highlighting the importance of ensuring that patients with obesity have access to interdisciplinary care, for the prevention and rehabilitation of musculoskeletal disorders.

Weight satisfaction, management strategies and health beliefs in knee osteoarthritis patients attending an outpatient clinic

BACKGROUND

Although weight control is important in managing knee osteoarthritis (OA), it is difficult to achieve. Understanding beliefs regarding weight management in people with knee OA may improve weight control.

AIMS

To examine differences in bodyweight satisfaction, weight management strategies and weight-related health-beliefs in obese, overweight and normal weight people with knee OA.

METHODS

The beliefs and attitudes to weight in 102 people with symptomatic knee OA were ascertained. Participants were classified as being obese, overweight or of normal weight.

RESULTS

Although obese and overweight participants were less satisfied with their bodyweight, they were more likely to want to lose weight and to report dieting compared with normal weight participants(P < 0.001 for all) and also more likely to report weight gain in the past 6 months (P < 0.001). While most participants rated food intake to be a main determinant of health, this belief was more common in normal weight participants (P = 0.04). When asked about their own weight gain, obese participants more frequently believed genetic and metabolic factors to be important than normal and overweight participants (P = 0.01). While 51 (53%) believed that increasing activity was more important than dietary change to avoid weight gain, this was more commonly believed by obese and overweight participants (P < 0.05).

CONCLUSIONS

Despite desiring and attempting to lose weight, obese people with symptomatic knee OA more commonly reported weight gain. Overweight and obese participants attributed weight gain to non-modifiable factors but believed physical activity is more important than dietary change in weight management. Thus, education regarding the importance of diet as compared with non-modifiable factors and physical activity may improve weight management in obese people with knee OA.

Obesity in early adulthood predicts knee pain and walking difficulties among men: A life course study

BACKGROUND

Few studies have addressed the role of obesity in young adulthood in knee problems later in life. We assessed the associations of overweight/obesity with knee pain and functional limitations of the knee across the life course.

METHODS

Military health records from 1967 to 2000 (baseline) were searched for 18- to 50-year-old Finnish men (n = 1913) who participated in the Health 2000 Study (follow-up). Visits to health care were followed during service. Height and weight were measured at baseline and follow-up and waist circumference at follow-up. Weight was inquired at follow-up for ages of 20, 30, 40 and 50 years, if applicable. Life course body mass index (BMI) was calculated. One-month knee pain and functional limitations (walking difficulties and limping) due to knee problems were enquired with interview at follow-up. Cox regression model, logistic regression and trajectory analysis were applied.

RESULTS

Body mass index at the age of 20 increased the risk of unilateral knee pain by 38% and functional limitations by 27% for one standard deviation increment of BMI, respectively. One-unit increment of Z-score of life course BMI increased knee pain by 32%. Development of severe obesity during the follow-up increased the risk of knee pain by 80% and functional limitations by 93%. The effect of obesity on functional limitations was partly mediated by traumatic knee problems during military service.

CONCLUSIONS

Reducing overweight already in adolescence and avoiding further weight gain during life course may prevent knee pain and associated disability. WHAT DOES THIS STUDY ADD?: BMI at the age of 20 increases the likelihood of knee pain and functional limitations of the knee later in life. Development of severe obesity in adulthood increases the risk of knee pain by 80% and functional limitations by more than 90%. Both general and abdominal obesity are associated with knee pain, associations being stronger for general obesity.

Physical Activity Predicts Higher Physical Function in Older Adults: The Osteoarthritis Initiative

OBJECTIVES

Physical activity reduces mobility impairments in elders. We examined the association of physical activity on risk of subjective and objective physical function in adults with and at risk for osteoarthritis (OA).

METHODS

Adults aged ≥ 60 years from the longitudinal Osteoarthritis Initiative, a prospective observational study of knee OA, were classified by sex-specific quartiles of Physical Activity Score for the Elderly scores. Using linear mixed models, we assessed 6-year data on self-reported health, gait speed, Late-Life Function and Disability Index (LLFDI) and chair stand.

RESULTS

Of 2252 subjects, mean age ranged from 66 to 70 years. Within each quartile, physical component (PCS) of the Short Form-12 and gait speed decreased from baseline to follow-up in both sexes (all P < .001), yet the overall changes across PASE quartiles between these 2 time points were no different (P = .40 and .69, males and females, respectively). Decline in PCS occurred in the younger age group, but rates of change between quartiles over time were no different in any outcomes in either sex. LLFDI scores declined in the 70+ age group. Adjusting for knee extensor strength reduced the strength of association.

CONCLUSIONS

Higher physical activity is associated with maintained physical function and is mediated by muscle strength, highlighting the importance of encouraging physical activity in older adults with and at risk for OA.

Vastus medialis fat infiltration - a modifiable determinant of knee cartilage loss

BACKGROUND

There is growing interest in the role of intramuscular fat and how it may influence clinical outcomes. Vastus medialis (VM) is a functionally important quadriceps muscle that helps to stabilise the knee joint. This longitudinal study examined the determinants of VM fat infiltration and whether VM fat infiltration influenced knee cartilage volume.

METHODS

250 participants without any diagnosed arthropathy were assessed at baseline between 2005 and 2008, and 197 participants at follow-up between 2008 and 2010. Ambulatory and sporting activity were assessed and magnetic resonance imaging (MRI) was used to determine knee cartilage volume and VM fat infiltration.

RESULTS

Age, female gender, BMI and weight were positively associated with baseline VM fat infiltration (P ≤ 0.03), while ambulatory and sporting activity were negatively associated with VM fat infiltration (P ≤ 0.05). After adjusting for confounders, a reduction in VM fat infiltration was associated with a reduced annual loss of medial tibial (β = -10 mm(3); 95% CI -19 to 0 mm(3); P = 0.04) and patella (β = -18 mm(3); 95% CI -36 to 0 mm(3); P = 0.04) cartilage volume.

CONCLUSION

This community-based study of healthy adults has shown that VM fat infiltration can be modified by lifestyle factors including weight loss and exercise, and reducing fat infiltration in VM has beneficial effect on knee cartilage preservation. The findings suggest that modifying VM fat infiltration via lifestyle interventions may have the potential to reduce the risk of knee OA.

A Cross-sectional Examination of Vitamin D, Obesity, and Measures of Pain and Function in Middle-aged and Older Adults With Knee Osteoarthritis

OBJECTIVES

The prevalence of knee osteoarthritis (OA) is increasing with the aging population and is exacerbated by the growing numbers of obese older adults. Low levels of vitamin D, measured by serum 25-hydroxyvitamin D (25(OH)D), in older adults and obese individuals are correlated with several negative health conditions, including chronic pain. This cross-sectional study sought to examine the interactive influence of 25(OH)D levels and obesity on knee OA pain and functional performance measures.

METHODS

The sample consisted of 256 (63% female) racially diverse (55% black/African Americans) middle-aged and older adults (mean age 56.8 y). Blood was collected for analysis of 25(OH)D by high-performance liquid chromatography. Participants provided self-report regarding knee OA pain and underwent a lower extremity functional performance test.

RESULTS

Results demonstrated that obesity was associated with lower levels of 25(OH)D. Participants with adequate 25(OH)D levels reported significantly less knee OA pain compared with participants with deficient or insufficient levels, regardless of obesity status. Furthermore, there was a significant interaction between obesity and 25(OH)D levels for lower extremity functional performance, such that obese individuals with adequate 25(OH)D levels demonstrated better performance than those obese participants with deficient or insufficient 25(OH)D levels.

DISCUSSION

The mechanisms by which adequate 25(OH)D levels are associated with pain severity and improved function have not been completely elucidated. It may be that the pleiotropic role of biologically active 25(OH)D influences pain and pain processing through peripheral and central mechanisms. Alternatively, higher levels of pain may lead to reduced outdoor activity, which may contribute to both obesity and decreased vitamin D. Thus, investigating vitamin D status in obese and nonobese individuals with knee OA warrants further study.

Multivariate Radiological-Based Models for the Prediction of Future Knee Pain: Data from the OAI

In this work, the potential of X-ray based multivariate prognostic models to predict the onset of chronic knee pain is presented. Using X-rays quantitative image assessments of joint-space-width (JSW) and paired semiquantitative central X-ray scores from the Osteoarthritis Initiative (OAI), a case-control study is presented. The pain assessments of the right knee at the baseline and the 60-month visits were used to screen for case/control subjects. Scores were analyzed at the time of pain incidence (T-0), the year prior incidence (T-1), and two years before pain incidence (T-2). Multivariate models were created by a cross validated elastic-net regularized generalized linear models feature selection tool. Univariate differences between cases and controls were reported by AUC, C-statistics, and ODDs ratios. Univariate analysis indicated that the medial osteophytes were significantly more prevalent in cases than controls: C-stat 0.62, 0.62, and 0.61, at T-0, T-1, and T-2, respectively. The multivariate JSW models significantly predicted pain: AUC = 0.695, 0.623, and 0.620, at T-0, T-1, and T-2, respectively. Semiquantitative multivariate models predicted paint with C-stat = 0.671, 0.648, and 0.645 at T-0, T-1, and T-2, respectively. Multivariate models derived from plain X-ray radiography assessments may be used to predict subjects that are at risk of developing knee pain.

Knee Pain and a Prior Injury Are Associated with Increased Risk of a New Knee Injury: Data from the Osteoarthritis Initiative

OBJECTIVE

We explored whether knee pain or a history of knee injury were associated with a knee injury in the following 12 months.

METHODS

We conducted longitudinal knee-based analyses among knees in the Osteoarthritis Initiative. We included both knees of all participants who had at least 1 followup visit with complete data. Our first sets of exposures were knee pain (chronic knee symptoms and severity) at baseline, 12-month, 24-month, and 36-month visits. Another exposure was a history of injury that we defined as a self-reported injury at any time prior to baseline, 12-month, 24-month, or 36-month visit. The outcome was self-reported knee injury during the past year at 12-month, 24-month, 36-month, and 48-month visits. We evaluated the association between ipsilateral and contralateral knee pain or history of injury and a new knee injury within 12 months of the exposure using generalized linear mixed model for repeated binary outcomes.

RESULTS

A knee with reported chronic knee symptoms or ipsilateral or contralateral history of an injury was more likely to experience a new knee injury in the following 12 months than a knee without chronic knee symptoms (OR 1.84, 95% CI 1.57-2.16) or prior injury (prior ipsilateral knee injury: OR 1.81, 95% CI 1.56-2.09. Prior contralateral knee injury: OR 1.43, 95% CI 1.23-1.66).

CONCLUSION

Knee pain and a history of injury are associated with new knee injuries. It may be beneficial for individuals with knee pain or a history of injury to participate in injury prevention programs.

Association of cartilage degeneration with four year weight gain--3T MRI data from the Osteoarthritis Initiative

OBJECTIVE

To determine the effect of weight gain on progression of early knee morphologic abnormalities using magnetic resonance imaging (MRI) in a longitudinal study over 48 months.

DESIGN

We studied the right knee of 100 subjects from the Osteoarthritis Initiative (OAI), selecting subjects aged ≥ 45 with osteoarthritis (OA) risk factors who demonstrated weight gain (minimum 5% increase in body mass index, BMI, n = 50) or no change in weight (BMI change < 2%, n = 50), frequency matched for age, gender, and baseline BMI. Baseline and 48 month knee MRI studies were scored for lesions using a modified whole organ MRI score (WORMS). Logistic regression models were used to compare the differences between the two groups.

RESULTS

The odds of worsening maximum cartilage (11.3, 95%, CI 3.5-51.4) and meniscal WORMS (4.5, 95% CI 1.4-17.3) were significantly greater in the weight gain group compared to the no change group, in addition to the odds of worsening cartilage defects at the patella and average meniscal WORMS (P < 0.05). Odds of worsening average bone marrow edema pattern (BMEP) were significantly greater for the weight gain group compared to the no change cohort (P < 0.05).

CONCLUSION

Our study demonstrated that weight gain is strongly associated with increased progression of cartilage degeneration in middle-aged individuals with risk factors for OA.

Correlates of cardiovascular disease risk scores in women in Riyadh, Kingdom of Saudi Arabia

Saudi Arabia has a high prevalence of obesity and physical inactivity. We measured cardiovascular (CVD) risk scores and determined the factors associated with them in women in Riyadh, Saudi Arabia. A cross-sectional study using a self-administered questionnaire was conducted on 291 women aged ≥ 30 years. Information was collected on socio-demographics and physical health status. Anthropometric and blood pressure measurements were taken. Physical activity was measured using Kaiser's Physical Activity Survey and Godin's Leisure Time Exercise questionnaire. CVD risk scores were calculated using the non-laboratory-based Framingham Risk (FRS) prediction model for primary care. FRS scores ranged from 0.50 to 21.9. A total of 2.7% (n = 8) of women had a high FRS score (>20), 5.5% (n = 16) had intermediate scores (11-20), and 91.8% (n = 267) of women had low scores (<10) CVD risk scores. Multiple linear regression results indicated that a one-unit change in physical activity (household/caregiver index), strenuous exercise, waist circumference, number of children, television watching, and knee pain were significantly associated with -0.20 (p < .01), -0.12 (p = .03), 0.19 (p = .001), 0.29 (p < .01), 0.13 (p = .04), and 0.11 (p = .05) unit change in CVD risk scores, respectively. Household activities and strenuous exercise had a protective role in females in relation to CVD risk. Programs recommending physical activity at all levels should be encouraged.

The steps to health randomized trial for arthritis: a self-directed exercise versus nutrition control program

BACKGROUND

Despite the established benefits of exercise for adults with arthritis, participation is low. Safe, evidence-based, self-directed programs, which have the potential for high reach at a low cost, are needed.

PURPOSE

To test a 12-week, self-directed, multicomponent exercise program for adults with arthritis.

DESIGN

Randomized controlled trial. Data were collected from 2010 to 2012. Data were analyzed in 2013 and 2014.

SETTING/PARTICIPANTS

Adults with arthritis (N=401, aged 56.3 [10.7] years, 85.8% women, 63.8% white, 35.2% African American, BMI of 33.0 [8.2]) completed measures at a university research center and participated in a self-directed exercise intervention (First Step to Active Health(®)) or nutrition control program (Steps to Healthy Eating).

INTERVENTION

Intervention participants received a self-directed multicomponent exercise program and returned self-monitoring logs for 12 weeks.

MAIN OUTCOME MEASURES

Self-reported physical activity, functional performance measures, and disease-specific outcomes (arthritis symptoms and self-efficacy) assessed at baseline, 12 weeks, and 9 months.

RESULTS

Participants in the exercise condition showed greater increases in physical activity than those in the nutrition control group (p=0.01). Significant improvements, irrespective of condition, were seen in lower body strength, functional exercise capacity, lower body flexibility, pain, fatigue, stiffness, and arthritis management self-efficacy (p values<0.0001). More adverse events occurred in the exercise than nutrition control condition, but only one was severe and most were expected with increased physical activity.

CONCLUSIONS

The exercise program improves physical activity, and both programs improve functional and psychosocial outcomes. Potential reasons for improvements in the nutrition control condition are discussed. These interventions have the potential for large-scale dissemination. This study is registered at Clinicaltrials.gov NCT01172327.

The impact of waist circumference on function and physical activity in older adults: longitudinal observational data from the osteoarthritis initiative

Background

We previously demonstrated that BMI is associated with functional decline and reduced quality of life. While BMI in older adults is fraught with challenges, waist circumference (WC) is a marker of visceral adiposity that can also predict mortality. However, its association with function and quality of life in older adults is not well understood and hence we sought to examine the impact of WC on six-year outcomes.

Methods

We identified adults aged ≥60 years from the longitudinal Osteoarthritis Initiative and stratified the cohort into quartiles based on WC. Our primary outcome measures of function at six year follow-up included: self-reported quality of life [Short Form-12 (SF-12)], physical function [Physical Activity Scale for the Elderly (PASE)] and disability [Late-life Disability Index (LLDI)]. Linear regression analyses predicted 6-year outcomes based on WC quartile category (lowest = referent), adjusted for age, sex, race, education, knee pain, smoking status, a modified Charlson co-morbidity index and baseline scores, where available.

Results

We identified 2,182 subjects meeting our inclusion criteria and stratified the study cohort by quartiles of WC. Mean age ranged from 67.5-68.7 years, 60-71% were female and 80-86% were white. The highest WC quartile compared to 50-75th, 25-50th or lowest quartile, was associated with a greater number of medications (4.3, 4.0, 3.6 and 3.4 [p < 0.001]), lower gait speeds (1.23, 1.27, 1.32, and 1.34 m/s[p < 0.001]), higher rates of knee osteoarthritis (70.2, 62.2, 60.2, 48.6;p < 0.001), higher Charlson co-morbidity scores and greater knee pain (WOMAC scores) (all p < 0.001). At follow-up, adjusted SF-12 physical function subscale and PASE scores, were lowest in the highest WC quartile as compared to the 50-75%, 25-50%, and lowest quartiles [(SF-12 scores: 45.5, 46.7, 47.6, and 47.9), and (PASE scores: 109.6, 128.7, 126.6, and 131.0). The LLDI limitation subscale for disability demonstrated lower scores in the high WC quartile as opposed to the referent group.

Conclusions

Elevated WC is associated with lower quality of life, a decline in physical function, and a slightly higher risk of disability over time. Intervention studies are needed to prevent functional decline in this high-risk population.

Correlation of Self-Reported Questionnaire (KOOS) with Some Objective Measures in Primary OA Knee Patients

Purpose. Objective of the present study was to see the correlation of subjectively measured KOOS questionnaire with objectively measured 6-minute walk test (6-MWT), age, height, weight, and BMI. Participants. 251 subjects with OA knee based on American College of Rheumatology criteria. Methods. After passing inclusion and exclusion criteria, the following parameters were recorded: age, height, weight, and BMI. Then subjects were asked to fill KOOS questionnaire; then all subjects were asked to do self-paced walk for 6 minutes. Analysis. Spearman rank test was done to see the correlation. Significant level was set at P < 0.05. Results. 6-MWT had a weak correlation with KOOS-ADL (rho 0.461) and strong correlation with KOOS-symptom, KOOS-pain, and KOOS-sports and very strong correlation with KOOS-QOL. BMI had a strong correlation with KOOS-pain, KOOS-symptom, KOOS-ADL, and KOOS-sports and very strong correlation with KOOS-QOL. Weight had a weak correlation with KOOS-symptom, KOOS-ADL, and KOOS-sports and strong correlation with KOOS-pain and KOOS-QOL. All the above values were significant with P < 0.001. Conclusion. KOOS is strongly positively correlated with 6-MWT and negatively correlated with BMI. Its correlation strength has decreased with weight.

A commercialized dietary supplement alleviates joint pain in community adults: a double-blind, placebo-controlled community trial

BACKGROUND

The purpose of this study was to assess the effect of 8-weeks ingestion of a commercialized joint pain dietary supplement (Instaflex™ Joint Support, Direct Digital, Charlotte, NC) compared to placebo on joint pain, stiffness, and function in adults with self-reported joint pain. Instaflex™ is a joint pain supplement containing glucosamine sulfate, methylsufonlylmethane (MSM), white willow bark extract (15% salicin), ginger root concentrate, boswella serrata extract (65% boswellic acid), turmeric root extract, cayenne, and hyaluronic acid.

METHODS

Subjects included 100 men and women, ages 50-75 years, with a history (>3 months) of joint pain, and were randomized to Instaflex™ or placebo (3 colored gel capsules per day for 8 weeks, double-blind administration). Subjects agreed to avoid the use of non-steroidal anti-inflammatory drugs (NSAID) and all other medications and supplements targeted for joint pain. Primary outcome measures were obtained pre- and post-study and included joint pain severity, stiffness, and function (Western Ontario and McMaster Universities [WOMAC]), and secondary outcome measures included health-related quality of life (Short Form 36 or SF-36), systemic inflammation (serum C-reactive protein and 9 plasma cytokines), and physical function (6-minute walk test). Joint pain symptom severity was assessed bi-weekly using a 12-point Likert visual scale (12-VS).

RESULTS

Joint pain severity was significantly reduced in Instaflex™ compared to placebo (8-week WOMAC, ↓37% versus ↓16%, respectively, interaction effect P = 0.025), with group differences using the 12-VS emerging by week 4 of the study (interaction effect, P = 0.0125). Improvements in ability to perform daily activities and stiffness scores in Instaflex™ compared to placebo were most evident for the 74% of subjects reporting knee pain (8-week WOMAC function score, ↓39% versus ↓14%, respectively, interaction effect P = 0.027; stiffness score, ↓30% versus ↓12%, respectively, interaction effect P = 0.081). Patterns of change in SF-36, systemic inflammation biomarkers, and the 6-minute walk test did not differ significantly between groups during the 8-week study

CONCLUSIONS

Results from this randomized, double blind, placebo-controlled community trial support the use of the Instaflex™ dietary supplement in alleviating joint pain severity in middle-aged and older adults, with mitigation of difficulty performing daily activities most apparent in subjects with knee pain.