Objective
To determine the dose response effect of weight loss on clinical and mechanistic outcomes in overweight and obese adults with knee osteoarthritis (OA).
Methods
This is a secondary analysis ...of the diet‐induced weight loss only (D) and diet‐induced weight loss plus exercise (D + E) groups in the Intensive Diet and Exercise for Arthritis randomized controlled clinical trial. The 240 participants were overweight and obese older community‐dwelling adults with pain and radiographic knee OA. Participants were assigned to 1 of 4 groups according to weight loss achieved over an 18‐month period: <5% (<5% group), 5–10% (≥5% group), 10–20% (≥10% group), and >20% (≥20% group).
Results
There were significant dose responses to weight loss for pain (P = 0.01), function (P = 0.0006), 6‐minute walk distance (P < 0.0001), physical (P = 0.0004) and mental (P = 0.03) health‐related quality of life (HRQoL), knee joint compressive force (P < 0.0001), and interleukin‐6 (P = 0.002). Greater weight loss resulted in superior clinical and mechanstic outcomes, with the highest weight loss group (≥20% group) distinguishing itself on all measures compared with the <5% and ≥5% groups; the ≥20% group had 25% less pain and better function compared with the ≥10% group and significantly (P = 0.006) better physical HRQoL.
Conclusion
Long‐term weight loss of 10–19.9% of baseline body weight has substantial clinical and mechanistic benefits compared with less weight loss. The value of an additional 10% weight loss includes significantly improved physical HRQoL and a clinically important reduction of pain and improvement in function.
IMPORTANCE: Some weight loss and exercise programs that have been successful in academic center–based trials have not been evaluated in community settings. OBJECTIVE: To determine whether adaptation ...of a diet and exercise intervention to community settings resulted in a statistically significant reduction in pain, compared with an attention control group, at 18-month follow-up. DESIGN, SETTING, AND PARTICIPANTS: Assessor-blinded randomized clinical trial conducted in community settings in urban and rural counties in North Carolina. Patients were men and women aged 50 years or older with knee osteoarthritis and overweight or obesity (body mass index ≥27). Enrollment (N = 823) occurred between May 2016 and August 2019, with follow-up ending in April 2021. INTERVENTIONS: Patients were randomly assigned to either a diet and exercise intervention (n = 414) or an attention control (n = 409) group for 18 months. MAIN OUTCOMES AND MEASURES: The primary outcome was the between-group difference in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain score (range, 0 none to 20 severe; minimum clinically important difference, 1.6) over 18 months, tested using a repeated-measures mixed linear model with adjustments for covariates. There were 7 secondary outcomes including body weight. RESULTS: Among the 823 randomized patients (mean age, 64.6 years; 637 77% women), 658 (80%) completed the trial. At 18-month follow-up, the adjusted mean WOMAC pain score was 5.0 in the diet and exercise group (n = 329) compared with 5.5 in the attention control group (n = 316) (adjusted difference, −0.6; 95% CI, −1.0 to −0.1; P = .02). Of 7 secondary outcomes, 5 were significantly better in the intervention group compared with control. The mean change in unadjusted 18-month body weight for patients with available data was −7.7 kg (8%) in the diet and exercise group (n = 289) and −1.7 kg (2%) in the attention control group (n = 273) (mean difference, −6.0 kg; 95% CI, −7.3 kg to −4.7 kg). There were 169 serious adverse events; none were definitely related to the study. There were 729 adverse events; 32 (4%) were definitely related to the study, including 10 body injuries (9 in diet and exercise; 1 in attention control), 7 muscle strains (6 in diet and exercise; 1 in attention control), and 6 trip/fall events (all 6 in diet and exercise). CONCLUSIONS AND RELEVANCE: Among patients with knee osteoarthritis and overweight or obesity, diet and exercise compared with an attention control led to a statistically significant but small difference in knee pain over 18 months. The magnitude of the difference in pain between groups is of uncertain clinical importance. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02577549
The mechanisms by which obesity affects osteoarthritis (OA) are of great concern to osteoarthritis researchers and clinicians who manage this disease. Inflammation and joint loads are pathways ...commonly believed to cause or to exacerbate the disease process. This article reviews the physiologic and mechanical consequences of obesity in older adults who have knee OA, the effects of long-term exercise and weight-loss interventions, the most effective nonpharmacologic treatments for obesity, and the usefulness and feasibility of translating these results to clinical practice.
The Relationships between Age and Running Biomechanics DEVITA, PAUL; FELLIN, REBECCA E; SEAY, JOSEPH F ...
Medicine and science in sports and exercise,
2016-January, 2016-Jan, 2016-01-00, 20160101, Letnik:
48, Številka:
1
Journal Article
Recenzirano
Running has high injury rates, especially among older runners. Most aging literature compares young with old runners without accounting for the progression of biomechanics throughout the lifespan. We ...used age as a continuous variable to investigate the continuum of age-related gait adaptations in running along with determining the chronology and rate of these adaptations.
PURPOSEThis study aimed to identify the relations among age and selected running biomechanics throughout the range of 18–60 yr.
METHODSExperienced (n = 110) healthy runners (male, 54%) provided informed consent and ran at their training pace while motion and force data were captured. Kinematics, ground reaction forces (GRF), and lower limb joint torques and powers were correlated with age using Pearson product–moment correlations and linear regression.
RESULTSRunning velocity was inversely related to age (r = −0.27, P = 0.005) because of decreased stride length (r = −0.25, P = 0.008) but not rate. Peak vertical GRF (r = −0.23, P = 0.016) and peak horizontal propulsive GRF decreased with age (r = −0.38, P < 0.0001). Peak ankle torque (r = −0.32, P = 0.0007) and peak negative (r = 0.34, P = 0.0003) and positive (r = −0.37, P < 0.0001) ankle power decreased with age. Age-based regression equations and per-year reductions in all variables significantly related to age are reported.
CONCLUSIONSData support previous work showing lower GRF, stride length, and velocity in old runners. Results are novel in showing the rate of decline in running biomechanics on a per-year basis and that mechanical reductions at the ankle but not at the hip or knee were correlated with age, confirming a previous observation of biomechanical plasticity with age showing reduced ankle but not hip function in gait.
Habitual (non-exercise) physical activity (PA) declines with age, and aging-related increases in inflammation and fatigue may be important contributors to variability in PA.
This study examined the ...association of objectively-measured PA (accelerometry over 7 days) with inflammation (plasma interleukin-6 and C-reactive protein) and with self-reported fatigue (SF-36 Vitality) at baseline and 18 months after a diet-induced weight loss, exercise, or diet-induced weight loss plus exercise intervention in 167 overweight/obese, middle-aged, and older adults.
At baseline, individuals with higher plasma interleukin-6, as well as those who reported feeling less energetic (more fatigued), took less steps per day and had lower PA energy expenditure and minutes of light and moderate-vigorous PA (p < .05 for all). At the 18-month follow-up, inflammation was lower in both weight loss groups, fatigue was reduced in all three groups with larger decreases in the combined group, and mean levels of habitual PA were not changed in any group. In longitudinal analyses with all groups combined, we found that participants reporting larger increases in vitality (eg, declines in fatigue) had greater increases in PA (p < .05 for all). Also, changes in steps/d and physical activity energy expenditure were indirectly associated with changes in interleukin-6 (β SEM for steps/d = -565 253; β SEM for physical activity energy expenditure = -22.4 10.17; p < .05).
Levels of habitual PA are lower in middle-aged and older adults with higher levels of chronic inflammation and greater self-reported fatigue. In addition, participants who experienced greater declines in inflammation during the interventions had greater declines in fatigue and larger increases in PA.
Persistent, low-grade inflammation is an independent predictor of several chronic diseases and all-cause mortality.
The intention of this study was to determine the independent and combined effects ...of diet-induced weight loss and exercise on markers of chronic inflammation.
Three hundred sixteen community-dwelling, older (> or = 60 y), overweight or obese body mass index (in kg/m2) > or = 28, sedentary men and women with radiographic evidence of knee osteoarthritis were randomly assigned to four 18-mo treatments: healthy lifestyle control, diet-induced weight loss, exercise, and diet plus exercise. The exercise intervention consisted of combined weight training and walking for 1 h 3 times/wk. The weight-loss intervention consisted of a weekly session with a registered dietitian to provide education and support for lowering energy intake.
The diet-induced weight-loss intervention resulted in significantly greater reductions in concentrations of C-reactive protein (P = 0.01), interleukin 6 (P = 0.009), and soluble tumor necrosis factor alpha receptor 1 (P = 0.007) than did no weight-loss treatment. Changes in soluble tumor necrosis factor alpha receptor 1 but not in C-reactive protein or interleukin 6 correlated with changes in body weight. Exercise training did not have a significant effect on these inflammatory biomarkers, and there was no significant interaction between weight loss and exercise training.
These findings provide evidence from a randomized controlled trial that a dietary intervention designed to elicit weight loss reduces overall inflammation in older, obese persons. Additional studies are needed to assess the effects of different modes and intensities of exercise on inflammation.
Obesity and knee osteoarthritis adversely affect activities of daily living in older adults. Together, the complexities of their interaction on mobility, including stair negotiation, are unresolved. ...The purpose of this study was to determine the relationship between obesity, pain, and stair negotiation in older adults with knee osteoarthritis.
Older adults with symptomatic knee osteoarthritis and overweight or obesity participated in the study (n = 28; age range = 57.0–78.0 yrs.; body mass index range = 26.6–42.8 kg•m−2). The Western Ontario and McMaster Universities Osteoarthritis Index pain subscale was used to measure knee pain. Measurements included a three-dimensional biomechanical analysis during descent on a set of force plate-instrumented stairs and a timed stair descent test. Pearson's r was used to determine associations between body mass index and pain, stair descent weight-acceptance phase vertical ground reaction force (vGRF) variables and lower extremity joint kinematics and kinetics, and timed stair descent performance.
Significant correlations existed between body mass index and pain (r = 0.41; p = 0.03), peak vGRF (r = 0.39; p = 0.04), vertical impulse (r = 0.49; p = 0.008), and peak ankle plantar flexor moments (r = 0.50; p = 0.007) in older adults with knee osteoarthritis.
Greater obesity in older adults with knee osteoarthritis was associated with greater knee pain and higher ankle joint loads during stair descent. These results support the recommendations of osteoarthritis treatment guidelines for weight-loss as a first-line of treatment for older adults with obesity and knee osteoarthritis.
•Obesity predicts pain in older adults with knee osteoarthritis.•Obesity predicts stair descent forces in older adults with knee osteoarthritis.•Obesity predicts stair descent ankle-joint load in people with knee osteoarthritis.
The aim of this systematic review was to identify principles of exercise interventions associated with improved physical function, weight management or musculoskeletal pain relief among young and ...middle-aged adults with obesity and propose an evidence-based exercise prescription that could assist in secondary prevention of osteoarthritis.
A structured electronic review was conducted using MEDLINE, PubMed, and SPORTDiscus. The search string included 1) "obes*" AND "exercise" AND "interven*" AND "musculoskeletal pain OR knee pain OR hip pain". Studies 1) were randomized controlled trials of humans, with a non-exercise control, 2) included participants aged 18-50 years, and 3) had outcomes that included physical function, musculoskeletal pain, and/or body composition. Studies were excluded if participants had peri-menopausal status, cancer, or obesity-related co-morbidities. A recommended exercise prescription was developed based on common principles used in the included exercise interventions with greatest change in function or pain.
Seven studies were included. Similarities in exercise intensity (40-80% VO
), frequency (three times per week), duration (30-60 min), and exercise mode (treadmill, cross-trainer, stationary bike, aquatic exercise) were observed in exercise interventions that resulted in improved physical function and/or pain, compared to non-exercise control groups.
Common principles in exercise prescription for improvements in weight management, physical function and pain relief among otherwise healthy people with obesity. Exercise prescription including moderate intensity exercise for 30-60 min, three times per week can be considered an effective treatment for weight management and obesity-related musculoskeletal symptoms. Exercise should be recommended to at-risk individuals as part of secondary prevention of osteoarthritis.
Osteoarthritis (OA) is a common chronic disease and there is a need for treatments that can be provided for the course of the disease with minimal adverse side effects. Exercise is a safe ...intervention in patients with knee OA with few contraindications or adverse events. Obesity is the most modifiable risk factor for knee OA. The mechanisms by which obesity affects OA are of great concern to researchers and clinicians who manage this disease. This article reviews the physiologic and mechanical consequences of obesity and exercise on older adults with knee OA, the effects of long-term weight loss and exercise interventions, and the utility and feasibility of translating these results to clinical practice.
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