OBJECTIVE: We wanted to assess the effect of rapid diet-induced weight loss on the function of obese, knee osteoarthritis (OA) patients.
METHODS: Eighty patients with knee OA, 89% women (n=71), were recruited. Mean (SD) body-mass index (BMI) was 35.9 (5.1) kg/m(2) and age 62.6 (11.1) years. Patients were randomized to either a low-energy diet (LED 3.4MJ/day), or a control diet (5MJ/day). The LED group had weekly dietary sessions, whereas the control group was given a booklet describing weight loss practices. Changes in body weight and body composition were examined as independent predictors of changes in knee OA symptoms. Symptoms were monitored by the Western Ontario and McMaster Universities' (WOMAC) OA index.
RESULTS: The LED and control group lost a mean (SE) of 11.1 (0.6)% and 4.3 (0.6)%, respectively, with a mean difference being 6.8% (95% confidence interval (CI): 5.5 to 8.1%; P<0.0001). The decrease in body fat percent was higher in the LED group, 2.2% (1.5 to 3.0%; P<0.0001). The total WOMAC index improved in the LED group (P<0.0001), but not in the control group (P=0.12), mean difference: -219.3mm (-369.2 to -69.4mm; P=0.005). The 'Number Needed to Treat (NNT)' to ensure an improvement in WOMAC>/=50% was 3.4 (2.1 to 8.8) patients. Changes in total WOMAC index were best predicted by the reduction of body fat percent, with a 9.4% (4.8 to 13.9%) improvement in WOMAC for each percent of body fat reduced (P=0.0005).
CONCLUSIONS: In our patients with knee OA, a weight reduction of 10% improved function by 28%. LED might be of advantage to control diet because of the rapidity of weight loss and a more significant loss of body fat.
OBJECTIVE: The Arthritis, Diet, and Activity Promotion Trial (ADAPT) was a randomized, single-blind clinical trial lasting 18 months that was designed to determine whether long-term exercise and dietary weight loss are more effective, either separately or in combination, than usual care in improving physical function, pain, and mobility in older overweight and obese adults with knee osteoarthritis (OA).
METHODS: Three hundred sixteen community-dwelling overweight and obese adults ages 60 years and older, with a body mass index of > or =28 kg/m(2), knee pain, radiographic evidence of knee OA, and self-reported physical disability, were randomized into healthy lifestyle (control), diet only, exercise only, and diet plus exercise groups. The primary outcome was self-reported physical function as measured with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes included weight loss, 6-minute walk distance, stair-climb time, WOMAC pain and stiffness scores, and joint space width.
RESULTS: Of the 316 randomized participants, 252 (80%) completed the study. Adherence was as follows: for healthy lifestyle, 73%; for diet only, 72%; for exercise only, 60%; and for diet plus exercise, 64%. In the diet plus exercise group, significant improvements in self-reported physical function (P < 0.05), 6-minute walk distance (P < 0.05), stair-climb time (P < 0.05), and knee pain (P < 0.05) relative to the healthy lifestyle group were observed. In the exercise group, a significant improvement in the 6-minute walk distance (P < 0.05) was observed. The diet-only group was not significantly different from the healthy lifestyle group for any of the functional or mobility measures. The weight-loss groups lost significantly (P < 0.05) more body weight (for diet, 4.9%; for diet plus exercise, 5.7%) than did the healthy lifestyle group (1.2%). Finally, changes in joint space width were not different between the groups.
CONCLUSION: The combination of modest weight loss plus moderate exercise provides better overall improvements in self-reported measures of function and pain and in performance measures of mobility in older overweight and obese adults with knee OA compared with either intervention alone.
OBJECTIVE: The purposes of this pilot study were to determine if a combined dietary and exercise intervention would result in significant weight loss in older obese adults with knee osteoarthritis, and to compare the effects of exercise plus dietary therapy with exercise alone on gait, strength, knee pain, biomarkers of cartilage degradation, and physical function.
DESIGN: Single-blind, two-arm, randomized clinical trial conducted for 24 weeks.
SETTING: A university health and exercise science center.
PARTICIPANTS: Twenty-four community-dwelling obese older adults aged > or = 60 years, body mass index > or = 28, knee pain, radiographic evidence of knee osteoarthritis, and self-reported physical disability.
INTERVENTION: Randomization into two groups: exercise and diet (E&D) and exercise alone (E). Exercise consisted of a combined weight training and walking program for 1 hour three times per week. The dietary intervention included weekly sessions with a nutritionist utilizing cognitive-behavior modification to change dietary habits to reach a group goal of an average weight loss of 15 lb (6.8 kg) over 6 months.
MEASUREMENTS: All measurements were conducted at baseline and 3 and 6 months, except for synovial fluid analysis, which was obtained only at baseline and 6 months. In addition, weight was measured weekly in the E&D group. Physical disability and knee pain were measured by self-report and physical performance was measured using the 6-minute walk and stair climb tasks. Biomechanical testing included kinetic and kinematic analysis of gait and isokinetic strength testing. Synovial fluid was analyzed for levels of total proteoglycan, keratan sulfate, and interleukin-1 beta.
RESULTS: Twenty-one of the 24 participants completed the study, with one dropout in the E&D group and two in the E group. The E&D group lost a mean of 18.8 lb (8.5 kg) at 6 months compared with 4.0 lb (1.8 kg) in the E group (P = .01). Significant improvements were noted in both groups in self-reported disability and knee pain intensity and frequency as well as in physical performance measures. However, no statistical differences were found between the two groups at 6 months in knee pain scores or self-reported performance measures of physical function. There was no difference in knee strength between the groups, with both groups showing modest improvements from baseline to 6 months. At 6 months, the E&D group had a significantly greater loading rate (P = .03) and maximum braking force (P = .01) during gait. There were no significant between-group differences in the other biomechanical measures. Synovial fluid samples were obtainable at both baseline and 6 months in eight participants (four per group). The level of keratan sulfate decreased similarly in both groups from an average baseline of 96.8 +/- 37.1 to 71.5 +/- 23 ng/microg total proteoglycan. The level of IL-1 decreased from 25.3 +/- 9.8 at baseline to 8.3 +/- 6.1 pg/mL. The decrease in IL-1 correlated with the change in pain frequency (r = -0.77, P = .043).
CONCLUSIONS: Weight loss can be achieved and sustained over a 6-month period in a cohort of older obese persons with osteoarthritis of the knee through a dietary and exercise intervention. Both exercise and combined weight loss and exercise regimens lead to improvements in pain, disability, and performance. Moreover, the trends in the biomechanical data suggest that exercise combined with diet may have an additional benefit in improved gait compared with exercise alone. A larger study is indicated to determine if weight loss provides additional benefits to exercise alone in this patient population.
OBJECTIVE: To determine the variable most closely related to symptomatic relief of osteoarthritis (OA) of the knee in response to a weight control program.
METHODS: Twenty-two patients diagnosed with knee OA whose body mass index (BMI) was more than 26.4 were treated with a low calorie diet, an appetite suppressant, and nonsteroidal antiinflammatory drugs for 6 weeks. The patients were instructed to follow a walking program. We analyzed BMI, percent body fat, the average number of steps per day by pedometer, and the metabolic correlates of obesity (blood pressure, fasting blood serum glucose, total cholesterol, triglycerides, and serum insulin) at the beginning and end of therapy. The correlation between the change in each variable and the remission score (delta score) using the Severity Index of Lequesne, et al was evaluated.
RESULTS: Delta score of knee OA was more strongly associated with reduction in percent body fat (p= 0.0013, r=0.62) than other variables. Significant correlation was also observed between the number of steps per day and delta score (p=0.0031, r=-0.58). No other variable, including weight loss, was significantly correlated with delta score. There was a significant correlation between delta percent body fat and the number of steps per day (p=0.012, r=-0.62).
CONCLUSION: In a weight control program, decreasing body fat and increasing physical activity are more important than body weight loss or decreasing other indices of obesity in producing symptomatic relief of knee OA, although there is not necessarily a cause and effect relationship between body fat and OA score.
We wanted to assess the effect of rapid diet-induced weight loss on the function of obese, knee osteoarthritis (OA) patients.
METHODS:
Eighty patients with knee OA, 89% women (n=71), were recruited. Mean (SD) body-mass index (BMI) was 35.9 (5.1) kg/m(2) and age 62.6 (11.1) years. Patients were randomized to either a low-energy diet (LED 3.4MJ/day), or a control diet (5MJ/day). The LED group had weekly dietary sessions, whereas the control group was given a booklet describing weight loss practices. Changes in body weight and body composition were examined as independent predictors of changes in knee OA symptoms. Symptoms were monitored by the Western Ontario and McMaster Universities' (WOMAC) OA index.
RESULTS:
The LED and control group lost a mean (SE) of 11.1 (0.6)% and 4.3 (0.6)%, respectively, with a mean difference being 6.8% (95% confidence interval (CI): 5.5 to 8.1%; P<0.0001). The decrease in body fat percent was higher in the LED group, 2.2% (1.5 to 3.0%; P<0.0001). The total WOMAC index improved in the LED group (P<0.0001), but not in the control group (P=0.12), mean difference: -219.3mm (-369.2 to -69.4mm; P=0.005). The 'Number Needed to Treat (NNT)' to ensure an improvement in WOMAC>/=50% was 3.4 (2.1 to 8.8) patients. Changes in total WOMAC index were best predicted by the reduction of body fat percent, with a 9.4% (4.8 to 13.9%) improvement in WOMAC for each percent of body fat reduced (P=0.0005).
CONCLUSIONS:
In our patients with knee OA, a weight reduction of 10% improved function by 28%. LED might be of advantage to control diet because of the rapidity of weight loss and a more significant loss of body fat.
