Table 2

Descriptive data for the included trials

Title/author/ yearAimEligibility criteriaMethodsComparatorOutcome measuresAssessment pointsResult
Exercise and weight loss in obese older adults with knee OA: a preliminary study.
Messier et al
1) To determine if a combined dietary and exercise intervention results in significant weight loss in older obese adults with knee OA
2) To compare the effects of exercise plus dietary therapy with exercise alone on gait, strength, knee pain, biomarkers of cartilage degradation and physical function
Aged ≥60 years
BMI ≥28 kg/m²
Knee pain, radiographic evidence of knee OA
Self-reported physical disability
Serious medical condition affecting safety
Planned change of abode or admission to a nursing home within next 6 months. Unable to walk at least 420 ft in 6 min without assistive device
Unable to walk on treadmill without assistive device
Current participation in an exercise programme or other study
Unable to participate or complete the study protocol
n=24 community-dwelling obese older adults
Goal of weight loss
15 lb (6.8 kg)
Period of intervention
6 months
University Health and Exercise Science Centre, USA
Combined weight training and walking programme for 1 hour three times per week
Dietary intervention
Nutrition class 1 hour/week to instruct participants how to modify caloric intake using cognitive behaviour modification to change dietary habits to reach a group goal of an average weight loss then three group and one individual session held per month
Exercise group (control)Body weight, self-report questionnaire, physical performance and gait analysis
Synovial fluid biomarkers (total proteoglycan (PG), keratan sulfate (KS) and interleukin-1β (IL-1β))
Frequency and intensity of knee pain (Likert scale)
Disability by self-reported physical function using the Fitness Arthritis and Seniors Trial
6 min walk test and timed stair climbing to measure physical performance
Kinetics and kinematics analysis of gait using motion analysis and force plate recorded at 3 and 6 months
Data recorded at baseline, 3 and 6 monthsBody weight reduced significantly in diet plus exercise group compared with exercise group with (p=0.007)
Within group differences:
The combined intervention group lost a mean of 18.8 lb (8.5 kg) at 6 months compared with 4.0 lb (1.8 kg) in the exercise group (p=0.01)
No statistical differences were found between groups in self-reported performance measures of physical function and knee strength
Statistically significant improvement in both groups in self-reported disability and knee pain intensity and frequency and physical performance
At 6 months, the combined intervention group had a significantly greater loading rate (p=0.03) and maximum braking force (p=0.01) during gait
No statistical differences were found between groups in knee pain scores
Concentration level of KS decreased similarly in both groups The decrease in IL-1 correlated with joint pain (r=−0.77, p=0.043)
Exercise and dietary weight loss in overweight and obese
older adults with knee OA
Messier et al
1) 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 OAInclusion
Aged ≥60 years
BMI ≥28 kg/m²
Knee pain, radiographic evidence of knee OA
Self-reported physical disability
Serious medical problem
Mini-Mental State Examination score of <24.3
Inability to finish 18 months study
Inability to walk without assistive device
Participation in another study
6-Reported alcohol consumption >14 drinks per week
ST segment depression of at least 2 mm at an exercise level of 4 metabolic equivalent tasks (METS) or less, hypotension or complex arrhythmia during exercise
Inability to complete the study protocol due to frailty, illness or other reason
n=316 community-dwelling obese older adults
Goal of weight loss
5% of the total body weight over 18 months
Period of intervention
18 months
The Claude D Pepper Older Americans Independence Centre, Wake Forest University, USA
1 hour 3 days/week consisted of an aerobic phase a resistance-training phase, a second aerobic phase and a cool-down phase
Dietary intervention
Based on principles from the group dynamics literature and social cognitive theory; divided into three phases: intensive (months 1–4), transition (months 5–6) and maintenance (months 7–18)
Dietary weight loss plus exercise Combined the exercise and dietary weight loss programmes
Usual care healthy lifestyle (control)
Exercise group
Dietary weight loss group
Primary outcome
Self-reported physical function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
Secondary outcomes Weight loss, 6 min walk distance, stair-climb time, WOMAC pain and stiffness scores and joint space width
Data recorded at baseline, 6 and 18 monthsSignificant body weight loss in diet groups (p<0.05). Diet plus exercise and diet group lost an average of 5.7% and 4.9% of their body weight, respectively with 1.2% for the healthy lifestyle group
Significant improvements in self- reported physical function (p<0.05), 6 min walk distance (p<0.05), stair-climb time (p<0.05) and knee pain (p<0.05) in the diet plus exercise group compared with the healthy lifestyle group
Significant improvement in the 6 min walk distance in the exercise group (p<0.05) The diet-only group was not significantly different from the healthy lifestyle group with respect to any of the functional or mobility measures
Changes in joint space width were not significantly different between groups
Effects of intensive diet and exercise on knee joint loads,
inflammation and clinical outcomes among overweight and obese adults with knee OA is
the Intensive Diet and Exercise for Arthritis randomised clinical trial
Messier et al (2013)3
To determine whether a 10% reduction in body weight induced by diet, with or without exercise, would improve mechanistic and clinical outcomes more than exercise aloneInclusion
Aged ≥55 years
14 grade 2 or 3 (mild or moderate) radiographic tibiofemoral OA or tibiofemoral plus patellofemoral OA of one or both knees, pain on most days due to knee OA.
BMI from 27 to 41
Sedentary lifestyle (<30 min per week of formal exercise for the past 6 months)
Participants usual medications could be maintained or adjusted depending on physician advice
Significant comorbid disease that would pose a safety threat or impair ability to participate, previous acute knee injury, patellofemoral OA in the absence of tibiofemoral OA
Ability and willingness to modify dietary or exercise behaviours
Excess alcohol use
Inability to finish 18-month study or unlikely to be compliant
Conditions that prohibit knee MRI
Significant cognitive impairment or depression
Goal of weight loss
10%–15% of the total body weight
Period of intervention
18 months
Wake Forest University and Wake Forest School of Medicine, USA
Intensive weight loss intervention
The diet included up to two meal-replacement shakes per day For the third meal, participants followed a weekly menu plan and recipes that were 500–750 kcal, low in fat and high in vegetables. Daily caloric intake was adjusted according to the rate of weight change between intervention visits. The initial diet plan provided an energy-intake deficit of 800– 1000 kcal/day as predicted by energy expenditure (estimated resting metabolism×1.2 activity factor)
The exercise intervention
It was conducted for 1 hour on 3 days/week for 18 months Participation was centre-based for the first 6 months After 6-month follow-up testing and a 2-week transition phase, participants could remain in the facility programme, opt for a home-based programme or combine that two. The programme consisted of aerobic walking (15 min), strength training (20 min), a second aerobic phase (15 min) and cool-down (10 min)
Exercise group (control group)
Dietary weight loss group
Primary outcomes knee joint compressive force and plasma IL-6 concentration
Secondary clinical outcomes
Self-reported pain (range 0–20), function (range 0–68), mobility and health-related quality of life
Participants were assessed at baseline, 6 and 18 monthsBody weight was reduced significantly in both diet groups (diet and diet plus exercise) more than exercise group (p<0.001)
Within group differences:
the diet plus exercise group lost about 10.6 kg (11.4%), the diet group lost 8.9 kg (9.5%) and 1.8 kg (2.0%) of base line body weight
No significant difference in walking speed and 6 min walk test between groups
Significant pain reduction was observed in the diet plus exercise group at 18 months compared with exercise group (mean score, 1.02; 95% CI 0.33 to 1.71; p=0.004)
The difference in the SF-36 (36-item short form survey) physical subscale was 2.81 units in diet plus exercise relative to exercise group (95% CI −4.76 to −0.86; p=0.005)
No significant difference in the mental subscale between groups
  • QA,osteoarthritis.