Table 3.
Effect of weight loss strategies on knee OA symptoms and structural changes in patients with obesity (Evidenced by RCTs over I-year follow-up from 2010).
| Duration (Study) | Interventions | Completed participants (Adherence); BMI | Effect on mean weight loss | Effect on symptoms | Effect on structural changes |
|---|---|---|---|---|---|
| 12 months [88] (Bliddal et al.) | LED program vs control (dietary consultations only) | −10.9 kg (11%) vs −3.6 kg (4%) | Pain reduction in both groups Slightly reduction of WOMAC index in LED group (p-0.066) |
N/A | |
| 12 months [89] (Christensen et al.) | Diary regimen followed by 3 maintenance programs: D: Dietary support; E: knee exercise support; C: control | N = 192 BMI≥30.0 kg/m2 |
D vs E vs C: 11 kg vs 6.2 kg vs 8.2 kg | Significant pain reduction in all groups No significant different between groups. |
N/A |
| 12 months [90] (Henriksen et al.) | An intensive 16 week weight loss program, followed by three treatment group: D, E, control (no-attention group) | N = 196 BMI≥30.0 kg/m2 |
D: gained 1.1 kg E: gained 6.6 kg C: gained 4.8 group |
N/A | No significant changes in cartilage loss, synovitis and effusion between groups. Increased number of medial tibiofemoral BMLs in the E group compared to the D, C groups. |
| 12 months [91] (Jafarzadeh et al.)< | Bariatric surgery/medical weight management and 1-year follow-up. A: large amount weight loss; B: Moderate weight loss | N = 75 BMI ≥35 kg/m2 |
A: with ≥20% weight loss; B: with <20% weight loss |
N/A | No significant changes of BML, synovitis, cartilage damage between groups. |
| 18 months [92] (Messier et al.) | D, E, D + E | N1 = 134 (89%) N2 = 129 (85%) N3 = 136 (89%) 27 ≤ BMI<41 kg/m2 |
E: −1.8 kg D: −8.9 kg D + E: −10.6 kg Significant more weight loss in diet plus exercise and diet groups compared to the exercise only group (p < 0.05) |
Those in diet and exercise group and diet only group had greater pain relief and functional improvement than those in the exercise group | Significantly lower levels of serum IL-6 in the diet group than those in the exercise only group Significantly lower levels of serum IL-6 in the diet and exercise group those in the in the exercise only group |
| 18 months [93] (Hunter et al.) | D; D + E; E | ND: 152; ND+E = 152; NE = 150; BMI = 27–41 kg/m2 |
D: −8.9 kg; D + E: −9.7 kg E: −1.7 kg Significant more weight loss in diet plus exercise and diet groups compared to the exercise only group (p < 0.05) |
N/A | No significant difference between groups in joint space width; No significant difference in MRI cartilage loss between groups. |
| 24 months [94] (Jenkinson et al.) | Dietary plus quadriceps strengthening training Dietary intervention Quadriceps strengthening training Advice leaflet only (control group) |
N1 = 86 (79%) N2 = 104 (85%) N3 = 61 (74%) N4 = 65 (86%) BMI≥28.0 kg/m2 |
Dietary vs non-dietary groups: 2.95 kg weight loss (1.44–4.46; p = 0.000) Quadriceps strengthening training vs non-training groups: 0.43 kg weight loss (−0.82 to 1.68; p = 0.501) Knee strengthening training was not associated with moderate weight loss |
WOMAC pain score Control: 7.04 ± 4.21 Diet only: 6.96 ± 4.33 Strength training only: 5.70 ± 3.96 Diet plus strength training: 6.39 ± 4.15 Significant knee pain reduction and function improvement in the exercise groups, compared to the non-exercises groups The difference in weight loss was not associated with improvement in knee pain or function |
N/A |
| 48 months [95] (Gersing et al.) | Moderate weight loss; Large amount weight loss; Control (stable weight) |
N1 = 180 N2 = 78 N3 = 258 BMI≥25 kg/m2 |
Moderate weight loss: 5–10% weight loss; Large weight loss: >10% weight loss Control: <3% |
Amount of weight loss is associated with less pain, stiffness and disability. | Amount of weight loss is significantly associated with change of cartilage; |
| 48 months [96] (Gersing et al.) | A: large amount weight loss; B: Moderate weight loss; C: stable weight |
NA = 82; NB = 238; NC = 320 BMI≥25 kg/m2 |
NA = with 10% weight loss NB = with 5–10% weight loss NC = stable weight |
N/A | The increase of cartilage Whole-Organ Magnetic Resonance Imaging Score (WORMS) is smaller is A and B, compared to C. Percentage of weight change is significantly associated with increase in cartilage WORMS |
| 96 months [97] (Gersing et al.) | Weight loss (diet and exercise, diet only, exercise only) vs control (stable weight) | N1 = 380 N2 = 380 BMI≥25 kg/m2 |
Weight loss group: weight loss >5% | N/A | Weight loss group slowed cartilage degeneration (significantly slower increase in global cartilage T2 in MRI), compared to control group; Slower cartilage degeneration in diet only and diet plus exercise group, but not in the exercise only group. |
D: Diet only, E: Exercise only, D + E: Diet plus Exercise; WORMS: Whole-Organ Magnetic Resonance Imaging Score;