Obesity is associated with increased pain with knee osteoarthritis and increase progression of knee osteoarthritis while weight loss intervention has been shown to reduce pain and requirement of total knee replacement. In this study, the investigators will assess using diet modification with exercise, and metformin, a common, safe, diabetes mellitus medication that has been in use for 70 years to achieve better weight control to reduce knee pain. This helps the investigators to understand whether the combined treatment can reduce joint pain, reduce body weight and improve symptoms and requirement of total knee replacement.
Men and women age between 40 and 80 years old, with overweight or obesity (body mass index ≥23 kg/m2) according to Hong Kong Centre for Health Protection definition of overweight and obesity.
Knee pain for 6+ months with Visual Analogue Scale (VAS) > 40mm/100mm and
Meet the American College of Rheumatology criteria for knee OA
OA referred for consideration for joint replacement
Severe radiographic knee OA (Kellgren-Lawrence grade 4) or severe knee pain (VAS>80mm/100 mm) that could not tolerate further conservative management;
inflammatory arthritis like rheumatoid arthritis, crystal arthritis, etc.
Preexisting diabetes on antidiabetic drug or drug allergy to metformin.
Recent knee surgery of the same knee