Lifestyle intervention trial in early stage knee osteoarthritis

Obesity is an important risk factor for knee osteoarthritis (OA). Hence, weight loss is recommended in many international guidelines for the treatment of overweight or obese patients with knee OA. Especially in the early stage of the disease, weight loss is important to prevent further clinical and structural progression. Since 2019 in the Netherlands, general practitioners (GP) can refer eligible patients to a combined lifestyle intervention (GLI) focused on exercise, nutrition, and behavioral change. However, GPs scarcely refer patients with knee OA because of the unfamiliarity with the intervention, unawareness of the target group with OA, and lack of scientific evidence on the (cost-)effectiveness. Also, for successful implementation of the lifestyle program insight into perceived facilitating factors and barriers, as in individual and environmental determinants are required. The aim of this study is to determine the (cost-)effectiveness of a combined lifestyle intervention in early stage knee OA patients in primary care.

We hypothesize that a combined lifestyle intervention added to usual care will result in a 5 kg or 5% weight reduction resulting in a greater reduction in knee pain, an increase in the quality of life, prevent structural progression, and is cost-effective from a societal perspective compared to usual care only.

All participants will be sent 3-monthly questionnaires and invited for a physical examination, blood sampling, and MRI assessment at baseline and after 24-month follow-up.

Multidisciplinary lifestyle interventions with a focus on diet and exercise show large potential for the treatment of knee OA. The 2-year lifestyle intervention (Beweegkuur-GLI) program is based on the combination of diet, increased physical activity (PA), and behavior modification. The general aim of the Beweegkuur-GLI is to lose at least 5% of body weight during the first year and to maintain this weight loss in the second year. Participants will be randomly allocated to either the combined lifestyle intervention program in combination with usual care or usual care only. Patients in the intervention group will be referred to a certified lifestyle coach to participate in the Beweegkuur-GLI. During the intervention patients will be supported by a team of health care professionals, including the lifestyle coach, a physical therapist, and a dietician. Patients in the control group will receive usual care by their GP following the NHG guideline non-traumatic knee complaints.