Lifestyle is associated with the development and progression of rheumatoid arthritis (RA) and osteoarthritis (OA), two of the most prevalent rheumatic diseases in Western societies. Medical costs for RA and OA together consume 2% of total healthcare costs in The Netherlands. A strong rise in prevalence - in particular for OA - is foreseen. RA and OA show overlapping prevalence with other chronic diseases with an inflammatory component, such as diabetes and coronary heart disease. The low-grade inflammation present in patients with these diseases strongly associates with the metabolic syndrome (MetS), which is especially frequent in patients with OA.
Separate non-pharmacological interventions aimed at reducing inflammation, such as a whole food plant-based diet (WFPD), exercise and stress management, were shown to be well-accepted and effective for both RA and OA but were not yet tested in a trial that combined those interventions in a multidisciplinary program. A program based on a WFPD, exercise and stress management, however, has been tested in coronary heart disease and was shown to be effective over 5 years.
To test the (cost-)effectiveness of a multidisciplinary lifestyle program (WFPD, exercise and stress management) in rheumatic diseases, we propose to perform three randomized controlled trials (RCT), comparing the program with usual care in (1) 80 RA patients with low to moderate disease activity; (2) 16 anti-citrullinated protein antibody (ACPA) positive arthralgia patients (at increased risk for RA, a pilot study) and (3) 80 patients with OA of hip and/or knee in combination with MetS. This lifestyle program (duration 4 months) includes an individual intake, 10 group meetings and online support, applied in mixed groups as the intervention is the same for RA, arthralgia and OA patients. After completion of the 4-month RCT, participants in the control group enter the program. All participants are followed for another 2 years after completing the 4-month lifestyle program in a less intensive program (four group meetings in the first year, two in the second) with online support provided by Vital10.
While medication is kept stable for patients in the RCT phase, a standardized schedule is used to taper medication in patients who are in remission during the extension period, thus revealing the potential medication-lowering capacity of the lifestyle program. The planned numbers of patients are based on power calculations using earlier studies of diet (for RA) and/or exercise (for OA).
Primary outcome measures for the RCT are the difference in change between baseline and 4 months between the intervention and control groups for: the disease activity score of 28 joints (DAS28 measured by an observer blinded to treatment, RA), the RA-risk score (arthralgia) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) for pain, stiffness and function (OA). Main outcome in the extension study is the retention of values attained at the end of the RCT. Secondary outcome measures include changes in physical, mental and social health using the Patient Reported Outcomes Measurement Information System (PROMIS®), inflammation, cortisol, body composition and metabolism (among others lipids, DEXA and heart rate variability), physical performance and pathogenic markers such as the in-depth autoantibody profile focusing on mucosa-associated auto-immunity in RA and arthralgia. Changes in oral and intestinal microbiome (including metabolites) will be studied to examine possible pathways, focusing on changes in bacterial diversity and in RA-related species. In OA patients MRI will be used to study changes in visceral and liver fat as well as intramuscular fat, including spectroscopy to verify changes in fatty acid composition.
Adherence will be related to outcome, and factors determining adherence will be examined by means of evaluation questionnaires and focus groups. In addition, participant (patients and health care professionals) experiences and evaluations of the program will be examined using structured interviews for patients and questionnaires and focus groups for health care professionals. The potential for implementation of the lifestyle program will be explored by means of qualitative research methods examining the barriers and facilitators of implementation of this intervention in all relevant stakeholders, including patients, health care professionals, care managers of health care institutions, and health care insurance companies, resulting in an implementation plan.
Novel elements of our study are: the multidisciplinary character of the intervention, which is first in kind in rheumatology, the use of eHealth applications to support patients and to measure (part of the) outcomes, and the investigation of the underlying physiology by performing MRI (spectroscopy) of liver and muscle, and microbiota sampling over time.