VIENNA -- Two years after completing a 4-month program to improve eating and exercise habits in a randomized controlled trial, the benefits in pain and function for patients with osteoarthritis (OA) were maintained for a full 2 years afterward without any sign of rebound, a researcher said here.
At final follow-up, mean Western Ontario-McMaster Universities Osteoarthritis Index (WOMAC) total scores stood at about 15 points below the original baseline for participants assigned to the intervention -- just about the same degree of improvement seen at month 4, when the program ended, Carlijn Wagenaar, MD, of the Reade Center for Rheumatology and Rehabilitation in Amsterdam, reported at the European Alliance of Associations for Rheumatology (EULAR) annual meeting.
The average WOMAC total score at month 4 in the 32-member intervention group stood at 23.8, versus a baseline mean of 35.8, according to the trial's primary results, which were published . Data she presented at EULAR this week indicated that mean scores had hardly changed 2 years later.
Wagenaar also reported on outcomes in the original control group, who were "waitlisted" for the program after the 4-month randomized phase was over. They, too, showed substantial reductions in total WOMAC scores during the subsequent 2 years, albeit by only about 9 points.
This was something of a mystery, she told ѻý. Her team found nothing in the objective data to explain the discrepant outcomes -- patients' baseline characteristics were similar (as expected in a randomized trial) and there was no indication that the waitlisted patients were less motivated to follow the program. Asked if perhaps the control patients somehow had diminished expectations of benefits from the program after having to wait 4 months to join it, Wagenaar agreed that "this may be the most logical answer."
When the two groups were combined, total WOMAC score averaged 38.2 at baseline, 26.9 after the 4-month program, and 27.0 at the 2-year mark. Improvements occurred in all three WOMAC domains: pain, stiffness, and function.
Called "Plants for Joints," the trial tested a three-part lifestyle improvement program for OA patients. (The same group also conducted a .) It encouraged patients to eat a "whole-food, plant-based" diet and included an exercise component along with sleep and stress management.
Participants had 10 group meetings lasting 2-3 hours and addressing all three components in equal measure; one meeting included a cooking class. (Because the trial overlapped the COVID-19 pandemic, many participants received some or all of the instruction online.) The exercise aspect was geared toward getting patients to perform 150 minutes of moderate-intensity activity per week, plus muscle- and bone-strengthening exercises 2 days per week.
The program did not entirely end at month 4. Participants continued to receive newsletters and webinars to promote adherence to the intervention. Evaluations were conducted periodically to assess OA symptoms.
Out of the original 64 participants, divided equally between the intervention and control groups during the randomized phase, 62 went on to the extension. Attrition was considerable, Wagenaar said, with 44 completing the full 2 years. Lack of effectiveness was not cited specifically as a reason to withdraw, but many said continued participation was too burdensome.
At baseline, mean participant age was 63, and more than 80% were women. About three-quarters had knee OA and roughly the same number had hip OA. Importantly, patients needed to have metabolic syndrome according to standard criteria in addition to an OA diagnosis -- this was because the investigators believed that patients with relatively normal weight and cholesterol would not derive much benefit from such a program. Thus, mean body mass index was about 33 for participants in the trial and most had hypertension and hyperlipidemia.
However, while there were trends toward improvements in most metabolic biomarkers, they did not reach statistical significance except for diastolic blood pressure, in which the mean value fell from 91 mm Hg at baseline to 85 at 2 years (P=0.0001).
Limitations to the study included its necessary unblinded nature and the substantial dropout rate during the extension. Also, Wagenaar did not report the costs associated with the program in her EULAR talk, although the investigators promised a cost-effectiveness evaluation at some point.
Disclosures
The trial was funded by the Reade rheumatology clinic in Amsterdam and several private foundations.
Wagenaar and several co-authors reported equity interest in a private company, Plants for Health. Another author reported a relationship with Horizon Therapeutics.
Primary Source
European Alliance of Associations for Rheumatology
Wagenaar C, et al "Long-term effectiveness of a lifestyle intervention for osteoarthritis: two-year follow-up after the 'Plants for Joints' randomized clinical trial" EULAR 2024; Abstract OP0217.