VIENNA — An intervention consisting of a plant-based diet, exercise, and sleep and stress advice improved pain, stiffness, and physical function in people with knee and/or hip osteoarthritis (OA) and metabolic syndrome, while in patients with rheumatoid arthritis (RA), disease activity improved significantly, and medication use was reduced.
At the annual European Congress of Rheumatology, Carlijn Wagenaar, MD, a PhD candidate in Clinical Immunology and Rheumatology at Amsterdam University Medical Center, presented 2-year extension study results for OA and RA and an overview of the possible biological mechanisms underpinning the plant-based intervention in RA.
“At 2 years, RA patients on the PFJ [Plants for Joints] intervention resulted in a significant improvement in disease activity of RA, and these outcomes were maintained 2 years after program end,” Dr. Wagenaar reported.
“Some initial improvements in body composition and metabolic outcomes were also maintained at the end of the 2-year extension phase, and there was a net decrease in antirheumatic medication use,” she continued.
In the patients with OA, Dr. Wagenaar said the PFJ intervention improved pain, stiffness, and physical function in people with knee and/or hip OA and metabolic syndrome. “In the 2-year extension study, these effects were maintained, and we saw lasting body composition changes and a decrease in cholesterol-lowering medications. There was also high acceptability of the program; the study shows long-term maintenance of clinically relevant effects.”
Significant Improvement in OA Pain, Stiffness, Physical Function
In the OA randomized controlled trial, 64 people with hip and/or knee OA and metabolic syndrome were randomized to the PFJ intervention or usual care (waitlist control group). A total of 62 participants (including those in the control group previously) entered the long-term effectiveness study, and 44 had 2 years of follow-up data for analysis. Twenty participants dropped out, with most being unreachable or too busy.
“The PFJ program is a theoretical and practical program where people learn about and follow a whole food, plant-based diet, and receive advice on sleep and stress management and exercise,” said Dr. Wagenaar.
The program lasted 16 weeks with group sessions of 6-12 participants. The diet was a plant-based version of the Dutch dietary guidelines with a focus on unprocessed food. It was rich in whole grains, legumes, nuts, seeds, fruit, and vegetables, but without calorie restrictions and participants had one-to-one contact with a dietitian. The exercise advice followed the Dutch exercise guidelines, which advise 150 minutes of moderate to intense exercise per week, as well as twice-weekly muscle strength exercises, noted Dr. Wagenaar.
The 2-year follow-up study involved twice-yearly visits and six adherence-promoting webinars per year, as well as monthly newsletters. Researchers also monitored changes in medication intensity (classified as “increased,” “stable,” or “decreased/stopped”) between the start of the PFJ intervention and end of the 2-year extension study, and they were grouped into medications for pain, blood pressure, glucose, and cholesterol.
Participants were encouraged to try to avoid making changes to medication during the intervention phase, but they could do so during the 2-year extension study, said Dr. Wagenaar. In fact, the researchers actively monitored and quantified medication changes between the start of the PFJ intervention and end of the 2-year follow-up period.
Patients in the 16-week trial had an average age of 64 years, 84% were women, and their mean body mass index (BMI) was 33 kg/m2. A total of 73% had knee OA and 78% hip OA, and their mean WOMAC score was 38.2, indicative of moderate to severe OA.
In participants who completed the 2-year extension study, the primary outcome (WOMAC score for mean stiffness and physical function) showed a significant improvement of −9.1 (95% CI, −12.8 to −5.3; P < .0001) compared with the start of the PFJ intervention.
“Looking at individual components of the WOMAC score — pain, stiffness, and physical function — we found these also all significantly improved at the end of the 2-year extension phase,” reported Dr. Wagenaar.
She added that after 2 years, there were significant improvements in weight loss (from 94.9 to 92.1 kg), BMI (from 33.3 to 32 kg/m2), and waist circumference (from 110 to 106.7 cm).
By the end of the trial and at 1 year of the extension study, there were significant improvements in A1c, fasting blood glucose, and low-density lipoprotein cholesterol, but at 2 years, these were no longer significant.
Regarding medications use, Dr. Wagenaar reported that, overall, there was no net change in use of pain, glucose-lowering, or hypertension medications, but 44% of patients using cholesterol-lowering medications were able to lower their dose or stop them.