Older patients with knee osteoarthritis (OA) who underwent lengthy diet and exercise interventions reported less pain and maintained some weight loss years after the program ended, according to a new study published in Arthritis Care & Research.
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“These data imply that clinicians who treat people with knee osteoarthritis have a variety of nonpharmacologic options that preserve clinically important effects 3.5 years after the treatments end,” wrote lead author Stephen P. Messier, PhD, professor and director of the J.B. Snow Biomechanics Laboratory at Wake Forest University, Winston-Salem, N.C.
The study involved patients with overweight or obesity aged 55 years or older who were previously enrolled in the 1.5-year Intensive Diet and Exercise for Arthritis (IDEA) trial.
“You have to remember, this is 3.5 years after the IDEA trial ended,” Dr. Messier said in an interview. “There was no contact with them for that entire time; you’d expect, based on the literature, that they’d revert back to where they were before they entered the trial. And certainly, there was some regression, there was some weight regain, but the important part of the study is that, even after 3.5 years, and even with some weight regain, there were some clinically important effects that lasted.”
Dr. Stephen P. Messier
“What we feel now is that if we can somehow prepare people better for that time after they finish a weight loss intervention, from a psychological standpoint, it will make a real difference,” he added. “We are very good at helping people have the confidence to lose weight. But having the confidence to lose weight is totally different than having confidence to maintain weight loss. If we can give folks an intervention that has a psychological component, hopefully we can increase their confidence to maintain the weight loss that they attained.”
Study details
Of the 184 participants who were contacted for a follow-up visit, 94 consented to participate, 67% of whom were females and 88% of whom were White. A total of 27 participants had completed the diet and exercise intervention, and another 35 completed the diet-only and 32 exercise-only interventions.
In the 3.5-year period between the IDEA trial’s end and follow-up, body weight increased by 5.9 kg in the diet and exercise group (P < .0001) and by 3.1 kg in the diet-only group (P = .0006) but decreased in the exercise-only group by 1.0 kg (P = .25). However, from baseline to 5-year follow-up, all groups saw a reduction in body weight. Mean weight loss was –3.7 kg for the diet and exercise group (P = .0007), –5.8 kg for the diet group (P < .0001), and –2.9 kg for the exercise group (P = .003). Body mass index also decreased in all groups: by –1.2 kg/m2 in the diet and exercise group (P = .001), by –2.0 kg/m2 in the diet group (P < .0001), and by –1.0 kg/m2 in the exercise group (P = .004).
Pain – as measured by the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score – was reduced in all groups across 5-year follow-up: –1.2 (P = .03) for the diet and exercise group, –1.5 (P = .001) for the diet-only group, and –1.6 (P = .0008) for the exercise-only group. WOMAC function also significantly improved relative to baseline by 6.2 (P = .0001) in the diet and exercise group, by 6.1 (P < .0001) in the diet group, and by 3.7 (P = .01) in the exercise-only group.