Blog | Thursday, September 26, 2013

QD: News Every Day--10% weight loss combined with exercise helped knee pain

A 10% weight loss and exercise led to less knee pain and better function after 18 months than diet or exercise alone, according to a study.

The randomized trial included 454 overweight and obese community-dwelling adults ages 55 years or older with a body mass index of 27 to 41 with pain and radiographic knee osteoarthritis from July 2006 to April 2011.

The interventions consisted of intensive diet-induced weight loss plus exercise, intensive diet-induced weight loss, or exercise. The diet and exercise interventions were center-based with options for the exercise groups to transition to a home-based program.

Results appeared in the September 25 issue of the Journal of the American Medical Association.

Mean weight loss for diet and exercise participants was 10.6 kg (11.4%); for the diet group, 8.9 kg (9.5%); and for the exercise group, 1.8 kg (2.0%), the authors wrote. After 18 months, knee compressive forces were lower in diet participants (mean, 2,487 N; 95% CI, 2,393 to 2,581) compared with exercise participants (2,687 N; 95% CI, 2,590 to 2,784, pairwise difference [Δ]exercise vs diet=200 N; 95% CI, 55 to 345; P=0.007).

Concentrations of interleukin 6 were lower in the diet and exercise patients (2.7 pg/mL; 95% CI, 2.5 to 3.0) and diet participants (2.7 pg/mL; 95% CI, 2.4 to 3.0) compared with exercise participants (3.1 pg/mL; 95% CI, 2.9 to 3.4; Δ exercise vs diet and exercise=0.39 pg/mL; 95% CI, −0.03 to 0.81; P=0.007; Δ exercise vs diet=0.43 pg/mL; 95% CI, 0.01 to 0.85, P=0.006).

The diet and exercise group had less pain (3.6; 95% CI, 3.2 to 4.1) and better function (14.1; 95% CI, 12.6 to 15.6) than the diet group (4.8; 95% CI, 4.3 to 5.2) and exercise group (4.7; 95% CI, 4.2 to 5.1, Δ exercise vs diet and exercise=1.02; 95% CI, 0.33 to 1.71; Ppain=.004; 18.4; 95% CI, 16.9 to 19.9; Δ exercise vs diet and exercise, 4.29; 95% CI, 2.07 to 6.50; Pfunction<0.001).

The authors wrote, “… intensive weight loss may have both anti-inflammatory and biomechanical benefits; when combining weight loss with exercise, patients can safely achieve a mean long-term weight loss of more than 10%, with an associated improvement in symptoms greater than with either intervention alone.”

A 2005 study published in Arthritis & Rheumatism assessed the joint load for 142 overweight and obese older adults and found that each pound lost translated to a fourfold lighter load on the adults’ knee joints, ACP Internist reported in its May 2013 issue.

The article stated that all too frequently, doctors overlook the painful joint disease at a stage when preventive measures such as exercise and weight loss could be most beneficial. It also examines the impact of updated guidelines from the American College of Rheumatology that highlight the value of trying exercise and weight loss first, whenever feasible.