Study under review: Comparative efficacy of different weight loss treatments on knee osteoarthritis: A network meta-analysis
Knee osteoarthritis (OA) is a degenerative joint disease of the knee. It typically results from the wear and tear and increasing loss of articular cartilage (specialized connective tissue that allows bones to glide smoothly against each other) and occurs most commonly in elderly people. OA is a progressive disease that can eventually lead to disability. The intensity of the clinical symptoms usually becomes more severe, frequent, and debilitating over time. Symptoms include knee pain, stiffness, tenderness, and swelling. Damage to the joints cannot be reversed, although symptoms can usually be managed by staying active and maintaining a healthy weight.
Obesity is a primary risk factor for knee OA. In a study of adults 63–94 years old, participants who were clinically defined as having obesity, i.e., a body mass index (BMI) of more than 30 kg/m2, were four times more likely to have knee OA than participants with a BMI of no more than 25 kg/m2. The obesity-induced pathogenesis associated with knee OA includes excessive loads on joints and inflammation. Obesity is associated with inflammation as the excess of macronutrients in adipose tissues stimulates them to release inflammatory mediators. Weight loss in people with overweight or obesity and knee OA can lead to clinically significant improvements in pain and slow down progression of joint structural damage. A study of adults with overweight or obesity and knee OA showed that losing one pound of weight resulted in four fewer pounds of peak compressive force applied to the knees. Weight loss has also been shown to reduce inflammation.
People with overweight or obesity and OA are recommended to lose weight to help improve symptoms and delay progression of the disease. Data from the famous Framingham study showed that a 5 kg reduction in weight resulted in a 50% decreased likelihood of developing symptomatic knee OA. A weight loss of 14% reduced the risk of invasive intervention of OA by 70% after one year and 80% after two years. For the current study, the researchers aimed to identify the most effective weight loss intervention(s) that would lead to a meaningful improvement of knee OA symptoms and clinical conditions in older participants with overweight and obesity.
Knee osteoarthritis is a degenerative joint disease that worsens over time, and people with obesity are more at risk. It is common among elderly people. Losing weight has been associated with improvement in symptoms associated with knee OA. This study examines various weight loss interventions to determine which is the most effective at reducing symptoms and improving clinical conditions associated with knee OA.
Other Articles in Issue #81 (July 2021)
Will cardio hurt your strength gains? It depends on your training level!
This recent meta-analysis suggests that concurrent endurance and resistance training only hurts strength gains for more experienced athletes.
Fit and full: Does exercise reliably affect appetite or calorie intake?
According to this meta-analysis, exercise may boost caloric intake a tad, but not enough to matter.
Deeper Dive: What are the differences between people who lose an expected amount of weight on a restricted diet and people who don't?
This retrospective analysis explored two possible causes of less-than-expected weight loss during caloric restriction: impaired fat oxidation and changes in resting energy expenditure.
Nulls: March-April 2021
A quick run-through of recently published studies that didn't find evidence of an effect.
Safety Spotlight: Omega-3 fatty acid supplementation can increase the risk of atrial fibrillation
Here's a quick rundown of a recent meta-analysis which explored whether EPA and DHA supplementation can increase the risk of atrial fibrillation. Currently, the answer appears to be "yes."
Deeper Dive: How effective are behavioral methods for preventing weight gain?
Interventions that set specific, measurable goals worked better for preventing weight gain than those that allowed more leeway, but weight gain is hard to curb entirely.
Zest with zinc: Fighting fatigue with zinc supplementation for older adults
This trial examined whether zinc supplementation could put the pep back in older adults' step. While the results look promising, the fact that it wasn't blinded or placebo-controlled means more follow-up is needed.