When it comes to easing the symptoms of kneeosteoarthritis (OA), the more weight loss, the better, according to researchers at Wake Forest University in Winston-Salem, North Carolina. In a study published recently online inArthritis Care & Research,Stephen Messier, PhD, and colleagues report that overweight and obese adults aged 55 and older with knee OA who lost 20 percent or more of their body weight saw far greater improvements in pain, function, quality of life, inflammation and knee joint stress than those who lost less.
In an earlier trial, the same researchers found that a weight loss of 10 percent – the amount the National Institutes of Health recommends for overweight and obese adults – improved mobility and decreased pain by 50 percent over an 18-month period. In their latest findings, they say doubling weight loss can cut pain and improve function by another 25 percent.
Diet Plus Exercise for Best Results
Patients in the earlier trial used one of three weight loss programs: diet alone, exercise alone or diet plus exercise. Diet plus exercise resulted in the greatestaverage weight loss, followed by diet alone; on average, participants in the exercise alone group barely lost any weight. The diet was based on an intake of approximately 1,100 calories a day for women and 1,200 for men. At the start of the study, calories initially came from two meal replacement shakes and one plant-based, 500- to 750-calorie meal.Exercisewas 15 minutes of aerobic walking (fast enough to get the heart rate up), 20 minutes of strength training and another 15 minutes of aerobic exercise followed by a cool down. Participants worked out for an hour at least three times a week. They also received nutrition education and cognitive behavioral therapy as well as weekly or biweekly weigh-ins.
在目前的研究中，研究人员分析了399名早期试验参与者中的240人的亚组数据，这些人包括饮食加运动组和只饮食组。在这项分析中，根据患者的体重减轻程度，他们被分为四类:小于5%(这被认为是不显著的)，在5%到9.9%之间，在10%到19.9%之间，或超过20%。(例如，对于一个200磅的人来说，减5%的体重等于10磅，减10%等于20磅，减20%等于40磅。)
Twice as Nice
By all measures, including pain reduction, the people who dropped more than 10 percent of their body weight fared better than those who lost less. But the greatest improvements were in the group that lost 20 percent or more. At 18 months, for example, those participants could walk 10 percent farther in 6 minutes than those who lost less than 5 percent (559 meters vs 508 meters).
“The importance of our study is that a weight loss of 20 percent or greater – double the previous standard – results in better clinical outcomes and is achievable without [drugs or surgery],” Messier says.
他承认，减掉任何数量的体重——并保持下去——都是很困难的。研究人员并没有跟踪研究参与者，看看他们是否能保持减肥效果。
Support is Key to Success
Messier also notes that, based on his experience and past studies, people who are successful at losing weight tend to have some things in common: They’re more likely to consistently use food logs, like MyFitnessPal; to exercise regularly, including adding extra workouts; to use meal replacements without becoming reliant on them; and to have strong family support. And those who struggle to lose weight are more likely to have lower incomes, work demanding jobs, live far from a gym or other place to work out, be primary caregivers and have multiple health problems.
These people need more support and help from health care providers, say experts such as Henning Bliddal, MD, a research professor at Copenhagen University Hospital in Denmark and chairman of the Danish National Board of Health’s commission for the treatment of knee osteoarthritis.
In 2014, Dr. Bliddal and colleagues published a study highlighting the importance of both exercise and at least a 10 percent weight loss as primarytreatments for OA, while also noting that sustained weight loss can be challenging for many people.
In response to the recent analysis, he writes that Messier and colleagues “demonstrate convincingly that the larger the weight loss, the better for all relevant outcomes, including pain and function. [Yet] weight loss above 10 percent is difficult without the use of meal replacements, which over the years have been a central part of the regimen in several successful weight loss trials for patients with knee OA.”
He points out that this is different from most diets, in which people lose only about 5 percent of body weight.
“The difficult part of the job then is to taper this intervention [meal replacements] and replace it with a maintenance regimen without losing momentum,” he notes. “The focus must be to obtain and maintain as many high losers – more than 10 percent – as possible. Such a strategy has the potential to alter the clinical course of OA.”
Dr. Bliddal says it remains to be seen whether these greater weight loss benefits would also stop the structural damage from OA, which would prevent or delay end-stage disease and reduce the need forknee replacements.
Author: Linda Rath
Related Resources:
- More About Knee Osteoarthritis
- Study Ranks Treatments for Knee OA
- More African Americans Could Benefit from Knee Replacement Surgery
- When Knees Need Support