Growing older is the leading risk factor for osteoarthritis, but obesity is another major cause of this common joint disease. Although you can’t turn back the clock, if you’re overweight or obese, you can lower your risk for osteoarthritis by losing some of those excess pounds.
And evidence suggests that if you already have osteoarthritis, taking steps to reduce your weight can ease painful symptoms. In fact, guidelines recommend nondrug, nonoperative treatments, including weight loss, as the first-line approach for hip and knee osteoarthritis.
Cutting calories combined with increasing physical activity is a tried-and-true way of shedding excess pounds, and research shows that losing weight this way can produce significant osteoarthritis-related benefits. But if those efforts don’t lead to success, medication or surgery to aid weight loss may be a reasonable choice for some. If you have osteoarthritis and need to lose weight, here’s what you should know about the options available to help you reach your goal.
A leading risk factor
It’s well established that obesity can cause or worsen osteoarthritis. Important findings come from the Framingham Osteoarthritis Study, which followed more than 1,400 people for more than 35 years, beginning in 1948.
An assessment of study participants in the 1980s identified 468 people who had developed osteoarthritis. Notably, obese men were 50 percent more likely to have developed knee osteoarthritis than those who weren’t obese. And women who were obese were twice as likely as females who weighed less to have knee osteoarthritis.
A 2010 review reported that individuals who were obese were seven times more likely than their nonobese counterparts to develop knee osteoarthritis. Studies have linked obesity to other forms of osteoarthritis, including arthritis in the hip and spine, though the association is somewhat less clear-cut.
Doctors used to think that obesity increases osteoarthritis risk simply because the extra weight exerts added stress on the joints. While that may be true, scientists now believe that other factors also contribute. Research suggests that abdominal fat triggers a cascade of events that causes the body to produce high levels of molecules that increase inflammation.
The inflammation damages cartilage—the tissue that cushions the bones and protects the joints from weight-bearing stress. What’s more, people who are overweight or obese often have weak muscles in the back and legs, which can contribute to knee osteoarthritis by interfering with the normal mechanical movement of the joint.
Diet and exercise are a must
Several studies indicate that losing weight improves osteoarthritis symptoms. For instance, in one study researchers assessed pain levels and ability to function in 80 people with osteoarthritis before and after they followed a reduced-calorie weight loss diet. After two months, people who lost 10 percent of their body weight experienced a 28 percent reduction in their osteoarthritis symptoms.
Another group reported that losing as little as 5 percent of body weight (10 pounds for a 200-pound person) led to significant improvement of osteoarthritis symptoms. Findings from the Arthritis, Diet and Activity Promotion Trial (ADAPT) demonstrated that people with knee osteoarthritis who combined diet with exercise lost more weight and reported greater improvements in pain and ability to function than individuals who used either method alone.
To lose 0.5 to 2 pounds per week—a gradual and safe rate of weight loss—you must consume 250 to 1,000 fewer calories per day than you need to maintain your weight. Regular aerobic exercise helps burn calories and means you won’t need to cut quite so many of them from your meals. (Weight-training, or resistance, exercises are recommended as well to build and maintain muscle strength as you lose weight.)
If you need help calculating your caloric requirements, ask your doctor to recommend a registered dietitian. A dietitian also can help design a weight loss plan that keeps in mind any other health problems you may have. Many people also have success with commercial weight loss programs, such as Weight Watchers. When it comes to exercise, choose low-impact activities that are easy on the joints, such as walking, bicycling or swimming.
Can medication help?
In recent years, the U.S. Food and Drug Administration (FDA) has approved four new drugs for long-term weight management: naltrexone/bupropion (Contrave), lorcaserin (Belviq), phentermine/ topiramate (Qsymia) and liraglutide (Saxenda). Unfortunately, they aren’t magic; for best results, these medications must be used along with diet and exercise.
You may be a candidate for medication if you fall into one of these groups:
• Have a body mass index (BMI) of 30 or more (considered obese).
• Have a BMI of 27 or higher and have another chronic health condition, such as high blood pressure, type 2 diabetes or high cholesterol levels, that places you at high risk of having a heart attack or stroke.
Use of weight-management medications in people with osteoarthritis has not been well studied, but these drugs have been shown to result in modest weight loss (about 5 to 10 percent after one year). If you don’t lose at least 5 percent of your initial body weight after three months, talk to your doctor about discontinuing use.
As with any medication, these drugs may cause side effects, and people with certain health conditions should not take them. In addition, their cardiovascular safety is still under study. If you plan to use any of these drugs, tell the prescribing doctor about any medical conditions you have. And be sure that you understand the medication’s limitations, benefits and risks.
Weight loss surgery
While there are several forms of weight loss, or bariatric surgery, the basic goal of each procedure is to reduce the size of the stomach, which limits the amount of food that a person can eat. Some types of bariatric surgery also alter the digestive tract in a way that reduces the amount of food that the body absorbs after a meal. Hormonal changes can occur that reduce appetite, as well. Studies show that the typical patient loses about 44 to 66 pounds.
Some evidence suggests people who undergo bariatric surgery experience a dramatic reduction in the pain and swelling associated with osteoarthritis. A 2015 analysis published in Obesity Reviews examined the results of 13 studies, involving 3,837 severely obese individuals who had bariatric surgery. The authors found that knee problems—pain, physical function, and stiffness—improved in about 73 percent of the patients. However, the authors cautioned that firm conclusions could not be reached because the quality of studies reviewed varied.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), you may be a candidate for bariatric surgery if you have a:
• BMI of 40 or higher, or
• BMI of 35 plus one or more serious obesity-related conditions, such as type 2 diabetes or heart disease.
If you have a BMI of 30 or higher and also have at least one other serious condition associated with obesity, you may be a candidate for a type of weight loss surgery that uses an adjustable gastric band, which was recently approved by the FDA.
Each procedure has specific pros and cons. Be sure you understand both before making a decision. And keep in mind that diet and exercise are still important before and after the procedure. In fact, some insurers require you to try to lose weight through diet and exercise before they will cover the cost of the operation.