How Obesity Affects Arthritis
Even as countries worldwide have populations that suffer from malnutrition, obesity has become a major worldwide health concern including in the United States. Its negative impact on overall patient health and quality of life has been well-documented in literature, and it’s a growing issue. People who have arthritis already have to manage symptoms and deal with pain, but being obese can dramatically worsen the problem. The more weight that already-damaged cartilage has to bear, the more it continues to break down and cause damage.1
Besides the pain that comes with years of wear and tear on joints, arthritis combined with obesity also means an increased need for hip and knee replacements. Dr. Bryan Springer, MD, and Susan Odum, PhD, looked at 753,268 total knee arthroplasty (TKA) patients from the National Inpatient Sample (NIS) data set and found that the proportion of obese TKA patients nearly doubled from 11% in 2002 to 20% in 2009. 2 By 2011 no state had less than 20% of its population as obese; 12 states had more than 30% (CDC). 3
Because obesity is such a rapidly-growing issue and can affect all ages, races and socioeconomic backgrounds, we asked Dr. Springer to answer some of our top questions about how obesity and arthritis can overlap.
- As a medical provider, what can you share about the obesity epidemic?
In 1990 there was no state in the US that had more than 15% of population obese. Now no state has a prevalence of obesity less than 20%, and as of just a year ago 19 states had a prevalence of obesity between 30% and <35%. It’s a growing problem in part because obesity has an enormous impact on our quality of life and other parts of our health.
- Is there a correlation between obesity and development of arthritis?
There is no question that there is a link between arthritis and people that are obese. We know that people who are overweight and obese have a substantially higher rate of developing osteoarthritis in their joints. There are a few theories as to why patients develop osteoarthritis; the most common is a mechanical risk factor when patients put more weight on their joints. If you take the knee joint, for example, and walk down the hallway, you’re putting three to five times your bodyweight across the knee joint when you walk. When you go up stairs, or get up from a chair, that’s magnified to six to eight times your bodyweight. If you gain 20 pounds, that’s 100 extra pounds of force each time you step.
- What other arthritis-related problems can be associated with obesity?
Chemical hormones are another issue. Obese patients produce higher levels of hormones that can be detrimental to the joint cartilage. These patients are also in a pro-inflammatory state; they have circulating factors that promote the breakdown of cartilage in their body. Obese patients have been shown to have twice the risk of developing osteoarthritis in their hips and knees than a non-obese person.
- How do you counsel patients who are obese with arthritis to lose weight?
The majority of patients don’t need weight loss surgery to lose weight. It can be done through simple diet and exercise. It’s a pretty simple formula – calories in versus calories out. One of the most important things they can do is monitor their diet and caloric intake. The other side of the equation is burning calories. Every little bit counts. Keeping it monitored is important; I recommend using a FitBit® or some kind of tracking device. The best kind of exercise for obese people is low impact; water aerobics or anything in the water, riding a stationary bike, taking frequent short walks.
- If a patient needs to have a joint replacement, what other factors do you consider when it comes to obesity?
In general, a BMI above 40 is the cutoff, meaning that we can’t do a replacement on someone with a BMI above 40. The reason for this is that there is a substantially higher risk for complications after joint surgery. Most morbidly obese patients aren’t just obese; they also have higher risk of heart disease and diabetes. Those factors mean higher risks for surgery.
- How can I prevent arthritis from happening?
Unfortunately there’s no pill or injection to slow the progression of arthritis; patients can only manage symptoms once develop it. One of the best ways to manage symptoms is to control weight, and the best ways to optimize your weight is through diet and mild to moderate low-impact exercise.
1Kane, Andrea. "How Fat Affects Arthritis." Obesity and Arthritis. Arthritis.org, n.d. Web. 14 Oct. 2015.
2 The Journal of Arthroplasty, August 2014.
3"Obesity Prevalence Maps." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 11 Sept. 2015. Web. 14 Oct. 2015.
Dr. Bryan Springer is a Fellowship-trained hip and knee surgeon with OrthoCarolina. He has been named one of the Top 22 North American Knee Surgeons in the United States and has been a member of the Hip Society and the Knee Society.