Jan. 9, 2018—The role of weight in long-term health has been debated for people with rheumatoid arthritis (RA).
Some research has suggested that obese people with the disease have a lower risk of death compared to those who weigh less. But a new study suggests that this link isn't tied directly to RA. Instead, it might be part of more general aging trends.
The obesity paradox
Recent studies have looked at the impact of body mass index (BMI) on people with RA. This research has linked obesity with death rates that are 34 to 67 percent lower than that of people with RA and a normal BMI.
But other studies have suggested that this obesity paradox may instead be tied to unintentional weight loss in the years leading up to death. Perhaps obesity wasn't protective at all. A new study set out to shed some light on the situation.
The latest research
The new study looked at 40 years of data from more than 120,000 women who provided information to the Nurses' Health Study. Researchers found 902 women who'd been diagnosed with RA. They matched and compared them to about 7,900 women who didn't have the disease.
Researchers found that weight loss of more than 30 pounds was tied to increased death rates compared to maintaining a stable weight. This was true for women around the time of an RA diagnosis, but it was also true for women without RA. So researchers concluded that the death risk wasn't specific to RA but was tied to the weight loss.
This discovery differs from some of the previous research. The researchers noted that earlier studies didn't compare people with RA to those without the disease. And people who had a normal BMI before death may have lost weight unintentionally due to sickness, frailty or aging. A person with a normal BMI could be less healthy than an overweight or obese individual who hasn't experienced severe unintentional weight loss.
The researchers found that obesity didn't protect against RA death.
The study was published in the journal Arthritis & Rheumatology.
RA is a complicated autoimmune disease. To learn more about it, you can read this article: "Understanding Rheumatoid Arthritis."