Type 2 Diabetes and Rheumatoid Arthritis, What’s the Relationship?
It is not uncommon for people to have more than one health issue, and that appears to be true for type 2 diabetes and rheumatoid arthritis. What is the relationship between these two diseases and what should you know about them? Here’s some background information as well as the results of two new studies on the topic.
Rheumatoid arthritis and type 2 diabetes
Compared with type 2 diabetes, which affects an estimated 24 million Americans (with about an additional 79 million at risk for the disease), rheumatoid arthritis is much less common. An estimated 1.5 million Americans live with the disease, according to the Centers for Disease Control and Prevention, and the majority are women.
One of the common factors between these two conditions is the presence of inflammation. Rheumatoid arthritis is characterized by chronic inflammation of the joints, while there is also evidence that inflammation plays a role in type 2 diabetes.
Another common factor is insulin resistance, a hallmark of type 2 diabetes. According to Daniel Solomon, MD, MPH, a rheumatologist at Brigham and Women’s Hospital and an associate professor of medicine at Harvard Medical School, “We know there is an increased risk of insulin resistance among people with RA.”
Then there is the issue of drug treatment. Corticosteroids are among the most prescribed drugs for treatment of rheumatoid arthritis, and they have been linked to an increased risk of diabetes since they can increase blood glucose levels.
What new research shows
In a recent study, investigators set out to determine if rheumatoid arthritis should be counted among the risk factors for type 2 diabetes. The authors used an insurance database of 1 million people who were older than 20 in 1998 and who had not been diagnosed with either disease before that year.
By 2009, a total of 600,695 individuals remained in the study pool (the rest had dropped their insurance coverage). Among this population 4,193 were diagnosed with rheumatoid arthritis and of that group, 799 also had type 2 diabetes.
After the authors crunched the numbers, they concluded that rheumatoid arthritis appears to be associated with an increased risk of developing type 2 diabetes.
Another new study takes a different angle. At the recent American College of Rheumatology Annual Meeting in San Diego, a researcher presented evidence that certain drugs taken to control type 2 diabetes may reduce the risk of developing autoimmune diseases such as rheumatoid arthritis and lupus.
Those certain drugs are in a class called dipeptidyl peptidase-4 (DPP-4) inhibitors, better known to consumers as linagliptin (Tradjenta), saxagliptin (Onglza), and sitagliptin (Januvia). An investigative team set out to determine the impact of these drugs on the development of autoimmune diseases in people with type 2 diabetes.
The researchers found that individuals who had type 2 diabetes and who starting taking DPP-4 inhibitors had a lower risk of developing rheumatoid arthritis or other autoimmune conditions than did those who were taking other antidiabetes drugs. More specifically:
- Individuals who took DPP-4 inhibitors seemed to be 34 percent less likely to be diagnosed with rheumatoid arthritis and 27 percent less likely to develop other autoimmune conditions than their peers who did not use these drugs
- When DPP-4 inhibitors were compared with sulfonylureas (e.g., glyburide, glipizide, tolbutamide), both drug types had a similar protective effect against autoimmune disorders, but the same could not be said for thiazolidinediones (e.g., pioglitazone)
According to the study’s lead investigator, Seoyoung C. Kim, MD, MSCE, people with type 2 diabetes who start DPP-4 inhibitor combination therapy seem to be at a reduced risk of developing rheumatoid arthritis and other autoimmune disorders when compared with their peers who start a different treatment approach.
Research indicates there is a relationship between type 2 diabetes and rheumatoid arthritis and that the use of certain antidiabetes drugs seem to reduce that risk. At the same time, everyone can take steps to reduce the risk of developing either of these conditions by following sensible lifestyle habits, including a nutritious diet, regular exercise, not smoking, practicing stress management, and maintaining a healthy weight.
Centers for Disease Control and Prevention
Su CC et al. Risk of diabetes in patients with rheumatoid arthritis: a 12-year retrospective cohort study. Journal of Rheumatology 2013 Sep; 40(9): 1513-18