It has been estimated that the risk of developing diabetes is increased by roughly 50% in individuals who have RA when compared to individuals without the condition.1 Not only is the risk of developing diabetes increased, but the actual incidence and prevalence of diabetes is higher for individuals with RA as well.2 This means that individuals with RA are not only at risk of developing diabetes but rather, many already have the condition along with their RA. It has also been hypothesized that individuals with RA are at a higher risk of having undiagnosed diabetes as well.2 This information seems to point towards a potential connection between the two conditions, however, the exact cause of this is not completely understood. Some common thoughts on the potential connection between RA and diabetes are below.
Inflammation and auto-immune characteristics
One of the hallmark characteristics of rheumatoid arthritis is widespread inflammation, especially in the joints. It has been hypothesized that this inflammation may help contribute to the development of insulin resistance, a key feature of Type 2 Diabetes (T2D). More specifically, levels of certain inflammatory cytokines, or cells that promote inflammation, are often increased in individuals with RA, as well as in individuals with Type 1 and Type 2 Diabetes, pointing toward a potential cellular connection. However, this potential association can also go both ways, as inflammation from diabetes could possibly pave the way for the development of RA in individuals at risk for the condition as well.1,3
Additionally, it has been estimated that up to a quarter of all individuals with an autoimmune condition will develop a second, or more, additional autoimmune conditions.4 Although the root cause of each individual autoimmune condition, as well as why they may co-occur is unknown, both RA and Type 1 Diabetes (T1D) fall into this category, and it could point to their potential co-occurrence. Similar to how the body attacks its own cells within the joints in RA, the body attacks its own pancreatic cells that make insulin in Type 1 Diabetes.
One potential explanation for the association between T1D and RA could be genetics. Many experts agree that autoimmune conditions may be derived from a variety of factors, including genetic and environment-related elements. However, on the genetic side, results from one large study pointed toward a specific version of a gene being of interest, called the 620W PTPN22 allele. This gene was found in both individuals with T1D and a specific subset of individuals with RA and may contribute to the development of both conditions.5
Since the human body is a delicate balance of many cells, molecules, proteins, and more, working together to keep us healthy, changing the amount or function of some of these elements may lead to the development of new conditions. One way the function or amount of key components in our bodies can be changed is through medications. For example, some medications, like steroids or statins that can be used to treat RA, may impact blood sugar and increase the risk of developing diabetes. Conversely, other RA drugs that reduce inflammation and decrease inflammation-producing cells in the body may help reduce the risk of developing diabetes in the future as well.1,2 If you are concerned about developing diabetes, or if you possess any risk factors of diabetes, it may be a good idea to talk with your doctor or healthcare team about your treatment regimen, to make sure you are treating your RA efficiently while minimizing your risk of developing other conditions.
Exercise and other lifestyle choices
As mentioned, in addition to genetic factors contributing to the development of autoimmune conditions, like RA and T1D, there are also environmental factors that may contribute to the development of these as well. Some environmental risk factors, such as smoking, obesity, and lack of exercise may contribute to the development of both RA and T1D. Additionally, poor diet, lack of blood sugar control, lack of exercise, obesity, and smoking, can all also contribute to T2D.1 Possessing one, or multiple, of these risk factors, can increase your risk of developing all of these conditions on their own, as well as together. If you have RA and are worried about developing diabetes, eliminating some (or all) of these modifiable risk factors by quitting smoking, eating well, and exercising regularly, may help reduce your risk of developing diabetes in the future.
It is important to consider that in some instances, RA-related pain and fatigue may decrease an individual’s ability to exercise regularly or effectively. If this is the case for you, consider talking to your healthcare team or a fitness expert or physical therapist trained in helping individuals with conditions like RA, to help create an effective, and manageable, exercise plan for you.
Inflammatory Arthritis and Diabetes: Managing Both. Arthritis Foundation. https://www.arthritis.org/living-with-arthritis/comorbidities/diabetes-and-arthritis/rheumatoid-arthritis-diabetes-risk.php. Accessed February 5, 2018.
Albrecht K, Ramos AL, et al. High prevalence of diabetes in patients with rheumatoid arthritis: results from a questionnaire survey linked to claims data. Rheumatology. 1 Feb 2018; 57(2), 329-336. Available from: https://academic.oup.com/rheumatology/article/57/2/329/4600773. Accessed February 5, 2018.
Doran M. Rheumatoid arthritis and diabetes mellitus: evidence for an association. The Journal of Rheumatology. March 2007; 34(3), 460-62.
Cojocaru M, Cojocaru IM, Silosi I. Multiple autoimmune syndrome. Maedica: A Journal of Clinical Medicine. Apr 2010; 5(2), 132-134. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3150011/. Accessed February 5, 2018.
Liao KP, Gunnarsson M, et al. A specific association exists between type 1 diabetes and anti-CCP positive rheumatoid arthritis. Arthritis Rheum. Mar 2009; 60(3), 653-660. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768389/. Accessed February 5, 2018.