Joshua Baker, MD, on the Risk of Diabetes Among Patients with RA

Dr Baker, from the University of Pennsylvania, discusses his recent research into the association of inflammation with the risk of diabetes among patients with rheumatoid arthritis.

Joshua Baker, MD, is an assistant professor of rheumatology and epidemiology at the University of Pennsylvania.

TRANSCRIPT:

Dr Joshua Baker:   Hi, everyone. I'm Josh Baker from the University of Pennsylvania, and the Philadelphia VA hospital. I'm a rheumatologist and epidemiologist. My primary interest is in rheumatoid arthritis and other types of arthritis.

We're going to talk to you today about the risk of diabetes in patients with rheumatoid arthritis. We were interested in the question of whether increased disease activity among patients with rheumatoid arthritis was associated with an increased risk of diabetes.

This stems from an interest in the general population with whether inflammation itself is associated with the risk of diabetes. In the general population, higher levels of inflammation in the blood are associated with an increased risk of diabetes.

This inflammation that predisposes people to diabetes appears to be largely due to the risk of the presence of intraabdominal fat in people with obesity. We were interested in thinking about this in rheumatoid arthritis, which is an inflammatory disease itself.

We were interested in learning about whether patients with rheumatoid arthritis who have an inflammatory disease were at increased risk, and whether the inflammation related to their disease was associated with that risk.

To date, there are conflicting studies about whether rheumatoid arthritis is associated with an increased risk of diabetes. There are some studies also showing that treating rheumatoid arthritis with certain drugs appears to reduce that risk, although the evidence is pretty sparse and not very definitive.

We were interested in looking at whether the activity of the disease itself was associated with risk of diabetes. We studied patients with rheumatoid arthritis from the VA rheumatoid arthritis registry. We measured disease activity at enrollment in the study, but also disease activity over time in the study.

We looked at whether disease activity was associated with the development of diabetes among patients that didn't have diabetes at the start of the study. What we found was that elevated disease activity was associated with a substantially increased risk of diabetes. People with high disease activity had about a 2‑fold increase in risk of diabetes over the follow-up.

Disease activity in rheumatoid arthritis is a difficult concept. We also wanted to look at individual measures of inflammation in the blood. We looked at cytokines and chemokines that were circulating in the blood.

At enrollment, people with higher levels of circulating cytokines and chemokines also had a higher risk of diabetes, suggesting that there's something about the inflammatory pathways that may increase the risk of diabetes.

There were other risk factors in the study that were important. The main risk factor that was important was obesity. Patients with severe obesity were substantially at higher risk for diabetes with about a 6‑fold increase in that risk. People that smoked actually had a lower risk.

The implications of the study are that we hope that lowering disease activity may help prevent patients from developing diabetes, although we need additional studies to prove that's the case.

The major limitation here was that we don't have measures of intraabdominal fat, or measures of fat distribution in these patients. While the effect of elevated disease activity inflammation was independent of measures of body mass, it may be that measuring things like direct measures of adiposity or abdominal fat may explain some of the risk of inflammation.

It may, in other words, be that the measures of inflammation that we are looking at are actually just a marker of different distribution of fat, and that's what the important thing is. We need additional studies to hone down whether addressing inflammation due to rheumatoid arthritis might prevent the risk of diabetes.

The premise here is that we have found some evidence here that inflammation may be at least correlated with the risk of diabetes, and gives some strength to the hypothesis that if we can intervene on some of these pathways, we can reduce the risk.

Thanks so much for listening. It's been a pleasure to be with you. Keep your patients' disease activity low. Let's hope that helps prevent metabolic complications like diabetes. Thanks a lot.