Immune modulators are the foundation of treatment in various rheumatologic diseases.1 These medications have proven to be effective for these conditions by altering the immune system, however, they have also been found to produce a variety of endocrine effects in patients as well. These effects include improving pancreatic function, inducing hypoglycemia and hyperglycemia, and altering erythrocyte survival, and have been shown to affect both diabetic and non-diabetic patients. Because of this, it is important for providers to consider the properties of a particular immune modulator when prescribing treatment as they can greatly affect a patient’s disease management.

Research has shown that rheumatologic disease and diabetes frequently go hand-in-hand.1 It has been found that in patients with type 1 diabetes, there is an increased risk in the development of rheumatoid arthritis. Additionally, patients with rheumatologic disease have increased rates of type 2 diabetes, cardiovascular risk factors, and cardiovascular mortality. Due to their ability to affect both rheumatologic disease as well as diabetes, it is particularly important for providers to know and understand the implications of use of immune-modulating agents in their patients.

A recent analysis by Pilla et al summarized the various effects immune modulators have on diabetic patients.1 The authors reviewed several studies analyzing the effects these agents have on type 1 and 2 diabetic patients as well as the effects of these agents on the prevention of diabetes. Several important conclusions were obtained regarding the effects of these agents on patients with type 2 diabetes, which are summarized in Table 1. The author’s analysis also found that, despite obtaining many important results, many of the immune-modulating agents analyzed did not have any studies completed in patients with type 2 diabetes. Table 2 lists the medications that did not have any associated studies found in this patient population.

In their review, Pilla et al described several studies that demonstrated the antihyperglycemic effect of hydroxychloroquine in patients with type 2 diabetes.1 This antimalarial agent is used first-line for rheumatoid arthritis and systemic lupus erythematosus and is thought to produce its glycemic effect by causing intracellular insulin metabolism changes in peripheral tissues. One randomized controlled trial found that, after 18 months, there was a 1.02% reduction in a patient’s HbA1c measurement when hydroxychloroquine was added to their sulfonylurea therapy (95% CI 0.24%, 1.81%).