Blood glucose changes surrounding initiation of tumor-necrosis factor inhibitors and conventional disease-modifying anti-rheumatic drugs in veterans with rheumatoid arthritis

AIM To determine the scope of acute hypoglycemic effects for certain anti-rheumatic medications in a large retrospective observational study. METHODS Patients enrolled in the Veterans Affairs Rheumatoid Arthritis (VARA) registry were selected who, during follow-up, initiated treatment with tumor necrosis factor inhibitors (TNFi's, including etanercept, adalimumab, infliximab, golimumab, or certolizumab), prednisone, or conventional disease-modifying anti-rheumatic drugs (DMARDs), and for whom proximate random blood glucose (RBG) measurements were available within a window 2-wk prior to, and 6 mo following, medication initiation. Similar data were obtained for patients with proximate values available for glycosylated hemoglobin A1C values within a window 2 mo preceding, and 12 mo following, medication initiation. RBG and A1C measurements were compared before and after initiation events using paired t-tests, and multivariate regression analysis was performed including established comorbidities and demographics. RESULTS Two thousands one hundred and eleven patients contributed at least one proximate measurement surrounding the initiation of any examined medication. A significant decrease in RBG was noted surrounding 653 individual hydroxychloroquine-initiation events (-3.68 mg/dL, P = 0.04), while an increase was noted for RBG surrounding 665 prednisone-initiation events (+5.85 mg/dL, P < 0.01). A statistically significant decrease in A1C was noted for sulfasalazine initiation, as measured by 49 individual initiation events (-0.70%, P < 0.01). Multivariate regression analyses, using methotrexate as the referent, suggest sulfasalazine (β = -0.58, P = 0.01) and hydroxychloroquine (β = -5.78, P = 0.01) use as predictors of lower post-medication-initiation RBG and A1C values, respectively. Analysis by drug class suggested prednisone (or glucocorticoids) as predictive of higher medication-initiation event RBG among all start events as compared to DMARDs, while this analysis did not show any drug class-level effect for TNFi. A diagnosis of congestive heart failure (β = 4.69, P = 0.03) was predictive for higher post-initiation RBG values among all medication-initiation events. CONCLUSION No statistically significant hypoglycemic effects surrounding TNFi initiation were observed in this large cohort. Sulfasalazine and hydroxychloroquine may have epidemiologically significant acute hypoglycemic effects.