TNF inhibitors and methotrexate produced similar reductions in HbA1c among patients with rheumatoid arthritis , atrophic arthritis or Marie-Strumpell disease who even have diabetes, consistent with data published in BMC Rheumatology.
“[TNF-alpha] has been found to market insulin resistance and disrupt insulin signaling,” Santhi Mantravadi, MD, of Jefferson University and therefore the University of Pennsylvania Perelman School of drugs , and colleagues wrote. “Thus, it’s going to be presumed that modulating this pathway in [inflammatory arthritis (IA)] patients with diabetes may improve insulin sensitivity.”
“Little is understood about the role of MTX in insulin resistance and existing studies have conflicting messages,” they added. “… Overall, little is understood about how TNFi and [methotrexate (MTX)] impact HbA1c in patients with IA and diabetes.”
To analyze whether TNF inhibitors or methotrexate would improve HbA1c in patients with PsA, RA or AS who even have diabetes, Mantravadi and colleagues conducted a retrospective cohort study of Optum’s Clinformatics Data Mart database. consistent with the researchers, Clinformatics provides de-identified administrative claims data, including demographics, prescription use, diagnostic codes, medical claims history and laboratory values, for about 13 million beneficiaries within the us .
Focusing on data from 2000 to 2014, the researchers included patients with PsA, RA or AS who also had diabetes, or an HbA1c level of seven or greater, who started treatment with either TNF inhibitors, methotrexate or metformin. Patients who received metformin served as a positive control. The researchers studied changes in HbA1c following drug initiation, and used the Wilcoxon rank sum test and rectilinear regression models to assess statistical differences, adjusting for potential confounders.
Among the available 10,389 drug initiations across 9,541 patients with PsA, RA or AS and available HbA1c values, a baseline of seven or greater was present in 254 TNF-inhibitor initiations, 361 methotrexate initiations and a couple of ,144 metformin initiations.
According to the researchers, the median change in HbA1c change –0.35 (IQR = –1.1 to 0.3) following initiation with TNF inhibitors, –0.4 (IQR = –1.2 to 0.3) following methotrexate, and –0.8 (IQR = –1.6 to –0.1) after metformin. within the adjusted analyses, TNF inhibitors produced less of a discount in HbA1c compared with methotrexate (Beta = 0.22; 95% CI, 0.004-0.43). Further, metformin demonstrated a significantly greater decrease in HbA1c than methotrexate (Beta = –0.38; 95% CI, –0.52 to –0.23).
“Initiation of a TNFi or MTX among patients with an elevated HbA1c is related to a modest decrease in HbA1c that’s approximately half the maximum amount (about 0.4units) because the decrease observed after initiation of metformin (about0.8units),” Mantravadi and colleagues wrote. “This study found no compelling evidence for a difference within the effect between TNFi and MTX, suggesting similar treatment effects.”
“This study suggests that, additionally to limiting glucocorticoid exposure in patients with diabetes, controlling disease may have off-target benefits, no matter the drug choice,” they added. “Future research is required to know the complex relationship between inflammatory arthritis, insulin resistance, glucocorticoids and metabolic pathways.”