The profound effect of diabetes mellitus control on outcomes of coccidioidomycosis.

Coccidioidomycosis is an endemic fungal infection caused by the soil-dwelling Coccidioides. One prior study showed that persons with diabetes mellitus (DM) with elevated glucose at the time of coccidioidomycosis had poorer coccidioidal outcomes compared to persons without DM. We aimed to assess the association between hemoglobin A1C (A1C) and outcomes among persons with coccidioidomycosis and coexisting DM. We conducted a retrospective case-control study of patients with DM (cases) and without DM (controls) with coccidioidomycosis to assess the effect of glycemic control on outcomes in patients with DM. From January 1, 2017, to October 13, 2022, we identified 138 DM patients with coccidioidomycosis and compared them with 283 non-DM control patients with coccidioidomycosis. Compared with controls, cases were more likely to require hospitalization (OR 1.20, P < .001), have a lung cavity (OR 1.36, P < .001) and cavitary complications (OR 1.09, P = .001), require surgical management (OR 1.07, P = .016), and experience relapsed infection (OR 1.09, P = .041). Among the cases, when baseline A1C was assessed as a continuous variable, each 1-unit increase of A1C had a significant effect on coccidioidomycosis-related hospitalizations (A1C OR 1.59, P = .005) and the presence of cavities (OR 1.42, P = .01). Controlling for Charlson Comorbidity Index did not change the significance of A1C influence on outcomes of hospitalization and lung cavities. DM patients with A1C levels ≤8.0 at presentation did not have increased adverse coccidioidomycosis outcomes. In summary, glycemic control profoundly impacts the outcomes of diabetic patients with coccidioidomycosis.