SAT-017 - Incident Hypercortisolism in Bexar County: A Retrospective Analysis of Diagnostic Trends (2014-2024)

Background: Obesity and diabetes continue to rise in the United States, and a subset of patients remains difficult to control despite modern therapies. Hypercortisolism can mimic or worsen metabolic disease and may be underrecognized in high-risk populations. We evaluated whether the incidence of confirmed Cushing syndrome changed over a 10-year period within an academic county hospital system serving Bexar County.

Objective: To describe trends in the incidence of Cushing syndrome from 2014 through 2024.

Methods: We performed a retrospective, single-center chart review using an Academic County Hospital electronic medical record (2014–2024). Incident Cushing syndrome cases were included when diagnosis occurred during the study period and was confirmed by either (1) corticotroph adenoma on surgical pathology or (2) at least two supportive biochemical criteria: abnormal overnight 1-mg dexamethasone suppression testing, elevated late-night salivary cortisol on three occasions, and/or elevated urine free cortisol on two occasions. Refractory referrals were excluded when the original diagnosis or treatment occurred outside the Academic County Hospital System or outside the study timeframe. The primary outcome was the number of confirmed incident cases per year.

Results: Among 239 charts reviewed, we identified 25 incident Cushing syndrome diagnoses from 2014–2024 (including one patient diagnosed twice: ACTH-independent in 2017 and ACTH-dependent in 2019). Annual incidence remained relatively low and stable from 2014–2023, ranging from 0–3 cases/year (mean 2.27 ± 2.49 cases/year). However, a marked increase was observed in 2024 (n=9) compared with 2023 (n=3), representing an approximate 200% year-to-year rise, with 2024 exceeding the overall mean by ~2.7 SD, suggesting a recent surge in incident diagnoses warranting further evaluation of testing practices and diagnostic thresholds.

Conclusions: Although Cushing syndrome remains rare, our data suggest a recent rise in incident diagnoses within our health system. Future analyses will incorporate complete 2025 data, quantify trends in cortisol testing frequency over time, and further evaluate whether the observed increase reflects a sustained epidemiologic trend versus changes in screening practices and diagnostic criteria. This pattern may represent year-to-year variability, increased diagnostic testing, or evolving diagnostic thresholds. Notably, the commonly used cutoff for the overnight dexamethasone suppression test shifted after 2008 from a post-test cortisol >5 µg/dL to >1.8 µg/dL, improving sensitivity but reducing specificity. In low-prevalence settings, lowering the threshold may increase abnormal screening results and false positives, which could partially explain the higher observed case counts.

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