Abstract
BACKGROUND: Severe spontaneous hypoglycemia (SSH) is a rare but high-risk condition in hospitalized patients, particularly among the critically ill. It is associated with increased mortality and may serve as a marker of disease severity. OBJECTIVE: To describe in-hospital mortality and clinical profile observed in patients with SSH. METHODS: A retrospective cohort study was conducted at Santa Izabel Hospital from November 1, 2023, to March 31, 2024. Among 5,803 hospitalized patients, 134 (2.3%) had severe hypoglycemia (≤ 40 mg/dL). After excluding insulin users and measurement errors, 47 patients (0.81%) were analyzed. Data included demographics, comorbidities, hypoglycemia recurrence, and hospital outcomes. RESULTS: SSH prevalence was 0.81% (n = 47) among all hospitalized patients with at least one blood glucose (BG) reading, with an overall mortality rate of 66% (n = 31). Recurrence within 24 h occurred in 46.8% (n = 22) of patients but was not significantly associated with increased mortality (82% with recurrence vs. 52% without recurrence; p = 0.063). Among total deaths (n = 31), 41.9% (n = 13) occurred within 24 h (43.8% with recurrence vs. 38.5% without recurrence) and 22.6% (n = 7) within 12 h. In the total SSH group, renal insufficiency (51%), infection (80.9%), malignancy (46.8%), and elevated lactate > 2.0 mmol/L (70.3%) were common. Patients who died had more comorbidities compared to survivors (median 4.00 vs. 2.00; [p < 0.001), elevated serum creatinine levels (1.44 vs. 0.87 mg/dL; p = 0.035), and increased serum lactate concentrations (3.60 vs. 1.15 mmol/L; p = 0.002). Fasting in the 48 h preceding the first hypoglycemic episode was significantly more common in the patients with at least one recurrence of SSH in 24 h (70.0% vs. 20.0%; p = 0.001). In the multivariable model, none of the analyzed variables remained significantly associated with mortality. CONCLUSION: SSH is rare but patients who experience it have elevated in-hospital mortality. It is often present in the context of rapid clinical deterioration, with many deaths in this cohort occurring within 24 h of the first episode. SSH may be a key marker of disease severity and can be further explored as a prognostic marker to guide management.