Prevalence and Risk Factors of Spontaneous Hypoglycemia in Hospitalized Patients: Cross-Sectional Observational Study and Literature Review

Introduction: Spontaneous hypoglycemia is a blood glucose level below 70 mg/dL unrelated to insulin or oral hypoglycemic agents. Objectives: To assess the prevalence of spontaneous hypoglycemia (<70 mg/dL) in adult patients admitted to Hospital Santa Izabel in 2023. Additionally, a narrative review was conducted to evaluate the prevalence, risk factors, main contributing factors, and mortality associated with spontaneous hypoglycemia in hospitalized patients. Methods: A cross-sectional observational study reviewed an electronic medical record database of adult patients. Capillary blood glucose measurements from patients admitted to general wards, intensive care units (ICUs), and emergency services at Hospital Santa Izabel (HSI) in 2023 were analyzed. A narrative review was also performed through a non-systematic PubMed search using the terms hypoglycemia, mortality, hospital, and individuals without diabetes. The search yielded 61 articles, which, along with reference analysis, brought the total to 81 articles. After excluding duplicates and studies irrelevant to the topic, 10 articles were selected for analysis. Results: In 2023, HSI recorded 6,609 episodes of hypoglycemia, accounting for 2.63% of the blood glucose measurements. The prevalence of spontaneous hypoglycemia in the reviewed articles ranged from 0.01% to 0.51%. Spontaneous hypoglycemia occurs more frequently in ICU patients and the elderly. Common risk factors included heart failure, renal failure, malignancy, and pre-existing diabetes. Severe conditions such as cirrhosis, multiple organ failure, polytrauma, and sepsis were also associated with hypoglycemia. Moreover, spontaneous hypoglycemia was linked to higher mortality, with 5 out of 10 studies showing mortality rates 2 to 3 times higher in patients who experienced at least one episode. This association was not commonly observed in insulin-induced hypoglycemia. Conclusion: Spontaneous hypoglycemia in hospitalized patients is a rare event, typically associated with severe acute conditions and advanced age. It is more frequently linked to higher mortality compared to medication-induced hypoglycemia, with mortality rates correlating with the severity of the hypoglycemic episodes.