Hypoglycemia is not uncommon in hospitalized patients with diabetes mellitus (DM), with an incidence ranging between less than 1% and over 32% [1–۹]. This wide range of incidence rates in diferent studies probably stems from the poor defnition of hypoglycemia. While in previous guidelines published by the American Diabetes Association in-hospital hypoglycemia was defned as any blood glucose level below 70 mg/dl [10], in the current guidelines from the International Hypoglycaemia Study Group, serious, clinically signifcant hypoglycemia (serious hypoglycemia) is now defned as glucose < ۵۴ mg/dl, while glucose alert value is defned as ≤ ۷۰ mg/dl, and can be important for adjustment of glucose lowering drugs [11]. Hypoglycemia is a major limiting factor in achieving optimal glycemic control in patients with DM, with solid evidence indicating that intensive insulin therapy leads to more episodes of hypoglycemia [12–۱۵]. Many factors may contribute to development of hypoglycemia in admitted patients, including poor nutrition, renal failure, heart failure, advanced liver disease, advance age, infections, and the intensity of treatment regimen [16–۱۹]. We have previously reported increased short- and longterm mortality in patients with spontaneous and insulinrelated hypoglycemia in hospitalized patients [8]. One of the most critical components of DM management includes prevention of hypoglycemia, thus, while our previous study focused on the detrimental efects of in-hospital hypoglycemia, in the current study we aim to take a step back and identify predictors and risk factors for in-hospital hypoglycemia in patients with DM.

Methods

The study was conducted at a large 1300-bed universityafliated tertiary medical center. The vast majority of admissions to the ten medical wards are through an emergency department. All patient data are recorded in electronic medical charts, based on the same database platform used in the community primary care facilities. The study was approved by the hospital’s Institutional Review Board. For the present study, historical prospectively collected observational data were extracted from the medical records of all patients with DM, admitted for any cause to the hospital’s medical wards between January 1, 2011 and December 31, 2013. Self-reported data regarding alcohol use, smoking and body mass index (BMI), as well as comorbidities were also collected from the database.