Hyperglycemia: An Independent Marker of In-Hospital Mortality in Patients with Undiagnosed Diabetes

TLDR

Admission hyperglycemia is linked to higher mortality in critically ill patients, but its impact on general ward admissions remains unclear. This study aimed to assess how common in‑hospital hyperglycemia is and to compare survival and functional outcomes among patients with and without a prior diabetes diagnosis. Researchers retrospectively reviewed 2,030 consecutive adult admissions to Georgia Baptist Medical Center (July–October 1998), defining new hyperglycemia as fasting ≥ 126 mg/dL or random ≥ 200 mg/dL on two or more measurements. Hyperglycemia occurred in 38% of admissions, with 26% having known diabetes and 12% newly diagnosed; newly hyperglycemic patients had a 16% mortality rate versus 3% in known diabetics and 1.7% in normoglycemics, along with longer stays, higher ICU admission, and poorer discharge disposition.

Abstract

Admission hyperglycemia has been associated with increased hospital mortality in critically ill patients; however, it is not known whether hyperglycemia in patients admitted to general hospital wards is associated with poor outcome. The aim of this study was to determine the prevalence of in-hospital hyperglycemia and determine the survival and functional outcome of patients with hyperglycemia with and without a history of diabetes. We reviewed the medical records of 2030 consecutive adult patients admitted to Georgia Baptist Medical Center, a community teaching hospital in downtown Atlanta, GA, from July 1, 1998, to October 20, 1998. New hyperglycemia was defined as an admission or in-hospital fasting glucose level of 126 mg/dl (7 mmol/liter) or more or a random blood glucose level of 200 mg/dl (11.1 mmol/liter) or more on 2 or more determinations. Hyperglycemia was present in 38% of patients admitted to the hospital, of whom 26% had a known history of diabetes, and 12% had no history of diabetes before the admission. Newly discovered hyperglycemia was associated with higher in-hospital mortality rate (16%) compared with those patients with a prior history of diabetes (3%) and subjects with normoglycemia (1.7%; both P < 0.01). In addition, new hyperglycemic patients had a longer length of hospital stay, a higher admission rate to an intensive care unit, and were less likely to be discharged to home, frequently requiring transfer to a transitional care unit or nursing home facility. Our results indicate that in-hospital hyperglycemia is a common finding and represents an important marker of poor clinical outcome and mortality in patients with and without a history of diabetes. Patients with newly diagnosed hyperglycemia had a significantly higher mortality rate and a lower functional outcome than patients with a known history of diabetes or normoglycemia.