Israel Medical Association Journal

Background: An increased serum glucose level is a common finding among patients admitted to hospital with acute illness, including the intensive care unit (ICU), even without a history of previous diabetes mellitus (DM). Glycated hemoglobin (HbA1c) is not only a diagnostic tool for DM but may also has prognostic value for diabetic and non-diabetic populations.

Objectives: To assess the relationship between HbA1c level on admission and clinical outcome among patients admitted to the ICU due to cardiopulmonary disorders with hyperglycemia.

Methods: Patients consecutively admitted to the ICU due to cardiopulmonary disorders who presented with hyperglycemia at admission were evaluated during a 6-month period. HbA1c and serum glucose levels were tested on admission and during the first 24–48 hours of hospitalization. Patients were divided according to HbA1c and compared in term of demographics. We evaluated the effect of HbA1c levels at admission on the clinical outcomes.

Results: Of patients with cardiopulmonary disorders who presented with hyperglycemia at admission to the ICU, 73 had HbA1c levels ≥ 6%, 92 had HbA1c levels < 6%: 63/165 (38.2%) known as diabetic patients. The 30-day all-cause mortality was higher in the group with high HbA1c levels; 38/73 vs. 32/98 (P = 0.02). Increased length of stay in the ICU and Acute Physiology and Chronic Health Evaluation II (APACHE II) score were associated with HbA1c ≥ 6% (P < 0.022 and P < 0.026), respectively

Conclusions: HbA1c ≥ 6% has an important clinical prognostic value among diabetic and non-diabetic patients with cardiopulmonary disorders and hyperglycemia.

Abstract

Background: The impact of admission glycated hemoglobin (HbA1c) on hospital outcome is controversial.

Objectives: To evaluate the association between admission glucose and HbA1c levels and mortality 1 year after hospitalization in the internal medicine ward.

Methods: HbA1c level of consecutive patients was measured during the first 24 hours of admission to the internal medicine ward and divided at the cutoff point of 6.5%. Three groups of patients were prospectively identified: patients with preexisting diabetes mellitus (DM), patients with glucose > 140 mg/dl (hyperglycemia) on admission and no known diabetes (H), and patients without diabetes or hyperglycemia (NDM). The primary end-point was 1 year all-cause mortality.

Results: A total of 1024 patients were enrolled, 592 (57.8%) belonged to the DM group, 119 (11.6%) to the H group and 313 (30.6%) to the NDM group. At 1 year, death occurred in 70 (11.9%) in the DM group, 12 (10.0%) in the H group and 15 (4.8%) in the NDM group (P = 0.002). Elevated admission glucose levels did not influence outcome in any of the groups. HbA1c levels were similar for survivors and non-survivors (P = 0.60). Within-group multivariate analysis adjusted for comorbidities and age showed that in the H group HbA1C levels of 6.5% or above were associated with increased mortality risk [hazard ratio (HR) 8.25, 95% confidence interval (CI) 1.93–35.21). In the DM group, HbA1c levels below 6.5% were associated with increased mortality risk (HR = 2.05, 95%CI 1.25–3.36).

Conclusions: Glucose levels upon admission did not affect mortality. However, HbA1c levels below 6.5% had opposite effects on 1 year mortality in diabetes patients and patients with hyperglycemia.