Hyperglycaemia is associated with poor outcomes in patients admitted to hospital with acute exacerbations of chronic obstructive pulmonary disease

Background: Hyperglycaemia is associated with poor outcomes from pneumonia, myocardial infarction and stroke, but the effect of blood glucose on outcomes from acute exacerbations of chronic obstructive pulmonary disease ( AECOPD) has not been established. Recent UK guidelines do not comment on measurement or control of blood glucose in AECOPD. A study was therefore undertaken to determine the relationship between blood glucose concentrations, length of stay in hospital, and mortality in patients admitted with AECOPD. Methods: Data were retrieved from electronic records for patients admitted with AECOPD with lower respiratory tract infection in 2001 - 2. The patients were grouped according to blood glucose quartile ( group 1, <6 mmol/ l ( n = 69); group 2, 6.0 - 6.9 mmol/ l ( n = 69); group 3, 7.0 - 8.9 mmol/ l ( n = 75); and group 4, >9.0 mmol/ l ( n = 71)). Results: The relative risk (RR) of death or long inpatient stay was significantly increased in group 3 ( RR 1.46, 95% CI 1.05 to 2.02, p = 0.02) and group 4 ( RR 1.97, 95% CI 1.33 to 2.92, p< 0.0001) compared with group 1. For each 1 mmol/ l increase in blood glucose the absolute risk of adverse outcomes increased by 15% ( 95% CI 4 to 27), p = 0.006. The risk of adverse outcomes increased with increasing hyperglycaemia independent of age, sex, a previous diagnosis of diabetes, and COPD severity. Isolation of multiple pathogens and Staphylococcus aureus from sputum also increased with increasing blood glucose. Conclusion: Increasing blood glucose concentrations are associated with adverse clinical outcomes in patients with AECOPD. Tight control of blood glucose reduces mortality in patients in intensive care or following myocardial infarction. A prospective study is now required to determine whether control of blood glucose can also improve outcomes from AECOPD.