Effect of comorbid diabetes on length of stay and risk of death in patients admitted with acute exacerbations of COPD

Background and objective: Hyperglycaemia during hospital admission is associated with poor outcomes in patients admitted with acute myocardial infarction, stroke and pneumonia. Less evidence exists for effect of diabetes mellitus (DM) on those admitted with an acute exacerbation of COPD (AECOPD). We proposed that comorbidity with DM is associated with an increased length of stay in patients admitted with AECOPD. Methods: Records of patients admitted with AECOPD during 2007 were reviewed. Data on the presence of diagnosed DM, length of stay and markers of disease severity and other comorbidities were collected. Analysis was performed using generalized estimating equations to adjust for correlation between multiple admissions in some individuals. Log-transformed length of stay and death were the dependent variables. Results: There were 246 admissions in 172 subjects. Diabetes was a comorbid condition in 22% of admissions for AECOPD. There was a trend for increased length of stay and deaths in those with diabetes (geometric mean 7.8 days and 8% mortality respectively) compared with those without diabetes (6.5 days and 4%). However, after adjustment for covariates, the differences were not statistically significant. Conclusions: Taken together with a previous study that revealed a similar trend, our study suggests that comorbid DM prolongs length of stay and increases risk of death in patients with AECOPD. Further studies are now required to elucidate the reasons for these poorer outcomes, in particular whether premorbid glycaemic control or inpatient control is responsible, as these are potentially modifiable factors.