In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury: A cohort study
Critical Care Medicine, 05/24/2012
Koh GCKW et al. – Diabetes mellitus is an independent risk factor for mortality in critically ill patients and failure to adjust for statins underestimates the size of this association. Diabetes mellitus is not associated with acute lung injury but is associated with cardiac overload. A diagnosis of cardiac overload excludes a diagnosis of acute lung injury. Investigators who do not account for cardiac overload as a competing alternative outcome may therefore falsely conclude that diabetes mellitus protects from acute lung injury.Methods
- From November 1, 2004, to October 1, 2007, a cohort of patients admitted ≥48hrs to the intensive care unit.
- Of 2,013 patients, 317 had diabetes mellitus.
- Ninety-day mortality was higher in the diabetes mellitus patients compared to patients without diabetes mellitus (hazard ratio 1.53, 95% confidence interval 1.29–1.80).
- This association strengthened after adjusting for confounders and for medication (hazard ratio 1.53, 95% confidence interval 1.07–2.17).
- The authors found no association between diabetes mellitus and acute lung injury (relative risk ratio 1.01, 95% confidence interval 0.78–1.32; adjusted relative risk ratio 0.99, 95% confidence interval 0.75–1.31), but diabetes mellitus was a risk factor for cardiac overload (relative risk ratio 1.91, 95% confidence interval 1.30–2.81; adjusted relative risk ratio 1.45, 95% confidence interval 0.97–2.18).
- Statins were associated with both a reduced risk of mortality (hazard ratio 0.74, 95% confidence interval 0.63–0.87; adjusted hazard ratio 0.53, 95% confidence interval 0.44–0.64) and a decreased risk of developing acute lung injury (relative risk ratio 0.71, 95% confidence interval 0.56–0.89; adjusted relative risk ratio 0.61, 95% confidence interval 0.47–0.79).