Body mass index and acute kidney injury in the acute respiratory distress syndrome
Critical Care Medicine, 08/21/2012
Soto GJ et al. – In acute respiratory distress syndrome patients, obesity is associated with increased development of acute kidney injury, which is not completely explained by severity of illness or shock. Although increased body mass index is associated with decreased mortality, acute kidney injury remained associated with higher mortality even after adjusting for body mass index.Methods
- Seven hundred fifty–one patients with acute respiratory distress syndrome.
- Acute kidney injury was defined as meeting the “Risk” category according to modified Risk, Injury, Failure, Loss, End–stage criteria based on creatinine and glomerular filtration rate because urine output was only available on the day of intensive care unit admission.
- Body mass index was calculated from height and weight at intensive care unit admission.
- The prevalence of acute kidney injury increased significantly with increasing weight (p=.01).
- The odds of acute kidney injury were twice in obese and severely obese patients compared to patients with normal body mass index, after adjusting for predictors of acute kidney injury (age, diabetes, Acute Physiology and Chronic Health Evaluation III, aspiration, vasopressor use, and thrombocytopenia [platelets≤80,000/mm3]).
- After adjusting for the same predictors, body mass index was significantly associated with acute kidney injury (odds ratioadj 1.20 per 5kg/m2 increase in body mass index, 95% confidence interval 1.07–1.33).
- On multivariate analysis, acute kidney injury was associated with increased acute respiratory distress syndrome mortality (odds ratioadj 2.76, 95% confidence interval 1.72–4.42) whereas body mass index was associated with decreased mortality (odds ratioadj 0.81 per 5kg/m2 increase in body mass index, 95% confidence interval 0.71–0.93) after adjusting for mortality predictors.