Nutritional assessment of the lung transplant patient: Body mass index as a predictor of 90-day mortality following transplantation

Background: It is well documented that malnourished and/or obese surgical patients have increased morbidity and mortality post-operatively. Only a few studies investigating the effect of nutritional status on mortality are available pertaining to the transplant population. Since limited data are available on the nutritional status and its effects on mortality in the lung transplant population, we sought to ascertain whether there is an association between mortality and preoperative nutritional status. Methods: We examined mortality during the first 3 months after transplantation. Patients were grouped by body mass index (BMI) categories as < 17 kg/m(2), 17 to < 20 kg/m(2), 20 to 25 kg/m(2) (reference group), > 25 to 27 kg/m(2), and > 27 kg/m(2). Additional risk factors retrieved from the pre-transplant records included age, gender, diagnosis, energy requirements, protein requirements, protein and caloric intake, and weight history. Logistic regression for univariate and multivariate analysis for mortality used recipient age, gender, disease category, pre-transplant cytomegalovirus (CMV) serology, transplant type (single or bilateral), and donor age, gender, and CMV serology. Results: The likelihood estimates or odds ratios (ORs) of the risk of death within 90 days of lung transplantation for the BMI categories compared to the reference group were 3.7 for BMI < 17 kg/m(2) (p = 0.085), 1.6 for BMI < 17 to 70 kg/m(2) (p = 0.455), 3.5 for BMI > 25 to 27 kg/m(2) (p = 0.069), and 5.0 for BMI > 27 kg/m(2) (p = 0.003). Conclusions: In patients with a pre-transplant BMI < 17 kg/m(2) or > 25 kg/m(2) the risk of dying within 90 days post-transplant was increased. In patients with a pre-transplant BMI of > 27 kg/m(2) the risk was significantly higher in than the reference group.