Natural history and predictors of obesity after orthotopic heart transplantation.

Excessive weight gain resulting in obesity is commonly seen after orthotopic heart transplantation. Obesity increases the risk for the development of many significant health problems and the associated morbidity and mortality. The purpose of this study was to define the occurrence, magnitude, and predictors of overweight/obesity in this group. We followed 47 consecutive patients for 1 year after orthotopic heart transplantation for changes in weight. Weight gain from baseline was significant at months 2, 4, 6, 8, and 10, with significant weight increments between each measurement interval (p < 0.05). The mean weight gain was 10.1 kg +/- 1.6 (standard error [SE]) at 12 months. Based on entry body mass index patients were divided into two groups: group I, overweight/obese, body mass index more than 27 kg/m2 (n = 11); group II, not overweight/obese, body mass index 27 kg/m2 or less (n = 36). No significant difference was found in the amount of weight gained between the two groups (group I, 10.3 kg +/- 1.2 [SE]; group II, 10.1 kg +/- 1.4 [SE]). Only age predicted weight gain, with younger patients gaining more than older patients after transplantation (14.2 +/- 13.2 kg versus 8.8 +/- 7.9 kg; p < 0.05). We found no relationship between the observed weight gain and any of the other measured predictors, that is, history of overweight, age, diabetes, family history of overweight, sex, patient's participation in cardiac rehabilitation. The universal nature of this weight gain and the lack of markers predicting patients at greatest risk for obesity underscores the seriousness of this problem.