Weight gain after liver transplantation and the insertion/deletion polymorphism of the angiotensin-converting enzyme gene

Background. Subjects who carry the D allele of the angiotensin-converting enzyme (ACE) gene have higher plasma and tissue angiotensin II levels, possibly concurrent with the development of obesity. In transplant recipients, treatment with calcineurin antagonists would magnify these effects. The present study verifies whether the allelic variants of ACE are a factor involved in excess weight gain after liver transplantation. Methods. A consecutive series of 108 liver transplant recipients (73 males) were studied. Recipient ACE genotypes, determined by a polymerase chain reaction-based method, were related to body mass changes 1 year after transplant. Results. Body mass index (BMI) increased from the pretransplant value of 25.1±3.3 kg/m² to 25.9±3.5 kg/m² (P<0.005). The difference was mainly attributable to recipients carrying 1 D allele or more (N=88) in whom the BMI increased from 25.3±3.1 kg/m² to 26.3±3.3 kg/m ² (P<0.005). A BMI of 25 kg/m² or greater was measured in 30 of 45 deletion/deletion homozygotes and 25 of 43 insertion/deletion heterozygotes; in contrast, 14 of 20 insertion/insertion homozygotes had a normal body mass (P<0.01). Among patients with normal body mass pretransplant (N=56), none of 13 insertion/insertion homozygotes reached a BMI value 25 kg/m² or greater posttransplant (P<0.005). At multi-variate analysis, pretransplant body mass and carriage of 1 D allele or more were independent predictors of body mass gain greater than 2 kg/m². Conclusions. Carriage of the D allele of the ACE gene is a strong, independent risk factor for excess weight gain after liver transplantation.