FTO (Fat Mass and Obesity-Associated) rs9939609 gene polymorphism and obesity: lack of association in kidney transplantation.

The fat mass and obesity-associated (FTO) gene is one of the most important obesity
susceptibility genes. Some FTO gene polymorphisms have been associated with obesity,
diabetes, and hypertension, all conditions for which, after transplant, there is increased
susceptibility, due to effects of immunosuppressive regimens. To evaluate whether FTO
could be a candidate for targeted preventive intervention in the transplant setting, we
investigated whether the common genetic variation, FTO rs9939609T>A, could affect
weight gain and risk of cardiovascular complications in kidney transplantation.
Methods. In 198 kidney transplant recipients, FTO rs9939609 was investigated in association
with body mass index (BMI)/obesity and with other clinical markers of posttransplant
risk, then monitored up to 5 years after transplantation. Genotyping was performed using an
allelic discrimination method on a real-time polymerase chain (PCR) system. Associations
were analyzed using the chi-square test; differences between genotypes were examined
with analysis of variance or Kruskal-Wallis test; tests for repeated measures and a general
linear model analysis controlling for age and gender were also utilized.
Results. Allele and genotype frequencies of FTO rs9939609 in recipients (T/T, 29.8%;
T/A, 49.0%; A/A, 21.2%; A, 45.7%; T, 54.3%) reflect those present in healthy Caucasian
populations. In the face of pre-/posttransplant differences in total cholesterol, triglycerides,
or fasting glucose, results did not show significant changes in these factors among genotypes
either before or after transplantation.
Conclusion. This study highlights a lack of association of FTO rs9939609T>A genotypes
and posttransplant weight gain, plasma lipids, and fasting blood glucose in kidney
transplantation.