Obesity and cardiac risk after kidney transplantation: experience at one center and comprehensive literature review.
BACKGROUND
The cardiac implications of obesity in kidney transplant recipients are not well-described.


METHODS
We examined associations of body mass index (BMI) at transplant with posttransplant cardiac risk among 1102 renal allograft recipients at a single center in 1991 to 2004. Cumulative posttransplant incidences of congestive heart failure (CHF), atrial fibrillation (AF), myocardial infarction, and a composite of these cardiac diagnoses were estimated by the Kaplan-Meier method. Bivariate (hazards ratio) and covariate (adjusted hazards ratio) relationships of BMI increments with cardiac risk were modeled by Cox's regression. We also systematically reviewed the literature on BMI and cardiac events after transplant.


RESULTS
In the local data, 5-year cumulative incidence of any cardiac diagnosis rose from 8.67% to 29.35% across the lowest to highest BMI quartiles (P=0.02), driven primarily by increases in CHF and AF. In contrast, the rate of myocardial infarction did not differ by BMI quartile (P=0.56). Each 5 U BMI increase predicted 25% higher risk of the cardiac composite (hazards ratio 1.25, 95% CI 1.07-1.47, P=0.005), a relationship that persisted with significance after covariate adjustment (adjusted hazards ratio 1.19, 95% CI 1.00-1.43, P=0.049). BMI independently predicted cardiac risk in subcohorts with pretransplant heart disease and with nondiabetic renal failure. Data from 26 original articles support BMI as a risk factor for posttransplant CHF and AF, whereas findings for coronary/ischemic outcomes are inconsistent and predominantly negative.


CONCLUSIONS
High BMI at transplant predicts increased cardiac risk, especially of CHF and AF. Further research should examine whether obesity treatment modifies cardiac risk after kidney transplantation.
Lentine
Krista L
KL
Center for Outcomes Research, Saint Louis University School of Medicine, St Louis, MO 63104, USA. lentine.krista@stanfordalumni.org
Rocca-Rey
Lisa A
LA
Bacchi
Giuliana
G
Wasi
Nadia
N
Schmitz
Leslie
L
Salvalaggio
Paolo R
PR
Abbott
Kevin C
KC
Schnitzler
Mark A
MA
Neri
Luca
L
Brennan
Daniel C
DC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000209:etiology*; D015992:Body Mass Index; D005260:Female; D006333:Heart Failure / Q000209:etiology*; D006801:Humans; D007674:Kidney Diseases / Q000150:complications* / Q000628:therapy*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology*; D017202:Myocardial Ischemia; D009765:Obesity / Q000150:complications*; D011183:Postoperative Complications; D016896:Treatment Outcome