The impact of kidney transplantation on heart failure risk varies with candidate body mass index.
BACKGROUND
The relationship of body mass index (BMI) with heart failure (HF) risk before and after kidney transplant is not well described.


METHODS
We examined United States Renal Data System records for 67,591 kidney transplant candidates (1995-2004) with Medicare insurance and BMI data at listing. Heart failure diagnoses were ascertained from Medicare billing claims. Body mass index was categorized per World Health Organization criteria. We modeled time-dependent associations (adjusted hazard ratio, aHR) of transplant with HF risk after listing compared with waiting in each BMI group by multivariable, stratified Cox regression. The time-dependent exposure variables partitioned relative risk of HF after transplant versus waiting into early (<or=90 days) and late (>90 days) posttransplant periods.


RESULTS
The BMI distribution of listed candidates was as follows: 3.7% under, 40.4% normal, 32.0% over, 16.2% obese, and 7.7% morbidly obese weight. The prevalence of HF among patients awaiting transplant reached 57.4% by 3 years. Deceased-donor transplant was associated with increased early HF risk compared with continued waiting-aHRs ranged from 2.23 for normal-BMI to 2.82 for morbidly obese patients. However, transplant reduced the risk of HF in the late posttransplant period from 54% (aHR 0.46) in normal-BMI to 32% (aHR 0.68) for morbidly obese patients. Relative benefits were largest for normal-weight candidates who received live-donor transplants (aHR 0.31).


CONCLUSIONS
Heart failure risk improves in obese patients in the long term after kidney transplant, but not as much as for nonobese patients. There is need for close monitoring and for new strategies to reduce HF risk in obese patients before and after transplant.
Lentine
Krista L
KL
Center for Outcomes Research, Saint Louis University School of Medicine, St Louis, MO 63104, USA. lentine.krista@stanfordalumni.org
Xiao
Huiling
H
Brennan
Daniel C
DC
Schnitzler
Mark A
MA
Villines
Todd C
TC
Abbott
Kevin C
KC
Axelrod
David
D
Snyder
Jon J
JJ
Hauptman
Paul J
PJ
D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D005260:Female; D006333:Heart Failure / Q000453:epidemiology*; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012306:Risk; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult