Obesity and Cardiac Risk After Kidney Transplantation: Experience at One Center and Comprehensive Literature Review

Abstract

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 post-transplant cardiac risk among 1,102 renal allograft recipients at a single center in 1991-2004. Cumulative post-transplant incidences of congestive heart failure (CHF), atrial fibrillation (AF), myocardial infarction (MI), and a composite of these cardiac diagnoses were estimated by the Kaplan-Meier method. Bivariate (hazards ratio, HR) and covariate-adjusted (aHR) 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 MI did not differ by BMI quartile (P=0.56). Each 5 U BMI increase predicted 26 % higher risk of the cardiac composite (HR 1.26, 95% CI 1.06 −1.48 2.14, P=0.008), a relationship that persisted with significance after covariate adjustment (aHR 1.19, 95% CI 1.00 −1.43, P=0.049). BMI independently predicted cardiac risk in sub-cohorts with pre-transplant heart disease and with non-diabetic renal failure. Data from 26 original articles support BMI as a risk factor for post-transplant 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.

Rola aktywności fizycznej w leczeniu pacjentów z przewlekłą chorobą nerek

“…W latach 1991-2004 naukowcy z Włoch i USA przeprowadzili badanie na 1102 biorcach nerki [18,19]. Celem pracy była ocena zależności pomiędzy wskaźnikiem masy ciała (BMI) a ryzykiem wystąpienia zaburzeń kardiologicznych takich jak: zastoinowa niewydolność serca, migotanie przedsionków i zawał mięśnia sercowego u osób poddanych zabiegowi transplantacji.…”

Cardiovascular risk factors following renal transplant

“…Initial BMI is an independent predictor for patient death and graft failure, and rates of morbidity (81% vs 89%) are higher and graft survival (71% vs 80%) is significantly reduced in obese RTRs at 5 years after transplantation [100] . Corticosteroids are recognised to cause a gain in weight, which may increase the risks of graft dysfunction and CV events [101] . Overall, the pattern of metabolic abnormalities caused by steroids is very similar to that seen in patients with metabolic syndrome [102] .…”

Associations of Pretransplant Weight and Muscle Mass with Mortality in Renal Transplant Recipients

“…Early studies had reported poorer kidney transplant outcomes in obese dialysis patients (1)(2)(3)(4), mainly because of cardiovascular (5) and infectious complications such as surgical wound infections (6). However, more recent studies have reported that weight change before transplantation did not correlate with graft loss and death after kidney transplantation (7), although obese recipients develop diabetes mellitus or surgical complications more frequently (6,8 -11).…”

“…In a recent report, BMI Ն 35 kg/m 2 was the third most common reason to deny transplant waitlisting and affecting 10% of potential renal transplant candidates (14). Because the long-term consequences of obesity after transplantation remain unclear (5,15), it is important to address the potential association between pretransplant body composition and posttransplant outcomes.…”