Pretransplantation and Posttransplantation Body Mass Indices and Prognosis in Renal Transplant Recipients: Low Versus Normal

Poor kidney graft survival in anorexia nervosa patients

BACKGROUND

Anorexia nervosa is a condition associated with poor outcomes in a variety of circumstances such as recurrence of eating disorders, psychiatric disorders, and organ damage.

OBJECTIVE

In the present study, we first sought to determine the 5-year kidney graft survival in patients with anorexia nervosa and then to evaluate the BMI course and medical complications.

METHODS

In this multicenter, retrospective, case-control study, we analyzed the impact of anorexia nervosa on graft outcomes compared to transplant recipients with low or normal BMI.

RESULTS

We enrolled 137 women in this study: 19 with anorexia nervosa, 59 with low BMI (BMI < 18.5 kg/m²), and 59 with normal BMI (18.5-24.9 kg/m²). Anorexia nervosa was significantly associated with lower graft survival compared to either of the other groups (hazard ratio 5.5 [95% CI 3.4-8.9], p = 0.005); there was no difference in graft survival between patients with low or normal BMI. Cardiovascular complications were more frequent in the anorexia nervosa group (37%) than in patients with low (6%) or normal BMI (7%) (p = 0.001).

CONCLUSION

We conclude that patients with anorexia nervosa should be considered a high-risk group.

LEVEL OF EVIDENCE

Level III, evidence obtained from well-designed cohort or case-control analytic studies.

Body mass index, weight-adjusted immunosuppression and the risk of acute rejection and infection after kidney transplantation: a cohort study

BACKGROUND

Body mass index (BMI) is associated with patient outcomes after kidney transplantation. We hypothesized that immunosuppression (IS) dosing is a contributing factor.

METHODS

Using Australia and New Zealand Dialysis and Transplant registry data, we included all adult kidney-only transplant recipients over 2000-14 treated with prednisolone, mycophenolate and tacrolimus/cyclosporin (n = 7919). The exposure was BMI and the outcomes were time to: (i) acute rejection, (ii) fatal infection, (iii) cancer and (iv) graft; and (v) patient survival. We modelled BMI and IS dosing (in quartiles) as time-varying covariates in extended Cox models.

RESULTS

Compared with a BMI of 25 kg/m2, a BMI of 35 was associated with acute rejection after adjusting for demographics and comorbidities [adjusted hazard ratio (aHR) = 1.29, 95% confidence interval (CI) 1.12-1.49]. This association virtually disappeared after correcting for IS (aHR = 1.09, 95% CI 0.93-1.29). A BMI of 35 was non-significantly associated with fewer fatal infections (aHR = 0.91, 95% CI 0.66-1.25), but this reversed after adjusting for IS (aHR = 1.54, 95% CI 1.03-2.28). Results for cancer were not significantly altered after adjusting for IS. Results for lower BMI were similarly not significantly altered though generally associated with worse outcomes.

CONCLUSIONS

Our findings show that the associations between high BMI, acute rejection and fatal infection after kidney transplantation were significantly altered after correcting for IS suggesting that relative under-dosing of obese patients may partially explain these associations.

Effect of Body Mass Index on Outcome in Pediatric Heart Transplant Patients

BACKGROUND

Obesity and cachexia are risk factors for adverse outcomes in adult transplant patients. However, little is known about the effects of body mass index (BMI) on outcomes in pediatric heart transplant patients.

METHODS

Patients > 2 years of age undergoing heart transplantation from 1985 to 2004 at our institution were included in this study. BMI was assessed at the time of transplant and at 1 year post-transplant. Long-term outcomes were assessed by weight group.

RESULTS

The cohort included 105 patients with a mean age at transplant of 9.6 +/- 5.3 years. The mean BMI percentile at the time of transplant was 39 +/- 34, with 22 (21%) patients underweight (< 5th percentile) and 8 (8%) patients overweight (> or = 95th percentile). Among patients surviving to 1 year (n = 92), the mean BMI percentile increased to 57 +/- 33 (p < 0.05). Overall graft survival was decreased in patients underweight at transplant, mean 6.7 years (95% confidence interval [CI] 3.6 to 9.9), vs normal weight patients, mean 10.6 years (95% CI 8.8 to 12.4) (p < 0.05). Patients overweight at transplant did not have decreased graft survival. Neither low nor high BMI at 1 year post-transplant was associated with adverse outcomes. On multivariate analysis, being underweight at transplant was an independent predictor of decreased graft survival (p = 0.03).

CONCLUSIONS

Weight gain was nearly universal post-transplant with only 4% of patients underweight at 1 year. In the small number of patients overweight at transplant, graft survival was similar to normal-weight patients. Conversely, being underweight at transplant was an independent predictor of decreased graft survival.

Weight Gain Post–Renal Transplantation and Its Association With Glomerular Filtration Rate

OBJECTIVE

Obesity may be a risk factor for renal graft loss. The purpose of this study was to assess weight gain and its association with glomerular filtration rate after kidney transplant.

METHODS

This retrospective analysis of 152 adult renal transplant outpatients (77 males, 75 females; mean age, 45.6 +/- 10.1 years) with at least 6 months posttransplantation (post-tx) included body weight and creatinine clearance (CrCl) measured pretransplantation (pre-tx) as well as at 6 months (post-tx1), 1 year (post-tx2), 5 years (post-tx3), 10 years (post-tx4), 15 years (post-tx5), and 20 years (post-tx6) post-tx. Weight gain was determined by subtracting patient preoperative weight from the post-tx weights.

RESULTS

The weight gain post-tx versus pre-tx was progressive and significant (P < .001) post-tx1, 8.7 +/- 10.9% (n = 152); post-tx2, 12.4 +/- 11.5% (n = 150); post-tx3, 16.6 +/- 14.8% (n = 102); post-tx4, 20.1 +/- 18.1% (n = 47); post-tx5, 20.8 +/- 19.8% (n = 17); and post-tx6, 21.0 +/- 32.5% (n = 11). There was a positive and significant correlation between weight gain and CrCl during most times post-tx: post-tx2 (r = 0.32; P < .000); post-tx3 (r = 0.54; P < .0001); post-tx4 (r = 0.47; P = .01); and post-tx6 (r = 0.92; P < .001).

CONCLUSIONS

There was a great increase in body weight after kidney transplantation. The excessive body weight gain was associated with a better glomerular filtration rate.