Authors' objectives:

The aim of this study was to perform a systematic review of the literature and to assess the effects of supplementation with omega-3 fatty acids (eicosapentaenoic acid [EPA; 20:5 n-3], docosahexaenoic acid [DHA; 22:6 n-3], commonly referred to as fish oil, and alpha-linolenic acid [ALA, 18:3 n-3]) on various transplant-related outcomes.

Authors' results and conclusions: All but 1 study used fish oil as the source of omega-3 fatty acids. Major concerns in all evaluated studies were their small size and methodological deficiencies. There was variability in the rigor with which endpoints were defined and measured. Important covariates (such as use of antihypertensive agents or the intensity of immunosuppression) were often poorly described or inconsistently applied even when the study considered outcomes that may have been confounded by these factors. No consistent benefits of fish oil supplementation were observed for any outcome with the exception of a modest benefit on triglycerides in kidney transplantation. Improvement in renal function was described in several studies, although discordant results were also reported. There were no clear patient- or study-related characteristics to account for the heterogeneity. At best, the degree of improvement was modest and did not translate into other clinically important outcomes such as improved graft survival, although the duration of the studies was generally less than one-year. A meta-analysis of rejection episodes in kidney transplantation found no significant benefit on either early (<6 months post transplant) or late rejection episodes. The overall relative risk of having at least one rejection episode in those receiving fish oil supplementation was 0.91 (95% CI 0.74, 1.10) in 4 studies with a total of 224 patients, all of which had a follow-up of 1 year (the longest follow-up reported). A meta-analysis of 7 randomized controlled trials (with a total of 470 patients) of graft survival in kidney transplantation found no significant benefit from fish oil supplementation (relative risk 1.00, 95% CI 0.96, 1.05). There was no significant heterogeneity between the studies. No clinically important interactions were observed between fish oil supplementation and the dose or trough-levels of cyclosporin A.

Authors' recommendations: Fish oil supplementation in organ transplant recipients is associated with a modest reduction in triglyceride concentrations, a benefit that has been established in the non-transplant setting. Inconsistent benefits on renal function across studies may suggest a potential benefit in a subset of patients, the characteristics of whom remain unclear. Whether administration of omega- 3 fatty acids prior to transplantation would improve its benefits is unclear. Long-term studies are needed to determine whether benefits on renal function translate into improved renal outcomes. Similarly, long-term follow-up in recipients of heart transplants will be required to determine whether fish oil supplementation reduces the risk of post-transplant atherosclerosis. Because of the scarcity of data, the effects of ALA supplementation in the transplant setting cannot be determined. Applicability of the results to contemporary transplantation procedures is uncertain since most of the studies were performed several years ago, with some more than a decade old. The technology for all transplantation procedures continues to improve with a larger choice of immunosupressive agents, a better understanding of how to use them, and means to address the known complications of transplantation including some of the important outcomes (such as hyperlipidemia and hypertension).

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/tp/o3organtp.htm

Year Published: 2005

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)