Relationship Between Body Mass Index and Mortality in Adults on Maintenance Hemodialysis: A Systematic Review

Objective

The primary objective of this systematic review was to determine the relationship between body mass index (BMI) and all-cause and cardiovascular mortality.

Design

Systematic review of primarily observational studies.

Patients

Adult patients from all gender, race, or ethnic groups on maintenance hemodialysis.

Methods

Medline, Science Citation Index, Academic Search Premier, Cochrane Library, and Embase electronic databases covering the period 1966 to December 2008 were searched with the help of a qualified librarian. Reference lists of included papers and collections also were searched. Each study was reviewed by 2 independent reviewers who also performed the data extraction from full papers. Differences between reviewers were resolved by consensus or by a third reviewer in the case of disagreements. The quality of studies selected for inclusion in the systematic review was also assessed by 2 independent reviewers.

Main Outcomes

BMI and mortality.

Results

Eighteen studies (60%) reported a significant inverse relationship between all-cause mortality and BMI. This inverse relationship was more prevalent in older patients, larger retrospective studies, and studies that did not adjust for inflammation. On the other hand, 57% of the 7 studies reporting on cardiovascular mortality found no significant relationship with BMI.

Conclusions

This systematic review shows evidence of an inverse relationship between BMI and all-cause mortality in adult patients on maintenance HD, especially in older patients, but the relationship with cardiovascular mortality is less clear.