Height Linked To Increased Mortality In Hemodialysis Patients

MedicalResearch.com Interview with:
Bryan B. Shapiro
Harold Simmons Center for Kidney Disease Research and Epidemiology and
Division of Nephrology and Hypertension
Los Angeles Biomedical Research Institute
Harbor–UCLA Medical Center Torrance, California

Medical Research: What is the background for this study? What are the main findings?

Response: The inverse relationship between body mass index (BMI) and mortality rates is well-documented in maintenance hemodialysis (MHD) patients. Virtually everyone has assumed that this relationship reflects the effect of body weight, and especially fat mass, on mortality in these patients. However, height is also a component of the BMI equation (BMI = body weight (kg)/height (m²)) and may be independently associated  with mortality in MHD patients. The results of this study, which examined 117, 644 MHD patients and was controlled for many demographic and laboratory variables, indicate that height, adjusted for body weight, is directly associated with mortality in a manner that is opposite to the weight-mortality relationship. Moreover, we found that the contribution of height to the inverse BMI-mortality relationship in dialysis is essentially as great as the contribution of weight.

Medical Research: What should clinicians and patients take away from your report?

Response: Because essentially all previous studies have surmised that the weight component is responsible for the inverse-BMI relationship, this study obliges a rethinking of this very intriguing and potentially very important inverse association between BMI and mortality in maintenance dialysis patients. In addition, our observations raise for the first time the important questions of why height is directly associated with an increased risk of death in maintenance hemodialysis patients and why this height-mortality relationship in MHD differs from the height–mortality relationships reported for the general adult population.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: This study prompts further research that explores mechanisms underlying the direct height-mortality relationship that we observed. One of the hypotheses that we put forward is that taller hemodialysis patients, adjusted for body weight, may have a greater lean body mass and therefore may be more likely to receive an inadequate dialysis dose per unit of lean body mass. Thus, they may have a greater burden of dialyzable toxins than shorter hemodialysis patients. For this reason, one might explore the relationships of dialysis dose with patient height.


Association of Height with Mortality in Patients undergoing Maintenance Hemodialysis

Bryan B. Shapiro, Elani Streja, Vanessa A. Ravel, Kamyar Kalantar-Zadeh, and Joel D. Kopple

CJASN CJN.07970814; published ahead of print March 30, 2015, doi:10.2215/CJN.07970814


MedicalResearch.com Interview with: Bryan B. Shapiro (2015). Height Linked To Increased Mortality In Hemodialysis Patients

Last Updated on April 7, 2015 by Marie Benz MD FAAD