Kidney Week

Abstract: FR-PO550

Change in Body Composition over Time and Its Association with Survival Among Patients on Hemodialysis

Session Information

• Physical Activity, Body Composition, Metabolism: Clinical
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Health Maintenance, Nutrition, and Metabolism

• 1302 Health Maintenance, Nutrition, and Metabolism: Clinical

Authors

• Delgado, Cynthia, Veterans Affairs Medical Center, San Francisco, California, United States

Cynthia Delgado,

• Chiang, Janet, University of California, San Francisco, San Francisco, California, United States

Janet Chiang,

• Grimes, Barbara A., UCSF, San Francisco, California, United States

Barbara A. Grimes,

• Kaysen, George A., University of California, Davis, Davis, California, United States

George A. Kaysen,

• Segal, Mark, UCSF, San Francisco, California, United States

Mark Segal,

• Johansen, Kirsten L., University of California, San Franicsco, San Francisco, California, United States

Kirsten L. Johansen,

Background

Patients with ESRD who have a higher body mass index have better survival, a phenomenon known as the obesity paradox. Accounting for body composition and for changes over time may help to elucidate this paradoxical association.

Methods

We leveraged repeated measures of body composition (at baseline, 12, and 24 months) by whole-body bioimpedance spectroscopy (BIS) from 286 prevalent ESRD patients from 7 dialysis facilities in the USRDS ACTIVE/ADIPOSE study to examine the obesity paradox. We performed BIS to estimate intracellular water as a proxy for muscle mass (ICW/m²), extracellular water (ECW/m²), and fat mass (FM/m²). Death data were ascertained through linkage with the USRDS through June 2016. We used linear mixed models to examine change in body composition over time and Cox models with BIS-derived estimates as time-varying predictors to examine survival after adjusting for covariates.

Results

Results: Participants’ mean age was 59 ± 15, and 66% were male. Over time, only ICW/m² declined (-0.08 95%CI -0.13, -0.04 L/m²/year) and neither ECW/m² (0.02 95%CI -0.03, 0.06 L/m²/year) nor FM/m² (-0.07 95%CI -0.20, 0.05 L/m²/year) changed significantly. In survival analysis with body composition parameters as time-varying predictors, ICW/m² was associated with lower mortality (HR 0.67, 95%CI 0.49, 0.93). Higher ECW/m² was associated with higher mortality (HR 1.75 95%CI 1.19, 2.60). Fat mass was not associated with survival (HR 0.99 95%CI 0.93, 1.06).

Conclusion

In this cohort of participants with repeated measures of body composition, muscle mass declined over time. Higher muscle mass was associated with better survival, but higher fat mas was not associated with survival independent of muscle mass.

Funding

• NIDDK Support