Relationship Between Interdialytic Weight Gain and Blood Pressure Among Prevalent Hemodialysis Patients

Inrig, Jula K.; Patel, Uptal D.; Gillespie, Barbara S.; Hasselblad, Vic; Himmelfarb, Jonathan; Reddan, Donal; Lindsay, Robert M.; Winchester, James F.; Stivelman, John; Toto, Robert; Szczech, Lynda A.

doi:10.1053/j.ajkd.2007.04.020

« Previous Next »American Journal of Kidney Diseases
Volume 50, Issue 1 , Pages 108-118.e4, July 2007

Relationship Between Interdialytic Weight Gain and Blood Pressure Among Prevalent Hemodialysis Patients

Jula K. Inrig, MD, MHS
- Department of Medicine, Duke University Medical Center, Durham, NC
- Duke Clinical Research Institute, Durham, NC
- Address correspondence to Jula K. Inrig, MD, MHS, Department of Medicine, Duke University Medical Center, DUMC Box 3646, Durham, NC 27705.
Uptal D. Patel, MD
- Department of Medicine, Duke University Medical Center, Durham, NC
- Duke Clinical Research Institute, Durham, NC
Barbara S. Gillespie, MD
- Department of Medicine, Duke University Medical Center, Durham, NC
- Duke Clinical Research Institute, Durham, NC
Vic Hasselblad, PhD
- Duke Clinical Research Institute, Durham, NC
Jonathan Himmelfarb, MD
- Maine Medical Center, Portland, ME
Donal Reddan, MD
- University College Galway, Galway, Ireland
Robert M. Lindsay, MD
- London Health Sciences Center and University of Western Ontario, London, Ontario, Canada
James F. Winchester, MD
- Beth Israel Medical Center, New York, NY
John Stivelman, MD
- Northwest Kidney Centers, Seattle, WA
Robert Toto, MD
- University of Texas Southwestern Medical Center at Dallas, Dallas, TX
Lynda A. Szczech, MD, MSCE
- Department of Medicine, Duke University Medical Center, Durham, NC
- Duke Clinical Research Institute, Durham, NC

Received 27 October 2006; accepted 26 April 2007.

Background

Hypertension is common in hemodialysis patients; however, the relationship between interdialytic weight gain (IDWG) and blood pressure (BP) is incompletely characterized. This study seeks to define the relationship between IDWG and BP in prevalent hemodialysis subjects.

Study Design, Setting, & Participants

This study used data from 32,295 dialysis sessions in 442 subjects followed up for 6 months in the Crit-Line Intradialytic Monitoring Benefit (CLIMB) Study.

Outcomes & Measurements

Mixed linear regression was used to analyze the relationship between percentage of IDWG (IDWG [%] = [current predialysis weight − previous postdialysis weight]/dry weight * 100) as the independent variable and systolic BP (SBP) and predialysis − postdialysis SBP (ΔSBP) as dependent variables.

Results

In unadjusted analyses, every 1% increase in percentage of IDWG was associated with a 1.00 mm Hg (95% confidence interval [CI], ±0.24) increase in predialysis SBP (P < 0.0001), 0.65 mm Hg (95% CI, ±0.24) decrease in postdialysis SBP (P < 0.0001), and 1.66 mm Hg (95% CI, ±0.25) increase in ΔSBP (P < 0.0001). After controlling for other significant predictors of SBP, every 1% increase in percentage of IDWG was associated with a 1.00 mm Hg (95% CI, ±0.24) increase in predialysis SBP (P < 0.0001) and a 1.08 mm Hg (95% CI, ±0.22) increase in ΔSBP with hemodialysis (P < 0.0001). However, in subjects with diabetes as the cause of end-stage renal disease, subjects with lower creatinine levels, and older subjects, the magnitude of the association between percentage of IDWG and predialysis SBP was less pronounced. The magnitude of percentage of IDWG on ΔSBP was less pronounced in younger subjects and subjects with lower dry weights. Results were similar with diastolic BP.

Limitations

Hemodialysis BP measurements are imprecise estimates of BP and true hemodynamic burden in dialysis subjects.

Conclusions

In prevalent hemodialysis subjects, increasing percentage of IDWG is associated with increases in predialysis BP and BP changes with hemodialysis; however, the magnitude of the relationship is modest and modified by other clinical factors. Thus, although overall volume status may impact on BP to a greater extent, day-to-day variations in weight gain have a modest role in BP increases in prevalent subjects with end-stage renal disease.

Index Words: Interdialytic weight gain, blood pressure, hemodialysis