Kidney Week

Abstract: FR-PO354

Volume Status by Bioimpedance and Blood Pressure in CKD

Session Information

• Hypertension, CVD, and the Kidneys: Epidemiology
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Hypertension and CVD

• 1602 Hypertension and CVD: Clinical

Authors

• Ravi, Katherine Scovner, Brigham and Women's Hospital, Boston, Massachusetts, United States

Katherine Scovner Ravi, MD, MPH

• Sayed, Enass, Brigham and Women's Hospital, Boston, Massachusetts, United States

Enass Sayed, PhD

• Neuen, Brendon Lange, The George Institute for Global Health, University of New South Wales, Sydney, New South Wales, Australia

Brendon Lange Neuen, MBBS, MS, PhD, FASN

• Chertow, Glenn M., Stanford University School of Medicine, Stanford, California, United States

Glenn M. Chertow, MD, MPH, FASN

• McCausland, Finnian R., Brigham and Women's Hospital, Boston, Massachusetts, United States

Finnian R. McCausland, MBChB, MS, FASN

Background

Hypertension is common among patients with chronic kidney disease (CKD) and is a risk factor for cardiovascular events and mortality. Though hypervolemia is thought to be a major contributor to hypertension, the association of objective biomarkers of volume status with blood pressure (BP) among patients with CKD is not well described.

Methods

Using data from the Chronic Renal Insufficiency Cohort (CRIC; n=5,384), we fit unadjusted and adjusted linear regression models and restricted cubic splines to examine the association of vector length (a bioimpedance proxy of volume status) with systolic and diastolic BP (SBP and DBP). We also assessed how the change in vector length over two years was associated with changes in SBP and DBP. Models adjusted for demographics, clinical history, BP medications, and laboratory covariates including log transformed 24-hour urine protein and urine sodium excretion.

Results

Mean age of participants was 59 ±11 years; 44% were female; 43% were Black; and mean SBP and eGFR were 129 ±21 mmHg and 48 ±16 mL/min/1.73m², respectively. The adjusted association of vector length with SBP was non-linear (Figure 1). The lowest quartile of vector length (a proxy for relative hypervolemia) was associated with a 3.0 mmHg (95%CI 0.9, 5.1) higher SBP, compared with the third quartile. Similarly, over two years, the lowest quartile of change in vector length (a proxy for more severe hypervolemia) was associated with the largest increase in SBP (3.8 mmHg; 95%CI 1.1, 6.4), compared with the third quartile. No association of vector length with DBP was observed.

Conclusion

Shorter vector length, a bioimpedance proxy of hypervolemia, is independently associated with higher SBP. Whether bioimpedance-guided volume management could improve BP control among patients with CKD requires further exploration.

Funding

• NIDDK Support