Kidney Week

Abstract: TH-PO1134

Kidney Function Decline Affects Endothelial Dependent Flow Mediated Dilation Independently of HDL, LDL, and HsCRP

Session Information

• CKD: Clinical, Outcomes, Trials - I
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 1902 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

• Whitfield, Victoria, Vanderbilt University Medical Center, Nashville, Tennessee, United States

Victoria Whitfield,

• Akwo, Elvis A., Vanderbilt University Medical Center, Nashville, Tennessee, United States

Elvis A. Akwo,

• Siew, Edward D., Vanderbilt University School of Medicine, Nashville, Tennessee, United States

Edward D. Siew,

• Ikizler, Talat Alp, Vanderbilt University Medical Center, Nashville, Tennessee, United States

Talat Alp Ikizler,

• Hung, Adriana, Vanderbilt University, Nashville, Tennessee, United States

Adriana Hung,

Background

Patients with CKD have a significant cardiovascular morbidity & mortality. Endothelial function is the earliest manifestation in the continuum of atherosclerosis. We investigated the relationship between glomerular filtration rate (GFR) and endothelium-dependent vascular function in a nondiabetic population.

Methods

Participants were 89 CKD patients and 22 with normal GFR who underwent brachial artery flow-mediated dilation (FMD_BA) by high resolution ultrasound. Clinical evaluation, renal function tests, lipid profile and high sensitivity C-reactive protein (hsCRP) assays were performed on all study participants. Multivariable linear regression models with robust standard errors were used to investigate the dose-response relationship between FMD% and estimated GFR (eGFR) – modeled as a restricted cubic spline with 4 knots. Covariates were age, sex, race, body mass index (BMI), systolic blood pressure (SBP), hsCRP, HDL and LDL cholesterol. Skewed variables were log transformed.

Results

Over 71% of participants were male, 21% were African-American. The mean (SD) age was 63.2 (13.7) years. Median (25^th, 75^th) FMD% was lower among CKD patients compared to controls [4.2 (2.9, 6.3) vs. 8.5 (4.8, 10.4); p = 0.0004] (figure 1). After full adjustment for baseline covariates, CKD patients had a significant 3.2% (95% CI: 0.7, 5.7, p = 0.01) lower FMD%. Percent FMD had a significant inverse correlation with age (r = -0.36, p = 0.001). In a minimal model adjusted for age, sex, race and BMI, eGFR had a significant (p = 0.0006) positive nonlinear relationship with FMD% with a trough on the dose-response curve occurring at an eGFR ~ 60mL/min/1.73m² (figure 1). The association remained significant (p = 0.0005) after further adjustment for SBP, log hsCRP, log HDL and log LDL.

Conclusion

Endothelium-dependent vascular function diminishes across the kidney function continuum, independently of traditional CVD risk factors. Further investigation into the underlying mechanisms involved maybe warranted.

Funding

• Veterans Affairs Support