Blood urea impairs brachial artery flow mediated dilation

Area of Science:

• Cardiovascular Physiology
• Renal Function Biomarkers
• Endothelial Function Assessment

Background:

• Serum urea, a key indicator of protein metabolism and renal function, is known to affect vascular health.
• The direct relationship between serum urea concentration and in vivo vascular reactivity remains under-explored, particularly in individuals without chronic kidney disease (CKD).

Purpose of the Study:

• To investigate the association between serum urea levels and endothelial function in subjects without CKD.
• To explore the correlation between serum urea concentration and vascular reactivity measured by flow-mediated dilation (FMD).

Main Methods:

• Eighty subjects without CKD (serum creatinine ≤1 mg/dL) were recruited.
• Serum analyses and endothelial function assessment using the flow-mediated dilation (FMD) technique were performed.
• Simple and multiple regression analyses were employed to determine associations between FMD and various parameters.

Main Results:

• Flow-mediated dilation (FMD) showed inverse associations with serum urea (r=-0.37; P<0.01), serum creatinine (r=-0.31; P<0.01), and age.
• Serum urea and brachial artery baseline diameter were identified as significant predictors of FMD in multiple regression analysis.
• Cardiovascular risk factors, age, and gender did not independently relate to FMD in this cohort.

Conclusions:

• Serum urea concentration is associated with endothelial function, as measured by FMD, in individuals without CKD.
• Accumulation of urea, a waste product of protein metabolism, may contribute to impaired vascular health even before the onset of overt kidney disease.