Lipoprotein(a) levels predict endothelial dysfunction in maintenance hemodialysis patients: evidence from vascular reactivity index assessment

Patients with maintenance hemodialysis (MHD) present endothelial dysfunction (ED), which is characterized by impaired vasodilation and a pro-inflammatory state. Lipoprotein(a) (Lp(a)) has pro-inflammatory and pro-atherogenic properties. No study has investigated the association between serum Lp(a) and ED in patients with MHD. This study was conducted to address this issue. We collected serum specimens from 123 fasting MHD patients. The endothelial function was measured using the vascular reactivity index (VRI) determined by digital thermal monitoring, and VRI values of ≥ 2.0, 1.0 to &lt;2.0, and &lt; 1.0, indicated good, intermediate, and poor vascular reactivity, respectively. Lp(a) levels were measured by enzyme-linked immunosorbent assay. Of the 123 MHD patients, 54 (43.9%) had good VRI, 51 (41.5%) had intermediate VRI, and 18 (14.6%) had poor VRI. Serum Lp(a) levels (<i>p</i> &lt; 0.001) were significantly higher in the poor and intermediate VRI groups than in the good VRI group. The log-transformed serum Lp(a) (log-Lp(a); <i>p</i> &lt; 0.001) showed a negative correlation with VRI values. Multivariate logistic regression analyses indicated that serum Lp(a) level was independently associated with vascular reactivity dysfunction (both intermediate and poor VRI; <i>p</i> = 0.001) and poor vascular reactivity (poor VRI; <i>p</i> &lt; 0.001). The areas under the receiver operating characteristic curve were 0.754 and 0.853 for predicting vascular reactivity dysfunction and poor vascular reactivity, respectively, by Lp(a). The serum Lp(a) level had a negative correlation with the VRI, and it may serve as a potential biomarker for early detection of ED in MHD patients.