Lipoprotein (a) is a residual risk of atherosclerotic renal artery stenosis in hypertensive patients: a population-based cross-sectional study.

Background: Low-density lipoprotein cholesterol (LDL-c) has been proven to be a risk factor for atherosclerotic cardiovascular disease (CVD), while lipoprotein (a) (Lp(a)) is a residual risk factor for CVD, even though LDL-c is well controlled by statin use. Importantly, the role of Lp(a) in atherosclerotic renal artery stenosis (ARAS) is still unknown.Methods: For this cross-sectional population-based study, patients who simultaneously underwent coronary and renal angiography were examined. ARAS was defined as a 50% reduction in the cross-sectional (two-dimensional plane) area of the renal artery. Data were collected and compared between ARAS and non-ARAS groups, including clinical history and metabolite profiles. Univariate analysis, three tertile LDL-c-based stratified analysis, and multivariate-adjusted logistic analysis were conducted, revealing a correlation between Lp(a) and ARAS.Results: A total of 170 hypertensive patients were included in this study, 85 with ARAS and 85 non-RAS. Baseline information indicated comparability between the two groups. Univariate analysis showed that systolic blood pressure and peripheral arterial disease were positively correlated with ARAS while coronary artery disease was negatively associated. Stratified analysis of LDL-c revealed a significant increase in the incidence of ARAS in patients who had high Lp(a) concentrations at low LDL-c levels (OR: 4.77, 95%CI:1.04-21.79, P = 0.044). Further logistic analysis with adjusted covariates also confirmed the result, indicating that high Lp(a) levels were independently associated with ARAS (OR: 8.16, 95%CI 1.12-59.12, P = 0.037). This relationship increased with increasing Lp(a) concentration based on a curve fitting graph. These results were not present in the low and intermediate LDL-c-level groups.Conclusion: In hypertensive patients who present low LDL-c, high Lp(a) was significantly associated with atherosclerotic renal artery stenosis and thus is a residual risk factor.