Nonlinear relationship with saturation effect observed between neutrophil to high-density lipoprotein cholesterol ratio and atherosclerosis in a health examination population: a cross-sectional study.

BACKGROUND: The relationships between inflammatory indexes and atherosclerosis as well as those between blood lipid indexes and atherosclerosis have been widely studied, but the relationship between the neutrophil to high-density lipoprotein cholesterol ratio (NHR) and atherosclerosis had not been investigated until the present study. METHODS: For this cross-sectional study, we continuously collected data from a health examination population in the Second Hospital of Hebei Medical University from January 2012 to December 2017 (N = 1978). The collected data included clinical data, hematological indexes, and brachial-ankle pulse wave velocity (Ba-PWV). Atherosclerosis was defined as Ba-PWV ≥ 1400 cm/s. The relationship between the NHR and atherosclerosis was explored via univariate regression analysis, multivariate regression analysis, smoothing function analysis, and analysis of a threshold saturation effect. RESULTS: Among 1978 participants, the mean age was 54 years, 1189 participants (60.11%) were male, and 1103 (55.76%) had a history of atherosclerosis. Univariate analysis showed a positive association between the NHR and atherosclerosis [odds ratio (OR) = 1.19, 95% confidence interval (CI): 1.11-1.27, P < 0.01], and this positive association remained significant on multivariate analyses with adjustments for confounding factors (OR = 1.14, 95% CI: 1.06-1.24, P < 0.01). Generalized additive model results revealed a non-linear relationship with a saturation effect between the NHR and atherosclerosis, with a threshold at 3.32. At values ≤ 3.32, the NHR was positively associated with atherosclerosis, but the association was not statistically significant for values > 3.32. CONCLUSION: A nonlinear relationship with a certain saturation effect was observed between the NHR and atherosclerosis in a health examination population.