A Non-Linear Association of Low-density lipoprotein cholesterol with All-Cause and Cardiovascular Mortality Among Patients with Hypertension

Background Although a few studies have examined the correlation between low-density lipoprotein cholesterol (LDL-C) and mortality, no study has explored these associations in hypertensive populations. This study aims to investigate the relationship between low-density lipoprotein cholesterol and cardiovascular and all-cause mortality in adults with hypertension. Methods Hypertensive participants aged ≥ 18 years old from the National Health and Nutrition Examination Survey (NHANES) 1999–2018 with blood lipid testing data and complete follow-up data until December 31, 2019 were enrolled in analysis. Univariate and multivariate Cox regression were conducted for the calculation of hazard ratios (HR) and 95% confidence intervals (CIs). Restricted cubic spline (RCS) curve was performed to visually represent the relationship between LDL-C and mortality. Survival analysis of Kaplan-Meier and stratification analysis were also carried out. Results We finally analyzed a cohort of 9,635 participants (49.6% male, mean age of 59.4 years). Following a median of 98 months of follow-up, there were 2,283(23.7%) instances of all-cause fatalities, with 758(7.9%) cases attributed to cardiovascular disease. Multivariate Cox regression analysis showed lower levels of LDL-C groups had a higher risk of all-cause and cardiovascular mortality; the LDL-C group's lowest level (< 2.198 mmol/L) still showed a 19.6% increased risk of all-cause mortality (p = 0.0068) in the model that has been completely adjusted. Both all-cause mortality and cardiovascular mortality showed a non-linear association with LDL-C concentration in restricted cubic spline regression analysis. Conclusions In individuals with hypertension, LDL-C was linked to cardiovascular and all-cause mortality, and we further demonstrated that this relationship was non-linear.