U-shaped Association Between Apolipoprotein B and All-Cause Mortality: Results from the National Health and Nutrition Examination Surveys

BackgroundApolipoprotein B (apoB), a significant component directly reflecting the number of atherogenic lipoprotein particles, gradually becomes a more conducive indicator to control blood lipids. However, epidemiological evidence on its relationship with mortality is limited, especially with all-cause mortality. MethodsParticipants from the National Health and Nutrition Examination Survey during 2007-2014 were grouped according to the apoB quartiles (15-76, 77-92, 93-110, 111-345mg/dL). We performed Cox proportional hazards models and Kaplan-Meier survival curves to evaluate the relationships of apoB with all-cause and cardiovascular mortality. Restricted cubic spline and piecewise linear regression were performed to detect their non-linear relationships. ResultsIn general, we enrolled 10375 participants among United States adults (mean age 46.3 ± 16.9, 47.88% men). On average, participants were followed up for 69.2 months, among whom 533 (5.14%) and 91 (0.88%) deaths were observed due to all -causes and cardiovascular diseases, respectively. After adjusting for confounders, apoB was independently associated with an elevated risk of cardiovascular death (hazard ratio [HR], 1.13; 95% confidence interval [CI], 1.03-1.24). However, in the third quartile of apoB, the risk of all-cause death decreased significantly (HR, 0.71; 95% CI, 0.56-0.91). Moreover, the non-linear relationship between apoB and all-cause death demonstrated an increased risk at both low and high level apoB concentrations, divided by the threshold point of 108 mg/dl. Conclusion Elevated apoB was significantly associated with an increased risk for cardiovascular mortality, while its association with all-cause mortality was non-linear correlated, with an increased risk at both low and high apoB levels.