The U Shaped Relationship Between High-Density Lipoprotein Cholesterol and All-Cause or Cause-Specific Mortality in Adult Population

Purpose: The associations of high-density lipoprotein cholesterol (HDL-C) with mortality are still unclear. We explored the associations of HDL-C with all-cause and cause-specific mortality in an adult population. Methods: Deaths were classified into all-cause, cardiovascular, and cancer mortality. Survival curve, multivariate Cox regression, and subgroup analyses were conducted, and hazard ratio (HR) and 95% confidence interval (CI) were performed. We fitted Cox regression models for all-cause, cardiovascular, and cancer mortality to evaluate their associations with categories of HDL-C (<= 30, 31-40, 41-50, 51-60 [reference], 61-70, >70 mg/dL). Results: A total of 42,145 (20,415 (48.44%) males, mean age 47.12 +/- 19.40 years) subjects were enrolled. At an average follow-up of 97.52 +/- 54.03 months, all-cause, cardiovascular, and cancer mortality numbers were 5,061 (12.01), 1,081 (2.56%), and 1,061 (2.52%), respectively. When compared with the reference group (HDL-C: 51-60 mg/dL), a U-shaped association was apparent for all-cause mortality, with elevated risk in participants with the lowest (<= 30 mg/dL) (HR=1.33; 95% CI=1.14-1.56) and highest (>70 mg/dL) (HR=1.14; 95% CI=1.02-1.27) HDL-C concentration. Associations for cardiovascular and cancer mortality were non-linear. An elevated risk for cancer mortality was observed in those with the highest HDL-C concentration (HR=1.06; 95% CI-0.84-1.34) compared with the reference group, although it was not statistically significant. The effect of HDL-C on mortality was adjusted by some traditional risk factors including age, gender, race, or comorbidities. Conclusion: A U-shaped association was observed between HDL-C and all-cause mortality among an adult population.