High lipoprotein(a) and high risk of mortality.

Abstract

Several lipoprotein(a)-lowering therapies are currently being developed with the long-term goal of reducing cardiovascular disease and mortality; however, the relationship between lipoprotein(a) and mortality is unclear. We tested the hypothesis that lipoprotein(a) levels are associated with risk of mortality. We studied individuals from two prospective studies of the Danish general population, of which 69764 had information on lipoprotein(a) concentrations, 98810 on LPA kringle-IV type 2 (KIV-2) number of repeats, and 119094 on LPA rs10455872 genotype. Observationally, lipoprotein(a) >93 mg/dL (199 nmol/L; 96th-100th percentiles) vs. <10 mg/dL (18 nmol/L; 1st-50th percentiles) were associated with a hazard ratio of 1.50 (95% confidence interval 1.28-1.76) for cardiovascular mortality and of 1.20 (1.10-1.30) for all-cause mortality. The median survival for individuals with lipoprotein(a) >93 mg/dL (199 nmol/L; 96th-100th percentiles) and ≤93 mg/dL (199 nmol/L; 1st-95th percentiles) were 83.9 and 85.1 years (log rank P = 0.005). For cardiovascular mortality, a 50 mg/dL (105 nmol/L) increase in lipoprotein(a) levels was associated observationally with a hazard ratio of 1.16 (1.09-1.23), and genetically with risk ratios of 1.23 (1.08-1.41) based on LPA KIV2 and of 0.98 (0.88-1.09) based on LPA rs10455872. For all-cause mortality, corresponding values were 1.05 (1.01-1.09), 1.10 (1.04-1.18), and 0.97 (0.92-1.02), respectively. Finally, for a similar cholesterol content increase, lipoprotein(a) was more strongly associated with cardiovascular and all-cause mortality than low-density lipoprotein, implying that the mortality effect of high lipoprotein(a) is above that explained by its cholesterol content. High levels of lipoprotein(a), through corresponding low LPA KIV-2 number of repeats rather than through high cholesterol content were associated with high risk of mortality. These findings are novel.