Complementary prediction of cardiovascular events by estimated apo- and lipoprotein concentrations in the working age population. The Health 2000 Study.

BACKGROUND: Apolipoprotein A-I (apoA-I) and B (apoB) and multiple lipoprotein cardiovascular risk factors can be computationally estimated with our extended Friedewald approach (EFW) from classical inputs. Their impact on cardiovascular events and mortality in the working age population is not known.
METHODS: The working age (≤ 65 years, n = 5956) prospective population-based cohort (follow-up of 7.8 ± 0.9 years; 46,572 patient years, 409 non-fatal incident cardiovascular events, and 55 cardiovascular and 266 all-cause deaths) had their total serum cholesterol (TC), triglycerides (TG), and HDL-C measured. Continuous net reclassification improvement (NRI) was calculated.
RESULTS: In Cox models adjusted with cardiovascular risk factors, EFW-HDL(2)-C (HR 0.78, 95% CI 0.67-0.91; NRI 16.5%), apoA-I (HR 0.78, 95% CI 0.69-0.89; NRI 15.2%), apoB/apoA-I (HR 1.23, 95% CI 1.08-1.40; NRI 20.6%), and VLDL-TG (HR 1.15, 95% CI 1.05-1.25; NRI 20.1%) were associated with incident non-fatal cardiovascular events and improved risk prediction compared with TC, LDL-C, or non-HDL-C. Cardiovascular deaths could be best predicted with EFW apoB (HR 1.81, 95% CI 1.18-2.77; NRI 77.3%).
CONCLUSIONS: EFW approach-derived HDL(2)-C, apoA-I, apoB/apoA-I, and VLDL-TG improve prediction of non-fatal cardiovascular events, and apoB of cardiovascular mortality, and can be utilized for risk estimation in a working age population without extra cost.