Short-term lipoprotein(a) change after statin initiation in statin-naïve patients: magnitude, baseline dependence, and clinical relevance

Statins are first-line therapies for atherosclerotic cardiovascular disease (ASCVD), but their effect on lipoprotein(a) [Lp(a)] is uncertain, ranging from no effect to a paradoxical increase. In a retrospective discovery cohort, statin-naïve patients with two Lp(a) measurements obtained within a short-term window of 14–30 days were studied ( N = 5,435; 2,030 initiators and 3,405 noninitiators). A critical difference (CD; 27.7%) distinguished true change from analytical variability. Overlap weighting balanced the substantial differences between initiators and noninitiators (confounding by indication). A prospective, self-controlled cohort of 113 statin-naïve patients on statin monotherapy had paired Lp(a) measured before and one month after initiation, in both mg/dL and nmol/L. After overlap weighting (all standardized mean differences ≈ 0), statin initiation was associated with a small, directional increase in Lp(a): more patients exceeded the CD (31.7% vs 25.8%; odds ratio [OR] 1.34, 95% confidence interval [CI] 1.17–1.53), with a weighted median change of + 1.2 mg/dL (+ 8.9%) versus +0.1 mg/dL (+ 0.3%). In the prospective cohort, Lp(a) was unchanged over one month in both units ( P = 0.36 and 0.70). Elevated baseline Lp(a) predicted incident MACE in primary prevention (HR 1.53), whereas the short-term change did not. In statin-naive patients, short-term changes in Lp(a) were modest and primarily determined by baseline levels, with no large net increase observed in prospective self-controlled measurements, although this cohort was underpowered to exclude small shifts. These findings do not support modifying guideline-indicated statin therapy. Selective postinitiation Lp(a) reassessment may be considered only when baseline values are near a clinical decision threshold. Trial registration The trial was registered with the Chinese Clinical Trial Registry (ChiCTR2400087539) on 30 July 2024.