Intra-individual Variability in Lipoprotein(a) Levels: Findings from a Large Academic Health System Population.

Aims: Lipoprotein(a) [Lp(a)] levels are known to be mainly genetically determined. However, only scarce data are available on the intra-individual variability of Lp(a) levels across time.

Methods: We included adult patients (≥18 years old) who had baseline and follow-up Lp(a) measurements (between 1997 and 2024) with a minimum of one year apart. Patients were categorized into three groups as follows: normal (<30 mg/dL), borderline (30 to 50 mg/dL) and high Lp(a) (≥50 mg/dL). Multivariable logistic regression was conducted to assess the predictors of the intra-individual changes in Lp(a) ≥10 mg/dL.

Results: A total of 11,669 individuals (median age: 54 years, 60% males) were included in our analysis, with median time between measurements of 4.5 years (IQR: 2.2, 10.6). The median Lp(a) was 16 mg/dL (IQR: 7, 52) at baseline, compared with 15 mg/dL (IQR: 7, 52) at follow-up. At follow-up, 96.4% of individuals with normal Lp(a) and 89.9% with high Lp(a) remained in their categories, while 51.2% with borderline Lp(a) changed their category. Of the included population, 24.9% had an intra-individual Lp(a) change ≥10 mg/dL. Female sex (p <0.001), history of ASCVD (p=0.003), statin therapy (p=0.003) and elevated low-density lipoprotein cholesterol (LDL-C) levels ≥100 mg/dL (p <0.001) were significantly associated with higher odds of intra-individual Lp(a) changes ≥10 mg/dL.

Conclusions: Lipoprotein(a) levels were generally stable over time; however, patients with borderline levels may require more than one Lp(a) measurement, especially if they are females, have a history of ASCVD, have elevated LDL-C levels or are on statins therapy.