LDL-C in the normal range cannot rule out very high Lp(a), Danish cohort of 1,346 (Lipids 2026)

Elevated plasma lipoprotein(a) (Lp(a)) (> 125 nmol/L) is highly prevalent and a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) that may contribute significantly to plasma levels of low-density lipoprotein-cholesterol (LDL-C). This study aimed to describe clinical characteristics across Lp(a) levels and to estimate the proportion of individuals with normal, moderately elevated, or elevated LDL-C earlier in life according to levels of Lp(a), to assess whether LDL-C levels are a reliable marker for an underlying elevated Lp(a) level. In this retrospective study, detailed information on clinical characteristics was collected through medical records, while biochemical data was retrieved from the North Denmark Region Clinical Laboratory System (LABKA) I and II between January 2021 and August 2024. A total of 1346 individuals were included of whom 28.5% had elevated Lp(a) levels ≥ 125 nmol/L. A history of ASCVD was found in 57.7% of patients with Lp(a) levels ≥ 400 nmol/L compared to 21.1% of patients with Lp(a) levels < 100 nmol/L and the median age of onset of ASCVD was 51 years and 56 years, respectively. Furthermore, in individuals with Lp(a) levels ≥ 300 nmol/L, we found that 7.6% had LDL-C < 3.0 mmol/L and 9.1% had LDL-C between 3.0 and 3.5 mmol/L when measured for the first time, respectively. This study highlights distinct clinical characteristics across Lp(a) levels. With increasing Lp(a) levels, the prevalence of ASCVD increased, while the age at onset of ASCVD decreased. Furthermore, we found that LDL-C within the normal range cannot be used to rule out highly elevated Lp(a) levels.