Prevalence and Biochemical Associations of Lipoprotein(a) with Markers of Cardiovascular Risk in Conditionally Healthy Residents of Karelia

This study is the first to investigate the biochemical interrelationships of circulating lipoprotein(a) (Lp(a)) with markers of dyslipidemia (apoB, non-HDL-C), systemic inflammation (hs-CRP), and the lipid metabolism regulator PCSK9 in a sample of conditionally healthy residents of the Republic of Karelia (n = 213, aged 40–59). Lp(a) levels were measured using immunoturbidimetry. An elevated Lp(a) level (>30 mg/dL) was found in 17.35% of the examined individuals. Lp(a) concentration did not differ between age groups (40–49 and 50–59 years) or between men and women, supporting its genetic determination. Correlation analysis revealed that significant positive associations of Lp(a) with atherogenic lipids (apoB, non-HDL-C, total cholesterol) and the TyG index were primarily characteristic of women. The strongest association in women was with apoB (ρ = 0.218; p < 0.001). No significant correlations between Lp(a) and the studied biochemical parameters were found in the male subgroup, a finding likely attributable to the small sample size. Weak but significant correlations of Lp(a) with markers of inflammation (hs-CRP, ρ = 0.232; p < 0.05) and the lipid metabolism regulator PCSK9 (ρ = 0.177; p < 0.05) were also detected in women. Linear regression models showed that the variability of Lp(a) levels is only minimally explained (R2 = 0.048–0.134) by these biochemical parameters, underscoring the dominant role of genetic factors. The obtained data, consistent with the current understanding of the role of oxidized phospholipids and low-grade inflammation in the atherogenicity of Lp(a), emphasize the importance of its measurement in regional populations and suggest that its elevated level in women may serve as an indicator of an overall unfavorable biological context, including dyslipidemia and inflammation.