Lipoprotein (a) in patients with hyperlipidaemia

Abstract

Abstract. Lipoprotein (a) [Lp(a)] is an atherogenic lipoprotein which is similar in structure to, but meta‐bolically distinct from, LDL. Factors modulating plasma Lp(a) concentrations are poorly understood. We hypothesized that patients with hyperlipidaemia have elevated Lp(a) levels and determined the pheno‐type, concentration and distribution of Lp(a) in a group of hyperlipidaemic patients (n=107) compared with a control group (n= 128). Lp(a) concentrations were significantly increased in the hyperlipidaemic patients (mean, 34pM4mgdL ‐1 ; median, 19mgdL ‐1 ) as compared with the controls (20pM3mgdL ‐1 ; 9mgdL ‐' ) (P<0.01). Interestingly, after dividing the patients into one group with elevated cholesterol (>200mgdL ‐1 ) (n = 44) and another group with elevated triglycerides (>200mgdL ‐1 ) (n = 51) we found that Lp(a) concentrations were 2.3‐fold higher in the high cholesterol patients (mean, 45 pM 5; median, 41mgdL ‐1 ) compared to the high triglyceride subjects (20pM 4; 8mgdL ‐1 ) (P<0.01). Furthermore, a negative correlation between triglyceride and Lp(a) plasma concentrations was found in patients exhibiting triglyceride levels > 300mgdL ‐1 (r=‐0–41, P = 004, n = 36) and with triglycerides >400mgdL ‐1 (r=‐0–52, P = 003, n=17). These data indicate that plasma Lp(a) concentrations are elevated in hyperlipidaemia if the patients have high cholesterol levels, whereas Lp(a) is normal to low in patients with elevated triglycerides. The dominating lipid elevation in this condition and increased Lp(a) levels may contribute to the increased risk of premature coronary artery disease (CAD) in hyperlipidaemic patients.