A-236 Lp(a) as an Independent Risk Factor for Cardiovascular Disease: Association with Lipid Profile Parameters and ApoAI and ApoB

Abstract Background Epidemiological studies have shown that Lp(a) levels are an independent and genetically determined risk factor of cardiovascular disease (CVD). High serum levels of Lp(a) (more than 50 mg/dL or 125 nmol/L), which are found in approximately 20% of the population, confer an increased risk of more than 1.6 times for a first cardiovascular event. Lp(a) is a lipoprotein particle that is formed by a two-step process involving interactions between an LDL particle and another protein, apo(a). Despite its significance as an independent risk factor for cardiovascular disease, Lp(a) and ApoAI and ApoB measurements are not routinely requested by physicians alongside standard lipid profiles. This study aimed to analyze the profile of Lp(a) as an independent risk factor and its association with other lipids parameters. Methods In the period from November to December 2024, 92 cases with a request for determination of Lp(a) levels and which had glycemia and glycated Hb were selected preliminarily, at the Clinical Laboratory of São Paulo - Brazil. In these samples, lipid profiles were performed and the parameters: calculated LDL, measured LDL, Non-HDL, ApoAI and ApoB fractions were analyzed to risk for CVD and correlation with Lp(a). Statistics: To assess the correlation between Lp(a) values and Non-HDL, calculated LDL, measured LDL, ApoAI and ApoB values, the Spearman correlation test (non-parametric) was applied. These analyses were conducted for the total sample and for the subgroups of interest: without and with dyslipidemia and diabetes. To assess the association between the CVD risk classifications of Lp(a) with these classifications defined by the values of Non-HDL, calculated LDL, measured LDL, ApoAI and ApoB, the chi-square test of independence was initially applied. All analyses were based on reference values. Results For the total of 92 cases, the correlation tests of Lp(a) with the lipid parameters obtained respectively: Non-HDL (p=0.163), calculated LDL (p=0.194), measured LDL (p=0.097), ApoAI (p=0.562) and Apo B (p=0.038). Only the ApoB value showed a statistically significant correlation with the Lp(a) values, n=57(p<0.05). In patients with dyslipidemia (n=28) no significant correlation was found between Lp(a) and the parameters mentioned above, however for diabetic patients (n=7) a positive correlation was also found between Lp(a) and ApoB (p=0.019). Conclusion The results demonstrated that, in agreement with the literature, Lp(a) presented an independent risk for CVD and only had a positive correlation (p < 0.05) with Apo B for the group without dyslipidemia and for the group with diabetes. The positive correlation indicates that the higher the Lp(a) value, the higher the ApoB value tends to be. Lp(a) and ApoB, therefore, unified and amplified the information from conventional lipid markers for atherogenic risk, CVD and for other causes according to the literature.