Serum Apolipoprotein B-48 Concentration Is Associated with a Reduced Estimated Glomerular Filtration Rate and Increased Proteinuria

Aim Apolipoprotein B-48 (apoB-48) is a constituent of chylomicrons and their remnants (chylomicron remnants). A high concentration of serum apoB-48 is suspected to be a major risk factor for the development of atherosclerotic cardiovascular disease. Proteinuria and a reduced estimated glomerular filtration rate (eGFR) are independent risk factors for cardiovascular events and renal dysfunction. In the present study, we examined whether the serum apoB-48 concentration is associated with renal dysfunction. Methods A total of 264 patients was enrolled and classified into four groups according to the eGFR and level of proteinuria: a high eGFR (＞60mL/min/1.73m(2)) without proteinuria (≥1＋ by urine dipstick) (n=50); a high eGFR with proteinuria (n=75); a low eGFR (＞60mL/min/1.73m(2)) without proteinuria (n=74); and a low eGFR with proteinuria (n=65). Biochemical markers of lipid metabolism, including the fasting serum apoB-48 concentration, were compared between the four groups. Results The serum log-apoB-48 and log-apoB-48/TG levels were significantly higher in the patients with a high eGFR with proteinuria, low eGFR with proteinuria and low eGFR without proteinuria than in those with a high eGFR without proteinuria, with the most significant differences for these parameters. The eGFR was found to be significantly correlated with the log-apoB-48 and log-apoB-48/TG levels, whereas urinary protein was found to be significantly correlated with the log-apoB-48 level only. A multiple regression analysis indicated that the log-apoB-48/TG level was a significant determinant of a reduced eGFR. Conclusions Both a low eGFR (＜60) and proteinuria (≥1＋) are independent determinants of a high apoB-48 concentration. Taken together, the present results suggest that an increased serum apoB-48 concentration contributes to an increased risk of cardiovascular events.