Comparison of Lipid and Fatty Acid Metabolism between Minimal Change Nephrotic Syndrome and Membranous Nephropathy

Abstract

Polyunsaturated fatty acids have been reported to be associated with atherosclerotic and inflammatory diseases, as they are the major components of cytoplasmic membranes and the precursor fatty acids for prostaglandins and leukotrienes. Nephrotic syndrome is associated with serum lipid disorders, such as hypercholesterolemia due to the increased production of lipoproteins by the liver. However, there are few reports regarding the fatty acid metabolism in patients with nephrotic syndrome. In the present study, serum lipid concentrations and plasma fatty acid composition were measured in patients with minimal change nephritic syndrome (MCNS) and membranous nephropathy (MN). Seven patients with MCNS (MCNS group), 11 patients with MN (MN group) and 8 healthy subjects (control group) were enrolled in the study. All patients were diagnosed by percutaneous renal biopsy. Fasting blood samples were obtained and the serum lipid profile was measured enzymatically. The fatty acid composition of plasma was analyzed by gas-chromatography after transmethylation. There were no significant differences in serum urea nitrogen and creatinine levels among the three groups. Patients with MN were older than those with MCNS. In the serum lipid profile, hypercholesterolemia was observed both in the MCNS and MN groups. Regarding the plasma fatty acid composition, alpha-linolenic acid levels in the MCNS group were significantly higher than those in the control group (1.06±0.08 wt% vs. 0.77±0.16 wt%, p=0.008) and docosahexaenoic acid levels in the MN group were significantly higher than those in the control group (5.51±1.17 wt% vs. 3.96±1.07wt%, p=0.005). These results suggest that nephrotic syndrome might not only disrupt lipid metabolism but also fatty acid metabolism.