Disclosed herein is the use of a sialic acid, a sialic acid precursor or a combination of the foregoing in the treatment or prevention of a diabetic condition or nephrotic syndrome in a subject. Specific embodiments include wherein the sialic acid precursor is N-acetyl-D-mannosamine (ManNAc), Bu4ManNAc, 3,4,6-O-Bu3ManNAc, 1,3,4-O-Bu3ManNAc, N-levulinoyl sialic acid, or N-levulinoylmannosamine, wherein the diabetic condition is diabetic nephropathy, diabetes mellitus, lupus nephritis or primary glomular disease, or characterized by the presence of hyposialylated form of Angpl4, and wherein the nephrotic syndrome is characterised as minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy/membranous glomerulonephritis, membranoproliferative glomerulonephritis or diabetic nephropathy.
