Concentrations of HDL-associated S1P in diabetes and controls. Peaks of S1P standard (A) and S1P in HDL (B) were obtained by UPLC-MS/MS. The S1P in HDL was extracted following the method of methanol precipitation of protein. S1P in isolated HDL-c (C) were compared among controls, type 2 diabetes mellitus (T2DM) and type 2 diabetes mellitus accompanied with atherosclersosis (T2DM-As) (n=15 for each group). Mann–Whitney U test. Bars show medians. * p < 0.05.