609-P: Effect of Rosuvastatin on Lipoprotein Sphingolipids in Patients with Type 2 Diabetes

Statin therapy reduces cardiovascular risk in type 2 diabetes (T2DM), partly by improving dyslipidemia, and partly through ‘pleiotropic’ effects. Sphingolipids, including ceramides, are amphiphilic components of lipoprotein surface monolayers. Sphingolipids regulate lipoprotein surface fluidity, and include key signaling molecules: ceramides are specifically associated with apoptosis and risk for premature coronary heart disease. Effects of statins on the sphingolipid content of lipoproteins are poorly defined. Using liquid chromatography/electrospray ionization-tandem mass spectrometry, we determined fasting plasma concentrations of individual ceramides (Cer), sphingomyelins (SM), and glycosphingolipids (hexosyl- and lactosyl-Cer) in plasma from 19 men and 21 women with T2DM, before and after treatment with rosuvastatin (10 mg/day, 6 weeks). Exclusion criteria were use of ‘statins’ in the preceding 6 months, and any current use of lipid-modifying agents. Using existing lipoprotein compositional data, we calculated effects of rosuvastatin therapy on non-HDL sphingolipid content. Results: Rosuvastatin reduced total cholesterol (C) (by 33%), triglycerides (20%), LDL-C (49%), and non-HDL particle number (34%); HDL-C was unaffected. It decreased total SM (15%), Cer (29%), and hexosyl- (30%) and lactosyl- (34%) Cer, independent of gender. Assuming HDL composition was unaffected, rosuvastatin reduced non-HDL SM by 42% and Cer by 61%: these reductions remained significant after correction for non-HDL-C and/or non-HDL lipoprotein surface area. Conclusions: In T2DM, rosuvastatin lowers not only the number of non-HDL particles, but also the sphingolipid, and especially the Cer, content of each particle. This effect is independent of gender, potentially anti-atherogenic, and may represent a new pleiotropic effect of statins. Further studies are needed to confirm these findings in isolated lipoprotein classes, and to determine mechanism(s). Disclosure C.B. Kelly: None. S.M. Hammad: None. R.L. Klein: None. M.F. Lopes-Virella: None. A. Gosmanova: None. M.J. Leyva: None. C.E. Aston: None. T. Lyons: None.