High-density lipoprotein-associated sphingosine-1-phosphate activity in heterozygous familial hypercholesterolaemia.

BACKGROUND: Patients with heterozygous familial hypercholesterolaemia (FH) suffer from high plasma cholesterol and an environment of increased oxidative stress. We examined its potential effects on high-density lipoprotein (HDL)-associated sphingosine-1-phosphate (S1P) content (HDL-S1P) and HDL-mediated protection against oxidative stress, both with and without statin treatment. MATERIALS AND METHODS: In a case-control study, HDL was isolated from 12 FH patients with and without statin treatment and from 12 healthy controls. The HDL-S1P content and the capacity of HDL to protect cardiomyocytes against oxidative stress in vitro were measured. RESULTS: HDL-associated S1P was significantly correlated with cell protection, but not with HDL-cholesterol or apolipoprotein AI. The latter did not correlate with HDL-mediated cell protection. Neither the HDL-S1P content nor HDL protective capacity differed between nontreated FH patients and controls. The relative amounts of apolipoprotein AI and apolipoprotein M were similar between controls and FH patients. Statin treatment had no effect on any of these measures. CONCLUSIONS: The FH environment is not detrimental to HDL-S1P content or HDL-S1P-mediated cell protection. Statin treatment does not modulate HDL function in this regard.