RESUMEN
(1) Background: the composition of high-density lipoproteins (HDL) becomes altered during the postprandial state, probably affecting their functionality vis-à-vis the endothelium. Since acute coronary syndrome (ACS) in women is frequently associated with endothelial dysfunction, it is likely that HDL are unable to improve artery vasodilation in these patients. Therefore, we characterized HDL from women with ACS in fasting and postprandial conditions. We also determined whether microencapsulated pomegranate (MiPo) reverts the HDL abnormalities, since previous studies have suggested that this fruit improves HDL functionality. (2) Methods: Eleven women with a history of ACS were supplemented daily with 20 g of MiPo, for 30 days. Plasma samples were obtained during fasting and at different times, after a lipid load test to determine the lipid profile and paraoxonase-1 (PON1) activity. HDL were isolated by sequential ultracentrifugation to determine their size distribution and to assess their effect on endothelial function, by using an in vitro model of rat aorta rings. (3) Results: MiPo improved the lipid profile and increased PON1 activity, as previously reported, with fresh pomegranate juice. After supplementation with MiPo, the incremental area under the curve of triglycerides decreased to half of the initial values. The HDL distribution shifted from large HDL to intermediate and small-size particles during the postprandial period in the basal conditions, whereas such a shift was no longer observed after MiPo supplementation. Consistently, HDL isolated from postprandial plasma samples hindered the vasodilation of aorta rings, and this endothelial dysfunction was reverted after MiPo consumption. (4) Conclusions: MiPo exhibited the same beneficial effects on the lipid profile and PON1 activity as the previously reported fresh pomegranate. In addition, MiPo supplementation reverted the negative effects of HDL on endothelial function generated during the postprandial period in women with ACS.
Asunto(s)
Síndrome Coronario Agudo/tratamiento farmacológico , Endotelio Vascular/efectos de los fármacos , Hipertrigliceridemia/tratamiento farmacológico , Hipolipemiantes/administración & dosificación , Lipoproteínas HDL/sangre , Extractos Vegetales/administración & dosificación , Granada (Fruta) , Periodo Posprandial , Triglicéridos/sangre , Vasodilatación/efectos de los fármacos , Síndrome Coronario Agudo/sangre , Síndrome Coronario Agudo/diagnóstico , Administración Oral , Adulto , Animales , Arildialquilfosfatasa/sangre , Biomarcadores/sangre , Endotelio Vascular/metabolismo , Endotelio Vascular/fisiopatología , Femenino , Frutas , Humanos , Hipertrigliceridemia/sangre , Hipertrigliceridemia/diagnóstico , Hipolipemiantes/efectos adversos , Persona de Mediana Edad , Extractos Vegetales/efectos adversos , Ratas Wistar , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Postprandial triglyceridemia may transitory affect the structure of HDL subclasses and probably their antiatherogenic properties but little is known in this field. We analyzed the HDL subclasses lipid content along postprandial period. METHODS: Fifteen metabolic syndrome (MS) patients and 15 healthy controls were enrolled. HDL were isolated from plasma samples obtained at fasting and every 2-h up to 8-h, after a 75-g fat meal. Cholesterol (C), triglycerides (TAG), and phospholipid (Ph) plasma concentrations of five HDL subclasses were determined by densitometry of electrophoresis gels enzymatically stained. RESULTS: The increase of postprandial triglyceridemia expressed as the incremental area under the curve (iAUC) was twice in MS patients than in controls. Only large HDL2b-TAG were higher in MS than controls at 4, 6 and 8h after meal intake, whereas cholesterol of HDL2a, 3a and 3b were lower at 8h. HDL size distribution shifted towards large HDL and HDL3a-, 3b- and 3c-subclasses had a lower content of cholesterol (estimated by the C-to-Ph ratio) in subjects whose iAUC>289.5mgh/dl (n=15) in comparison with those subjects with iAUC below this cutoff point (n=15), independently of the MS status and fasting TAG. Triglycerides content of HDL subclasses changed only discreetly along the postprandial period, whereas paraoxonase-1 remained unchanged. CONCLUSIONS: A high postprandial triglyceridemia conditions the shift of HDL size distribution towards large particles and the decrease of cholesterol in HDL3 subclasses. These data demonstrate that postprandial hypertriglyceridemia contributes to a transitory hypoalphalipoproteinemia that may increase the risk of cardiovascular disease.