Background: Metabolic syndrome (MetS) refers to clustered cardiovascular risk factors (abdominal obesity, pre-diabetes, high blood pressure, dyslipidaemia). Therapies targeting oxidative stress may delay progression to atherosclerosis and diabetes. We investigated the anti-oxidative effect of a supplement combining red yeast rice and olive extract in patients with MetS.
Methods: A double-blind, placebo-controlled, randomised trial was conducted with 50 patients with MetS as defined by National Cholesterol Education Program Adult Treatment Panel III criteria. Forty-nine subjects randomly assigned to red yeast rice-olive extract (RYR-olive extract; 10.82 mg of monacolins and 9.32 mg of hydroxytyrosol per Cholesfytolplus capsule) or placebo completed the 8-week trial. Whereas effects on cardiovascular risk parameters of MetS have been reported recently, the observed significant 20% increase in oxidised low-density lipoprotein (OxLDL) prompted us to investigate other oxidative stress-related parameters: malondialdehyde (MDA), lipoprotein-associated phospholipase A2 (Lp-PLA2) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Statistical calculations included univariate quantitative analysis, multivariate linear regression and correlation analysis.
Results: The updated results indicate that an RYR-olive extract supplement significantly reduced Lp-PLA2 by 7% (p < 0.001), but it failed to show a significant decrease in plasma MDA and 8-OHdG (p > 0.05). Reductions in OxLDL (20%) and Lp-PLA2 (7%) were associated with each other (r = 0.740, p < 0.001).
Conclusions: RYR-olive extract significantly reduced Lp-PLA2 in correlation with the marked reduction in plasma OxLDL, which may lead to a reduced risk for cardiovascular disease in patients with MetS.
Trial registration: ClinicalTrials.gov identifier: NCT02065180 . Registered on 13 February 2014.
Keywords: Metabolic syndrome; Olive; Oxidative stress; Red yeast rice.