263 Mediterranean diet decrease homocysteine levels and increase thiolactonase activities in elderly patients at high risk of cardiovascular disease

Abstract

Food items might have a synergistic and antagonistic effect on health. The Mediterranean diet (MD) has long been associated with lower incidence of cardiovascular disease and cancer. Elevated blood homocysteine is a risk factor for cardiovascular disease. A 5-mmol/L increase is associated with an approximately 70% increase in relative risk of cardiovascular disease in adults. For patients with established risk factors, this risk is likely even greater. Thiolactonase; the antioxidant enzymatic component of HDL plays a crucial role in metabolizing homocysteine thiolactone and reducing homocysteine endothelial damages. A total of 53 elderly coronary artery disease patient swere recruited and divided into diabetic patient (n = 27; age = 68.3 years) and non diabetics (n = 26; age = 68.7 years). We evaluated plasma homocysteine levels (tHcy); thiolactonase activity (HTase) and studied the effects of adherence to a Mediterranean diet on them. Plasmatic tHcy was determined by capillaryGC-MS; HTLase activity was estimated by a kit immunoassay. Dietary intakes were evaluated by a validated food frequency questionnaire and transformed into a score traducing adherence to MD. Significantly higher median tHcy levels were found in diabetic patients as compared to the non diabetic ones (18.5 μmol/L vs. 5.8; p = 0.057) associated to lower HTase activities (266.8U/L vs. 327.4; p = 0.058). Moreover, in the diabetic patients tHcy levels were negatively associated with thiolactonase activities (r= −0.637; p 0.00). In this group, MD reduced diastolic blood pressure (r= −0.558; p = 0.014). In the non diabetic group, tHcy levels were negatively correlated with HTase activities (r = 0.759; p = 0.00) and diet score (r = −0.0706; p = 0.013) while HTase activities were positively correlated with diet score (r = 0.0759; p = 0.00). Elevated homocysteine in diabetic patients may partly be explained by the diminished thiolactonase activities and could be considered as an additional risk factor for cardiovascular events. Adherence to MD could be the first efficient step to prevent these complications.