Browsing by Author "Correia, Cristina"
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- Plasma aminothiol status in the population of the Island of São Jorge (The Azores Archipelago, Portugal)Publication . Ferin, Rita; Correia, Cristina; Raposo, Mafalda; Gonçalves, Bruno; Gonçalves, C.; Baptista, José; Pavão, Maria LeonorHcy, Cys, Cys-Gly and GSH are low molecular weight thiols that play important roles in the metabolism and homeostasis of the organism. An altered plasma aminothiols status can cause oxidative stress, thus contributing to atherogenesis. The aim of this study was to evaluate the plasma levels of total Hcy, Cys, Cys-Gly and GSH, as well as GGT activity in apparently healthy subjects from the Island of S˜ao Jorge, taking into consideration gender and lipid profile. The study group was formed by 73 subjects with no chronic diseases, aged 20 to 60 years, born living in the island of S˜ao Jorge. The evaluation of the four aminothiols was carried out by HPLC with an isocratic reversephase column using a fluorescence detector. Mean values of GSH (1.8±0.6mM) and Cys (240±35mM) content were under reference values, but Cys-Gly was above. Plasma total Hcy, Cys and Cys-Gly levels, as well as GGT activity were significantly higher in men than in women (respectively, 30%, 7%, 17% and 65%). About 63% of subjects were hyperlipidemic, mainly hypercholesterolemic. Cys concentration was increased by 9% in hyperlipidemics vs. normolipidemics. In subjects with altered thiol status men, but not women, revealed a moderate hyperhomocysteinemia. Also Cys-Gly concentrations were significantly higher in men than in women. In spite of being apparently healthy, all subjects (namely men) have depleted antioxidant defenses, indicating high oxidative stress. Alterations in plasma GSH, Cys-Gly and Cys concentrations, taken together, and independently of dyslipidemia, could be considered as early markers of atherosclerosis.
- Relationship of the APOE polymorphism and lipid profile: A population-based study in the Azores Islands (Portugal)Publication . Raposo, Mafalda; Dahmani, Yahya; Silva, Francisca; Tavares, M.; Cymbron, Teresa; Santos, Cristina; Bettencourt, Conceição; Ferin, Rita; Correia, Cristina; Pavão, Maria Leonor; Lima, ManuelaThe factors leading to a two-fold mortality rate from coronary artery disease (CAD) in the Azores, as compared to Mainland Portugal, have not been elucidated. Previous studies reported a population tendency for hypercholesterolemia, one of the main factors contributing to the development of atherosclerosis (AT), considered the primary cause of CAD. Apolipoprotein E has a key role in plasma lipid metabolism, given its function as a ligand for cell-surface receptor mediated uptake of lipoproteins. Polymorphism in the apolipoprotein gene (APOE) results in three major isoforms encoded by three codominant alleles (E2, E3 and E4). With the purpose of establishing the pattern of variation at the APOE locus and determining its association with lipid profile, we studied a random sample of 298 unrelated, apparently healthy individuals of Azorean origin. In nearly 50% of the sample total cholesterol (TC) was above 200mg/dl; in 25% of the individuals LDL-cholesterol (LDL-C) was higher than 130 mg/dl. Allele frequencies were 0.0833, 0.8317 and 0.0850 for E2, E3 and E4, respectively. Genotype frequencies were higher for E3*E3 genotype (66.1%); genotype distribution displayed conformity with Hardy-Weinberg expectations. No differences in allelic frequencies were found in comparison with other Caucasian populations, namely with mainland Portugal. E3*E4 individuals presented the highest cholesterol levels. Analysis of variance performed with the most represented genotypes (E2*E3, E3*E3 and E3*E4) revealed a clear association between the genotypic composition and TC, as well as LDL-C, thus confirming in this population, the role of APOE as one of the genetic determinants of AT.
- Serum atherogenic lipid markers in subjects from three islands of The Azores Archipelago (Portugal): a comparison studyPublication . Ferin, Rita; Correia, Cristina; Raposo, Mafalda; Castro, Ana Rita; Reis, C.; Vieira, T.; Gonçalves, Bruno; Pavão, Maria LeonorSão Miguel (SM), Graciosa (GR) and São Jorge (SJ) are three islands of the Azores’ Archipelago, where the death rate from coronary artery disease is abouttwice than in mainland Portugal. The aim of this study was to evaluate and compare serum atherogenic lipid markers as reflected by lipid profile, as well as by apoB/apoA-1 ratio in apparently healthy subjects from those islands. The study group was formed by 321 subjects with no chronic diseases, aged 20 to 60 years, born living in the respective island (156 from SM, 92 from GR and 73 from SJ). In all cases, about 64% of subjects were hyperlipidemic, mainly hypercholesterolemic. LDL-C and HDL-C concentrations were respectively, lower and higher in SM than in SJ or GR. ApoB concentration was 40% and 17% higher in SJ than in SM and GR, respectively, while apoA-1 reached the maximum in SM (178±38 mg/dL). Regarding apoB/apoA-1 ratio, taken as a better atherogenic marker then conventional lipid profile, subjects from GR exhibited the highest mean value (0.85±0.4), followed by those from SJ (0.75±0.3) and SM (0.58±0.2). Particularly in men from GR and SJ, ratios were 1.0 and 0.9, respectively, which corresponds to a high risk of developing a cardiovascular incident.