Cardiology Research and Practice 2.3. Sociodemographic and Lifestyle Variables. Additionally to the physical activity and dietary status, the study’s questionnaire included demographic characteristics such as, the ﬁnancial status of the study’s participants which was recorded as the mean annual income during the past three years and their educational level (as a proxy of social status) which was measured in years of school. Information about smoking habits was also collected using a standardized questionnaire developed for the study. Current smokers were deﬁned as those who smoked at least one cigarette per day and former smokers were characterized as those who had stopped smoking for at least 1 yr. All other individuals were classiﬁed as nonsmokers. Occasional smokers (<7 cigarettes per week) were recorded and combined with current smokers due to their small sample size. For a more precise evaluation of smoking habits, the pack-years (cigarette packs per day multiplied by years of smoking) were calculated. In order to take into account various types of cigarettes consumed (i.e., light, heavy, very heavy), we used as a unit 1 cigarette with nicotine content of 0.8 mg. 2.4. Anthropometrics, Clinical, and Biochemical Characteris- tics. Standing height and weight were recorded, and body mass index (BMI) was calculated as weight (kg) divided by standing height (m2). Arterial blood pressure was measured three times, at the end of the physical examination with subject in sitting position. All participants were at least 30 minutes at rest. Patients whose average blood pressure levels were greater or equal to 140/90 mmHg or were under antihypertensive medication were classiﬁed as hypertensive. Blood samples were collected from an antecubital vein between 8 to 10 AM, with the subjects in a sitting position after 12 hours of fasting and avoiding of alcohol. TAC was measured through colorimetric test in serum (ImAnOx, Immunodiagnostik AG, Bensheim, Germany). In particular, the determination of antioxidant capacity was performed by the reaction of antioxidants in the sample with a deﬁned amount of exogenously provided hydrogen peroxide. The intra-, interassay coeﬃcients of variation of TAC did not exceed 2% and 5%, respectively. Further blood lipid examinations, that is, serum total cholesterol, and low-density lipoprotein cholesterol, were measured using chromatographic enzymic method in an automatic analyzer (RA-1000, Mecon Ltd, Athens, Greece). The intra- and interassay coeﬃcients of variation of all cholesterol levels did not exceed 4%. Hypercholesterolemia was deﬁned as total serum cholesterol levels greater than 200 mg/dL or the use of lipid lowering agents. 2.5. Statistical Analysis. Continuous variables are presented as mean values ± standard deviation. Categorical variables are presented as absolute and relative frequencies. Asso- ciations between categorical variables were tested by the calculation of chi-squared test, while diﬀerences between categorical and several biochemical, clinical, and nutritional variables were tested by the use of Student’s t-test and Mann-Whitney test (for the normally distributed and the skewed variables, resp.). Comparisons between TAC and 3 tertiles of the diet score were performed using one-way Analysis of Variance, after adjusting for sex. However, due to multiple comparisons, we used the Bonferroni correction in order to account for the increase in Type I error. Multiple linear regression was applied to test the association between the MedDietScore and TAC, after controlling for several potential confounders. Colinearity between independent variables was evaluated through the condition index, while model’s goodness-of-ﬁt was graphically evaluated (standard- ized residuals against ﬁtted values). All reported P-values are based on two-sided tests and compared to a signiﬁcance level of 5%. SPSS 14 (SPSS Inc., Chicago, IL, USA) software was used for all the statistical calculations. 3. Results The descriptive characteristics of the participants are pre- sented separately in men and women according to the MedDietScore in Table 1. TAC was positively correlated with diet score (rho = 0.24, P < .005), indicating that greater adherence to the Mediterranean diet was associated with increased TAC levels. In particular, people in the highest tertile of diet score had higher TAC levels as compared to people in the lowest tertile. Both men and women that were grouped in the higher tertile of the diet score had greater levels of physical activity as assessed by the METs min/week. Furthermore, both male and female participants in the highest tertile of the diet score were older, had lower body mass index, lower systolic blood pressure, and lower prevalence of hypertension. No associations were found between diet score and the other blood lipids measured, current smoking, and ﬁnancial status (Table 1). Figure 1 conﬁrms the previous relationships by present- ing the correlation of physical activity categories with TAC levels, as well as the combined eﬀect that exercise and compliance to the Mediterranean diet has on TAC. It is shown that highly active people (HEPA active) have higher TAC levels compared to less active ones. The highest TAC levels were observed among people that have both the greater adherence to the Mediterranean diet and the highest level of physical activity. However, residual confounding may exist. Thus, the unadjusted analyses were repeated after controlling for age, sex, and body mass index (factors that are known to inﬂuence both physical activity status and TAC levels). Table 2 illustrates the association of physical activity status on TAC levels, by dietary habits, after various adjustments made. The results demonstrate that people with increased physical activity combined with close or very close adherence to the Mediterranean diet had higher levels of TAC compared to those who were inactive. 4. Discussion In a sample of 3042 free-living people, it was revealed that increased physical activity in combination with greater adherence to the Mediterranean diet was associated with increased TAC levels.