Elizabeth Fragopoulou

The association between adherence to the Mediterranean diet and adiponectin levels among healthy adults: the ATTICA study

Adiponectin is thought to exert anti-inflammatory actions. The aim of the present work was to evaluate the association of long-term adherence to the Mediterranean diet with adiponectin levels, in a sample of cardiovascular disease-free adults. In a random sub-sample of ATTICA study, 532 men and women, serum adiponectin was measured. Among several sociodemographic, clinical and biological factors, adherence to the Mediterranean diet was assessed by a special diet score (MedDietSCore) that incorporated the inherent characteristics of this traditional diet. Unadjusted analysis revealed that participants who were in the highest tertile of the diet score had an average 41% higher adiponectin levels, as compared to those who were in the lowest tertile (P<.001). Multiadjusted data analysis showed that compared to the highest tertile of diet score, participants in the middle or the lowest one had an average 0.99+/-0.22 (P=.001) and 1.05+/-0.27 microg/ml (P=.001) lower adiponectin levels after adjusting for age, sex and various bioclinical factors. Adherence to the Mediterranean diet was associated with an increase on adiponectin levels. This finding may partially explain beneficial effects of this traditional healthy diet on the cardiovascular system.

Caffeinated Coffee Does Not Acutely Affect Energy Intake, Appetite, or Inflammation but Prevents Serum Cortisol Concentrations from Falling in Healthy Men

Our aim in this crossover study was to investigate the acute effects of caffeinated and decaffeinated coffee consumption on appetite feelings, energy intake, and appetite-, inflammation-, stress-, and glucose metabolism-related markers. Sixteen healthy men (age range, 21-39 y; BMI range, 19.7-28.6 kg/m(2)) received in a random order on 3 separate occasions a standard breakfast snack with 200 mL of either caffeinated coffee (3 mg caffeine/kg body weight), decaffeinated coffee, or water (control). Before intervention (-15 min) and at standard time points following breakfast consumption (0, 15, 30, 60, 90, 120, 150, and 180 min), participants recorded their appetite feelings and we collected blood samples for measurements of circulating glucose, insulin, cortisol, and appetite- and inflammation-related markers. At 180 min, participants consumed a meal ad libitum. The appetite-related ratings, the appetite plasma hormonal responses as well as the plasma glucose, serum insulin, and plasma and serum inflammatory marker responses did not show an overall intervention effect or a time x intervention interaction. Ad libitum energy intake did not differ among the 3 interventions. However, a significant intervention effect (P = 0.04) and a time x intervention interaction (P-interaction = 0.02) were found for serum cortisol; cortisol concentrations were significantly higher following the caffeinated coffee intervention, compared to control, at 60 min and thereafter. In conclusion, the usually consumed amount of caffeinated coffee does not have short-term effects on appetite, energy intake, glucose metabolism, and inflammatory markers, but it increases circulating cortisol concentrations in healthy men.

Serum Total Selenium Status in Greek Adults and Its Relation to Age. The ATTICA Study Cohort

The trace element selenium is an essential micronutrient for human health and its low levels in serum are implicated in the pathogenesis of several chronic diseases. Therefore, the determination of total selenium in serum may contribute to the assessment of the health and nutritional status of certain populations. The objective of the present work was to determine total selenium in the serum of 506 healthy volunteers that participated in the ATTICA study. Selenium was determined in serum by using the technique of inductively coupled plasma mass spectrometry. The mean serum selenium concentration was determined to be 91.8u2009±u200933.7xa0μg/L (Nu2009=u2009506); 87.6% of women and 88.5% of men had serum selenium concentration below 125xa0μg/L, the cutoff considered to be required for optimal glutathione peroxidase activity. No association was found between serum selenium levels and the gender of the participants while a significant decline of selenium with age (pu2009<u20090.0001) was observed. According to our results, no anthropometric, lifestyle, nutritional, or biochemical indices were able to affect the association between serum selenium and age. This result may indicate that other factors such as selenium distribution as well as retention may be affecting the relationship between serum selenium and age.

In vitro assessment of antioxidant activity of tyrosol, resveratrol and their acetylated derivatives.

Consumption of phenolic compounds is associated with beneficial effects in humans even though many of them are poorly absorbed. The aim of this study was to investigate the in vitro antioxidant activity of tyrosol (T), resveratrol (R) and their acetylated derivatives (AcD), as increased lipophilicity has been reported to improve absorption. The chemically synthesized AcDs were evaluated by their ability to scavenge DPPH radicals, inhibit non-enzymatic linoleic acid peroxidation, inhibit human serum oxidation in the presence of copper ions and inhibit lipoxygenase activity. T showed an inhibitory effect only in serum oxidation, where the T-acetylated at aromatic-OH was the most active. The T-acetylated at aliphatic-OH and 3,5-diacetyl-R exhibited the most powerful effect in non-enzymatic linoleic acid peroxidation with IC50 values 2.4 mM ± 0.21 and 0.055 mM ± 0.0018, respectively. In all other tests R was the most potent among all its AcD and T. Increasing lipophilicity by acetylation improves antioxidant activity of phenolic compounds in non-enzymatic lipid peroxidation assays.

In Vitro and In Vivo Effects of Statins on Platelet-Activating Factor and Its Metabolism

Platelet activating factor (PAF) is implicated in cardiovascular disease (CVD). Statins are widely used in these situations. Therefore, we assessed their effect on the biological activities and metabolism of PAF. Several statins, including simvastatin, exhibited an inhibitory effect against PAF, comparable with that of PAF-inhibitors. Simvastatin also suppressed in vivo PAF-biosynthesis via the de novo pathway, in leukocytes of 6 simvastatin-treated volunteers. Total cholesterol and low-density lipoprotein cholesterol were also significantly decreased, whereas high-density lipoprotein cholesterol, triacylglycerol, EC50, and lag time were unaffected in these participants. Simvastatin with an intact lactone ring also inhibited PAF-activities, while incubation of human mesangial cells with it also resulted in decreased de novo PAF-biosynthesis. This suggests that these simvastatin-dependent effects are independent of its lactone ring. These new actions of statins should be further studied in PAF-implicated pathological conditions such as CVD, cancer, and renal disease.

Effect of different amounts of coffee on dietary intake and appetite of normal‐weight and overweight/obese individuals

To investigate the effects of different coffee amounts on dietary intake and appetite feelings in normal‐weight and overweight/obese individuals.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) activity, platelet-activating factor acetylhydrolase (PAF-AH) in leukocytes and body composition in healthy adults

BackgroundLipoprotein-associated phospholipase A2 (Lp-PLA2) also known as serum platelet activating factor acetylhydrolase (PAF-AH) activity constitutes a novel risk marker for cardiovascular disease. Leukocytes constitute one main cellular source of circulating Lp-PLA2. The aim of the present study was to evaluate the association of both serum and leukocyte PAF-AH activities with fat distribution and lean tissue. One hundred healthy volunteers without cardiovascular disease history participated in this study (n = 52 men, 44 ± 13 years and n = 48 women, 43 ± 13 years). Body composition was assessed with dual-energy X-ray absorptiometry, while anthropometrical indices were also measured. The activity of Lp-PLA2 and levels of lipid and glycemic parameters were determined in fasting samples.ResultsMean Lp-PLA2 activity was 24.8 ± 4.5 and 19.6 ± 5.0 nmol/min/mL in men and women, respectively (P < 0.001). Mean activity of PAF-AH in leukocyte homogenates was 386 ± 127 pmol/min/mg and 292 ± 92 pmol/min/mg in men and women, correspondingly (P < 0.001). In multiple regression models upper and total adiposity measures were positively associated with Lp-PLA2 activity in men after adjusting for LDL-cholesterol, age, smoking, hs-CRP and physical activity, whereas no associations were found with PAF-AH leukocyte homogenates activity. Hierarchical analysis revealed that the variables with the highest explanatory ability of Lp-PLA2 activity in men, were DXA deriving L1–L4 region of interest and arms fat (increase in R2 = 0.136, P = 0.005 and increase in R2 = 0.118, P = 0.009, respectively), followed by trunk fat and total fat. In women, no association of body composition variables with Lp-PLA2 nor PAF-AH leukocyte homogenates activity was found.ConclusionLp-PLA2 activity is differentiated across levels of adiposity and topology of adipose tissue, whereas no association was found regarding PAF-AH leukocyte homogenates activity. Our findings suggest that Lp-PLA2 may compensate for the adiposity-associated increases in inflammatory and oxidative burden, in men.

Gender and body mass index modify the effect of increasing amounts of caffeinated coffee on postprandial glucose and insulin concentrations; a randomized, controlled, clinical trial

OBJECTIVEnTo examine the effects of different coffee amounts on blood glucose and insulin concentrations of healthy volunteers, and to assess potential effect modification by sex and body mass index category.nnnMATERIALS/METHODSnThirty-three volunteers [16 ♀/17 ♂, 16 normal-weight and 17 overweight/obese, 27.3 ± 7.2 (19-44) y] took part in this randomized, crossover study. Ιn the morning of each experimental day volunteers received a standardized meal along with 200 mL of water or instant coffee containing either 3 or 6 mg of caffeine/kg body weight. Blood samples were obtained and analyzed for glucose and insulin concentrations in the fasting state, immediately after meal/drink consumption and at standard time points for the next 3h thereafter.nnnRESULTSnCoffee delayed the rise of insulin in response to the standardized meal and the fall of glucose concentrations from its maximum levels in the entire study sample. Glucose incremental area under the curve (IAUC) was significantly different between interventions (P=.009) with both coffee amounts inducing a greater area compared to water. Secondary, subgroup analysis at the nominal level showed that this might be more evident among females (PIAUC=.05) and overweight/obese participants (PIAUC=.03). Furthermore, coffee, mainly the 6 mg dose, could be lowering insulin concentrations the first 30 min after its consumption compared to water in men and overweight/obese participants.nnnCONCLUSIONSnCoffee exerts an acute effect on postprandial glucose and insulin concentrations. This effect may be modified by sex and overweight/obese status. Future research is necessary to elucidate underlying mechanisms.

Platelet-Activating Factor and Its Basic Metabolic Enzymes in Blood of Naive HIV-Infected Patients

Platelet-activating factor (PAF), a mediator of proatherosclerotic inflammatory processes, is also implicated in endothelial dysfunction during human immunodeficiency virus (HIV) infection. We examined PAF metabolism in blood of naive male patients, 8 with early HIV infection (group A) and 17 just before treatment initiation (group B), versus 18 healthy age-matched males (group C). Statistical analysis was performed with 1-way analysis of variance (ANOVA) criterion and Pearson r test. Higher PAF biosynthesis in patients’ leukocytes versus group C was accompanied by an increase in lipoprotein-associated phospholipase A2 (Lp-PLA2) activity that degrades PAF. Moreover, PAF synthesis was higher and Lp-PLA2 activity was lower in group B compared to group A. Lipoprotein-associated phospholipase A2 was positively correlated with viral load and negatively correlated with CD4 cell counts in group B. The activities of PAF-basic biosynthetic enzymes in patients’ leukocytes were also negatively correlated with CD4 cell counts. The observed continuous increase in PAF biosynthesis during HIV infection progress seems to amplify the risk of AIDS manifestations and/or cardiovascular complications in HIV-infected patients, while a subsequent increase in Lp-PLA2 activity seems to be a host response.

Lipid minor constituents in wines. A biochemical approach in the French paradox

The French paradox is the observation that the French suffer a relatively low incidence of coronary heart disease, despite having a diet relatively rich in saturated fats. Several theories have been proposed in order to explain this phenomenon and several debates arose. One of them attributed this phenomenon to the regular and moderate consumption of wine in France. More specifi c, it is thought that the existence of bioactive compounds in wine could have an effect on the cardiovascular system, preventing or delaying atherosclerosis. The mechanisms mediating these benefi cial effects include: low-density lipoprotein oxidation; endothelium function; smooth muscle cells proliferation; platelet aggregation and angiogenesis. Several mediators participate in these pathophysiological mechanisms, among them are platelet- activating factor (PAF) and oxidized phospholipids that play a crucial and essential role in the initiation and the progression of atherogenesis. In this review, apart from the already known and well characterized biological effects of wine bioactive compounds, the co-existence of compounds that could modulate the production and the actions of PAF is highlighted. The existence of bioactive compounds in wine that could reduce PAF production and inhibit its actions may offer a new insight into the well known French paradox and expand the already reported mechanisms by including the inhibition of PAF actions.