Kalliopi Karatzi

Effect of coffee on endothelial function in healthy subjects: the role of caffeine

Coffee is one of the most widely used pharmacologically active beverages. The present study was designed to evaluate the acute effect of coffee ingestion on endothelial function in healthy individuals, and the potential role of caffeine. We studied 17 healthy young adults (28.9+/-3.0 years old; nine men), who were regular non-heavy coffee drinkers. The endothelial performance was estimated by endothelium-dependent FMD (flow-mediated dilatation) of the brachial artery before and 30, 60, 90 and 120 min after ingestion of a cup of caffeinated coffee (80 mg of caffeine) or the corresponding decaffeinated beverage (< 2 mg of caffeine) in two separate sessions, following a randomized single-blind cross-over design. There was no difference in baseline FMD values between the two sessions [7.78 compared with 7.07% after caffeinated and decaffeinated coffee respectively; P = NS (not significant)]. Caffeinated coffee led to a decline of FMD (7.78, 2.86, 2.12, 4.44 and 4.57% at baseline, 30, 60, 90 and 120 min respectively; P < 0.001). This adverse effect was focused at 30 (P = 0.004) and 60 min (P < 0.001). No significant effect on FMD was found with the decaffeinated coffee session (7.07, 6.24, 5.21, 7.41 and 5.20%; P = NS). The composite effect of the type of coffee consumed over time on FMD was significantly different (P = 0.021). In conclusion, coffee exerts an acute unfavourable effect on the endothelial function in healthy adults, lasting for at least 1 h after intake. This effect might be attributed to caffeine, given that decaffeinated coffee was not associated with any change in the endothelial performance.

Constituents of red wine other than alcohol improve endothelial function in patients with coronary artery disease.

BackgroundSeveral studies suggest that red wine is beneficial in coronary artery disease (CAD). Although the long-term effect of moderate red wine consumption on endothelial function is currently under investigation, there is little knowledge about its effect on postprandial endothelial function and haemostatic factors. The aim of the present study was to investigate the postprandial effects of alcohol content and the antioxidants of red wine on endothelial function and fibrinogen levels in CAD patients. MethodsFifteen males with angiographically documented CAD were recruited for the study. All volunteers ingested 250 ml of either red wine or de-alcoholized red wine on two different days. Blood samples (for analysis of fibrinogen and blood lipids) were collected and flow-mediated dilatation (FMD) was determined before and 30, 60 and 90 min following consumption of each beverage ResultsFMD was higher following the consumption of de-alcoholized red wine [type of wine effect, P=0.05 repeated measures analysis of variance (ANOVA)]. Furthermore, the pattern of the response was different between the two beverages, as FMD increased following the ingestion of de-alcoholized red wine, but it decreased after consumption of regular red wine (type of wine by time interaction effect, P=0.006 repeated measures ANOVA). Fibrinogen concentrations were unaltered ConclusionsAcute ingestion of red wine without alcohol led to higher FMD than ingestion of regular red wine in CAD patients. The acute effect of red wine on endothelial function may be different than its long-term effect and it could be attributed to its constituents other than alcohol.

Red wine's antioxidants counteract acute endothelial dysfunction caused by cigarette smoking in healthy nonsmokers

BACKGROUND Long-term smoking is believed to cause endothelial dysfunction via increased oxidative stress, whereas short-term smoking impairs vasodilatation through an as yet undefined mechanism. However, red wine and its constituents have a powerful antioxidant effect both in long-term and acute consumption. The aim of the current study was to investigate whether red wine, with or without alcohol, influences endothelial dysfunction induced by acute cigarette smoking. METHODS Sixteen healthy volunteers (8 males and 8 females) were recruited for a double-blind, crossover study, comprising 3 study days. Each subject smoked 1 cigarette, or smoked and drank 250 mL of red wine, or smoked and drank 250 mL of dealcoholized red wine. Flow-mediated dilatation (FMD) was measured after fasting and 15, 30, 60, and 90 minutes after each trial (smoke or smoke and drink either beverage). RESULTS Acute smoking of 1 cigarette caused a reduction in FMD (P <.001), which was statistically significant 15, 30, and 60 minutes after the inhalation of smoke compared to baseline levels (P <.001, P <.001, P =.043, respectively). However, simultaneous ingestion of either red wine or dealcoholized red wine with smoking did not lead to a change in FMD. CONCLUSIONS Acute smoking caused a significant impairment in endothelial function. Simultaneous consumption of red wine or dealcoholized red wine with smoking decreased smokes harmful effect on endothelium.

Postprandial Improvement of Endothelial Function by Red Wine and Olive Oil Antioxidants: A Synergistic Effect of Components of the Mediterranean Diet

Objective: Consumption of olive oil may cause postprandial impairment of endothelial function, while acute ingestion of red wine seems to improve it. The purpose of the present study was to investigate the combined postprandial effects of two essential components of the Mediterranean diet, red wine and olive oil, on endothelial function. Methods: Fifteen healthy subjects were enrolled in the study, which was comprised of 4 study days. Subjects were asked to consume a standard meal at each study day containing 50gr of olive oil and 250 ml of wine. Two types of wine (red and white; rich and poor in antioxidants respectively) and two types of olive oil (green and refined; rich and poor in antioxidants respectively) were used in a 2*2 design. Endothelium dependent, flow mediated dilatation (FMD) was measured with a B-Mode ultrasound device at fast and 1, 2 and 3 hours postprandially. Results: Combined consumption of red wine and green olive oil (both rich in antioxidants) improved FMD postprandially (p = 0.002, ANOVA for repeated measures), which remained significant 1 hour (p = 0.002) and 2 hours (0.037) following the meal compared to fasting levels. No other combination of wine and olive oil caused any significant alteration on FMD. Conclusion: Acute consumption of both red wine and green olive oil, rich in antioxidants, led to an improvement in the postprandial endothelial function in healthy subjects. These findings provide an additional favorable effect of components of the Mediterranean diet and of their antioxidant substances on endothelial function, at the postprandial state.

Hour-to-hour and week-to-week variability and reproducibility of wave reflection indices derived by aortic pulse wave analysis: implications for studies with repeated measurements.

Background Wave reflections are implicated increasingly in clinical research. Aims The purpose of the present study was to investigate whether wave reflection indices are reproducible when measured repeatedly (more than twice) at longer time intervals, namely hour-to-hour and week-to-week, in healthy subjects; something that has not yet been examined. Methods Bland–Altman plots, the interclass correlation coefficients (ICC) and coefficient of variation were used for this purpose. Two series, with measurements repeated in triplicate, were performed in 22 healthy subjects: the first at intervals of 1 h and the second at 1-week time intervals. Augmentation index (AIx), heart rate-corrected AIx (AI@75) and arrival time of reflected waves at the central aorta (tr) were calculated by aortic pulse wave analysis. Results AIx and AI@75 presented very good to excellent reproducibility (ICC = 0.86) for hour-to-hour repeated measurements, while tr was also highly reproducible (ICC = 0.79). AIx, AI@75 and tr were substantially reproducible when measured repeatedly with 1-week intervals, providing ICCs greater than 0.70. Bland–Altman plots confirmed these results, indicating that more than 90% of AIx, AI@75 and tr measurements fell within two standard deviations of the mean difference. Conclusions Wave reflections are substantially reproducible even when measurements repeated in triplicate are performed at longer time intervals (hours and weeks). A quantifiable amount of variation was reported, which should be taken carefully into consideration in interventional studies with repeated measurements and in observational studies investigating differences or correlations of these indices.

Combined acute effects of red wine consumption and cigarette smoking on haemodynamics of young smokers

Objective Red wine seems to improve haemodynamic variables, while smoking provokes adverse effects. The haemodynamic effects of their combined use is unknown. The purpose of the present study was to examine the acute effects of red wine and its constituents, in combination with the smoking of one cigarette, on haemodynamic parameters, such as blood pressure and wave reflections, in a group of smokers. Methods Twenty smokers (12 males, eight females) participated in a double-blind, crossover study comprised of 3 study days. All subjects either smoked one cigarette, or smoked and drank 250 ml of red wine, or 250 ml of de-alcoholized red wine (containing the same type and similar concentration of antioxidants). Applanation tonometry and generalized transfer functions were used to estimate aortic pressure waveforms at baseline and 30, 60 and 90 min after each trial. The augmentation index (AIx) was used to express wave reflections. Results Smoking increased peripheral systolic blood pressure (P < 0.005) 30 min later, but simultaneous consumption of either type of red wine caused no such effect. Additionally, smoking caused no overall effect on AIx, while smoking and drinking either regular or de-alcoholized red wine reduced AIx (P < 0.001). The reduction of AIx after red wine consumption was significantly greater than the respective reduction after de-alcoholized red wine (P = 0.004). Conclusion Antioxidant substances in red wine counteracted the smoking–induced increase in peripheral systolic blood pressure. Both alcohol and antioxidants in red wine decrease wave reflections in uncomplicated habitual smokers postprandially, indicating an additional favourable effect of red wine.

Acute combined effects of olive oil and wine on pressure wave reflections: another beneficial influence of the Mediterranean diet antioxidants?

Objectives Combined consumption of olive oil and wine is common in the Mediterranean diet, but there are no data concerning their synergistic haemodynamic response. We sought to determine the combined postprandial effects of wine and olive oil on wave reflections and central haemodynamics. Methods Fifteen healthy subjects consumed four standard meals on different days, containing 50 g of olive oil and 250 ml of wine, in a randomized cross-over study design. Two types of wine [red (R) and white (W)] and two types of olive oil [green (G) and refined (O) (rich and poor in antioxidants, respectively)] were used in all possible combinations (RO, RG, WO and WG). Applanation tonometry and aortic pulse wave analysis were performed when fasting and 1, 2 and 3 h postprandially. A second group of 15 healthy individuals matched for age, gender and body mass index served as the control group. Results All meals decreased AIx (RO and RG, P < 0.001; WO, P = 0.007; and WG, P = 0.039). The AIx reduction after RG, RO, WO and WG was significantly different from the respective AIx response of the control group. No difference was observed in the reduction of AIx between sessions, but a significantly earlier peak decrease in AIx, as well as a more prolonged decreasing effect, was observed after RG and RO consumption compared to WO and WG. Central systolic and diastolic pressures were diminished after all four combinations of wine and olive oil (P < 0.05). Conclusions Combined consumption of wine and olive oil provided beneficial postprandial effects on haemodynamics. These findings reveal an additional favourable effect of components of the Mediterranean diet on haemodynamics in the postprandial state.

Acute Smoking Induces Endothelial Dysfunction in Healthy Smokers. Is This Reversible by Red Wine's Antioxidant Constituents?

Objective: Acute smoking causes endothelial dysfunction through impairment of nitric oxide (NO) production, or increased oxidative stress, but the exact mechanism still needs to be elucidated. In healthy non-smokers acute endothelial dysfunction caused by smoking one cigarette was counterbalanced by red wines antioxidants. The aim of the present study is to investigate whether red wines antioxidant substances could counteract the acute endothelial dysfunction induced by acute cigarette smoking in healthy smokers as well. Methods: Twenty healthy volunteers (12 males) participated in a double-blind, cross-over study, comprised of three study days. All subjects either smoked one cigarette, or smoked and drank 250 ml of red wine, or smoked and drank 250 ml of dealcoholized red wine in each one of the study days. Flow mediated dilatation (FMD) was measured at fast and 30, 60 and 90 minutes after each trial. Results: Smoking one cigarette induced a significant decrease in FMD (p < 0.001), which remained significant 30 (p < 0.001), and 60 (p = 0.003) minutes after the end of smoking. FMD remained statistically unchanged after consumption of either regular red wine, or dealcoholized red wine together with smoking. Conclusions: The observed endothelial dysfunction following smoking of one cigarette was counterbalanced by consumption of either red wine or dealcoholized red wine in healthy smokers. It is possible that acute endothelial dysfunction caused by smoking could be attributed to increased oxidative stress and red wines antioxidants counteract these acute effects of smoke on endothelium.

Effects of red wine on endothelial function: postprandial studies vs clinical trials.

AIMS There are several epidemiological studies suggesting that moderate daily consumption of red wine may reduce cardiovascular risk. Additionally, results from a great number of in vitro studies indicate that constituents found in red wine are responsible for quite a few beneficial effects on endothelial cells. However, comparison of postprandial studies and clinical trials concerning red wine consumption leads to controversial results about its effect on endothelial function and especially flow-mediated dilatation (FMD). Endothelial function is an early indicator of atherosclerosis and vessel damage and at the same time, it is an independent prognostic factor for cardiovascular risk. Therefore, it is very important to investigate the known acute postprandial effects of red wine consumption, which is highly advised by dieticians and doctors, especially in high-risk populations, such as patients with coronary artery disease (CAD). DATA SYNTHESIS This is a review of studies investigating acute and short-term effects of red wine on endothelial function, as well as relevant in vitro studies. CONCLUSION Analysis of all data about the acute effects of red wine constituents on endothelial function, is inconclusive and it is obvious that new studies are necessary in order to elucidate this matter. Undoubtedly, one should be very careful in suggesting red wine consumption in high-risk populations, as its acute postprandial effect is not yet clear.

Sesame oil consumption exerts a beneficial effect on endothelial function in hypertensive men

Background: The aim of the study was to investigate the effects of sesame oil on endothelial function and to detect the underlying mechanisms, both in the postprandial state and after long-term consumption. Design: We enrolled 30 hypertensive men in a two-phase study. In the first phase, 26 volunteers consumed 35 g of either sesame oil or control oil. Endothelial function, inflammatory activation and nitric oxide syntase (NOS) inhibition was assessed after a 12-hour fast and 2 hours after consumption of an oil-containing standardized meal. In the second phase, 30 volunteers consumed 35 g of sesame oil or control oil daily for 2 months and the above-mentioned parameters were assessed at baseline, 15, 30 and 60 days. Methods: Endothelial function was estimated by endothelium-dependent FMD (flow-mediated dilatation) of the brachial artery. Results: Flow-mediated dilatation (FMD) improved significantly both after acute (p = 0.001) and long-term sesame oil consumption (p = 0.015, p = 0.005 and p = 0.011 for 15, 30 and 60 days respectively). Intracellular adhesion molecule (ICAM) levels decreased significantly after only 60 days of daily sesame oil intake (p = 0.014). By contrast, no changes were observed in the control group in either phase of the study. Conclusions: This is the first study to show that sesame oil consumption exerts a beneficial effect on endothelial function and this effect is sustained with long-term daily use.