Function In Healthy Men Research Articles

The influence of acute hyperglycaemia on brachial artery flow-mediated dilatation in the early and late follicular phases of the menstrual cycle.

What is the central question of the study? This is the first study to examine the impact of acute hyperglycaemia on endothelial function [flow-mediated dilatation (FMD)] in premenopausal women across the early and late follicular (EF and LF) phases of the menstrual cycle. What is the main finding and its importance? Flow-mediated dilatation was impaired 90 min after glucose ingestion, with no significant difference between phases. This indicates that women are susceptible to acute hyperglycaemia-induced endothelial dysfunction in both the EF and LF phases of the menstrual cycle, despite potentially vasoprotective elevations in estradiol levels during the LF phase. Acute hyperglycaemia transiently impairs endothelial function in healthy men when assessed via flow-mediated dilatation (FMD). However, research in female participants is lacking, and the impact of menstrual phase [early follicular (EF) and late follicular (LF)] on vulnerability to acute hyperglycaemia-induced endothelial dysfunction is unknown. Seventeen healthy, naturally menstruating women [21±1 years old (mean ± SD)] participated in three visits. During two visits (EFGlucose and LFGlucose ), brachial artery FMD was assessed before and 60, 90 and 120min after an oral glucose challenge (75g glucose). During an additional EF visit, participants ingested 300ml of water (EFTimeControl ). Blood glucose and insulin increased 30 min after glucose ingestion (P<0.001), with no difference between phases. Flow-mediated dilatation did not change in EFTimeControl (P=0.748) but was reduced 90min after glucose ingestion (Pre, 8.5±2.5%; Post90, 6.6±2.4%, P=0.001; Cohen's d=0.82), with no difference between phases (main effect of phase, P=0.506; phase by time interaction, P=0.391). To account for individual variability in the time course of the impact of hyperglycaemia, the maximal hyperglycaemia-induced impairment in FMD was determined in each participant and compared between phases, revealing no significant phase differences (EFGlucose , -3.1±2.8%; LFGlucose , -2.4±2.1%, P=0.181; d=0.34). These results indicate that, similar to findings in men, acute hyperglycaemia results in FMD impairment in young women. We did not detect significant protection from acute hyperglycaemia-induced endothelial dysfunction in the LF 'high-oestrogen' phase in this sample, and further research is needed to examine the potential for a protective effect of oestrogen exposure, including oral contraceptive pills and hormone replacement therapy.

Does underestimated penile size impact erectile function in healthy men?

The aim of this study is to assess the impact of objective (stretched) and subjective penile size in the erectile function in a urological check-up program on a cross-sectional study including 689 men aged 35-70 years. IIEF-5 questionnaire, physical examination (penile length, prostate volume, blood pressure, body mass index-BMI), metabolic syndrome (MS), comorbidities, habits (sexual intercourse frequency, physical activity, alcohol, and tobacco use), level of education, serum glucose, total testosterone, estradiol, PSA, lipid profile, and self-perceptions (ejaculation time and subjective penile size) were examined in multivariate models using logistic and linear regressions. Penile objective mean length was 13.08 cm ± 2.32 and 67 (9.72%) patients referred small penis self-perception. Seventy-six (11.03%) participants had severe erectile dysfunction (ED), 75 (10.88%) had mild to moderate and moderate ED, 112 (16.25%) had mild ED and 426 (61.83%) had no ED. Risk factors for ED that held statistical significance were self-perceived small penis (OR = 2.23, 95% CI 1.35-3.69, p = .0017), sexual intercourse frequency (per week) (OR = 0.45, 95% CI 0.38-0.52, p < .0001), satisfactory ejaculation time (no vs. yes, OR = 2.06, 95% CI 1.46-2.92, p < .0001), comorbidity (yes vs. no, OR = 2.01, 95% CI 1.46-2.76, p < .0001), age >65 years (OR = 2.93, 95% CI 1.53-5.61, p < .0001), tobacco use (yes vs. no, OR = 1.41, 95% CI 1.02-1.96, p < .0375), regular physical activity (no vs. yes, OR = 1.59, 95% CI 1.13-2.23, p < .0083), serum total testosterone < 200 ng/dl (OR = 3.48, 95% CI 1.69-7.16, p = 0.0009), serum glucose > 100 mg/dl (OR = 1.69, 95% CI 1.18-2.43, p = 0.0044) and systolic blood pressure > 130 mmHg (OR = 1.60, 95% CI 1.16-2.19, p = 0.0037). Results suggest that in addition to previously reported risk factors, patient's subjective impressions of penile size negatively impacts sexual life in about 10% of men considered healthy, while objective penile length does not play significant role in erectile function.

Brachial artery endothelial function is unchanged after acute sprint interval exercise in sedentary men and women.

What is the central question of this study? What is the acute brachial artery endothelial function response to sprint interval exercise and are there sex-based differences? What is the main finding and its importance? Brachial artery endothelial function did not change in either men or women following an acute session of SIT consisting of 3×20s 'all-out' cycling sprints. Our findings suggest this low-volume protocol may not be sufficient to induce functional changes in the brachial artery of sedentary, but otherwise healthy adults. Sprint interval training (SIT) is a potent metabolic stimulus, but studies examining its acute effects on brachial artery endothelial function are limited. The influence of oestradiol on the acute arterial response to this type of exercise is also unknown. We investigated the brachial artery endothelial function response to a single session of SIT in sedentary healthy men (n=8; 22±4years) and premenopausal women tested in the mid-follicular phase of the menstrual cycle (n=8; 21±3years). Participants performed 3×20s 'all-out' cycling sprints interspersed with 2min of active recovery. Brachial artery flow-mediated dilatation (FMD) and haemodynamic parameters were measured before and 1 and 24h post-exercise. Despite attenuations in some haemodynamic parameters at 1 h post-exercise, there were no changes in absolute (P=0.23), relative (P=0.23) or allometrically scaled FMD (P=0.38) following a single session of SIT. Resting and peak dilatory diameters did not change in men or women (P>0.05 for all) and there were no interactions between time and sex for any measure (P>0.05). Oestradiol was not correlated with relative FMD at baseline (r=-0.22, P=0.42) or with the change in relative FMD from baseline to 1h post-exercise (r=0.24, P=0.40). Overall, brachial artery FMD appears to be unchanged in men and women following an acute session of SIT, and the higher oestradiol concentrations in women do not augment the baseline or post-exercise FMD response. The 3×20s model of low-volume sprint interval exercise may not be sufficient to alter brachial artery endothelial function in healthy men and women.

Effect of adding milk to black tea on vascular function in healthy men and women: a randomised controlled crossover trial.

Tea consumption may improve endothelial function and blood pressure via increased bioavailability and bioactivity of nitric oxide. However, questions remain as to the impact of the common practice of adding milk. To investigate the effect of regular consumption of black tea, with and without milk, on vascular function and blood pressure in healthy volunteers. A randomised, controlled, crossover study was performed in 17 healthy volunteers; 7 men and 10 women, mean age 22.4 ± 3.0 years. Participants received each of the following treatments in random order for 4 weeks, with no washout period in between, (i) hot water, (ii) black tea and (iii) black tea with milk. Vascular function was assessed using flow-mediated dilatation (FMD) of the brachial artery at the end of each treatment period. In addition, participants monitored their home blood pressure for the last 7 days of each treatment period. A blood and urine sample was also collected at the end of each treatment period. Black tea increased FMD compared to the hot water control group (1.00 ± 0.18%, P < 0.0001). Black tea with milk decreased FMD compared to both the hot water control (-0.64 ± 0.19%, P = 0.001) and black tea (-1.64 ± 0.19%, P < 0.0001). Compared with hot water, black tea did not alter blood pressure, while black tea with milk increased systolic (1.1 ± 0.5 mmHg, P = 0.03) and diastolic blood pressure (2.0 ± 0.5 mmHg, P < 0.0001). Black tea (-1.8 ± 0.5 bpm, P < 0.001) and black tea with milk (-1.8 ± 0.6 bpm, P < 0.001) lowered heart rate compared to hot water. No significant difference for plasma nitrate or nitrite was observed between treatment groups. The addition of milk to black tea alters the acute/short-term impact of regular tea consumption on vascular function and blood pressure in young healthy men and women. The exact mechanism for this affect remains unknown and longer-term trials to establish this effect in a range of populations are warranted.

Non-Smoking Tobacco Affects Endothelial Function in Healthy Men in One of the Largest Health Studies Ever Performed; The Nord-Trøndelag Health Study in Norway; HUNT3.

BackgroundOral tobacco (snuff) is taking a large market share in Scandinavia, especially with young users. However, long-term health effects are unknown. Small studies show association between snuff and reduced endothelial function, representing an early stage of vascular injury that often precedes manifest cardiovascular disease by several years. We therefore determined the associations between snuff and endothelial function in a large sample of healthy Norwegian men.Methods and DesignIn the Fitness substudy of the Nord-Trøndelag Health Study (HUNT3), endothelial function was measured by flow-mediated dilation (FMD). Aerobic fitness was measured by peak oxygen uptake (VO2peak). A cross-sectional design including 1 592 self-reported healthy men compared these observations with records of present tobacco use, standard cardiovascular risk factors, and socioeconomic status, using general linear models.ResultsFMD was lower in snuff users (FMD: 4.12%, 3.63, 4.61) compared to non-users (FMD: 4.52%, 4.27, 4.78) after adjustment for age (difference: -0.57%, -1.12, -0.01). After further adjustment for potential confounders, FMD still tended to be lower in snuff users than in non-users (difference: -0.53%, -1.09, 0.02). This difference was even more pronounced in the inactive snuff users (-0.83%, -1.59, -0.06) and in the low fit snuff users (-0.74%, CI -0.55, 0.079).ConclusionsOral tobacco is associated with a tendency towards reduced endothelial function, indicating vascular changes that precede cardiovascular disease. The strongest associations were found in men with low physical activity or reduced aerobic fitness.

Cranberry (poly)phenol metabolites correlate with improvements in vascular function: A double-blind, randomized, controlled, dose-response, crossover study.

Cranberries are rich in potentially bioactive (poly)phenols. The aim of this paper was to investigate whether cranberry juice intake can improve vascular function in healthy men in a dose- and time-dependent manner, and to understand which of the circulating (poly)phenol metabolites correlate with vascular effects. A double-blind randomized controlled crossover trial was conducted in ten healthy males. Flow-mediated dilation (FMD), blood pressure, pulse wave velocity and augmentation index were investigated at baseline, 1, 2, 4, 6, and 8 h post-consumption of cranberry juices containing 409, 787, 1238, 1534, and 1910 mg of total cranberry (poly)phenols (TP), and a control drink. Plasma (poly)phenol metabolites were analyzed by UPLC-Q-TOF MS using authentic standards. We observed dose-dependent increases in FMD at 1, 2, 4, 6, and 8 h with a peak at 4 h and maximal effects with juice containing 1238 mg TP. A total of 60 metabolites were quantified in plasma after cranberry consumption. Twelve (poly)phenol metabolites significantly correlated with the increases in FMD, including ferulic and caffeic acid sulfates, quercetin-3-O-ß-D-glucuronide and a γ-valerolactone sulfate. (Poly)phenols in cranberry juice can improve vascular function in healthy males and this is linked to the presence of specific newly identified plasma metabolites.

Lack of effect of supplementation with EPA or DHA on platelet-monocyte aggregates and vascular function in healthy men

Background and AimsEicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oil are postulated to have favourable effects on platelet, endothelial and vascular function. We investigated whether EPA has differential effects on in vivo platelet aggregation and other markers of cardiovascular risk compared to DHA. Methods and ResultsFollowing a 2 wk run-in taking encapsulated refined olive oil, 48 healthy young men were randomly allocated using a parallel design to receive EPA-rich (3.1 g EPA/d) or DHA-rich (2.9 g DHA/d) triglyceride concentrates or refined olive oil (placebo), for a total supplementary lipid intake of 5 g/d. The specified primary outcome was change in platelet monocyte aggregates (PMA); secondary outcomes were capillary density, augmentation index, digital pulse volume measurements, 24 h ambulatory BP, plasma 8-isoprostanes-F2α. Changes in the proportions of DHA and EPA in erythrocytes and non-esterified fatty acid composition indicated compliance to the intervention. There was no significant treatment effect on PMA (P = 0.382); mean changes (%) (95% CI) were placebo −0.5 (−2.0, 1.04), EPA 0.4 (−0.8, 1.6), DHA 0.3 (−1.5, 2.0). R-QUICKI, an index of insulin sensitivity, was greater following EPA compared to placebo (P < 0.05). No other significant differences were noted. ConclusionNeither EPA- nor DHA-rich fish oil supplementation influence platelet-monocyte aggregation or several markers of vascular function after 6 wk in healthy young males. This trial was registered at clinicaltrials.gov as NCT01735357.

Acute effects of apple and blackcurrant polyphenol-rich extracts on postprandial glycaemia and vascular function in healthy men and women

Acute effects of apple and blackcurrant polyphenol-rich extracts on postprandial glycaemia and vascular function in healthy men and women

Vasomotor endothelial function in healthy individuals: Association with the types of character

The vascular endothelial vasomotor function has been studied in healthy young subjects as dependent on the type of character accentuation and levels of neuroticism, depression, and anxiety. It has been shown that the types of character accentuation influence the endothelial vasomotor function in healthy men and women. Personality characteristics of a person can be a significant risk factor for diseases where endothelial vasomotor dysfunction is a trigger factor of pathogenesis.

Intake and time dependence of blueberry flavonoid–induced improvements in vascular function: a randomized, controlled, double-blind, crossover intervention study with mechanistic insights into biological activity

There are very limited data regarding the effects of blueberry flavonoid intake on vascular function in healthy humans. We investigated the impact of blueberry flavonoid intake on endothelial function in healthy men and assessed potential mechanisms of action by the assessment of circulating metabolites and neutrophil NADPH oxidase activity. Two randomized, controlled, double-blind, crossover human-intervention trials were conducted with 21 healthy men. Initially, the impact of blueberry flavonoid intake on flow-mediated dilation (FMD) and polyphenol absorption and metabolism was assessed at baseline and 1, 2, 4, and 6 h after consumption of blueberry containing 766, 1278, and 1791 mg total blueberry polyphenols or a macronutrient- and micronutrient-matched control drink (0 mg total blueberry polyphenols). Second, an intake-dependence study was conducted (from baseline to 1 h) with 319, 637, 766, 1278, and 1791 mg total blueberry polyphenols and a control. We observed a biphasic time-dependent increase in FMD, with significant increases at 1-2 and 6 h after consumption of blueberry polyphenols. No significant intake-dependence was observed between 766 and 1791 mg. However, at 1 h after consumption, FMD increased dose dependently to ≤766 mg total blueberry polyphenol intake, after which FMD plateaued. Increases in FMD were closely linked to increases in circulating metabolites and by decreases in neutrophil NADPH oxidase activity at 1-2 and 6 h. Blueberry intake acutely improves vascular function in healthy men in a time- and intake-dependent manner. These benefits may be mechanistically linked to the actions of circulating phenolic metabolites on neutrophil NADPH oxidase activity. This trial was registered at clinicaltrials.gov as NCT01292954 and NCT01829542.

Effects of Short-Term Nutritional Interventions on Right Ventricular Function in Healthy Men

BackgroundA physiological model of increased plasma nonesterified fatty acid (NEFA) levels result in myocardial triglyceride (TG) accumulation, which is related to cardiac dysfunction. A pathophysiological model of increased plasma NEFA levels result in hepatic steatosis, which has been linked to abnormal myocardial energy metabolism. Hepatic steatosis is accompanied by hepatic inflammation, reflected by plasma cholesteryl ester transfer protein (CETP) levels. The current study aimed to investigate effects of these models via different nutritional interventions on right ventricular (RV) function.MethodsFifteen men (age 25.0±6.6 years) were included and underwent magnetic resonance imaging and spectroscopy in this prospective crossover intervention study. RV function, myocardial and hepatic TG content, and CETP levels were assessed on three occasions: after normal diet, very low-calorie diet (VLCD, physiological model) and high-fat high-energy (HFHE, pathophysiological model) diet (all 3-days diets, randomly ordered, washout phase at least 14 days).ResultsVLCD induced a decrease in mean E deceleration by 27%. Myocardial TG content increased by 55%, whereas hepatic TG content decreased by 32%. Plasma CETP levels decreased by 14% (all P<0.05). HFHE diet induced a decrease in E/A by 19% (P<0.05). Myocardial TG content did not change, whereas hepatic TG content increased by 112% (P<0.01). Plasma CETP levels increased by 14% (P<0.05).ConclusionsThese findings show that RV diastolic function is impaired after short-term VLCD and HFHE diet in healthy men, respectively a physiological and a pathophysiological model of increased plasma NEFA levels. After short-term VLCD, myocardial lipotoxicity may be of importance in decreased RV diastolic function. RV diastolic dysfunction is accompanied by increased hepatic TG content and plasma CETP levels after short-term HFHE diet, suggesting that systemic inflammation reflecting local macrophage infiltration in the heart may be involved in RV dysfunction.

Oxytocin Reduces Reward-Driven Food Intake in Humans

Experiments in animals suggest that the neuropeptide oxytocin acts as an anorexigenic signal in the central nervous control of food intake. In humans, however, research has almost exclusively focused on the involvement of oxytocin in the regulation of social behavior. We investigated the effect of intranasal oxytocin on ingestion and metabolic function in healthy men. Food intake in the fasted state was examined 45 min after neuropeptide administration, followed by the assessment of olfaction and reward-driven snack intake in the absence of hunger. Energy expenditure was registered by indirect calorimetry, and blood was repeatedly sampled to determine concentrations of blood glucose and hormones. Oxytocin markedly reduced snack consumption, restraining, in particular, the intake of chocolate cookies by 25%. Oxytocin, moreover, attenuated basal and postprandial levels of adrenocorticotropic hormone and cortisol and curbed the meal-related rise in plasma glucose. Energy expenditure and hunger-driven food intake as well as olfactory function were not affected. Our results indicate that oxytocin, beyond its role in social bonding, regulates nonhomeostatic, reward-related energy intake, hypothalamic-pituitary-adrenal axis activity, and the glucoregulatory response to food intake in humans. These effects can be assumed to converge with the psychosocial function of oxytocin and imply possible applications in the treatment of metabolic disorders.

Glucocorticoid treatment impairs microvascular function in healthy men in association with its adverse effects on glucose metabolism and blood pressure: a randomised controlled trial

Glucocorticoids (GCs) are widely used anti-inflammatory agents that frequently induce side effects, including insulin resistance, diabetes and hypertension. Here, we investigated the contribution of microvascular dysfunction to the development of these adverse effects in healthy men. In a randomised, placebo-controlled, dose-response intervention study, 32 healthy normoglycaemic men (age: 21 ± 2 years; BMI: 21.9 ± 1.7 kg/m(2)) were allocated to receive prednisolone 30 mg once daily (n = 12), prednisolone 7.5 mg once daily (n = 12) or placebo (n = 8) for 2 weeks using block randomisation. A central office performed the treatment allocation, and medication was dispersed by the hospital pharmacy that was also blinded. Treatment allocation was kept in concealed envelopes. Participants, study personnel conducting the measures and assessing the outcome were blinded to group assignment. The study was conducted at a university hospital. Primary endpoint was prednisolone-induced changes in microvascular function, which was assessed by capillary microscopy. Insulin sensitivity was determined by hyperinsulinaemic-euglycaemic clamp and postprandial glycaemic excursions by standardised meal tests. Compared with placebo, prednisolone 7.5 mg and 30 mg decreased insulin-stimulated capillary recruitment by 9 ± 4% and 17 ± 3%, respectively (p < 0.01). In addition, prednisolone 7.5 mg and 30 mg reduced insulin sensitivity (M value) by -11.4 ± 4.5 μmol kg(-1) min(-1) and -25.1 ± 4.1 μmol kg(-1) min(-1) (p < 0.001) and increased postprandial glucose levels by 11 ± 5% and 27 ± 9% (p < 0.001), respectively. Only high-dose prednisolone increased systolic blood pressure (6 ± 1.2 mmHg, p = 0.006). Prednisolone-induced changes in insulin-stimulated capillary recruitment were associated with insulin sensitivity (r = +0.76; p < 0.001), postprandial glucose concentrations (r = -0.52; p < 0.03) and systolic blood pressure (r = -0.62; p < 0.001). Prednisolone increased resistin concentrations, which were negatively related to insulin-stimulated capillary recruitment (r = -0.40; p = 0.03). No effects were noted on adiponectin and leptin concentrations. Prednisolone treatment was well tolerated; none of the participants left the study. Prednisolone-induced impairment of insulin-stimulated capillary recruitment was paralleled by insulin resistance, increased postprandial glucose levels, hypertension and increased circulating resistin concentrations in healthy men. We propose that GC-induced impairments of microvascular function may contribute to the adverse effects of GC treatment on glucose metabolism and blood pressure. isrctn.org ISRTCN 78149983. The study was funded by the Dutch Top Institute Pharma T1-106.

Serum testosterone levels are related to cognitive function in men with schizophrenia

Sex steroids such as oestrogen and testosterone are potent neurodevelopmental hormones that also play a role in neuromodulation and neuroprotection of the mature brain. Sex steroid hormones may also be involved in the pathophysiology of schizophrenia as reduced circulating sex steroid levels and changes in brain sex steroid receptors are found in people with schizophrenia compared to controls. In men with schizophrenia, recent studies have documented an inverse correlation between serum testosterone and negative symptoms. Our study sought to confirm whether men with schizophrenia had lower levels of testosterone relative to controls and to determine whether lower testosterone levels were related to higher symptom severity and impaired cognition. Circulating serum hormone levels (testosterone, oestrogen, and prolactin), cognitive function and symptoms were assessed in 29 chronically ill men with schizophrenia or schizoaffective disorder. Twenty healthy men were recruited as a comparison group. A series of regression analyses were performed to determine the extent to which circulating sex steroid hormone levels predict cognition and symptoms in men with schizophrenia. We did not find a significant difference in serum testosterone levels between groups. However, circulating testosterone levels significantly predicted performance on verbal memory, processing speed, and working memory in men with schizophrenia. With the exception of an effect of oestrogen on verbal memory, circulating sex steroid levels did not predict cognitive function in healthy men. Testosterone levels were not related to positive or negative symptom severity, but testosterone influenced excitement/hostility levels in our schizophrenia sample. The results suggest that circulating sex steroids may modulate cognitive deficits associated with schizophrenia.

Wolfgang Kiowski

Wolfgang Kiowski

Postprandial Hyperglycemia Impairs Vascular Endothelial Function in HealthyMen by Inducing Lipid Peroxidation and Increasing Asymmetric Dimethylarginine:Arginine

Postprandial hyperglycemia induces vascular endothelial dysfunction (VED) and increases future cardiovascular disease risk. We hypothesized that postprandial hyperglycemia would decrease vascular function in healthy men by inducing oxidative stress and proinflammatory responses and increasing asymmetric dimethylarginine:arginine (ADMA:arginine), a biomarker that is predictive of reduced NO biosynthesis. In a randomized, cross-over design, healthy men (n= 16; 21.6 ± 0.8 y) ingested glucose or fructose (75 g) after an overnight fast. Brachial artery flow-mediated dilation (FMD), plasma glucose and insulin, antioxidants, malondialdehyde (MDA), inflammatory proteins, arginine, and ADMA were measured at regular intervals during the 3-h postprandial period. Baseline FMD did not differ between trials (P> 0.05). Postprandial FMD was reduced following the ingestion of glucose only. Postprandial MDA concentrations increased to a greater extent following the ingestion of glucose compared to fructose. Plasma arginine decreased and the ratio of ADMA:arginine increased to a greater extent following the ingestion of glucose. Inflammatory cytokines and cellular adhesion molecules were unaffected by the ingestion of either sugar. Postprandial AUC0–3 hfor FMD and MDA were inversely related (r= -0.80;P< 0.05), suggesting that hyperglycemia-induced lipid peroxidation suppresses postprandial vascular function. Collectively, these findings suggest that postprandial hyperglycemia in healthy men reduces endothelium-dependent vasodilation by increasing lipid peroxidation independent of inflammation. Postprandial alterations in arginine and ADMA:arginine also suggest that acute hyperglycemia may induce VED by decreasing NO bioavailability through an oxidative stress-dependent mechanism. Additional work is warranted to define whether inhibiting lipid peroxidation and restoring arginine metabolism would mitigate hyperglycemia-mediated decreases in vascular function.

Flavonoid-rich apples and nitrate-rich spinach augment nitric oxide status and improve endothelial function in healthy men and women: a randomized controlled trial

Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Dietary flavonoids and nitrates can augment nitric oxide status via distinct pathways, which may improve endothelial function and lower blood pressure. Recent studies suggest that the combination of flavonoids and nitrates can enhance nitric oxide production in the stomach. Their combined effect in the circulation is unclear. Here, our objective was to investigate the independent and additive effects of flavonoid-rich apples and nitrate-rich spinach on nitric oxide status, endothelial function, and blood pressure. A randomized, controlled, crossover trial with healthy men and women (n=30) was conducted. The acute effects of four energy-matched treatments (control, apple, spinach, and apple+spinach), administered in random order, were compared. Measurements included plasma nitric oxide status, assessed by measuring S-nitrosothiols+other nitrosylated species (RXNO) and nitrite, blood pressure, and endothelial function, measured as flow-mediated dilatation of the brachial artery. Results are means and 95% CI. Relative to control, all treatments resulted in higher RXNO (control, 33nmol/L, 26, 42; apple, 51nmol/L, 40, 65; spinach, 86nmol/L, 68, 110; apple+spinach, 69nmol/L, 54, 88; P<0.01) and higher nitrite (control, 35nmol/L, 27, 46; apple, 69nmol/L, 53, 90; spinach, 99nmol/L, 76, 129; apple+spinach, 80nmol/L, 61, 104; P<0.01). Compared to control, all treatments resulted in higher flow-mediated dilatation (P<0.05) and lower pulse pressure (P<0.05), and apple and spinach resulted in lower systolic blood pressure (P<0.05). No significant effect was observed on diastolic blood pressure. The combination of apple and spinach did not result in additive effects on nitric oxide status, endothelial function, or blood pressure. In conclusion, flavonoid-rich apples and nitrate-rich spinach can independently augment nitric oxide status, enhance endothelial function, and lower blood pressure acutely, outcomes that may benefit cardiovascular health.

Effect of simulated dives on diastolic function in healthy men

Scuba diving may elicit acute changes to human cardiovascular function. Environmental stresses such as immersion, cold, and venous gas microbubbles all have been shown to contribute to right ventricular overload and impaired left ventricular filling after single dives. We investigated cardiac function after simulated dry chamber dives. Twenty male divers [mean age 31 years, standard deviation (SD) 8 years, mean body mass index 26 kgm(-2) (SD 3 kgm(-2))] participated in the study. All subjects had normal ECG, stress-ECG, and transthoracic echocardiography at rest. Echocardiographic assessment of diastolic function [E/A-ratio, deceleration time (DT), isovolumic relaxation time (IVRT), E/e'-ratio] was performed directly prior to and 20 and 80 min after two simulated dry hyperbaric chamber dives (maximal pressure 600 kPa, duration 60 min) that were conducted within 1 week. DT statistically significantly decreased from 163 ms (SD 14 ms) to 125 ms (SD 15 ms) 20 min after the dive (p < 0.0001), whereas 80 min after decompression these changes tended to return to baseline [146 ms (SD 14 ms); p = 0.06]. There was no statistically significant change in heart rate, E/A-ratio or E/e'-ratio after 20 or 80 min compared to baseline. These changes could be reproduced after the second dry chamber dive. No gas microbubbles were detectable during or after decompression from either dive. Simulated hyperbaric dry chamber dives were associated with a transient decrease in deceleration time in healthy men. Factors other than immersion, cold, or nitrogen microbubbles may contribute to acute changes in cardiac function after single scuba dives.

Bicycle Riding: Impact on Lower Urinary Tract Symptoms and Erectile Function in Healthy Men

PurposeRecently, reports in the mass media have implicated that bicycle riding increases the risk of erectile dysfunction and prostatic diseases. So, we evaluate the impact of bicycle riding on erectile function and lower urinary tract symptoms (LUTS) in healthy general men.MethodsFrom 26 June 2010 to 20 July 2010, we investigate degree of LUTS (voiding and storage symptoms), using International Continence Society-male Questionnaire (ICS-mQ) and erectile function using International Index of Erectile Function-5 Questionnaire (IIEF-5) in 5 work places (personnel of public office, hospital, university, etc.) of which bicycle riding club members were doing active club activities. Respondents, who participated in club activities for 6 months and longer, were classified as the bicycle club (142 men; age, 44.02±8.56). Ones who do not ride bicycles were classified as the control group (83 men; age, 42.13±7.85). People who were having the history of urological and other chronic diseases (diabetes, vascular disease, heart disease, etc) were excluded from both groups.ResultsBicycle club is not significantly associated with increased prevalence of LUTS (bicycle club, 2.1 to 57.7% control, 4.8 to 73.5%) and erectile dysfunction (bicycle club, 46.1% control, 55.4%). The total mean score (storage/voiding/erectile function) of bicycle club (13.93±1.95/11.14±3.49/20.46±5.30) were not significantly different from control (14.35±2.49/11.52±3.38/20.40±4.07) (P=0.190 to 0.968).ConclusionsThese results suggested that bicycle riding as exercise or hobby has no negative effect on LUTS and erectile function in healthy general men, although this research data were limited to the questionnaire analysis.

Effects of lycopene supplementation on oxidative stress and markers of endothelial function in healthy men

ObjectiveThe objective was to determine the effects of lycopene supplementation on endothelial function assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT) and oxidative stress. MethodsHealthy men (n=126) were randomized to receive placebo (n=38), 6mg (n=41), or 15mg (n=37) lycopene daily for 8-week. ResultsSerum lycopene increased in a dose-dependent manner after 8-week supplementation (P<0.001). The 15mg/day group had greater increase in plasma SOD activity (P=0.014) and reduction in lymphocyte DNA comet tail length (P=0.042) than the placebo group. Intragroup comparison revealed a 23% increase in RH-PAT index from baseline (1.45±0.09 vs. 1.79±0.12; P=0.032) in the 15mg/day group after 8-week. hs-CRP, systolic blood pressure, sICAM-1 and sVCAM-1 significantly decreased, and β-carotene and LDL-particle size significantly increased only in the 15mg/day group. Interestingly, the beneficial effect of lycopene supplementation on endothelial function (i.e., RH-PAT and sVCAM-1) were remarkable in subjects with relatively impaired endothelial cell function at initial level. Changes in RH-PAT index correlated with SOD activity (r=0.234, P=0.017) especially in the 15mg lycopene/day group (r=0.485, P=0.003), lymphocyte DNA comet tail moment (r=−0.318, P=0.001), and hs-CRP (r=−0.238, P=0.011). In addition, changes in lycopene correlated with hs-CRP (r=−0.230, P=0.016) and SOD activity (r=0.205, P=0.037). ConclusionAn increase in serum lycopene after supplementation can reduce oxidative stress which may play a role in endothelial function.