Effects of alcohol intake on blood pressure and sympathetic nerve activity in normotensive humans: a preliminary report

Binge Alcohol Consumption Elevates Sympathetic Transduction to Blood Pressure: A Randomized Controlled Trial

BACKGROUND

Alcohol consumption is associated with cardiovascular disease, and the sympathetic nervous system is a suspected mediator. The present study investigated sympathetic transduction of muscle sympathetic nerve activity to blood pressure at rest and in response to cold pressor test following evening binge alcohol or fluid control, with the hypothesis that sympathetic transduction would be elevated the morning after binge alcohol consumption.

METHODS

Using a randomized, fluid-controlled (FC) crossover design, 26 healthy adults (12 male, 14 female, 25±6 years, 27±4 kg/m2) received an evening binge alcohol dose and a FC. All participants underwent next-morning autonomic-cardiovascular testing consisting of muscle sympathetic nerve activity, beat-to-beat blood pressure, and heart rate during a 10-minute rest period and a 2-minute cold pressor test. Sympathetic transduction was assessed at rest and during the cold pressor test in both experimental conditions.

RESULTS

Evening alcohol increased heart rate (FC: 60±9 versus alcohol: 64±9 bpm; P=0.010) but did not alter resting mean arterial pressure (FC: 80±6 versus alcohol: 80±7 mm Hg; P=0.857) or muscle sympathetic nerve activity (FC: 18±9 versus alcohol: 20±8 bursts/min; P=0.283). Sympathetic transduction to mean arterial pressure (time×condition; P=0.003), diastolic blood pressure (time×condition; P=0.010), and total vascular conductance (time×condition; P=0.004) was augmented after alcohol at rest. Sympathetic transduction during the cold pressor test was also elevated after evening binge alcohol consumption (P=0.002).

CONCLUSIONS

These findings suggest that evening binge alcohol consumption leads to augmented morning-after sympathetic transduction of muscle sympathetic nerve activity to blood pressure, highlighting a new mechanism whereby chronic or excessive alcohol consumption contributes to cardiovascular disease progression via altered end-organ responsiveness to sympathetic neural outflow.

REGISTRATION

URL: https://clinicaltrials.gov/study/NCT03567434; Unique identifier: NCT03567434.

Alcohol Intake and Risk of Hypertension: A Systematic Review and Dose-Response Meta-Analysis of Nonexperimental Cohort Studies

BACKGROUND

Alcohol consumption has been associated with higher blood pressure and an increased risk of hypertension. However, the possible exposure thresholds and effect-modifiers are uncertain.

METHODS

We assessed the dose-response relationship between usual alcohol intake and hypertension incidence in nonexperimental cohort studies. After performing a systematic literature search through February 20, 2024, we retrieved 23 eligible studies. We computed risk ratios and 95% CI of hypertension incidence using a nonlinear meta-analytic model based on restricted cubic splines, to assess the dose-response association with alcohol consumption.

RESULTS

We observed a positive and almost linear association between alcohol intake and hypertension risk with risk ratios of 0.89 (0.84-0.94), 1.11 (1.07-1.15), 1.22 (1.14-1.30), and 1.33 (1.18-1.49) for 0, 24, 36 and 48 g/d, respectively, using 12 g alcohol/d as the reference value. In sex-specific analyses, the association was almost linear in men over the entire range of exposure but only observed above 12 g/d in women, although with a steeper association at high levels of consumption compared with men. The increased risk of hypertension above 12 to 24 g alcohol/d was similar in Western and Asian populations and considerably greater in White than in Black populations, mainly due to the positive association in women at moderate-to-high intake.

CONCLUSIONS

Overall, our results lend support to a causal association between alcohol consumption and risk of hypertension, especially above an alcohol intake of 12 g/d, and are consistent with recommendations to avoid or limit alcohol intake. Sex and ethnicity appear to be major effect-modifiers of such association.

Acetic Acid: An Underestimated Metabolite in Ethanol-Induced Changes in Regulating Cardiovascular Function

Acetic acid is a bioactive short-chain fatty acid produced in large quantities from ethanol metabolism. In this review, we describe how acetic acid/acetate generates oxidative stress, alters the function of pre-sympathetic neurons, and can potentially influence cardiovascular function in both humans and rodents after ethanol consumption. Our recent findings from in vivo and in vitro studies support the notion that administration of acetic acid/acetate generates oxidative stress and increases sympathetic outflow, leading to alterations in arterial blood pressure. Real-time investigation of how ethanol and acetic acid/acetate modulate neural control of cardiovascular function can be conducted by microinjecting compounds into autonomic control centers of the brain and measuring changes in peripheral sympathetic nerve activity and blood pressure in response to these compounds.

Alcohol Use and Blood Pressure Among Adults with Hypertension: the Mediating Roles of Health Behaviors

BACKGROUND

Alcohol use is associated with increased blood pressure among adults with hypertension, but it is unknown whether some of the observed relationship is explained by mediating behaviors related to alcohol use.

OBJECTIVE

We assess the potential indirect role of smoking, physical inactivity, unhealthy diet, and poor medication adherence on the association between alcohol use and blood pressure among Black and White men and women with hypertension.

DESIGN

Adjusted repeated-measures analyses using generalized estimating equations and mediation analyses using inverse odds ratio weighting.

PARTICIPANTS

1835 participants with hypertension based on ACC/AHA 2017 guidelines in three most recent follow-up exams of the longitudinal Coronary Artery Risk Development in Young Adults cohort study (2005-2016).

MAIN MEASURES

Alcohol use was assessed using both self-reported average ethanol intake (drinks/day) and engagement in heavy episodic drinking (HED) in the past 30 days. Systolic and diastolic blood pressure (SBP, DBP) were measured by trained technicians (mmHg). Smoking, physical inactivity, and diet were self-reported and categorized according to American Heart Association criteria, and medication adherence was assessed using self-reported typical adherence to antihypertensive medications.

KEY RESULTS

At baseline (2005-2006), 57.9% of participants were Black and 51.4% were women. Mean age (standard deviation) was 45.5 (3.6) years, mean SBP was 128.7 (15.5) mmHg, and mean DBP was 83.2 (10.1) mmHg. Each additional drink per day was significantly associated with higher SBP (β = 0.713 mmHg, 95% confidence interval (CI): 0.398, 1.028) and DBP (β = 0.398 mmHg, 95% CI: 0.160, 0.555), but there was no evidence of mediation by any of the behaviors. HED was not associated with blood pressure independent of average consumption.

CONCLUSIONS

These findings support the direct nature of the association of alcohol use with blood pressure and the utility of advising patients with hypertension to limit consumption in addition to other behavioral and pharmacological interventions.

Ethanol Inhibits Pancreatic Projecting Neurons in the Dorsal Motor Nucleus of the Vagus

Alcohol use disorder (AUD) is a rapidly growing concern in the United States. Current trending escalations of alcohol use are associated with a concurrent rise in alcohol-related end-organ damage, increasing risk for further diseases. Alcohol-related end-organ damage can be driven by autonomic nervous system dysfunction, however studies on alcohol effects on autonomic control of end-organ function are lacking. Alcohol intake has been shown to reduce insulin secretions from the pancreas. Pancreatic insulin release is controlled in part by preganglionic parasympathetic motor neurons residing in the dorsal motor nucleus of the vagus (DMV) that project to the pancreas. How these neurons are affected by alcohol exposure has not been directly examined. Here we investigated the effects of acute ethanol (EtOH) application on DMV pancreatic-projecting neurons with whole-cell patch-clamp electrophysiology. We found that bath application of EtOH (50mM) for greater than 30minutes significantly enhanced the frequency of spontaneous inhibitory post synaptic current (sIPSC) events of DMV pancreatic-projecting neurons suggesting a presynaptic mechanism of EtOH to increase GABAergic transmission. Thirty-minute EtOH application also decreased action potential firing of these neurons. Pretreatment of DMV slices with 20μM fluoxetine, a selective serotonin reuptake inhibitor, also increased GABAergic transmission and decreased action potential firing of these DMV neurons while occluding any further effects of EtOH application, suggesting a critical role for serotonin in mediating EtOH effects in the DMV. Ultimately, decreased DMV motor output may lead to alterations in pancreatic secretions. Further studies are needed to fully understand EtOH's influence on DMV neurons as well as the consequences of changes in parasympathetic output to the pancreas.

Alcohol Consumption: A New Risk Factor for Arterial Stiffness?

The relationship between alcohol consumption and cardiovascular disease risk is complex. Low-to-moderate daily alcohol consumption (1–2 drinks/day) is associated with reduced risk, whereas greater amounts of alcohol consumption and a “binge” pattern of drinking are associated with increased cardiovascular risk and mortality. Arterial stiffness may help explain the complex relationship. This integrated review summarizes data from studies examining the associations between alcohol consumption and pulse wave velocity, a gold standard measure of arterial stiffness. We also briefly review the concept and methodology of pulse wave velocity measurement as well as the mechanisms of alcohol-induced arterial stiffening. Findings among the different studies reviewed were inconsistent with methodological challenges related to alcohol use assessment. While making specific conclusions regarding this relationship is tenuous; the data suggest that excessive alcohol consumption or a binge drinking pattern is associated with increased arterial stiffness.

Effects of acute alcohol consumption on neuronal activity and cerebral vasomotor response

Introduction

In the majority of European countries, driving after drinking small-moderate amount of alcohol is legal. Motivated by our previous studies on cerebral hemodynamics, we aimed to study whether a small-moderate blood alcohol content (BAC), at which driving is legal in some countries (0.8 g/L), influences the neuronal activity, neurovascular coupling, and cerebral vasoreactivity.

Methods

Analyses of pattern-reversal visual evoked potential (VEP) and transcranial Doppler (TCD) examinations were performed in thirty young healthy adults before and 30 min after alcohol consumption. Cerebral vasoreactivity was evaluated by breath holding test in both middle cerebral arteries. By using a visual cortex stimulation paradigm, visually evoked flow velocity response during reading was measured in both posterior cerebral arteries (PCA).

Results

The BAC was 0.82 g/L and 0.94 g/L 30 and 60 min after drinking alcohol, respectively. Latency of the VEP P100 wave increased after alcohol consumption. Resting absolute flow velocity values increased, whereas pulsatility indices in the PCA decreased after alcohol ingestion, indicating vasodilation of cerebral microvessels. Breath holding index and the visually evoked maximum relative flow velocity increase in the PCA and steepness of rise of the flow velocity curve were smaller after than before alcohol consumption.

Conclusion

BAC close to a legal value at which driving is allowed in some European countries inhibited the neuronal activity and resulted in dilation of cerebral arterioles. Cerebral vasodilation may explain the decrease of cerebral vasoreactivity and might contribute to the disturbance of visually evoked flow response after alcohol consumption.

Morning sympathetic activity after evening binge alcohol consumption

Binge alcohol consumption elicits acute and robust increases of muscle sympathetic nerve activity (MSNA), yet the impact of evening binge drinking on morning-after MSNA is unknown. The present study examined the effects of evening binge alcohol consumption on polysomnographic sleep and morning-after MSNA. We hypothesized that evening binge drinking (i.e. 4-5 drink equivalent in <2 h) would reduce sleep quality and increase morning-after blood pressure (BP) and MSNA. Following a familiarization night within the sleep laboratory, 22 participants (12 men, 10 women; 25 ± 1 yr) were examined after simulated binge drinking or fluid control (randomized, crossover design). Morning MSNA was successfully recorded across both conditions in 16 participants (8 men, 8 women) during a 10-min baseline and three Valsalva's maneuvers (VM). Binge drinking reduced rapid eye movement (REM) sleep (15 ± 1 vs. 20 ± 1%, P = 0.003), increased stage II sleep (54 ± 1 vs. 51 ± 1%, P = 0.002), and increased total urine output (2.9 ± 0.2 vs. 2.1 ± 0.1 liters, P < 0.001) but did not alter morning-after urine specific gravity. Binge drinking increased morning-after heart rate [65 (54-72) vs. 58 (51-67) beats/min, P = 0.013] but not resting BP or MSNA. Binge drinking elicited greater sympathoexcitation during VM (38 ± 3 vs. 43 ± 3 bursts/min, P = 0.036). Binge drinking augmented heart rate (P = 0.002), systolic BP (P = 0.022), and diastolic BP (P = 0.037) reactivity to VM phase IV and blunted cardiovagal baroreflex sensitivity during VM phases II (P = 0.028) and IV (P = 0.043). In conclusion, evening binge alcohol consumption disrupted REM sleep and morning-after autonomic function. These findings provide new mechanistic insight into the potential role of binge drinking on cardiovascular risk.NEW & NOTEWORTHY Chronic binge alcohol consumption is associated with future cardiovascular disease (CVD) risk in both men and women. In addition, binge alcohol consumption is known to disrupt normal sleep quality during the early morning hours, coinciding with the morning sympathetic surge. In the present study, an evening of binge alcohol consumption increased baseline morning heart rate and cardiovascular reactivity during the Valsalva maneuver (VM) strain. Specifically, muscle sympathetic nerve activity and phase IV hemodynamic responses increased during VM the morning after binge alcohol consumption. The autonomic dysfunction and increased cardiovascular reactivity during VM suggests a contributing mechanism to CVD risk present in individuals who binge drink.

The effects of repeated binge drinking on arterial stiffness and urinary norepinephrine levels in young adults

OBJECTIVES

The aim of this study was to investigate the effect of repeated binge drinking and moderate alcohol consumption in young adults on arterial stiffness and sympathetic activity.

METHODS

We enrolled 49 healthy young adults, free of cardiovascular diseases (25 men; age: 23.5 ± 0.4 years; BMI: 23.4 ± 0.4 kg/m; mean ± S.E). Individuals included were those with a history of repeated binge drinking (>2 years duration; n = 20), drank at moderate levels (MODs, >5 years duration; n = 16) and abstained from alcohol (last 2-3 years; n = 13). Arterial stiffness was assessed using carotid to femoral pulse wave velocity (cfPWV) and sympathetic activity was assessed using 24-h urinary norepinephrine levels. Also measured was aortic SBP and augmentation index (AIx), a measure of wave reflection.

RESULTS

Binge drinkers and MODs had higher cfPWV than alcohol abstainers (0.6 and 0.5 m/s, respectively; P ≤ 0.04). In addition, binge drinkers had higher urinary norepinephrine levels than MODs and alcohol abstainers (P < 0.05). Higher cfPWV were correlated with higher norepinephrine levels (r = 0.35. P = 0.02). Aortic SBP (P = 0.2) and AIx (P = 0.96) were similar among binge drinkers, MODs and alcohol abstainers.

CONCLUSION

Our findings suggest that repeated exposure to alcohol, regardless of drinking pattern, may increase aortic arterial stiffness in healthy young adults. In addition, sympathetic activation, reflected by increased 24-h urinary norepinephrine levels, may contribute to alcohol-induced arterial stiffening in young adults.

Lifestyle interventions for the prevention and treatment of hypertension

Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.

Race- and sex-specific association between alcohol consumption and hypertension in 22 cohort studies: A systematic review and meta-analysis

BACKGROUND AND AIMS

The alcohol-hypertension relation has been well documented, but whether women have protective effect or race and type of beverage consumed affect the association remain unclear. To quantify the relation between total or beverage-specific alcohol consumption and incident hypertension by considering the effect of sex and race.

METHODS AND RESULTS

Articles were identified in PubMed and Embase databases with no restriction on publication date. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated by random effects models. Restricted cubic splines were used to model the dose-response association. This study involved 22 articles (31 studies) and included 414,477 participants. The hypertension risk was different among liquor, wine, and beer at 5.1-10 g/d of ethanol consumption (P_{-across subgroups} = 0.002). The hypertension risk differed between men (RR: 1.14, 95% CI: 1.07, 1.20) and women (RR: 0.98, 95% CI: 0.89, 1.06) at 10 g/d (P_{-across subgroups} = 0.005). We found a linear alcohol-hypertension association among white (P-_linearity = 0.017), black people (P-_linearity = 0.035), and Asians (P-_linearity<0.001). With 10 g/d increment of consumption, the RRs for hypertension were 1.06 (95% CI: 1.04, 1.08), 1.14 (95% CI: 1.01, 1.28), and 1.06 (95% CI: 1.01, 1.10) for Asians, black, and white people, respectively.

CONCLUSION

Sex modifies the alcohol-hypertension association at low level of alcohol consumption and we did not find evidence of a protective effect of alcohol consumption among women. Black people may have higher hypertension risk than Asians and white people at the same ethanol consumption.

Effect of alcohol on blood pressure

BACKGROUND

Alcohol is consumed by over 2 billion people worldwide. It is a common substance of abuse and its use can lead to more than 200 disorders including hypertension. Alcohol has both acute and chronic effects on blood pressure. This review aimed to quantify the acute effects of different doses of alcohol over time on blood pressure and heart rate in an adult population.

OBJECTIVES

Primary objective To determine short-term dose-related effects of alcohol versus placebo on systolic blood pressure and diastolic blood pressure in healthy and hypertensive adults over 18 years of age. Secondary objective To determine short-term dose-related effects of alcohol versus placebo on heart rate in healthy and hypertensive adults over 18 years of age.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to March 2019: the Cochrane Hypertension Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 2), in the Cochrane Library; MEDLINE (from 1946); Embase (from 1974); the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov. We also contacted authors of relevant articles regarding further published and unpublished work. These searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing effects of a single dose of alcohol versus placebo on blood pressure (BP) or heart rate (HR) in adults (≥ 18 years of age).

DATA COLLECTION AND ANALYSIS

Two review authors (ST and CT) independently extracted data and assessed the quality of included studies. We also contacted trial authors for missing or unclear information. Mean difference (MD) from placebo with 95% confidence interval (CI) was the outcome measure, and a fixed-effect model was used to combine effect sizes across studies.  MAIN RESULTS: We included 32 RCTs involving 767 participants. Most of the study participants were male (N = 642) and were healthy. The mean age of participants was 33 years, and mean body weight was 78 kilograms. Low-dose alcohol (< 14 g) within six hours (2 RCTs, N = 28) did not affect BP but did increase HR by 5.1 bpm (95% CI 1.9 to 8.2) (moderate-certainty evidence). Medium-dose alcohol (14 to 28 g) within six hours (10 RCTs, N = 149) decreased systolic blood pressure (SBP) by 5.6 mmHg (95% CI -8.3 to -3.0) and diastolic blood pressure (DBP) by 4.0 mmHg (95% CI -6.0 to -2.0) and increased HR by 4.6 bpm (95% CI 3.1 to 6.1) (moderate-certainty evidence for all).  Medium-dose alcohol within 7 to 12 hours (4 RCTs, N = 54) did not affect BP or HR. Medium-dose alcohol > 13 hours after consumption (4 RCTs, N = 66) did not affect BP or HR. High-dose alcohol (> 30 g) within six hours (16 RCTs, N = 418) decreased SBP by 3.5 mmHg (95% CI -6.0 to -1.0), decreased DBP by 1.9 mmHg (95% CI-3.9 to 0.04), and increased HR by 5.8 bpm (95% CI 4.0 to 7.5). The certainty of evidence was moderate for SBP and HR, and was low for DBP. High-dose alcohol within 7 to 12 hours of consumption (3 RCTs, N = 54) decreased SBP by 3.7 mmHg (95% CI -7.0 to -0.5) and DBP by 1.7 mmHg (95% CI -4.6 to 1.8) and increased HR by 6.2 bpm (95% CI 3.0 to 9.3). The certainty of evidence was moderate for SBP and HR, and low for DBP. High-dose alcohol ≥ 13 hours after consumption (4 RCTs, N = 154) increased SBP by 3.7 mmHg (95% CI 2.3 to 5.1), DBP by 2.4 mmHg (95% CI 0.2 to 4.5), and HR by 2.7 bpm (95% CI 0.8 to 4.6) (moderate-certainty evidence for all).  AUTHORS' CONCLUSIONS: High-dose alcohol has a biphasic effect on BP; it decreases BP up to 12 hours after consumption and increases BP > 13 hours after consumption. High-dose alcohol increases HR at all times up to 24 hours. Findings of this review are relevant mainly to healthy males, as only small numbers of women were included in the included trials.

Effects of ethanol and ethanol metabolites on intrinsic function of mesenteric resistance arteries

Evidence suggests that ethanol-induced hypertension is associated with increased cardiovascular responsiveness to vasopressors in vivo and enhanced reactivity of isolated arteries to vasopressors ex vivo. The underlying mechanisms are not well understood and the contribution of ethanol metabolites to vascular effects induced by ethanol consumption are unclear. Mesenteric resistance arteries were harvested from Sprague-Dawley rats. Pressure myography was utilized to test effects of ethanol, acetaldehyde and phosphatidylethanol on myogenic tone and on vasoconstriction induced by phenylephrine, arginine vasopressin (aVP), endothelin-1 and KCl. Ethanol, acetaldehyde and phosphatidylethanol concentrations were monitored during the experiments. Ethanol concentrations in the vessel bath decreased with a half-life of 25min; acetaldehyde and phosphatidylethanol concentrations remained constant. Pretreatment with ethanol dose-dependently increased the potency of phenylephrine to induce vasoconstriction 4-fold (p<0.01). These effects were comparable when arteries were pre-treated with a single dose of ethanol for 30min and when ethanol concentrations were kept constant during 30min and 60min of pretreatment. While ethanol also dose-dependently increased the potency of aVP to induce vasoconstriction 1.7-fold (p<0.05), it did not affect vasoconstriction induced by endothelin-1 or KCl. Acetaldehyde pre-treatment (30 min) dose-dependently increased the potency of phenylephrine to induce vasoconstriction 2.7-fold (p<0.01) but did not affect other vasoconstrictor responses. Phosphatidylethanol did not affect any vasoconstrictor responses. Ethanol and its metabolites did not affect myogenic tone. These data suggest that ethanol and acetaldehyde selectively sensitize intrinsic constrictor responses upon activation of vascular α₁-adrenergic and/or vasopressin receptors at clinically relevant concentrations. Our findings support the concept that enhanced vasoreactivity to vasoactive hormones contributes to the development of hypertension induced by ethanol consumption. Ex vivo exposure of resistance arteries to ethanol and acetaldehyde resembles effects of chronic ethanol consumption on intrinsic vascular function, and thus could serve as test platform to evaluate interventions aimed to mitigate vascular effects associated with ethanol consumption.

Early and Late Cardiovascular and Metabolic Responses to Mixed Wine: Effect of Drink Temperature

Aim: Red wine is usually ingested as an unmixed drink. However, mixtures of wine with juices and/or sucrose (mixed wine) are becoming more and more popular and could be ingested at either cold or hot temperature. Although the temperature effects on the cardiovascular system have been described for water and tea, with greater energy expenditure (EE) and lower cardiac workload with a colder drink, little information is available on the impact of temperature of alcoholic beverages on alcoholemia and cardiometabolic parameters. The purpose of the present study was to compare the acute cardiovascular and metabolic changes in response to mixed wine ingested at a cold or at a hot temperature.

Methods: In a randomized crossover design, 14 healthy young adults (seven men and seven women) were assigned to cold or hot mixed wine ingestion. Continuous cardiovascular, metabolic, and cutaneous monitoring was performed in a comfortable sitting position during a 30-min baseline and for 120 min after ingesting 400 ml of mixed wine, with the alcohol content adjusted to provide 0.4 g ethanol/kg of body weight and drunk at either cold (3°C) or hot (55°C) temperature. Breath alcohol concentration was measured intermittently throughout the study.

Results: Overall, alcoholemia was not altered by drink temperature, with a tendency toward greater values in women compared to men. Early responses to mixed wine ingestion (0–20 min) indicated that cold drink transiently increased mean blood pressure (BP), cardiac vagal tone, and decreased skin blood flow (SkBf) whereas hot drink did not change BP, decreased vagal tone, and increased SkBf. Both cold and hot mixed wine led to increases in EE and reductions in respiratory quotient. Late responses (60–120 min) led to similar cardiovascular and metabolic changes at both drink temperatures.

Conclusion: The magnitude and/or the directional change of most of the study variables differed during the first 20 min following ingestion and may be related to drink temperature. By contrast, late changes in cardiometabolic outcomes were similar between cold and hot wine ingestion, underlying the typical effect of alcohol and sugar intake on the cardiovascular system.

The Effect of Acute Ethanol Consumption on the Human Retinal Circulation: A Study in Diabetic and Non-Diabetic Subjects

The effects of acute ethanol consumption on retinal haemodynamics and retinal vascular autoregulation to oxygen in the human retinal circulation were studied in 10 diabetic (mean age +/- SD: 38.2 +/- 11.1) and 16 non-diabetic (mean age +/- SD: 32.4 +/- 8.8) subjects. Subjects drank 0.5 g of ethanol, as vodka, per kg of body weight, diluted in sugar-free orange juice. Retinal blood flow was determined using laser Doppler velocimetry and computerised image analysis. The effect of ethanol on oxygen reactivity, as a measure of autoregulation, was also determined after 60% oxygen inhalation. All subjects demonstrated a significant fall in mean arterial blood pressure (control group 3.3%, p = 0.04, diabetic subjects 5.7%, p = 0.05), after ethanol intake. Ethanol caused no significant change in retinal blood flow. Oxygen reactivity was found to be 38.3% (22.4-47.7, median and interquartile range) in the non-diabetic subjects at baseline, and 30.7% (10.8-42.1) after ethanol ingestion. In diabetic subjects, the oxygen reactivity was 33.2% (19.8-46.8) at baseline and 24.5% (21.1-32.1) after ethanol. In this study ethanol did not significantly affect retinal blood flow or impair autoregulation. These results suggest that the retinal circulation may be able to autoregulate despite the presence of ethanol, in contrast to other vascular beds where ethanol changes flow.

Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review

BACKGROUND

To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements.

METHODS

A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles.

RESULTS

A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP.

CONCLUSION

A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.

Evaluation of the brachial artery endothelial function in chronic alcohol consumption among males by high-frequency ultrasonography

OBJECTIVE

There is evidence suggesting that different volumes of chronic alcohol consumption have different effects on the endothelium. Therefore, using high-frequency ultrasonography, we evaluate the effects of the different volume and duration of alcohol intake on brachial artery endothelial function in chronic drinkers.

METHODS

Ninety-two male chronic episodic alcoholics were grouped by alcohol intake amount and duration: mild (group B, n=30); ≤90 mg ethanol daily, 3-5 days/wk for 5-8 years; moderate (group C, n=30); 90-150 mg ethanol daily, 3-5 days/wk for 9-20 years; and severe (group D, n=32); ≥150 mg ethanol daily, 6-7 days/wk for more than 10 years. Thirty male nondrinkers were recruited as the control group A. High-frequency ultrasonography was used to measure brachial artery diameter during rest, during reactive hyperemia and following the administration of nitroglycerin. Endothelial-dependent brachial artery flow-mediated dilatation (FMD) and endothelial-independent brachial artery nitrate-mediated dilatation (NMD) were calculated.

RESULTS

Flow-mediated dilatation values for group C and D were significantly lower than those for group A and B (V_C =7.63±0.22, V_D =5.85±0.23 vs V_A =13.35±0.35, V_B =12.81±0.36, P<.01). The FMD of group D was significantly lower than that of group C (P<.01). Meanwhile, the NMD of group D was significantly lower than that of the other groups (V_D =17.33±6.21 vs V_A =25.35±7.42, V_B =24.52±8.30, V_C =23.35±7.27, P<.01).

CONCLUSIONS

Chronic moderate-to-heavy alcohol consumption caused endothelial dysfunction, even damaging vascular smooth muscle cells in cases of heavy alcohol consumption, while abstinence and chronic mild alcoholics caused no effect on endothelial function.

Large-Artery Hemodynamics After Acute Alcohol Administration in Young, Healthy Volunteers

The objective of the present study was to investigate the acute effects of alcohol on blood flow volume and velocity, on wall motion of superficial large arteries, and on systemic hemodynamics in humans. In 10 healthy volunteers small doses of alcohol were administered either orally (0.3 g/kg in 250 mL water) or intravenously (7.5 mg/kg/minute in 250 mL saline in 40 minutes). The effects of alcohol were compared with those of saline 250 mL infused for 40 minutes (6.25 mL/min). Blood velocity and systodiastolic changes of wall diameter were measured in the common carotid, femoral, and brachial arteries simultaneously with cardiac output and finger blood pressure. Skin temperature was measured at the cheek, hand, and toe. Ethanol administration caused a transitory blood pressure increase accompanied by a rise in peripheral resistances at 20 minutes. Arterial blood flow was not changed by either mode of alcohol administration at any of the measurement sites. However, this result was achieved through different compensatory mechanisms in each artery. In fact, mean carotid diameter increased after both oral and intravenous ethanol administration but remained unchanged at the brachial and femoral level. Mean blood velocity was reduced after alcohol administration at the carotid but was unchanged at the brachial and femoral level after oral or intravenous alcohol administration. Skin temperature increased 20 minutes after alcohol administration at all sites. This study shows that although acute alcohol administration does not change blood flow in superficial large arteries, it causes different autoregulatory local responses of vessel walls.

Molecular Properties of Red Wine Compounds and Cardiometabolic Benefits

Wine has been used since the dawn of human civilization. Despite many health benefits, there is still a lot of discussion about the real properties of its components and its actions on cells and molecular interactions. A large part of these issues permeate the fine line between the amount of alcohol that causes problems to organic systems and the amount that could be beneficial for the health. However, even after the process of fermentation, wine conserves different organic compounds from grapes, such as polysaccharides, acids, and phenolic compounds, such as flavonoids and nonflavonoids. These substances have known anti-inflammatory and antioxidant capacities, and are considered as regulatory agents in cardiometabolic process. In this study, the main chemical components present in the wine, its interaction with molecules and biological mechanisms, and their interference with intra- and extracellular signaling are reviewed. Finally, the properties of wine that may benefit cardiovascular system are also revised.

The acute effects of alcohol on cerebral hemodynamic changes induced by the head-up tilt test in healthy subjects

BACKGROUND

Alcohol is a known triggering factor for orthostatic dysfunction, increasing the risk of neurally-mediated syncope. Since orthostatic tolerance may be affected by both systemic and cerebral hemodynamic changes, our aim was to investigate the acute effects of alcohol on cerebral vasoreactivity measured during the head-up tilt (HUT) test in 20 healthy subjects.

METHODS

Mean arterial blood pressure (mBP), heart rate, and flow parameters in both middle cerebral arteries (MCAs) were continuously recorded in the supine and during a 10-minute HUT positions before and after alcohol intake.

RESULTS

The HUT test resulted in a more prominent decline of adjusted mBP at the level of MCAs (mBPMCA) and a significantly larger decrease of MCA mean flow velocities (MFVMCA) in the post-alcohol period than before alcohol intake. During the HUT phase, the relative decrease in MFVMCA was significantly smaller than the reduction in mBPMCA before drinking alcohol, while these changes were similar after alcohol ingestion. The cerebrovascular resistance index (CVRi) decreased during the HUT phase in the control period, however, it increased after alcohol intake.

CONCLUSION

The similar decrease in mBPMCA and MFVMCA during orthostatic stress after alcohol ingestion together with the increased CVRi indicated the impairment of the compensatory vasodilation of cerebral resistance vessels, i.e. impaired cerebral autoregulation. These findings suggest that alcohol may contribute to impaired orthostatic tolerance not only by a hypotensive response but also by the alteration of cerebral blood flow regulation.

Blood Pressure Reactivity to the Cold Pressor Test Predicts Hypertension Among Chinese Adults: The GenSalt Study

BACKGROUND

Blood pressure (BP) hyper-reactivity to the cold pressor test (CPT) has been suggested as a predictor of hypertension. We examined whether BP reactivity to the CPT was associated with hypertension incidence among the Genetic Epidemiology Network of Salt Sensitivity (GenSalt) study participants from China.

METHODS

A total of 1,961 GenSalt study participants without any antihypertensive treatment completed the CPT at the baseline examination. Hypertension status was assessed at baseline (2003-2005) and 2 follow-up visits (2008-2009 and 2011-2012).

RESULTS

After adjustment for multiple covariates, both systolic BP (SBP) and diastolic BP reactivity to the CPT were significantly associated with hypertension incidence. For example, the multivariable adjusted odds ratios (ORs, 95% CI) of developing hypertension were 0.92 (0.66, 1.29), 1.42 (1.03, 1.97), and 1.45 (1.05, 2.00) for participants with maximum SBP responses of 6.7-12.0, 12.1-19.2, and ≥19.3mm Hg, respectively, compared to those with responses of <6.7mm Hg (P for trend = 0.006). Likewise, the multivariable-adjusted ORs (95% CI) of hypertension were 1.12 (0.79, 1.57), 1.62 (1.15, 2.29), and 1.82 (1.30, 2.55) for participants with the area under the curve of SBP responses of 3.0-16.0, 16.1-29.9, and ≥ 30.0mm Hg·min, respectively, compared to those with responses of < 3.0mm Hg·min (P for trend = 0.0001). The associations between BP reactivity variables and the risk of hypertension were not different among subgroups of sex, age, and baseline BP levels.

CONCLUSIONS

BP hyperreactivity to the cold stimulus may predict the risk of hypertension among Chinese adults.

Quantification of the acute effect of a low dose of red wine by nonlinear measures of RR and QT interval series in healthy subjects

The measures of nonlinear properties of RR interval and QT interval time series are sensitive to physiologically- or pathologically-induced complexity/regularity changes, but were not used to estimate the effect of alcohol intake. We wanted to examine the potential of these measures to quantify the acute effect of a low dose of red wine in healthy subjects. In separate experiments, fourteen young volunteers drank 200ml of red wine and a control drink with equal concentration of ethanol. ECG in supine position was recorded 20min before and 60min after drink intake. RR interval and QT interval series were extracted from ECG and we calculated variability, scaling exponents (α1 and α2) and sample entropy (SampEn) for both series. Systolic and diastolic blood pressures (BP) were measured every 10min. The immediate effect of both the drinks was equal: HR, BP and QT variability exhibited a sudden increase and then a decrease. However, the prolonged effect of wine and the control drink was different. Wine decreased both BP (p<0.05) and reduced complexity of RR and QT series (increased scaling exponents and decreased SampEn). The control drink prolonged QT and RR intervals (p<0.05). These results point out that the nonlinear properties of RR and QT interval series could be used to differentiate the effect of wine and ethanol. Changes in RR and QT interval series induced by a low dose of red wine are more detectable by methods that quantify the structure of the series than by methods that quantify their variability.

Sympathoexcitation and pressor responses induced by ethanol in the central nucleus of amygdala involves activation of NMDA receptors in rats

The central nervous system plays an important role in regulating sympathetic outflow and arterial pressure in response to ethanol exposure. However, the underlying neural mechanisms have not been fully understood. In the present study, we tested the hypothesis that injection of ethanol in the central nucleus of the amygdala (CeA) increases sympathetic outflow, which may require the activation of local ionotropic excitatory amino acid receptors. In anesthetized rats, CeA injection of ethanol (0, 0.17, and 1.7 μmol) increased splanchnic sympathetic nerve activity (SSNA), lumbar sympathetic nerve activity (LSNA), and mean arterial pressure (MAP) in a dose-dependent manner. A cocktail containing ethanol (1.7 μmol) and kynurenate (KYN), an ionotropic excitatory amino acid receptor blocker, showed significantly blunted sympathoexcitatory and pressor responses compared with those elicited by CeA-injected ethanol alone (P < 0.01). A cocktail containing ethanol and d-2-amino-5-phosphonovalerate, an N-methyl-d-aspartate (NMDA) receptor antagonist, elicited attenuated sympathoexcitatory and pressor responses that were significantly less than ethanol alone (P < 0.01). In addition, CeA injection of acetate (0.20 μmol, n = 7), an ethanol metabolite, consistently elicited sympathoexcitatory and pressor responses, which were effectively blocked by d-2-amino-5-phosphonovalerate (n = 9, P < 0.05). Inhibition of neuronal activity of the rostral ventrolateral medulla (RVLM) with KYN significantly (P < 0.01) attenuated sympathoexcitatory responses elicited by CeA-injected ethanol. Double labeling of immune fluorescence showed NMDA NR1 receptor expression in CeA neurons projecting to the RVLM. We conclude that ethanol and acetate increase sympathetic outflow and arterial pressure, which may involve the activation of NMDA receptors in CeA neurons projecting to the RVLM.

Alcohol-induced hypertension: Mechanism and prevention

Epidemiological, preclinical and clinical studies established the association between high alcohol consumption and hypertension. However the mechanism through which alcohol raises blood pressure remains elusive. Several possible mechanisms have been proposed such as an imbalance of the central nervous system, impairment of the baroreceptors, enhanced sympathetic activity, stimulation of the renin-angiotensin-aldosterone system, increased cortisol levels, increased vascular reactivity due to increase in intracellular calcium levels, stimulation of the endothelium to release vasoconstrictors and loss of relaxation due to inflammation and oxidative injury of the endothelium leading to inhibition of endothelium-dependent nitric oxide production. Loss of relaxation due to inflammation and oxidative injury of the endothelium by angiotensin II leading to inhibition of endothelium-dependent nitric oxide production is the major contributors of the alcohol-induced hypertension. For the prevention of alcohol-induced hypertension is to reduce the amount of alcohol intake. Physical conditioning/exercise training is one of the most important strategies to prevent/treat chronic alcohol-induced hypertension on physiological basis. The efficacious pharmacologic treatment includes the angiotensin-converting enzyme (ACE) inhibitors or angiotensin II type 1 receptor blockers (ARBs) which have antioxidant activity and calcium channel blockers. The most effective prevention and treatment of alcohol-induced hypertension is physical exercise and the use of ACE inhibitors or ARBs in the clinic

Factors associated with blood pressure response to the cold pressor test: the GenSalt Study

BACKGROUND

Blood pressure (BP) response to the cold pressor test (CPT) has been associated with increased risk of cardiovascular disease. We studied risk factors associated with BP response to CPT.

METHODS

We conducted the CPT among 2,682 individuals in rural north China. BP was measured using a standard mercury sphygmomanometer prior to and at 0, 1, 2, and 4 minutes after the participants immersed their right hand in ice water for 1 minute.

RESULTS

Sex, age, and baseline BP levels were significantly associated with BP response to the CPT. For example, maximum systolic BP response (mean ± SD) was greater in women than in men (15.5±10.7 vs. 13.8±10.0mm Hg; P < 0.0001), correspondingly higher with age (12.4±8.7, 13.8±10.0, and 16.4±11.2mm Hg for those aged < 35, 35-44, and ≥ 45 years, respectively; P for trend < 0.0001), and greater with higher BP (13.5±10.0, 14.9±10.2, and 17.4±11.5mm Hg for those with baseline BP < 120/80, 120-139/80-89, and ≥ 140/90mm Hg, respectively; P for trend < 0.0001). In multivariable analyses, we also observed that higher body mass index, physical inactivity, and alcohol consumption were significantly associated with greater BP response to the CPT.

CONCLUSIONS

Our study indicates that females, older age, and elevated baseline BP levels are associated with greater BP response to the CPT. In addition, physical inactivity, higher weight, and alcohol consumption may also be related to BP hyperreactivity to stress.

Association of body mass index and alcohol intake with hypertension subtypes among HAN Chinese

Obesity and excessive drinking are major risk factors for development of hypertension. We aimed to explore association of body mass index (BMI) and alcohol intake with isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and combined systolic/diastolic hypertension (SDH) among Shandong Shengli Oil field workers. A total of 26,681 subjects were cross-sectionally analyzed. Statistical calculations included polytomous logistic regression and interaction analysis. After assigning normotensives as a reference, the odds of being ISH decreased by 4% for moderate drinkers, whereas that of being IDH and SDH increased significantly by 1.50 and 1.15 folds (P < 0.001). The odds for heavy drinkers of being ISH, IDH, and SDH increased by 1.38, 2.41, and 2.25 folds, respectively (P < 0.001). For BMI, the odds of being ISH, IDH, and SDH increased in a dose-response manner (P < 0.001). For patients with BMI of [23, 25), [25, 27), [27, 30) and ≥ 30 kg/m(2), the odds (95% confidence interval (CI)) of being SDH increased significantly by 2.28 (2.07-2.50), 3.22 (2.93-3.55), 5.44 (4.93-6.01), and 8.45 (7.31-9.77) folds, respectively. Interaction analysis indicated that BMI and alcohol intake were interactively associated with ISH (P ≤ 0.045) rather than IDH (P ≥ 0.161). Our results demonstrated that BMI and alcohol intake interactively influenced systolic hypertension, especially for overweight and obese patients.

Influence of acute alcohol ingestion on sympathetic neural responses to orthostatic stress in humans

Acute alcohol consumption is reported to decrease mean arterial pressure (MAP) during orthostatic challenge, a response that may contribute to alcohol-mediated syncope. Muscle sympathetic nerve activity (MSNA) increases during orthostatic stress to help maintain MAP, yet the effects of alcohol on MSNA responses during orthostatic stress have not been determined. We hypothesized that alcohol ingestion would blunt arterial blood pressure and MSNA responses to lower body negative pressure (LBNP). MAP, MSNA, and heart rate (HR) were recorded during progressive LBNP (-5, -10, -15, -20, -30, and -40 mmHg; 3 min/stage) in 30 subjects (age 24 ± 1 yr). After an initial progressive LBNP (pretreatment), subjects consumed either alcohol (0.8 g ethanol/kg body mass; n = 15) or placebo (n = 15), and progressive LBNP was repeated (posttreatment). Alcohol increased resting HR (59 ± 2 to 65 ± 2 beats/min, P < 0.05), MSNA (13 ± 3 to 19 ± 4 bursts/min, P < 0.05), and MSNA burst latency (1,313 ± 16 to 1,350 ± 17 ms, P < 0.05) compared with placebo (group × treatment interactions, P < 0.05). During progressive LBNP, a pronounced decrease in MAP was observed after alcohol but not placebo (group × time × treatment, P < 0.05). In contrast, MSNA and HR increased during all LBNP protocols, but there were no differences between trials or groups. However, alcohol altered MSNA burst latency response to progressive LBNP. In conclusion, the lack of MSNA adjustment to a larger drop in arterial blood pressure during progressive LBNP, coupled with altered sympathetic burst latency responses, suggests that alcohol blunts MSNA responses to orthostatic stress.

Human and laboratory rodent low response to alcohol: is better consilience possible?

If people are brought into the laboratory and given alcohol, there are pronounced differences among individuals in many responses to the drug. Some participants in alcohol challenge protocols show a cluster of 'low level of responses to alcohol' determined by observing post-drinking-related changes in subjective, motor and physiological effects at a given dose level. Those individuals characterized as having low level of response (LR) to alcohol have been shown to be at increased risk for a lifetime diagnosis of alcohol dependence (AD), and this relationship between low LR and AD appears to be in part genetic. LR to alcohol is an area where achieving greater consilience between the human and the rodent phenotypes would seem to be highly likely. However, despite extensive data from both human and rodent studies, few attempts have been made to evaluate the human and animal data systematically in order to understand which aspects of LR appear to be most directly comparable across species and thus the most promising for further study. We review four general aspects of LR that could be compared between humans and laboratory animals: (1) behavioral measures of subjective intoxication; (2) body sway; (3) endocrine responses; and (4) stimulant, autonomic and electrophysiological responses. None of these aspects of LR provide completely face-valid direct comparisons across species. Nevertheless, one of the most replicated findings in humans is the low subjective response, but, as it may reflect either aversively valenced and/or positively valenced responses to alcohol as usually assessed, it is unclear which rodent responses are analogous. Stimulated heart rate appears to be consistent in animal and human studies, although at-risk subjects appear to be more rather than less sensitive to alcohol using this measure. The hormone and electrophysiological data offer strong possibilities of understanding the neurobiological mechanisms, but the rodent data in particular are rather sparse and unsystematic. Therefore, we suggest that more effort is still needed to collect data using refined measures designed to be more directly comparable in humans and animals. Additionally, the genetically mediated mechanisms underlying this endophenotype need to be characterized further across species.

Variables influencing heart rate

In both physiologic and pathological conditions, instantaneous heart rate value is the result of a rather complex interplay. It constantly varies under the influence of a number of factors: nonmodifiable and modifiable ones. Pharmacologic blockade with beta-adrenergic antagonists and/or with parasympathetic antagonists such as atropine have permitted the identification of the mechanisms of autonomic nervous regulation of heart rate in a variety of physiologic and pathological conditions. The analysis of heart rate and blood pressure variability has yielded additional information on the autonomic control of the circulation, which has proven to have diagnostic and prognostic implications in a number of clinically relevant conditions such as hypertension, acute myocardial infarction, heart failure, and predisposition to sudden cardiac death. This article will summarize, based on available epidemiologic and clinical studies, the key variables influencing heart rate and heart rate variability in view of the known association between heart rate and cardiovascular disease.

Short-term red wine consumption promotes differential effects on plasma levels of high-density lipoprotein cholesterol, sympathetic activity, and endothelial function in hypercholesterolemic, hypertensive, and healthy subjects

OBJECTIVES

To compare the metabolic, hemodynamic, autonomic, and endothelial responses to short-term red wine consumption in subjects with hypercholesterolemia or arterial hypertension, and healthy controls.

METHODS

Subjects with hypercholesterolemia (n=10) or arterial hypertension (n=9), or healthy controls (n=7) were given red wine (250 mL/night) for 15 days. Analyses were performed before and after red wine intake.

RESULTS

Red wine significantly increased the plasma levels of HDL-cholesterol in the controls, but not in the other groups. The effects on hemodynamic measurements were mild, non-significantly more prominent in healthy subjects, and exhibited high interindividual variability. Across all participants, mean blood pressure decreased 7 mmHg (p <0.01) and systemic vascular resistance decreased 7% (p = 0.05). Heart rate and cardiac output did not significantly change in any group. Red wine enhanced muscle sympathetic fibular nerve activity in hypercholesterolemic and hypertensive patients, but not in controls. At baseline, brachial artery flow-mediated dilation was impaired in patients with hypercholesterolemia and arterial hypertension; red wine restored the dilation in the hypercholesterolemic group but not in the hypertensive group.

CONCLUSIONS

Red wine elicits different metabolic, autonomic, and endothelial responses among individuals with hypercholesterolemia or arterial hypertension and healthy controls. Our findings highlight the need to consider patient characteristics when evaluating the response to red wine.

COMT genotype influences the effect of alcohol on blood pressure: results from the COMBINE study

BACKGROUND

Heavy drinking can cause chronic hypertension, possibly due to effects on the autonomic nervous system. Catechol- O-methyltransferase (COMT) inactivates catecholamines, and a G to A substitution in codon 108 in the soluble COMT mRNA (or codon 158 in the membrane-bound form) substitutes methionine for valine and alters enzyme activity.

METHODS

We evaluated the association of COMT genotype at this locus with blood pressure (BP) in 839 alcohol-dependent individuals before and during participation in an alcoholism treatment trial. Hierarchical linear models were used to account for within-subject correlation on repeated BP measurements, and findings were adjusted for age, gender, ethnicity, alcohol use, body mass index, current smoking, hypertension history, and study site.

RESULTS

Relative to those with the val-val genotype, those with the met-met genotype had higher adjusted systolic (+4.9 mm Hg, P < 0.01) and diastolic (+3.2 mm Hg, P < 0.01) BP at baseline. Those with the val-met genotype did not significantly differ from the val-val genotype. Changes in BP between baseline and 4 weeks of alcohol treatment also differed by genotype. Relative to the val-val genotype, the met-met genotype had a greater reduction in adjusted systolic pressure (-3.9 mm Hg, P < 0.01) and diastolic pressure (-2.8 mm Hg, P < 0.01). Corresponding relative reductions for the val-met genotype were -2.2 mm Hg systolic (P = 0.070) and -1.5 mm Hg diastolic (P < 0.05).

CONCLUSION

Findings suggest that alcohol-induced BP elevation may be related to the effects of catecholamines and their genetically determined inactivation.

Autonomic activation associated with ethanol self-administration in adult female P rats

The present study examined changes in heart rate (HR) prior to and during limited access ethanol drinking in adult female P rats. P rats were implanted with radio-telemetric transmitters to measure HR. Daily testing involved a 90-min pre-test period (water only available) and a subsequent 90-min test period [either water (W) or ethanol available]. After a week of habituation, one ethanol group had access to ethanol for 7 weeks (CE), and another ethanol group had access for 4 weeks, was deprived for 2 weeks and then had access for a final week (DEP). Analyses of HR revealed that CE and DEP rats had significantly higher HR than W rats during test periods that ethanol was present and that DEP rats displayed higher HR during the early test period of the ethanol deprivation interval, as well. These data indicate that ethanol drinking induces HR activation in adult female P rats, and that this activation can be conditioned to the test cage environment, paralleling reports on contextual conditioning and cue-reactivity in alcoholics exposed to alcohol-associated stimuli. Therefore, this behavioral test may prove advantageous in screening pharmacotherapies for reducing craving and relapse, which are associated with cue-reactivity in abstinent alcoholics.

Sex differences in environmental and genetic factors for hypertension

BACKGROUND

Sex differences are observed in many aspects of mammalian cardiovascular function and pathology. Hypertension is more common in men than in women of the same age. Although the effects of gonadal hormones on blood pressure are considered contributing factors, the reasons for sex differences in hypertension are still not fully understood. The present study was undertaken to compare the differences in several environmental and genetic factors between men and women in the Hei Yi Zhuang, an isolated subgroup of the Zhuang minority in China.

METHODS

Information on demography, diet, and lifestyle was collected in 835 women and 834 men aged 15 to 84 years. Genotyping of angiotensin-converting enzyme, adrenergic receptor beta(3), aldehyde dehydrogenase 2, calpastatin, connexin 37, hepatic lipase, lipoprotein lipase, peroxisome proliferator-activated receptor gamma, thyrotropin-releasing hormone receptor, and von Willebrand factor also was performed in these subjects.

RESULTS

The levels of systolic and diastolic blood pressure, and the prevalence, awareness, and treatment of hypertension were lower in women than in men (P < .05). Hypertension was positively associated with age, physical activity, alcohol consumption, body mass index, waist circumference, hyperlipidemia, total energy, total fat, sodium intake, and sodium/potassium ratio, and negatively associated with education level, total dietary fiber, potassium intake, angiotensin-converting enzyme, aldehyde dehydrogenase 2, and hepatic lipase genotypes in men (P < .05). Hypertension was positively associated with age, hyperlipidemia, total energy, total fat, sodium intake, sodium/potassium ratio, calpastatin, and von Willebrand factor genotypes, and negatively associated with education level, total dietary fiber, potassium, calcium intake, lipoprotein lipase, and thyrotropin-releasing hormone receptor genotypes in women (P < .05).

CONCLUSION

Sex differences in the prevalence of hypertension in the Hei Yi Zhuang population may be mainly attributed to the differences in dietary habits, lifestyle choices, sodium and potassium intakes, physical activity level, and some genetic polymorphisms.

Diet, lifestyle, and blood pressure of the middle-aged and elderly in the Guangxi Bai Ku Yao and Han populations

BACKGROUND

Bai Ku Yao is an isolated subgroup of the Yao minority in China. Little is known about the association of diet and lifestyle with the prevalence of hypertension in this population.

METHODS

A total of 485 subjects of Bai Ku Yao and 501 participants of Han Chinese aged 40-89 were surveyed using stratified randomized cluster sampling. Information on diet and lifestyle was collected by using standard questionnaires. Blood pressure (BP) and serum lipid levels were measured.

RESULTS

Physical activity levels, carbohydrate, vegetal protein, and dietary fiber intake were higher in Bai Ku Yao than in Han, whereas educational level, height, weight, body mass index (BMI), waist circumference, and total energy, fat, protein, dietary cholesterol, and salt intake were higher in Han than in Bai Ku Yao. Systolic, diastolic, and pulse pressure (PP) levels and the prevalence of hypertension (21.9% vs. 28.9%, P < 0.05)were lower in Bai Ku Yao than in Han. Hypertension was positively correlated with age, physical activity,BMI, and waist circumference, as well as with total energy, fat, and salt intake, and negatively associated with educational levels and dietary fiber intake in both ethnic groups (P < 0.05 for all). Hypertension was also positively correlated with triglycerides (TGs) in Bai Ku Yao and alcohol consumption in Han (P < 0.05 for each).

CONCLUSIONS

The differences in BP levels and the prevalence of hypertension among the middle-aged and elderly between Bai Ku Yao and Han might result from different dietary patterns, lifestyle choices, physical activity levels, sodium intake, and even genetic factors.

Dose-related effects of red wine and alcohol on hemodynamics, sympathetic nerve activity, and arterial diameter

The cardiovascular benefits of light to moderate red wine consumption often have been attributed to its polyphenol constituents. However, the acute dose-related hemodynamic, vasodilator, and sympathetic neural effects of ethanol and red wine have not been characterized and compared in the same individual. We sought to test the hypotheses that responses to one and two alcoholic drinks differ and that red wine with high polyphenol content elicits a greater effect than ethanol alone. Thirteen volunteers (24–47 yr; 7 men, 6 women) drank wine, ethanol, and water in a randomized, single-blind trial on three occasions 2 wk apart. One drink of wine and ethanol increased blood alcohol to 38 ± 2 and 39 ± 2 mg/dl, respectively, and two drinks to 72 ± 4 and 83 ± 3 mg/dl, respectively. Wine quadrupled plasma resveratrol ( P < 0.001) and increased catechin ( P < 0.03). No intervention affected blood pressure. One drink had no heart rate effect, but two drinks of wine increased heart rate by 5.7 ± 1.6 beats/min; P < 0.001). Cardiac output fell 0.8 ± 0.3 l/min after one drink of ethanol and wine (both P < 0.02) but increased after two drinks of ethanol (+0.8 ± 0.3 l/min) and wine (+1.2 ± 0.3 l/min) ( P < 0.01). One alcoholic drink did not alter muscle sympathetic nerve activity (MSNA), while two drinks increased MSNA by 9–10 bursts/min ( P < 0.001). Brachial artery diameter increased after both one and two alcoholic drinks ( P < 0.001). No beverage augmented, and the second wine dose attenuated ( P = 0.02), flow-mediated vasodilation. One drink of ethanol dilates the brachial artery without activating sympathetic outflow, whereas two drinks increase MSNA, heart rate, and cardiac output. These acute effects, which exhibit a narrow dose response, are not modified by red wine polyphenols.

Effects of alcohol consumption and other lifestyle behaviors on blood pressure for the middle-aged and elderly in the Guangxi Hei Yi Zhuang and Han populations

Han is the largest group and Zhuang is the largest minority among the 56 ethnic groups in China. Geographically and linguistically, Zhuang can be classified into 43 ethnic subgroups, in which Hei Yi Zhuang is proved to be the most conservative subgroup. Little is known about the relationship between alcohol consumption and blood pressure levels in this population. Therefore, the present study was undertaken to compare the effects of alcohol consumption and other lifestyle behaviors on blood pressure levels for the middle-aged and elderly in the Guangxi Hei Yi Zhuang and Han populations. A total of 657 subjects of Hei Yi Zhuang aged 40 and older were surveyed by a stratified randomized cluster sampling. Information on demography, diet, and other lifestyle factors was collected by standard questionnaires. Anthropometric parameters and serum lipid levels were also obtained in all subjects. The results were compared with those in 520 participants of Han Chinese from the same region. The levels of systolic blood pressure and pulse pressure in Hei Yi Zhuang were higher than those in Han (P < .01-.001). Hypertension was positively correlated with sex (male), age, physical activity, alcohol consumption, serum triglyceride levels, and total energy, total fat, and salt intakes, and negatively associated with educational level in Hei Yi Zhuang (P < .05-.001), whereas positively correlated with sex (male), age, physical activity, alcohol consumption, body mass index, waist circumference, serum total cholesterol levels, and total energy, total fat, and salt intakes, and negatively associated with educational level in Han (P < .05-.001). The difference in blood pressure levels between the two ethnic groups might result from different dietary habit, lifestyle, sodium intake, educational level, physical activity, and even genetic factors.

Secondary hypertension due to drugs and toxins

This review summarizes the current state of knowledge about drugs, other chemical substances, and toxins on blood pressure. Many classes of drugs, such as steroids, sympathomimetic amines, immunosuppressive agents, nonsteroidal anti-inflammatory agents, antidepressants, erythropoietin, substances of abuse and other agents can induce transient or sustained hypertension, exacerbate well-controlled hypertension, antagonize the effects of antihypertensive therapy, or precipitate hypertensive emergencies. Heightened awareness on the part of the physician is important to avoid unnecessary tests in search for other etiologies, and to reduce antihypertensive medication prescriptions by eliminating contributing agents whenever possible. These agents represent an important modifiable cause of secondary or resistant hypertension.

Is Isolated Nocturnal Hypertension a Novel Clinical Entity?

We reported previously that normotensive Chinese had higher nighttime diastolic blood pressure compared with non-Chinese. We, therefore, studied the prevalence and characteristics of isolated nocturnal hypertension (HT) and its association with arterial stiffness, an intermediate sign of target organ damage. We recorded ambulatory blood pressure, the central and peripheral systolic augmentation indexes, the ambulatory arterial stiffness index, and brachial-ankle pulse wave velocity in 677 Chinese enrolled in the JingNing population study (53.6% women; mean age: 47.6 years). Prevalence was 10.9% for isolated nocturnal HT (≥120/70 mm Hg from 10:00 pm to 4:00 am ), 4.9% for isolated daytime HT (≥135/85 mm Hg from 8:00 am to 6:00 pm ), and 38.4% for day-night HT. Patients with isolated nocturnal HT, compared with subjects with ambulatory normotension (45.8%), were older (53.7 versus 40.7 years), more often reported alcohol intake (68.9% versus 51.0%), had faster nighttime pulse rate (62.8 versus 60.7 bpm), had higher serum cholesterol (5.12 versus 4.77 mmol/L), and had higher blood glucose (4.84 versus 4.38 mmol/L). Similar to patients with isolated daytime HT or day-night HT, patients with isolated nocturnal HT had higher indexes of arterial stiffness ( P <0.05) than subjects with ambulatory normotension (central augmentation index: 140% versus 134%; peripheral augmentation index: 82.6% versus 76.5%; ambulatory arterial stiffness index: 0.40 versus 0.35 U; brachial-ankle pulse wave velocity: 16.2 versus 14.7 m/s). Of 74 patients with isolated nocturnal HT, only 4 (5.4%) had hypertension on conventional office blood pressure measurement (≥140/90 mm Hg). In conclusion, isolated nocturnal HT can only be diagnosed by ambulatory blood pressure monitoring, is prevalent among Chinese, and is associated with increased arterial stiffness.

Relationship between central sympathetic drive and magnetic resonance imaging-determined left ventricular mass in essential hypertension

BACKGROUND

Sympathetic activation has been implicated in the development of left ventricular hypertrophy (LVH). However, the relationship between sympathetic activation and LV mass (LVM) has not been clearly defined across a range of arterial pressure measurements. The present study was planned to determine that relationship, using cardiac magnetic resonance imaging to accurately quantify LVM, in hypertensive patients with and without LVH and in normal subjects.

METHODS AND RESULTS

Twenty-four patients with uncomplicated and untreated essential hypertension (LVH[-]) were compared with 25 patients with essential hypertension and left ventricular hypertrophy (LVH[+]) and 24 normal control subjects. Resting muscle sympathetic nerve activity was quantified as multiunit bursts and single units. Cardiac magnetic resonance imaging-determined LVM was indexed to body surface area (LVM index); in the LVH[-] group, LVM index was 67+/-2.1 g/m2, a value between those of the LVH[+] (91+/-3.4 g/m2) and normal control (57+/-2.2 g/m2) groups, respectively. The sympathetic activity in the LVH[-] group (53+/-1.3 bursts per 100 cardiac beats and 63+/-1.6 impulses per 100 cardiac beats) was between (at least P<0.001) those of the LVH[+] (66+/-1.7 bursts per 100 cardiac beats and 77+/-2.2 impulses per 100 cardiac beats) and normal control (39+/-3.0 bursts per 100 cardiac beats and 45+/-3.4 impulses per 100 cardiac beats) groups. Significant positive correlation existed between sympathetic activity and LVM index in the LVH[-] and LVH[+] groups (at least r=0.76, P<0.0001) but not in the normal control group. However, no consistent relationship existed between arterial blood pressure and sympathetic activity or LVM index.

CONCLUSIONS

These findings further support the hypothesis that central sympathetic activation is associated with the development of LVH in human hypertension.

Effects of Demographic Characteristics, Health-Related Behaviors and Lifestyle Factors on the Prevalence of Hypertension for the Middle-Aged and Elderly in the Guangxi Hei Yi Zhuang and Han Populations

BACKGROUND/AIMS

Hei Yi (meaning black worship and black dress) Zhuang is the most conservative group among the 43 ethnic subgroups of Zhuang in China due to its unique culture and customs. The prevalence of hypertension in this population has not been well defined. Therefore, the present study was undertaken to compare the effects of the demographic characteristics, health-related behaviors and lifestyle factors on the prevalence of hypertension in the middle-aged and elderly of the Guangxi Hei Yi Zhuang and Han populations.

METHODS

A total of 657 people of Hei Yi Zhuang aged 40 and over were randomly selected from 7 villages in Napo County of China. Information on the demographic characteristics, health-related behaviors and lifestyle factors was collected by questionnaire. Blood pressure, height, weight, waist circumference, serum lipid and apolipoprotein levels were measured, and body mass index (BMI) was calculated as a measure of weight relative to height. The results were compared with those of 520 Han who live in the same district.

RESULTS

The prevalence of hypertension and isolated systolic hypertension in Hei Yi Zhuang was significantly higher than in Han (32.9 vs. 24.6%, p < 0.01, and 16.7 vs. 5.2%, p < 0.001, respectively). The systolic blood pressure levels and pulse pressure in Hei Yi Zhuang were also significantly higher than in Han (129 +/- 20.1 vs. 125.8 +/- 17.4 mm Hg, p < 0.01, and 51.5 +/- 16.1 vs. 47.1 +/- 12.0 mm Hg, p < 0.01, respectively). The prevalence of hypertension was positively correlated with triglycerides, male, age, and alcohol consumption in Hei Yi Zhuang, whereas it was positively correlated with total cholesterol, male, age, alcohol consumption and BMI in Han. The rates of awareness, treatment and control in Hei Yi Zhuang and Han are 7.9 vs. 19.5%, 4.2 vs. 13.3% and 1.4 vs. 9.4% (p < 0.01 for all), respectively.

CONCLUSION

The current study reveals a significant difference in the prevalence of hypertension, blood pressure levels, and the relative factors between the Hei Yi Zhuang and Han ethnic groups, which may have been due to differences in geographical characteristics, lifestyle, sodium intake, education levels, and even genetic factors.

Effects of alcohol on thermoregulation during mild heat exposure in humans

We investigated the effects of alcohol on thermoregulatory responses and thermal sensations during mild heat exposure in humans. Eight healthy men participated in this study. Experiments were conducted twice for each subject at a room temperature of 33 degrees C. After a 30-min resting period, the subject drank either 15% alcohol (alcohol session) at a dose of 0.36 g/kg body weight or equal volume of water (control session). Skin blood flow and chest sweat rate in the alcohol session significantly increased over those in controls 10 min after drinking. Deep body temperature in the alcohol session started to decrease 20 min after the onset of sweating and eventually fell 0.3 degrees C lower than in the controls. Whole body hot sensation transiently increased after alcohol drinking, whereas it changed little after water drinking. The increased "hot" sensation would presumably cause cool-seeking behavior, if permitted. Thus, alcohol influences thermoregulation so that body core temperature is lowered not only by automatic mechanisms (sweating and skin vasodilation) but also behaviorally. These results suggest that decreases in body temperature after alcohol drinking are not secondary to skin vasodilation, a well-known effect of alcohol, but rather result from a decrease in the regulated body temperature evidenced by the coordinated modulation of various effectors of thermoregulation and sensation.

Alcohol intake and hypertension subtypes in Chinese men

OBJECTIVE

To examine the associations between alcohol intake and isolated systolic hypertension (ISH), systolic-diastolic hypertension (SDH), and isolated diastolic hypertension (IDH).

DESIGN

Cross-sectional study of Chinese adults.

METHODS

We analyzed data from 5317 Chinese males who were not on antihypertensive medications from a nationally representative sample of Chinese adults aged 35-74 years. ISH was defined as a mean systolic blood pressure (SBP) >/=140 mmHg and a mean diastolic blood pressure (DBP) < 90 mmHg, SDH as a SBP >/= 140 mmHg and DBP >/= 90 mmHg, and IDH as SBP < 140 mmHg and DBP >/= 90 mmHg. Alcohol intake was determined using an interviewer-administered questionnaire and participants were categorized either as non-drinkers (<12 drinks in the prior year) or by tertile of alcohol intake.

RESULTS

The odds ratios of all three hypertension subtypes were higher at higher levels of alcohol intake, with those in the highest alcohol intake category (>/=30 drinks/week) 2.0 (95% confidence interval: 1.3, 3.0), 2.2 (1.6, 3.1), and 2.1 (1.4, 3.1) times more likely to have ISH, SDH, or IDH, respectively, than non-drinkers. The population attributable risk percentage due to heavy drinking (>/=30 drinks/week) was 13.9% for ISH, 13.4% for SDH, and 12.0% for IDH. Liquor drinking, specifically, was associated with a higher odds ratio of ISH, while SDH and IDH associations did not differ by type of alcoholic beverage.

CONCLUSIONS

In Chinese males, higher intake of alcohol is associated with higher risk of ISH, SDH, and IDH. Efforts to reduce hypertension in China should include a strong focus on decreasing heavy alcohol consumption.