Influence of alcohol intake on circadian blood pressure variation in Japanese men: the Ohasama study

Sexually dimorphic role of circadian clock genes in alcohol drinking behavior

Sex differences in alcohol use and abuse are pervasive and carry important implications for the prevention and treatment of alcohol use disorder (AUD), yet insight into underlying sexually dimorphic mechanisms is limited. Growing experimental and clinical evidence points to an important influence of circadian rhythms and circadian clock genes in the control of alcohol drinking behavior and AUD. Sex differences in the expression of circadian rhythms and in the molecular circadian clock that drive these rhythms have been reported in humans and animals. While studying the role of striatal circadian clock gene expression in the control of affective and goal-directed behaviors, we uncovered a novel sexually dimorphic function of the clock genes Bmal1 and Per2 in the control of voluntary alcohol consumption in mice, which may contribute to sex differences in alcohol drinking behavior. In this mini review, we briefly discuss relevant literature on AUD, circadian rhythms and clock genes, and on sex differences in these domains, and describe our own findings on clock genes as sexually dimorphic regulators of alcohol drinking behavior in mice.

A personal history of research on hypertension From an encounter with hypertension to the development of hypertension practice based on out-of-clinic blood pressure measurements

In the 1970s, many people had severe hypertension and related cardiovascular and cerebrovascular diseases; however, antihypertensive treatments were not available at the time. The author encountered such conditions during the initial exposure to medicine. The author subsequently entered the field of hypertension medicine to prevent such conditions and engaged in hypertension research for more than 50 years. The author's central interest was the physiological and clinical aspects of blood pressure (BP) variability. Out-of-clinic BP measurements were the focus of clinical research. It was anticipated that self-measurement of BP at home (HBP) would improve medical practice surrounding hypertension. To establish evidence-based hypertension medicine, the Ohasama study (an epidemiology based on HBP) was conducted. The study provided firm evidence of the clinical significance of HBP and diagnostic criteria for hypertension and normotension. To establish target HBP levels for antihypertensive therapy, the Hypertension Objective treatment based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study (a prospective intervention study) was also conducted. Application of HBP measurements expanded to obstetric, clinical pharmacology, pathophysiology, and genetic studies. During these studies, crucial information on the clinical significance of BP variability (such as circadian and day-by-day variation of BP, nocturnal BP, white-coat hypertension, and masked hypertension) was established. Finally, the author described the priority of HBP over clinic-measured BP for the diagnosis of hypertension in the 2014 Japanese Society of Hypertension Guidelines. In this article, the author's history of hypertension research, from the first encounter with hypertension to the construction of guidelines on hypertension, is reviewed.

A Randomized Trial of Home Blood-Pressure Reduction by Alcohol Guidance During Outpatient Visits: OSAKE Study

BACKGROUND

To evaluate the effectiveness of the nurse-led alcohol guidance to control home blood pressure (HBP) in the morning among male patients with hypertension during outpatient visits.

METHODS

We enrolled 53 male patients with an HBP of ≥135/85 mm Hg with excessive drinking (alcohol ≥210 g/week or ≥60 g/day habitually) among outpatients in a randomized trial. Patients were assigned to a nurse-led alcohol guidance intervention or to the control. The primary outcomes were the mean HBP of 5 consecutive days at 6 months and alcohol consumption.

RESULTS

Twenty-eight and 25 patients were randomized to intervention and control groups, respectively (mean age; 62.7 years old and 64.5, respectively). At baseline, the groups were well balanced across most characteristics. At 6 months, the mean HBP was 131/82 mm Hg in the intervention group vs. 145/87 mm Hg in the control group (SBP <0.001, DBP = 0.09). An HBP level of less than 135/85 mm Hg was achieved among 55.6% of the participants in the intervention group vs. 16.7% in the control group (P = 0.004). The alcohol consumption at 6 months was 256 ± 206 g/w vs. 413 ± 260 g/w, respectively (P = 0.020).

CONCLUSIONS

We confirmed the effectiveness of the nurse-led alcohol guidance to control the HBP in male patients with hypertension during outpatient visits.

PUBLIC TRIALS REGISTRY NUMBER

UMIN000017454 (UMIN Clinical Trials Registry).

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.

Home blood pressure level, blood pressure variability, smoking, and stroke risk in Japanese men: the Ohasama study

BACKGROUND

Hypertension and smoking independently contribute to the risk of stroke. Our objective was to investigate home blood pressure (HBP) levels, day-by-day BP variability, and smoking in the prediction of stroke in Japanese men.

METHODS

In this study, 902 men (mean age, 58.6 years) without a past history of stroke were evaluated. HBP was measured once every morning for 4 weeks. Day-by-day BP variability was defined as within-subject standard deviations (SD) of HBP. Smoking history was obtained from a standardized questionnaire. Hazard ratios (HRs) for stroke were examined by Cox regression model, with adjustment for possible confounders.

RESULTS

During 13.1 years (median) of follow-up, 89 cerebral infarctions, 28 intracranial hemorrhages, and six other strokes occurred. Systolic HBP levels (HR = 1.59 per 14.6 mm Hg increase, P < 0.0001) and variability (HR = 1.26 per 3.1 mm Hg increase, P = 0.03) of +1 between-subject SD were significantly associated with cerebral infarction. The relationship between HBP and cerebral infarction differed with smoking status (interaction P = 0.021 and 0.017 for systolic level and variability, respectively). In analyses stratified according to smoking, systolic level (HR = 1.78, P < 0.0001) and variability (HR = 1.38, P = 0.006) were significantly associated with cerebral infarction in ever smokers (N = 511), but not in never smokers (N = 391; P ≥ 0.6 for both). No significant association was found between smoking and the risk of intracranial hemorrhage.

CONCLUSIONS

In ever smokers, both HBP levels and variability are significantly associated with the risk of cerebral infarction. Our findings further validate the benefit of smoking cessation in preventing cardiovascular disease (CVD), especially cerebral infarction.

Alcohol intake and atherosclerotic risk factors in normotensive and prehypertensive men

BACKGROUND

The purpose of this study was to determine whether relationships between alcohol intake and atherosclerotic risk factors were different in normotensive and prehypertensive persons.

METHODS

Japanese men aged 35-60 years who showed normal blood pressure (n = 4,778) or prehypertension (n = 9,728) without any drug therapy for hypertension were divided into non, light (<22 g ethanol/day), heavy (≥ 22 and < 44 g ethanol/day) and very heavy (≥ 44 g ethanol/day) drinkers.

RESULTS

In subjects with prehypertension, body mass index (BMI) and waist circumference were significantly lower and smaller, respectively, in light, heavy and very heavy drinkers than in nondrinkers. In subjects with normal blood pressure, BMI was significantly lower in light and heavy drinkers but not in very heavy drinkers than in nondrinkers, and waist circumference was not significantly different in non, light and heavy drinkers and was significantly larger in very heavy drinkers than in nondrinkers. Both in the prehypertensive and normotensive groups, compared with nondrinkers, hemoglobin A(1C) and low-density lipoprotein (LDL) cholesterol were significantly lower and high-density lipoprotein (HDL) cholesterol was significantly higher in light, heavy and very heavy drinkers, and log-converted triglycerides was significantly higher in very heavy drinkers.

CONCLUSIONS

The association of alcohol intake with a lower occurrence of obesity is stronger in prehypertensives than in normotensives, while the associations of alcohol intake with lower occurrences of hyperglycemia and abnormal cholesterol profile, such as lowered HDL cholesterol and elevated LDL cholesterol, and a higher occurrence of elevated triglycerides are similar in normotensive and prehypertensive persons.

Diurnal blood pressure variation and related behavioral factors

Blood pressure (BP) varies according to many internal and external factors, and behavioral factors have an important role in diurnal BP variation. BP rises sharply on waking in the morning and falls during sleep at night, although it varies throughout the day and night. These changes in BP are closely related to mental and physical activities, and the sympathetic nervous system mainly contributes to the diurnal variation in BP. Other behavioral factors, such as food consumption and obesity, dietary intake of sodium, drinking and smoking habits, consumption of coffee and tea, and bathing, also affect the diurnal variation in BP. Alterations in diurnal BP variation due to behavioral factors are frequently seen in patients with hypertension and can be classified as morning hypertension, daytime hypertension and nighttime hypertension. Appropriate lifestyle modifications may normalize or improve both the level and rhythm of BP in these patients.

Relationship of self-reported alcohol consumption to ambulatory blood pressure in a sample of healthy adults

BACKGROUND

Habitual alcohol consumption has shown positive associations with office blood pressure (BP). Less well established, however, is alcohol consumption's relationship to various measures of ambulatory BP (ABP) in healthy, normotensive persons.

METHODS

We investigated alcohol consumption's relationship to mean ABP, ABP variability, and the ABP arterial stiffness index in a sample of nonsmoking adults who were free of hypertension and cardiovascular disease (CVD; n = 157). Total alcohol consumption, intake of specific alcoholic beverages, and binge drinking were assessed by self-report. ABP was measured every 30 min for 24 h.

RESULTS

In multivariable-adjusted linear regression models, higher levels of total weekly alcohol consumption were associated with higher ABP. For those consuming 0, 1-2, and 3 or more alcoholic drinks per week, mean 24-h systolic ABP values were 112.2, 115.2, and 116.6 mm Hg, respectively (P = 0.05), and mean 24-h diastolic ABP values were 70.6, 71.9, and 74.2 mm Hg, respectively (P = 0.02). Beer and liquor consumption showed stronger positive associations with ABP than did wine consumption. Among nonbinge drinkers and binge drinkers, mean 24-h systolic ABP values were 113.3 and 118.6 mm Hg, respectively (P = 0.04) and mean 24-h diastolic ABP values were 71.3 and 75.0 mm Hg, respectively (P = 0.04). Alcohol consumption was not significantly related to ABP variability or the ABP arterial stiffness index.

CONCLUSION

Total habitual alcohol consumption, consumption of specific alcoholic drinks, and binge drinking are associated with higher mean ABP in healthy, normotensive adults.

Factors associated with day-by-day variability of self-measured blood pressure at home: the Ohasama study

BACKGROUND

We previously reported that high day-by-day blood pressure (BP) variability derived from self-measured BP at home (home BP) predicted cardiovascular mortality over and beyond other risk factors. The objective of this study is to clarify the determinants of the day-by-day home-BP variability.

METHODS

We conducted a cross-sectional community survey in 1,215 inhabitants (female gender 59%, mean age 62 years) of Ohasama, Japan. The subjects measured their BP and heart rate once every morning and once every evening for 4 weeks. The day-by-day BP variability and heart rate variability were defined as within individual standard deviation of all home BP and heart rate, respectively. We also considered coefficient of variation (CV). These parameters in the morning and those in the evening were calculated separately.

RESULTS

The level and standard deviation of home systolic/diastolic BP (SBP/DBP) in the morning were 123.4 +/- 15.1/75.7 +/- 9.0 mm Hg and 8.6 +/- 3.1/5.8 +/- 2.0 mm Hg. Multivariate linear regression analysis demonstrated that older age, female gender, elevated home BP, low home heart rate, and elevated home heart rate variability were significant determinants of elevated home-BP variability. In addition to these factors, alcohol intake and sedentary lifestyle were also determinants of elevated home-BP variability in the evening.

CONCLUSIONS

Day-by-day home-BP variability was associated with home BP, alcohol intake or sedentary lifestyle. Whether modifying these factors would reduce BP variability and whether such reduction would lead to better outcomes needs further study.

Period 2 gene deletion abolishes beta-endorphin neuronal response to ethanol

BACKGROUND

Ethanol exposure during early life has been shown to permanently alter the circadian expression of clock regulatory genes and the beta-endorphin precursor proopiomelanocortin (POMC) gene in the hypothalamus. Ethanol also alters the stress- and immune-regulatory functions of beta-endorphin neurons in laboratory rodents. Our aim was to determine whether the circadian clock regulatory Per2 gene modulates the action of ethanol on beta-endorphin neurons in mice.

METHODS

Per2 mutant (mPer2(Brdml)) and wild type (C57BL/6J) mice were used to determine the effect of Per2 mutation on ethanol-regulated beta-endorphin neuronal activity during neonatal period using an in vitro mediobasal hypothalamic (MBH) cell culture model and an in vivo milk formula feeding animal model. The beta-endorphin neuronal activity following acute and chronic ethanol treatments was evaluated by measuring the peptide released from cultured cells or peptide levels in the MBH tissues, using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Per2 mutant mice showed a higher basal level of beta-endorphin release from cultured MBH cells and a moderate increase in the peptide content in the MBH in comparison with control mice. However, unlike wild type mice, Per2 mutant mice showed no stimulatory or inhibitory beta-endorphin-secretory responses to acute and chronic ethanol challenges in vitro. Furthermore, Per2 mutant mice, but not wild type mice, failed to show the stimulatory and inhibitory responses of MBH beta-endorphin levels to acute and chronic ethanol challenges in vivo.

CONCLUSIONS

These results suggest for the first time that the Per2 gene may be critically involved in regulating beta-endorphin neuronal function. Furthermore, the data revealed an involvement of the Per2 gene in regulating beta-endorphin neuronal responses to ethanol.

History of antihypertensive therapy influences the relationships of alcohol with blood pressure and pulse pressure in older men

BACKGROUND

Blood pressure is known to be higher in heavy drinkers than in nondrinkers. The aim of this study was to determine whether the alcohol-blood pressure relationship is modified by therapy for hypertension in the elderly.

METHODS

Men aged > or = 65 years (n = 1,396) with or without current history of antihypertensive therapy were divided into four groups by alcohol intake (non-, light (<22 g ethanol/day), heavy (> or = 22 and <44 g ethanol/day), and very heavy (> or = 44 g ethanol/day) drinkers). Blood pressure and pulse pressure were compared among the groups.

RESULTS

Systolic blood pressure and pulse pressure were significantly higher in subjects receiving antihypertensive therapy than in subjects not receiving antihypertensive therapy, whereas diastolic blood pressure was not different between the two groups. In multivariate analysis with adjustment for age, smoking history, and body mass index (BMI), systolic and diastolic blood pressure and pulse pressure in the group not receiving antihypertensive therapy were significantly higher in heavy and very heavy drinkers than in nondrinkers, whereas in the group receiving antihypertensive therapy, systolic and diastolic blood pressure and pulse pressure were not different between each drinker group and the nondrinker group.

CONCLUSIONS

Alcohol intake was associated with blood pressure and pulse pressure in older men not receiving therapy for hypertension but not in those receiving antihypertensive therapy. The indicated possibility that changes in drinking do not have a substantial impact on blood pressure among treated hypertensives should be examined in longitudinal studies and preferably in clinical trials.

Diurnal blood pressure variation and cardiovascular prognosis in a community-based study of Ohasama, Japan

The introduction of 24-h ambulatory blood pressure (BP) monitoring has enabled BP evaluations at specific times of the day. Associations between diurnal BP variation and cardiovascular prognosis have been investigated in the Ohasama study, which is an epidemiological survey of hypertension using ambulatory and home BP monitoring that has been ongoing since 1985 in the general population of Ohasama, a town located in northern Japan. A diminished nocturnal decline in systolic BP was associated with a greater common carotid intima-media thickness as well as a higher risk of cardiovascular morbidity and mortality, especially the risk for cerebral infarction. The consumption of large amounts of alcohol was associated with a higher morning pressor surge. A large nocturnal decline in BP and a large morning pressor surge were both associated with a risk of cerebral hemorrhage. Ambulatory BP monitoring provides not only static, but also dynamic information about BP that should be considered to ensure effective management of hypertension and cardiovascular diseases.

Electrocardiographic abnormalities and home blood pressure in treated elderly hypertensive patients: Japan home versus office blood pressure measurement evaluation in the elderly (J-HOME-Elderly) study

This study compares relationships between each of morning home blood pressure (BP), evening home BP and office BP with electrocardiographic (ECG) abnormalities among treated hypertensive Japanese patients. We defined ECG left ventricular hypertrophy (LVH) as Sokolow-Lyon voltage and/or Cornell voltage duration product. Abnormal T waves and ST segment depression were categorized based on the Minnesota code. Office BP was calculated as the mean of four readings taken during two visits. Morning and evening home BP were calculated as the mean of five readings measured once each morning and evening for 5 days, respectively. Multivariate analysis showed that ECG-LVH in 747 hypertensives (mean age: 72 years; women: 63%) was more closely associated with morning home BP than with either office or evening home BP. Even the first reading of morning home BP on day 1 was significantly associated with ECG-LVH independently of office BP. The association between home BP and ECG-LVH increased with the cumulative number of home BP measurements. The results for abnormal T waves were similar. Home and office BP did not significantly differ between patients with and without ST segment depression. Morning home BP was more closely associated with ECG-LVH and abnormal T waves than either office or evening home BP among treated hypertensive Japanese patients.