Early morning blood pressure surge

Alterations in the circadian rhythm of blood pressure, whether a loss of the nighttime dip or an exaggeration of the early morning increase that occurs upon rising, indicate increased cardiovascular risk. Estimates of the magnitude of the blood pressure surge on rising vary depending on technique and population, but it is usually around 10-30 mm Hg systolic and 7-23 mm Hg diastolic. The magnitude of the surge increases with age, alcohol consumption, and smoking and is greater in whites. Blood pressure variations and morning plasma aldosterone are closely correlated. A high morning surge is linked to increased target organ damage as well as strokes and other cardiovascular complications. Therapeutic options exist to reduce the magnitude of the morning blood pressure surge-notably, the use of drugs with a long duration of action, the use of medications that specifically antagonize the morning surge (such as alpha blockers), and the administration of drugs upon awakening but before rising.     

Early morning surge in blood pressure

Early-morning blood pressure is generally viewed as an important therapeutic target, for two reasons. First, for antihypertensive agents taken once daily in the morning, the timing of the trough plasma drug level, and thereby the lowest pharmacodynamic effect, often coincides with the early morning rise in blood pressure and heart rate. Evidence has been accumulated to suggest that blood pressure control throughout the 24 h period may be necessary to gain complete benefit from antihypertensive medication. In fact, in a longitudinal study, the regression of cardiac hypertrophy in patients with hypertension was more accurately predicted by treatment-induced changes in average 24 h ambulatory blood pressure than by clinic or home-monitored blood pressure readings. The other reason for the importance of morning blood pressure is that cardiovascular risk is heightened at this time of day. A morning surge in sympathetic activity alters haemodynamic forces and predisposes vulnerable coronary atherosclerotic plaques to rupture. At the same time as this risk of plaque rupture is greatest, circadian variations in haemostatic and fibrinolytic factors result in morning hypercoagulability and hypofibrinolysis, promoting the formation of intraluminal thrombi. We recently showed that, in older hypertensives, a greater morning blood pressure surge, mediated at least in part by an exaggerated alpha-sympathetic activity, is associated with more advanced silent cerebrovascular disease as well as a higher future incidence of stroke. The early morning surge in blood pressure could become a new therapeutic target for preventing target-organ damage and subsequent cardiovascular events in hypertension. Of greatest interest is the potential benefit of a chronotherapeutic approach, involving, for example, long-acting chronoformulations, which has not yet been extensively studied.     

A genome-wide linkage analysis investigating the determinants of blood pressure in whites and African Americans

Evidence for genomic regions influencing systolic and diastolic blood pressure (BP) were assessed in a whole genome linkage analysis in 211 African American and 160 white families as part of the GenNet network of the National Heart, Lung and Blood Institute-sponsored Family Blood Pressure Program. Multipoint regression and variance components linkage methods were used to analyze 372 polymorphic markers. Statistically compelling evidence for linkage (P values .0057 and .00023, respectively) was found on chromosome 1. Our results support the idea that BP regulation is most likely governed by multiple genetic loci, each with a relatively weak effect on BP in the population at large.     

血压晨峰现象的研究进展

高血压是多种心、脑血管疾病的重要病因和危险因素,影响重要脏器如心、脑、肾的结构和功能,最终导致这些靶器官损害.血压受各种因素的影响产生明显波动,存在血压变异,而清晨血压变异程度最为显著.长期的临床观察发现心脑血管疾病的发生也有明显的昼夜节律,且多发生在清晨时段.因此,人们推测清晨血压的骤升是发生恶性心脑血管事件的危险因素之一.     

Blood pressure and mortality risk in older people: comparison between African Americans and whites

OBJECTIVES: To determine the risk from hypertension for all-cause mortality in a racially mixed sample of community-dwelling older adults. DESIGN: Baseline blood pressure was assessed between 1985 and 1986 in a sample of persons 65 years of age and older from five counties of the Piedmont of North Carolina (N = 4,162). All-cause mortality was monitored annually over the subsequent 6 years as part of the Established Populations for Epidemiologic Studies of the Elderly (EPESE) sponsored by the National Institute on Aging. SETTING: Eighteen percent of all respondents in the sample had a systolic blood pressure of > 160 (17% for whites and 18% for African Americans) and 16% had a diastolic blood pressure of >90 (14% for whites and 20% for African Americans). During the 6 years of follow-up, 29% of the sample died (with no difference in mortality rates between whites and African Americans). PARTICIPANTS: 4,000 community-dwelling people age 65 years and older; 1,846 were white and 2,154 were African American. MEASUREMENTS: Systolic and diastolic blood pressure and all-cause mortality. RESULTS: Systolic blood pressure positively related to mortality during the 6 years of follow-up (relative risk = 1.05). Among whites the relationship of diastolic pressure to mortality was nonlinear, with those at the upper and lower ends of the distribution at increased risk. Among African Americans, diastolic pressure was unrelated to mortality. The analyses were controlled for age; gender; education; body mass index (BMI); smoking history; taking a medication to manage blood pressure; a history of cancer, diabetes mellitus, heart attack, or stroke; poor subjective health; impaired functional status; and cognitive impairment. CONCLUSIONS: The findings confirm that among older adults there is a significant relationship overall between systolic blood pressure and mortality over 6 years of follow-up in both whites and African Americans. Diastolic pressure was a risk factor for whites only.     

清晨血压及血压晨峰的临床诊断价值

目的：探讨清晨血压在疾病诊断中的临床价值。方法对我院动态血压室近三个月的24 h 动态血压数据进行统计,分析心脑血管病患者的24 h 动态血压,对其清晨时段的血压状况进行研究。结果308例普通高血压患者中有202例清晨时段血压控制不佳,心脑血管病患者中有70％～80％清晨血压控制不佳。结论清晨血压升高在高血压患者中的发生率较高、危险性大,与心脑血管事件密切相关。清晨血压对隐匿性高血压的诊断具有临床意义。     

The morning blood pressure surge: therapeutic implications

Adverse cardiovascular events such as myocardial infarction, stroke, arrhythmias, and sudden cardiac death are well known to follow a circadian pattern, peaking in the morning hours of 6 AM to 12 PM. Many physiologic factors have been shown to follow a circadian pattern and together may create an environment that promotes intraluminal thrombi formation. Blood pressure follows this pattern with a "dip" at night and an increase on awakening. This morning surge may lead to hemodynamic forces that predispose patients to plaque rupture. The clinical impression of these known physiologic patterns associated with adverse cardiovascular events suggests that a strict treatment schedule targeting this phenomenon is needed. The goal of this review is to provide clinicians with an overview, allowing for informed decisions about chronotherapeutic formulations tailored to provide blood pressure control throughout the day and night.     

Reproducibility of morning blood pressure surge and its relation to blood pressure reactivity

This study examined the stability of the morning blood pressure surge (MBPS) and its relation to blood pressure (BP) reactivity in untreated hypertensives. Thirty-six participants completed a stress task at baseline. Ambulatory BP monitoring was carried out three times on a weekday. The MBPS demonstrated small reproducibility and large coefficient of variation. The MBPS correlated with nighttime BP (p = 0.001) but not morning BP or BP reactivity. Dippers had greater MBPS than did nondippers (p < 0.05). The MBPS provides distinct information that is different from the BP response to mental stress.     

奥美沙坦酯与苯磺酸氨氯地平治疗高血压晨峰血压的疗效对比

目的:评价奥美沙坦治疗高血压晨峰血压(MBPS)的疗效。方法:103例原发性高血压MBPS患者随机分为2组,分别接受奥美沙坦(53例,20 mg/d)和苯磺酸氨氯地平(50例,5 mg/d)治疗8周,于治疗前和治疗后4、8周做24 h动态血压监测,调整药物剂量和观测服药前后清晨血压变化。结果:2组药物治疗8周,24 h、白天、夜间及最后2~4 h平均血压均降至正常范围。奥美沙坦组最后2~4 h舒张压(DBP)的降低幅度大于氨氯地平组(19.3±11.8 vs 9.0±6.6 mmHg,P=0.031)。2组降晨峰血压(MBPS)的幅度相近,△收缩压(15.8±6.7 vs 17.0±6.8 mmHg,P0.05);△舒张压(12.8±5.9 vs 9.3±2.1 mmHg,P0.05)。2组治疗后脉率均稍有上升(3.4±1.8 vs 4.2±1.3次/min,P0.05)。2组治疗后收缩压和舒张压的平滑指数(SI)无统计学差异。结论:奥美沙坦酯能有效平稳的控制原发性高血压MBPS,奥美沙坦能强效抑制清晨舒张压的波动。     

血压正常高值者血压晨峰与冷加压试验的相关性

目的:探讨血压正常高值者血压晨峰现象与冷加压试验后血压变化的相关性。方法:将258例受试者按血压水平分为理想血压组、血压正常高值组和高血压病组。所有受试者均进行24小时动态血压监测及冷加压试验。结果:血压正常高值者清晨血压上长幅度为（27±9）mmHg,冷加压后0 s及60 s SBP增加幅度分别为(14±6)mmHg及(9±5)mmHg,晨峰及冷加压试验阳性发生率分别为45%及26%,低于高血压病组,但明显高于理想血压组（P<0.05）。血压晨峰、吸烟史、年龄及高密度脂蛋白胆固醇是影响0 s SBP增加幅度的主要因素;血压晨峰、年龄及空腹血糖是影响60 s SBP增加幅度的主要因素。结论:血压正常高值者清晨血压上升明显,冷加压后血压显著上升,冷加压后血压增幅与血压晨峰相关。     

Ambulatory blood pressure monitoring and morning surge in blood pressure in adult black and white South Africans

We examined whether there were differences in the circadian variation in blood pressure and the morning surge in blood pressure between black and white Africans. Clinic and ambulatory blood pressure data obtained from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was examined (n = 406; 49% black African). Ambulatory blood pressure readings were fitted to a six‐parameter double logistic equation to determine the power and rate of the morning surge in blood pressure. Multiple linear regression analysis was used to examine differences in blood pressure between black and white participants. Clinic and ambulatory blood pressure were higher in black participants throughout the day and night. In those taking medications, blood pressure was less well controlled in black subjects. Despite the higher systolic blood pressure, the day‐night difference estimated by the logistic function was similar in black and white participants. However, the rate of rise and power in the morning surge in blood pressure was lower in black participants. We conclude that black participants of the SABPA study present with higher blood pressure throughout the day and night but have a lower power of the morning surge in blood pressure due to a slower morning rate of increase. Moreover, they had an increased prevalence of undiagnosed hypertension and, in those taking medication, were less likely to have their blood pressure controlled than their white counterparts.     

A case of vertebral artery dissection associated with morning blood pressure surge.

We report a case of a middle-aged man who suffered a cerebral infarction resulting from dissection of a vertebral artery associated with morning blood pressure surge. A 56-year-old man was transferred to our hospital with dizziness and vomiting in the early morning on a cold day in winter. He reported that he had been standing in front of the sink after bathing when he suddenly felt dizzy and fell down. He did not lose consciousness, and by the time he reached the hospital by ambulance, his dizziness had subsided, but he complained of severe headache and vomited 3 times. On admission, he was alert, and there were no neurological or radiological abnormalities (CT, MR angiography) in the brain. However, infarction in the left cerebellar hemisphere was detected by brain MRI on the 5th day of hospitalization. String sign of the left vertebral artery was noted by angiography, confirming the diagnosis of dissection of the left vertebral artery. Ambulatory blood pressure monitoring was performed after discharge. Although the mean 24-h blood pressure was in the normal range, a marked morning blood pressure rise was observed. We speculated that the acute rise of blood pressure in the early morning might have contributed to the dissection of the vertebral artery.     

Childhood blood pressure predicts adult microalbuminuria in African Americans,but not in whites: the Bogalusa Heart Study

BACKGROUND: Microalbuminuria is considered as a strong predictor of cardiovascular diseases. However, limited information is available for childhood blood pressure (BP) levels and microalbuminuria in adulthood. METHODS: This study examined 2,122 individuals enrolled in the Bogalusa Heart Study as children, aged 5 to 17 years, and as adults, aged 20 to 37 years, with an average follow-up period of 16 years. Microalbuminuria is defined as urinary albumin (in milligrams per liter) to creatinine (mmoles per liter) ratio at or above the 90th percentile specific for age, ethnicity, and sex or urinary albumin levels >/=30 mg/L. RESULTS: As children, African American boys had higher BP than white boys. As adults, African Americans had higher BP and urinary albumin/creatinine ratio than whites. After adjusting for age, sex, and body mass index (BMI), African Americans with microalbuminuria in adulthood by either measure had higher systolic (P =.03) and diastolic (P =.02) BP as adults, and higher diastolic (P <.01) as children than those without this condition. On the other hand, whites showed no such significant association. In a multivariate regression analysis, adjusting for sex, childhood BMI, and age, and current smoking status, childhood BP and rate of change in BP from childhood to adulthood were significant predictors of increased urine albumin excretion in African Americans, but not in whites. CONCLUSIONS: Elevated BP beginning in childhood is associated with microalbuminuria in adulthood in African Americans, but not in whites, suggesting that African Americans may be more susceptible than whites to BP-related renal damage.     

高血压患者血压晨峰与急性冠状动脉事件的关系

目的探讨高血压患者血压晨峰与急性冠状动脉事件的相关性。方法选择186例高血压患者采用动态血压监测仪记录24 h血压。血压晨峰值≥32.6 mm Hg(1 mm Hg=0.133 kPa)患者为晨峰组(42例),血压晨峰值32.6 mm Hg为非晨峰组(144例),并对患者进行3年随访。患者同时具备胸痛、心电图动态变化或心肌酶学变化为急性冠状动脉事件(不稳定性心绞痛、急性心肌梗死)诊断标准。比较2组年龄、动态血压参数、急性冠状动脉事件发生率。结果与非晨峰组比较,晨峰组患者血压晨峰值、清晨动脉压、急性冠状动脉事件发生率均明显升高,差异有统计学意义(P0.05,P0.01);晨峰组24 h平均动脉压、清晨脉压虽高于非晨峰组,但差异无统计学意义(P0.05)。晨峰组患者血压晨峰值与急性冠状动脉事件发生率呈正相关(r=0.9),非晨峰组患者血压晨峰值与急性冠状动脉事件发生率无相关性(r=0.3)。结论高血压患者血压晨峰与急性冠状动脉事件发生密切相关,可能是冠状动脉事件的独立危险因素。