Non-dipper phenomenon in essential hypertension is related to blunted nocturnal rise and fall of sympatho-vagal nervous activity and progress in retinopathy

Nakano, Yukiko; Oshima, Tetsuya; Ozono, Ryoji; Higashi, Yukihito; Sasaki, Shota; Matsumoto, Toshiyuki; Matsuura, Hideo; Chayama, Kazuaki; Kambe, Masayuki

doi:10.1016/s1566-0702(01)00238-7

Cited by 94 publications

(55 citation statements)

References 23 publications

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“…Patients with hypertension show blunted day-night rhythms in sympathetic and parasympathetic heart tone. 8,9 Patients with coronary heart disease, a major complication of chronic hypertension, show a blunted day-night rhythm in vasodilatation 10 and suppressed nighttime melatonin levels. 11 We demonstrated recently that in comparison with normotensive subjects, the levels of three important SCNneurotransmitters are reduced by more than 50% in patients with essential hypertension, 12 corroborating its functional impairment.…”

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Daily Nighttime Melatonin Reduces Blood Pressure in Male Patients With Essential Hypertension

et al. 2004

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Abstract-Patients with essential hypertension have disturbed autonomic cardiovascular regulation and circadian pacemaker function. Recently, the biological clock was shown to be involved in autonomic cardiovascular regulation. Our objective was to determine whether enhancement of the functioning of the biological clock by repeated nighttime melatonin intake might reduce ambulatory blood pressure in patients with essential hypertension. We conducted a randomized, double-blind, placebo-controlled, crossover trial in 16 men with untreated essential hypertension to investigate the influence of acute (single) and repeated (daily for 3 weeks) oral melatonin (2.5 mg) intake 1 hour before sleep on 24-hour ambulatory blood pressure and actigraphic estimates of sleep quality. Repeated melatonin intake reduced systolic and diastolic blood pressure during sleep by 6 and 4 mm Hg, respectively. The treatment did not affect heart rate. The day-night amplitudes of the rhythms in systolic and diastolic blood pressures were increased by 15% and 25%, respectively. A single dose of melatonin had no effect on blood pressure. Repeated (but not acute) melatonin also improved sleep. Improvements in blood pressure and sleep were statistically unrelated. In patients with essential hypertension, repeated bedtime melatonin intake significantly reduced nocturnal blood pressure. Future studies in larger patient group should be performed to define the characteristics of the patients who would benefit most from melatonin intake. The present study suggests that support of circadian pacemaker function may provide a new strategy in the treatment of essential hypertension. Key Words: blood pressure monitoring Ⅲ circadian rhythm Ⅲ hormones Ⅲ human Ⅲ hypertension T he endogenous circadian pacemaker, located in the suprachiasmatic nucleus (SCN), imposes 24-hour biological rhythms by endocrine and autonomic mechanisms. 1 For example, the circadian rhythm in adrenal cortex activity is regulated via an endocrine and a sympathetic route, 2,3 that of heart and liver via sympathetic and parasympathetic control, 4 -6 and of the pineal gland via the sympathetic nervous system. 7 Thus, the SCN promotes adaptation to the rest and activity periods by regulating, for example, the morning increase in cortisol, heart rate, and glucose, and the evening increase in melatonin.Evidence for disturbed circadian pacemaker function in essential hypertension is accumulating. Patients with hypertension show blunted day-night rhythms in sympathetic and parasympathetic heart tone. 8,9 Patients with coronary heart disease, a major complication of chronic hypertension, show a blunted day-night rhythm in vasodilatation 10 and suppressed nighttime melatonin levels. 11 We demonstrated recently that in comparison with normotensive subjects, the levels of three important SCNneurotransmitters are reduced by more than 50% in patients with essential hypertension, 12 corroborating its functional impairment. Furthermore, we provided anatomical support for a changed SCN output to the symp...

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Daily Nighttime Melatonin Reduces Blood Pressure in Male Patients With Essential Hypertension

et al. 2004

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“…However, data suggest that nondippers have an increase in sympathetic nervous system activity (32,33) and a decrease in parasympathetic nervous system activity throughout the night (32,34). Nondipping is more commonly found among individuals with renal diseases, autonomic neuropathies, diabetes, sleep apnea, autonomic dysfunction, malignant hypertension and secondary hypertension (35,36).…”

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Night-time blood pressure patterns and target organ damage: A review

Routledge

McFetridge-Durdle

Dean

2007

Canadian Journal of Cardiology

119

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A mbulatory blood pressure monitoring (ABPM) is a noninvasive, automated portable technology that measures and records blood pressure (BP) over a 24 h period (1). This technique has allowed researchers and clinicians to measure the percentage of elevated BP readings, as well as 24 h BP loads and BP patterns (2). Consequently, it has been discovered that BP varies over 24 h in a diurnal manner, being higher during the day and lower at night (3). The normal variation in BP is characterized by a 10% to 20% reduction in BP from day to night (2). Individuals with this decline in night-time BP are known as 'dippers', and those who experience a blunted decline in night-time BP are known as 'nondippers' (4). Researchers have determined individuals to be nondippers on the basis of a less than 10% reduction in night-time systolic BP (SBP) (5-11), diastolic BP (DBP) (5) or both SBP and DBP measurements (12-31).The exact mechanisms of action responsible for nondipping are not fully understood. However, data suggest that nondippers have an increase in sympathetic nervous system activity (32,33) and a decrease in parasympathetic nervous system activity throughout the night (32,34). Nondipping is more commonly found among individuals with renal diseases, autonomic neuropathies, diabetes, sleep apnea, autonomic dysfunction, malignant hypertension and secondary hypertension (35,36). In addition, approximately 25% of individuals with essential hypertension have a nondipping BP profile (37).There is evidence to suggest that individuals who exhibit a nondipping BP profile are at higher risk of cardiac and extracardiac morbidity (38). Verdecchia et al (39) used data from the Progetto Ipertensione Umbria Monitoraggio Ambulatoriale (PIUMA) study to examine the morbidity and mortality rates of 715 essential hypertensive patients over a one-to 13-year BACKGROUND: Individuals who do not have a 10% to 20% reduction in blood pressure (BP) during the night are known as 'nondippers'. The cause of this nondipping phenomenon is not fully understood; however, there is a growing body of evidence linking a nondipping BP pattern with target organ damage. OBJECTIVE: To review the literature and present an overview of the target organ damage found to be associated with a nondipping BP pattern. METHODS: PubMed, CINAHL and Medscape searches of all available English language articles from 1986 to 2005 were performed. Search terms included 'BP nondipping', 'BP dipping' and 'target organ damage'. RESULTS: There is evidence to suggest that individuals with hypertension who exhibit a nondipping BP profile are at higher risk of cardiac and extracardiac morbidity and mortality. In particular, nondippers with essential hypertension have been found to have more advanced left ventricular hypertrophy, left ventricular mass and left ventricular mass index, carotid artery wall thickness, carotid artery atherosclerotic plaques, silent cerebral infarct, stroke, cognitive impairment and microalbuminuria. CONCLUSION: A better understanding of the importance of the cir...

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“…15,16 It has been suggested that a reduced nighttime drop of heart sympathetic tone in nondippers would lead to observed dampening in 24-hour BP rhythm amplitude. Indeed, inadequate stroke volume and cardiac index nighttime fall were found in nondipper patients.…”

Section: Discussionmentioning

confidence: 99%

Disruption of Ultradian and Circadian Rhythms of Blood Pressure in Nondipper Hypertensive Patients

et al. 2004

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Abstract-Ultradian rhythms in blood pressure (BP) are known to exist, but their modification in hypertension is largely unknown. The present study was undertaken to assess the integrity of ultradian and 24-hour BP rhythms in dipper (nϭ100) and nondipper (nϭ20) hypertensive patients compared with 44 dipper normotensive individuals. Fourier analysis was used to fit ultradian (12, 8, and 6 hour) and 24-hour rhythms in BP and heart rate (HR). Mesor, amplitude, and acrophase were calculated for individual and overall rhythm curves. All subjects showed significant ultradian or 24-hour BP and HR rhythms. Systolic and diastolic BP mesor was higher in hypertensive patients compared with normotensive patients. The percentage of variability in ambulatory BP that could be explained by fitting ultradian and 24-hour rhythms was reduced in nondippers compared with normotensives or dippers. Amplitude of ultradian and 24-hour rhythms in BP increased in dippers and decreased in nondippers. Ultradian and 24-hour rhythms in HR did not differ among the 3 groups examined. Results indicate that in nondippers, blunted ultradian and 24-hour rhythm amplitude in BP was accompanied by a loss of rhythm integrity. Key Words: blood pressure monitoring, ambulatory Ⅲ human Ⅲ hypertension, arterial Ⅲ circadian rhythm C ircadian rhythm in blood pressure (BP) has been recognized as a prognosis marker in hypertensive patients. 1 In normotensives as well as in noncomplicated hypertensive patients, a significant nocturnal decline in BP occurs, although in hypertensive patients, BP oscillates at a higher level. Nondipper hypertensive patients (ie, those in whom nighttime BP drop is Ͻ10%) have a worse prognosis as a result of increased target organ damage. 2 In this group, significantly greater left ventricular hypertrophy, microalbuminuria, and stroke frequency have been described. 2,3 Determination of ultradian components of BP rhythm (ie, those rhythmic components with a period Ͻ24 hours) has often been used as a tool to improve accuracy of the mathematical analysis of 24-hour rhythm parameters. 4 However, because ultradian rhythms have been shown to vary independently of 24-hour rhythms in various situations, 5,6 the possibility arises that their genesis and regulation could be somewhat independent from those regulating 24-hour rhythmicity.We undertook the present study to compare ultradian rhythm parameters in normotensives and dippers and nondipper hypertensive patients. Because disturbances in 24-hour rhythms were implicated in the physiopathology of hypertension, we also assessed the integrity of 24-hour and ultradian rhythms in the same patient groups. Materials and Methods PatientsAmong 265 patients who underwent ambulatory BP monitoring (ABPM), 180 were included in this study. To be included, each patient's recording should extend for Ն22.5 hours but not Ͼ25.5 hours and with Ͻ5 single measurements missing. Patients were classified as hypertensive if they were under pharmacological treatment or if they showed an average diurnal BP of Ͼ135/ 85...

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Non-dipper phenomenon in essential hypertension is related to blunted nocturnal rise and fall of sympatho-vagal nervous activity and progress in retinopathy

Cited by 94 publications

References 23 publications

Daily Nighttime Melatonin Reduces Blood Pressure in Male Patients With Essential Hypertension

Daily Nighttime Melatonin Reduces Blood Pressure in Male Patients With Essential Hypertension

Night-time blood pressure patterns and target organ damage: A review

Disruption of Ultradian and Circadian Rhythms of Blood Pressure in Nondipper Hypertensive Patients

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