Abolished nocturnal blood pressure fall in a boy with glucocorticoid-remediable aldosteronism

Glucocorticoid-remediable aldosteronism (GRA) is a rarely recognised cause of arterial hypertension. We report the features of a 13-year-old boy with hypertension (casual blood pressure (BP) 140-180/95-110 mm Hg) discovered during a routine paediatric check. Ambulatory BP monitoring (ABPM) revealed significant hypertension with an abolished nocturnal BP fall (mean daytime BP 155/108 mm Hg, mean night-time BP 156/104 mm Hg, nocturnal BP fall 0/4%) which was indicative of secondary hypertension. Despite triple antihypertensive drug therapy the hypertensive control was unsatisfactory. Laboratory tests revealed hypokalaemia (3.0 mmol/l), suppressed plasma renin activity (0.012 nmol/l/h) and high plasma aldosterone (1.190 nmol/l). The diagnosis of primary hyperaldosteronism was established and GRA was further confirmed by the presence of the chimaeric GRA-gene and dexamethasone therapy was initiated. During the next 2 months of dexamethasone therapy all three antihypertensive drugs were discontinued and BP remained under control with restoration to a normal nocturnal BP fall (mean daytime BP 129/77 mm Hg, mean night-time BP 113/64, nocturnal BP fall 12/17%). A change of therapy from dexamethasone to spironolactone was necessary due to the side effects of corticosteroids after 3 months. Spironolactone alone (0.8-2 mg/kg/day) was able to control the BP sufficiently. In conclusion, to our knowledge, this is the first reported case of abolished nocturnal BP fall in a patient with genetically proven GRA. This study indicates that GRA can cause severe hypertension even in children, associated with an abolished nocturnal BP fall. GRA thus should be excluded in all hypertensive patients with circadian BP rhythm disturbances.     

肾血管性与原发性高血压患者24h动态血压的比较

目的 比较肾血管性高血压(RVH)与原发性高血压(EH)患者24 h动态血压的差别.方法 应用动态血压监测仪观察51例RVH患者的24 h动态血压,并与年龄、性别与之相匹配的51例EH患者的24 h动态血压进行比较.结果 RVH组24 h、白天及夜间动态收缩压、舒张压及脉压均值都比EH组有不同程度的升高(P<0.05),尤以夜间收缩压升高明显;血压负荷增加明显,24 h收缩压、舒张压负荷分别达到58.96%和35.98%,而EH组血压负荷均在20.00%左右,两组比较差异有统计学意义(P<0.05).EH组夜间血压下降率为10.36%,血压曲线呈勺型(60.8%的患者夜间血压下降率>10%);而RVH组夜间血压下降率为5.39%,血压曲线呈非勺型(仅有27.50%的患者夜间血压下降率>10%).结论 RVH患者动态血压均值、脉压和血压负荷明显增加,昼夜节律减弱.

Abstract：

Objective To compare 24 h ambulatory blood pressure changes between patients with renovascular hypertension and essential hypertension.Methods The 24 h ambulatory blood pressure of patients with age and gender matched renovascular hypertension (RVH, n=51) was compared with that of patients with essential hypertension (EH, n=51).Results The 24 h, daytime and nighttime systolic blood pressures(SBP),diastolic blood pressures(DBP) and pulse pressures (PP) in RVH were significantly higher than in EH (all P<0.05), especially the nocturnal SBP (P<0.05). The SBP and DBP loads in RVH were 58.96% and 35.98% respectively, while blood pressure loads were around 20.00% in EH (P<0.05). In patients with RVH, The nocturnal blood pressure fall was 5.39%, and only 27.50% patients were dippers, while the nocturnal blood pressure fall was 10.36% and 60.8% patients were dippers in EH.Conclusion RVH patients have higher dynamic BP, PP, BP loads and blunted diurnal rhythm compared to those with EH.     

CAPD patients exhibit a nocturnal fall in blood pressure: a single-centre study

Background: In 29 CAPD (continuous ambulatory peritoneal dialysis) patients the height and diurnal variation of the blood pressure (BP) and heart-rate (HR) were analyzed by means of 24-hour ambulatory blood pressure monitoring (ABPM).Methods: Normal diurnal variation was defined as a fall of 10% or more during nighttime (NT) compared with daytime (DT) BP or HR (DT = 10.00 a.m.–9.00 p.m., NT = midnight–06.00 a.m.). To evaluate high BP in the course of time we used the concept of “whole-day BP load”, defined as the percentage of BP readings above 140/90 mmHg during a 24-h period. A “hypertensive BP load” was defined as a systolic BP (SBP) load of more than 50% and/or a diastolic BP (DBP) load in excess of 40%. In addition to analysis of the circadian rhythm of BP and HR and the prevalence of a hypertensive BP load in CAPD patients, the influence of various factors such as gender, creatinine clearance, recombinant human erythropoietin, antihypertensive medication, haematocrit, whole-day BP load, and the nightly dialysis glucose concentration on the diurnal variation of BP and HR were studied.Results: Based on the 95% confidence intervals for the proportional nocturnal decrease, normal diurnal variation of BP and HR was present in most CAPD patients. No correlation could be demonstrated between a blunted circadian rhythm and the variables mentioned above. However, when other time-period definitions (DT = 6.00 a.m.–11.00 p.m., NT = 11.00–6.00 and DT = 8.00 a.m.–8.00 p.m., NT = 8.00 p.m.–8.00 a.m.) were applied to the data, considerably fewer patients displayed normal diurnal variation. Whereas all patients showed normal home BP readings, ABPM of 21 out of 29 patients displayed a hypertensive BP load.Conclusion: The majority of our CAPD patients exhibited normal diurnal variation of SBP and DBP depending, however, on the definitions of DT and NT used. The absence of a normal circadian rhythm could not be explained by any of the variables analyzed. Surprisingly, uncontrolled hypertension, as defined by a hypertensive BP load, was found in 72% of the patients.     

继发性高血压24小时动态血压研究

目的研究继发性高血压（ＳＨ）２４小时动态血压变化。方法应用美国Ｓｐａｃｅｌａｂｓ９０２０７动态血压监测仪观察了８０例ＳＨ２４小时动态血压并与年龄、性别相配对的８０例高血压病（ＥＨ）患者进行比较。结果ＳＨ患２４小时血压节律与ＥＨ患者不同,ＳＨ患者夜间血压下降不明显,夜间血压明显高于ＥＨ患者（Ｐ＜００１）;ＳＨ患者夜间血压负荷在６０％左右,而ＥＨ患者夜间血压负荷则在１５％左右;ＳＨ患者与ＥＨ患者２４小时血压曲线：白昼（６：００～２２：００）曲线呈重叠、交叉状态,而夜间（２２：００～６：００）曲线呈分离状态,ＥＨ夜间曲线段明显降低。ＳＨ组非杓型明显多于ＥＴ组（Ｐ＜００１）。ＳＨ患者夜间血压／日间血压的比值大于９０％的例数明显多于ＥＨ患者。结论２４小时动态血压监测显示夜间血压下降不明显,夜间血压负荷在５０％以上,呈非杓型,夜间血压／日间血压的比值大于９０％,提示有ＳＨ可能,应作进一步检查。     

Reproducibility of nocturnal blood pressure fall in early phases of untreated essential hypertension: a prospective observational study

A number of studies have shown that a smaller than normal nocturnal blood pressure (BP) decrease is associated with cardiovascular disease. However, no large prospective studies have examined the reliability of nocturnal dipping within individuals. The aim of our study was to investigate the short-term variability of nocturnal BP fall in a large cohort of patients with recently diagnosed essential hypertension. In all, 414 uncomplicated never treated hypertensive patients referred to our outpatient hypertension hospital clinic (mean age 46+/-12 years; 257 M, 157 F) prospectively underwent: (1). repeated clinic BP measurements; (2). routine examinations recommended by WHO/ISH guidelines; and (3). ambulatory BP monitoring (ABPM) twice within a 4-week period. Dipping pattern was defined as a reduction in the average systolic and diastolic BP at night greater than 10% compared to average daytime values. Overall, 311 patients (75.1%) showed no change in their diurnal variations in BP. Of the 278 patients who had a dipping pattern on the first ABPM, 219 (78.7%) confirmed this type of profile on the second ABPM, while 59 (21.3%) showed a nondipping pattern. Among 37 dipper patients with >20% of nocturnal systolic BP decrease (extreme dippers), only 16 (43.2%) had this marked fall in BP on the second ABPM. Of the 136 patients who had a nondipping pattern on the first ABPM, 92 (67.6%) confirmed their initial profile on the second ABPM, while 44 (32.4%) did not. Patients with reproducible nondipping profile were older (48+/-12 years) than those with reproducible dipping profile (44+/-12 years, P<0.05). These findings indicate that: (1). short-term reproducibility of nocturnal fall in BP in untreated middle-aged hypertensives is rather limited: overall, one-fourth of patients changed their initial dipping patterns when they were studied again after a few weeks; (2). this was particularly true for extreme dipping and nondipping patterns; (3). abnormalities in nocturnal BP fall, assessed by a single ABPM, cannot be taken as independent predictors of increased cardiovascular risk.     

Peculiarities of regulatory mechanisms of autonomic nervous system in patients with arterial hypertension and disturbed 24-hour blood pressure profile

BACKGROUND: Insufficient nocturnal blood pressure (BP) decline is associated with elevated risk of complications of hypertensive disease. Heart rate variability (HRV) reflects activity of sympathetic and parasympathetic parts of autonomic nervous system. AIM: To elucidate special characteristics of HRV in patients with various types of 24-hour BP rhythm. Material and methods. Bifunctional 24-hour monitoring and echocardiography were carried out in 42 men with stage I-II hypertensive disease and I-II degree of arterial hypertension (mean age 21.7+/-4.5 years) and 16 practically healthy young people (mean age 24.6+/-5.2 years). RESULTS: Subjects with insufficient (<10%) and adequate nocturnal BP decline (non-dippers and dippers) were distinguished (groups ND and D, respectively). Patients with hypertension in group ND had elevation of systolic BP variability during night and day time, augmentation of nocturnal and diurnal HRV low frequency power, lowering of nocturnal high frequency power, lowering of pNN50 and rMSSD values at night. HRV parameters of control subjects in this group did not differ from those of healthy people. All HRV parameters in group D were characterized by significant 24-hour rhythmicity. This rhythmicity was substantially disturbed in patients of group ND. Parameters of central hemodynamics were similar in groups D and ND. CONCLUSION: These results evidence for the presence of enhanced activity of sympathetic part of autonomic nervous system in non-dipper patients with hypertensive disease throughout 24 hours and during night time and for disturbed circadian rhythm of autonomic nervous system activity. This can serve as a basis for increased rate of cardiovascular complications in this category of patients.     

Therapy of patients with arterial hypertension with fixed dose combination of losartan and hydrochlorothiazide. Effect on 24 hour blood pressure and left-ventricular hypertrophy

Twenty four hour blood pressure (BP) monitoring was carried out and structural state of left ventricular myocardium assessed in 20 patients with mild and moderate hypertension before and after 24 weeks of therapy with Hyzaar - fixed dose combination of losartan (50 mg) and hydrochlorothiazide (12.5 mg). According to data of 24-hour BP monitoring the use of Hyzaar was associated with lowering of diurnal (by 26.9/17.2+/-3/2 mm Hg, p<0.001), nocturnal (by 32.6/18.9+/-3/2 mm Hg, p<0.001), pulse (p<0.001) BP, and rate of morning systolic BP rise (p<0.05), decrease of nocturnal systolic and diastolic BP variability, and improvement of 24-hour BP rhythm. Trough/peak coefficients for systolic and diastolic BP (70 and 76%, respectively) reflected sufficient and steady hypotensive effect throughout 24 hours after single dose of Hyzaar. Target BP level was achieved in 70% of patients. At the background of 24-week treatment with Hyzaar left ventricular myocardial mass index significantly decreased (from 120.1+/-3.5 to 108.6+/-3.1 g/m2, D=11.5+/-1.0, p<0.001) and became normal in 60% of patients. Correlation analysis revealed independence of cardioprotective action of therapy from its hypotensive activity. Thus therapy with Hyzaar produced hypotensive and cardioprotective effects which were independent from each other.     

Ambulatory blood pressure and cardiovascular risk in chronic kidney disease

Diagnosis of hypertension is critically dependent on accurate blood pressure (BP) measurement, especially in patients with chronic kidney disease (CKD), in whom early antihypertensive treatment is imperative to prevent cardiovascular events. Ambulatory BP monitoring (ABPM) has successfully identified hypertensive patients at increased risk, but its role in management of CKD patients is not well defined. Loss of the nocturnal decline in BP, which is common in CKD, is associated with adverse cardiovascular events. Increased BP variability has been documented as related to worse outcome, and patients on dialysis are subject to marked BP swings. Traditional measurement in the office fails to provide a thorough picture of the 24-hour BP pattern in CKD patients. Thus, ABPM appears mandatory to better define the hypertensive status in these subjects because it provides information on diurnal BP rhythm and variability and allows identification of subjects with white-coat and masked hypertension.     

Determinants of circadian blood pressure rhythm in essential hypertension

It has been postulated that the lack of nocturnal blood pressure fall in patients called nondippers is associated with more serious end organ damages by hypertension than in dippers whose blood pressure falls during the night. Recently, we found that sodium restriction shifted circadian rhythm of blood pressure from that of a nondipper to a dipper in patients with essential hypertension. In the present study, we aimed to clarify these important findings from the different approaches, and examined which factors affected the diurnal rhythm of blood pressure. A total of 70 patients with essential hypertension were maintained on high and low sodium diets for 1 week each. Nocturnal fall in mean arterial pressure was calculated in each patient, and, based on multiple regression analysis, independent factors affecting this nocturnal fall were examined. Thirty-eight patients were classified as non–sodium-sensitive, whereas 32 were considered sodium sensitive, based on a >10% change in 24-h mean arterial pressure by sodium restriction. In all 70 patients, sodium sensitivity of blood pressure, as well as an interaction between sodium sensitivity and sodium restriction, were identified as independent factors affecting the nocturnal fall. In sodium-sensitive types, in addition to sodium restriction, glomerular filtration rate was identified, whereas, in non–sodium sensitive types, there was no significant factor.Based on multiple regression analysis, the present study reached the same important conclusion as our previous findings: namely, that the enhanced sodium sensitivity was an independent determinant for the diminished nocturnal fall in essential hypertension and that sodium restriction could restore the nocturnal decline, especially in patients with enhanced sodium sensitivity whose nocturnal decline was diminished. Reduced renal sodium excretory capability may be one of the mechanisms involved in nondipping.     

Diurnal blood pressure curve in children and adolescents

OBJECTIVE: To investigate the diurnal blood pressure curve in healthy normotensive children. Thirty-one children were re-examined after a median interval of 123 days in order to study the reproducibility of the diurnal profile. SUBJECTS: Twenty-four-hour ambulatory blood pressure monitoring and conventional blood pressure readings were obtained in 228 normotensive children, whose ages ranged from 6 to 16 years and of whom 116 were boys and 112 girls. RESULTS: The conventional blood pressure averaged 99+/-11/57+/-9 mmHg in boys and 98+/-12/56+/-9 mmHg in girls (means+/-SD); the corresponding 24 h pressures were 111+/-7/66+/-5 mmHg and 109+/-7/65+/-5 mmHg, respectively. Of the children, 83% had a significant diurnal blood pressure rhythm for systolic pressure and 89% for diastolic pressure. The nocturnal blood pressure fall was normally distributed, averaging 12.0+/-6.3 mmHg systolic and 14.2+/-5.9 mmHg diastolic. There was no evidence for a bimodal distribution. The amplitude of the diurnal blood pressure curve, determined by the Fourier approach, was positively skewed with a mean of 12.5+/-4.2 mmHg for systolic and 14.0+/-4.1 mmHg for diastolic blood pressure. The daily blood pressure maximum occurred at 1344+/-4 h 46 min for systolic and 1321+/-4 h 22 min for diastolic blood pressure. For systolic blood pressure the cumulative sum (cusum)-derived circadian alteration magnitude was 1.7+/-6.2 mmHg higher in boys than in girls, whereas the cusum plot height was also 7.3+/-27.0 mmHg x h higher in male subjects. The repeatability coefficient (2SD of the difference between paired recordings, expressed as a percentage of nearly maximal variation) was 80% for the conventional systolic pressure and 40% for the conventional diastolic blood pressure. The repeatability coefficients for the ambulatory blood pressure levels varied from 32 to 45% and for the parameters describing the diurnal blood pressure profile from 42 to 78%. CONCLUSION: A significant diurnal blood pressure rhythm is observed in most normotensive children and adolescents. There is no evidence for a bimodal distribution of the nocturnal blood pressure fall. The reproducibility of the parameters of the diurnal blood pressure curve tended to be less than that of the ambulatory blood pressure level. Thus, one 24 h recording is probably insufficient to characterize a child's diurnal blood pressure profile fully.     

Neurohumoral characteristics of older hypertensive patients with abnormal nocturnal blood pressure dipping

Abnormal patterns of diurnal blood pressure (BP) variation have been reported to be related to advanced target organ damage and poor cardiovascular prognosis. However, the neurohumoral characteristics of patients with such variation have not been fully investigated. We measured BP and plasma levels of neurohumoral factors (norepinephrine [NE], epinephrine, renin, and arginine vasopressin [VP]) during the 70 degree head-up tilt test (10 min supine and 15 min tilting) in 120 older subjects (mean age 71 years) who had sustained hypertension as determined by ambulatory BP monitoring. They who were subclassified according to the nocturnal systolic BP fall as follows: 28 extreme dippers with >20% nocturnal BP fall; 78 dippers with >0% but <20% fall; and 14 nondippers with <0% fall. Plasma renin activity (r = 0.22, P = .02) and VP level (r = 0.36, P < .0001) after tilting were positively associated with the nocturnal systolic BP fall. Plasma NE levels were significantly higher in nondippers than in dippers in both the supine and tilting positions (supine 519 v 315 pg/mL, P = .001; tilting 803 v 550 ng/mL, P < .01), whereas the increase of NE induced by tilting was comparable in the two groups. Plasma renin activity in both the supine and tilting positions was comparable in the three groups, but the increase of this activity caused by tilting was less marked in the nondippers than in the extreme dippers (0.05 v 0.26 ng/mL/min, P = .02) and dippers (0.21 ng/mL/min, P = .07). Plasma VP was markedly increased after tilting in the extreme dippers compared with dippers (3.8 v 2.6 pg/mL, P < .001) and nondippers (v 2.0 pg/mL, P < .001), whereas the levels in the supine position were comparable in the three groups (2.0 pg/mL for extreme dippers, 1.9 pg/mL for dippers, 1.6 pg/mL for nondippers). In conclusion, diurnal BP variation in elderly hypertensive individuals was significantly associated with neurohumoral factors regulating circulating blood volume. Increased VP after tilting in extreme dippers might counteract reduced circulating blood volume, whereas nondippers appear to have alpha- and beta-adrenergic subsensitivity that may be induced by their chronic exposure to high NE levels.     

Nocturnal blood pressure in untreated essential hypertensives

AIM. Prevalence, correlates and reproducibility of nocturnal hypertension (NH) as defined by fixed cut-off limits in uncomplicated essential hypertension are poorly defined. Therefore, we assessed such issue in a cohort of 658 untreated hypertensives. METHODS. All subjects underwent procedures including cardiac and carotid ultrasonography, 24-h urine collection for microalbuminuria, ambulatory blood pressure monitoring (ABPM), over two 24-h periods within 4 weeks. NH was defined according to current guidelines (i.e. night-time blood pressure, BP ? 120/70 mmHg) and non-dipping status as a reduction in average systolic (SBP) and diastolic BP (DBP) at night lower than 10% compared with daytime values. RESULTS. A total of 477 subjects showed NH during the first and second ABPM period; 62 subjects had normal nocturnal BP (NN) in both ABPM sessions. Finally, 119 subjects changed their pattern from one ABPM session to the other. Overall, 72.5% of subjects had reproducible NH, 18% variable pattern (VP) and 9.5% reproducible NN. In the same group, figures of reproducible non-dipping, variable dipping and reproducible dipping pattern were 24%, 24% and 52%, respectively. Among NH patients, 56% of whom were dippers, subclinical cardiac organ damage was more pronounced than in their NN counterparts. CONCLUSIONS. In uncomplicated essential hypertensives, NH is a more frequent pattern than non-dipping; NH is associated with organ damage, independently of dipping/non-dipping status. This suggests that options aimed at restoring a blunted nocturnal BP fall may be insufficient to prevent cardiovascular complications unless night-time BP values are fully normalized.     

A new method for assessing 24-h blood pressure variability after excluding the contribution of nocturnal blood pressure fall

OBJECTIVES: To assess quantitatively the relationship between nocturnal blood pressure (BP) fall and 24-h BP variability; to propose a new method for computing 24-h BP variability, devoid of the contribution from nocturnal BP fall; and to verify the clinical value of this method. METHODS AND RESULTS: We analysed 3863 ambulatory BP recordings, and computed: (1) the standard deviation (SD) of 24-h BP directly from all individual readings and as a weighted mean of daytime and night-time SD (wSD); and (2) the size of nocturnal BP fall. Left ventricular mass index (LVMI) was assessed by echocardiography in 339 of the patients. The 24-h SD of BP was significantly greater than the 24-h wSD. Nocturnal BP fall was strongly and directly related to 24-h SD, the relationship with 24-h wSD being much weaker and inverse. The difference between SD and wSD was almost exclusively determined by the size of nocturnal BP fall. wSD of systolic BP was significantly related to LVMI, while 24-h SD was not. CONCLUSION: Conventional 24-h SD of BP is markedly influenced by nocturnal BP fall. The weighted 24-h SD of BP removes the mathematical interference from night-time BP fall and correlates better with end-organ damage, therefore it may be considered as a simple index of 24-h BP variability superior to conventional 24-h SD.     

Risers and extreme-dippers of nocturnal blood pressure in hypertension: antihypertensive strategy for nocturnal blood pressure

There is increasing evidence that disruption of diurnal blood pressure (BP) variation is a risk factor for hypertensive target organ damage and cardiovascular events. Especially, the risers (extreme non-dippers), who exhibit a nocturnal BP increase compared with daytime BP, have the worst cardiovascular prognosis, both for stroke and cardiac events. On the other hand, extreme-dippers (with marked nocturnal BP falls) are at risk for non-fatal ischemic stroke and silent myocardial ischemia, particularly extreme-dippers complicated with atherosclerotic arterial stenosis and excessive BP reduction due to antihypertensive medication. Extreme-dipping status of nocturnal BP is closely associated with excessive morning BP surge and orthostatic hypertension. Hypertensive patients who have these conditions and exhibit marked BP variations are likely to have silent cerebral infarct and to be at high-risk with regard to future stroke. Individualized antihypertensive medication targeting disrupted diurnal BP variation might thus be beneficial for such high-risk hypertensive patients.     

Association of insulin resistance and nocturnal fall of blood pressure in GH-deficient adults during GH replacement

The GH deficiency syndrome in adults is characterized by changes in body composition, metabolic, cardiovascular and psychological profile. Such alterations fit the metabolic syndrome. Changes of blood pressure (BP) levels related to the presence of insulin resistance (IR) may be present in the GH-deficient adult prior to or after therapy with recombinant GH (hGH). The purpose of the study was to assess the relationship between BP and IR in GH-deficient adults after 24 months of replacement with hGH. Thirteen GH-deficient adults were studied [7 men and 6 women, with an average age of 38.6+/-14.14 yr body mass index (BMI) 25.83+/-2.26 kg/m2]. The BP was assessed by means of ambulatory monitoring of BP (AMBP), prior to the treatment and 12 and 24 months after replacement with hGH. Glucose metabolism was assessed by the homeostatic model assessment (HOMA), during the same periods. The average dosage of hGH utilized was 0.67+/-0.15 mg/day. In the analysis of BP levels, we observed a decrease of the diurnal systolic BP (SB P) (p=0.043) and a reduction of the diurnal systolic (p=0.002) and diastolic pressure loads (p=0.038). During the night there were no changes in BP levels. We observed an increase in the percentage of patients with a non-physiological nocturnal fall (non dippers) after replacement with hGH (61.53%). The mean HOMA, insulin and glucose in the fasting state did not present any statistically significant changes. Although the patients within the nondipper group had higher HOMA and insulin levels throughout the study, there were no changes in any of these parameters after GH replacement. All patients with HOMA >2.5 were within the non-dipper group, whereas all dippers had HOMA <2.5. In conclusion, 24 months of therapy with hGH do not seem to have affected glucose homeostasis, and since there is no relationship with the increase of the percentage of non-physiological nocturnal fall, we will need a longer observation time to discover the effects of this finding.     

Value of nocturnal blood pressure in treated non-insulin-dependent hypertensive patients]

The purpose of the study was to evaluate the loss of nocturnal (N) decline in blood pressure (BP) in type II treated hypertensive diabetics. The study concerned 36 hypertensive diabetics 59 +/- 10 years old, 20 men and 16 women, with poor metabolic control (HbA1C: 9.6 +/- 3%), without dysautonomia; 14 had macroproteinuria and/or microalbuminuria (mu alb) (< 30 micrograms/min). An ambulatory BP monitoring (Spacelabs 90207) was performed in all patients. Left ventricular mass index (LVMI) and E/A were determined by Doppler-echocardiography. Two groups (G) were individualized: G1 (n = 17), with a normal circadian rhythm (diurnal and N.BP significantly different); G2 (n = 19) with a loss of N decline in systolic (S) and diastolic (D) BP or both; and compared to non diabetic treated hypertensive controls (G3). There was no difference neither in LVMI (125 +/- 43 g/m2), E/A (0.7), 24 h-mean (M) BP in the three groups, nor in HbA1C levels and mu alb occurrence in G1 and G2. Mean N.SBP and mean N.DBP were more closely related to LVMI in G2 than in G1 and G3. [table: see text] Half of these hypertensive diabetics, with bad metabolic control, have an altered circadian BP pattern; the prognostic value of nocturnal BP, related to LVMI despite the antihypertensive treatment, is suggested.     

Reproducibility of nighttime home blood pressure measured by a wrist‐type nocturnal home blood pressure monitoring device

The authors investigated the reproducibility of nighttime home blood pressure (BP) measured by a wrist‐type BP monitoring device. Forty‐six hypertensive patients (mean 69.0±11.6 years, 56.5% male) self‐measured their nighttime BP hourly using simultaneously worn wrist‐type and upper arm‐type nocturnal home BP monitoring devices at home on two consecutive nights. Using the average 7.4±1.3 measurements on the first night and the average 7.0 ± 1.8 measurements on the second night, the authors assessed the reliability and the reproducibility of nighttime BP measured on the two nights. The difference between nights in systolic BP (SBP) measured by the wrist‐device was not significant (1.6±7.0 mmHg, p = .124), while the difference in diastolic BP (DBP) was marginally significant (1.4±4.9 mmHg, p = .050). The intraclass correlation coefficients (ICCs) for agreement between nights were high both in SBP and DBP average (SBP: 0.835, DBP: 0.804). Averaging only three points of SBP resulted in lower ICC values, but still indicated good correlations (ICC > 0.6). On the other hand, the correlations of the standard deviation and average real variability of SBP between nights were low, with ICCs of 0.220 and 0.436, respectively. In conclusion, the average SBP values measured on the first night were reliable even when averaging only three readings. The reproducibility of nighttime BP variability seemed inferior to that of BP average; it might be better to measure nighttime BP over multiple nights to assess BP variability. However, this hypothesis needs verification in other study population. In addition, our study population had well‐controlled BP, which limits the generalizability of this findings to all hypertensive patients.     

Clinical significance of nocturnal blood pressure monitoring.

Although there are certain technical problems in determining nocturnal BP by ambulatory BP monitoring, the information provided on nocturnal BP has possible clinical significance. Short-term BP variability, an elevated BP during sleep and amplitude and sleep of nocturnal BP decline might be responsible for cardiovascular mortality. Furthermore, circadian BP variation might also be responsible for cardiovascular morbidity and mortality. The nocturnal BP level, even in extreme dippers with diurnal hypertension, is equivalent to or higher than that in normotensive subjects. Antihypertensive effects of drugs with different pharmacologic properties positively correlate with basal ambulatory BP. Therefore, there is a critical BP level at which the antihypertensive effect disappears. The critical BP level for each drug is in normal BP range but not in the hypotensive range. Therefore, an antihypertensive regimen would be safe even in extreme-dipper hypertension without excessive nocturnal hypotension, and might even be beneficial because of the decreasing amplitude and speed of the nocturnal BP decline. We conclude that an antihypertensive drug regimen should control BP throughout a 24-h period regardless of circadian BP variation.     

The circadian blood pressure rhythm in non-diabetic hemodialysis patients.

This study investigates the circadian blood pressure variation of non-diabetic chronic hemodialysis (HD) patients on both HD and non-HD days as well as the factors affecting diurnal BP variation. Forty-nine HD patients aged 61.8 +/- 12.9 years who were on daytime HD for 97 +/- 68 months were studied. No significant difference was found in every daytime and nighttime BP between the first (HD) and the second (non-HD) day. However, the ratio nighttime/daytime BP was significantly higher on the second day. Each BP diurnal variability pattern was classified as either Dipper (D: the ratio nighttime/daytime mean BP 0.8-0.9), non-dipper (0.9 < ND < 1.0), or inverted dipper (ID > 1.0). More than 75% of the cases were classified as ND (26 cases) or ID (11 cases). The ultrafiltration rate in D was significantly less than that in ND and ID. The difference of plasma renin activity between pre- and post-HD (dRen) was significantly higher in ID than in D and ND. The amount of dialysis (Kt/V) was found to be significantly correlated with nighttime BP fall. Ultrafiltration, dRen and Kt/V were independent factors for the abnormal BP diurnal variability. In conclusion, the decreased nocturnal BP fall seen in non-diabetic HD patients is associated with increased extracellular fluid even in the patients without overt overhydration, whereas relatively insufficient amount of dialysis (low Kt/V) may be another possible cause. The increased dRen observed only in ID patients may reflect occult cardiovascular damage or functional disturbances in aortic and carotid baroreflexes caused by arterial structural changes.     

Role of ambulatory blood pressure monitoring for the management of hypertension in Asian populations

Out‐of‐clinic blood pressure (BP) measurement, eg, ambulatory BP monitoring, has a strong association with target organ damage and is a powerful predictor of cardiovascular events compared with clinic BP measurement. Ambulatory BP monitoring can detect masked hypertension or various BP parameters in addition to average 24‐hour BP level. Short‐term BP variability assessed by standard deviation or average real variability, diminished nocturnal BP fall, nocturnal hypertension, and morning BP surge assessed by ambulatory BP monitoring have all been associated with target organ damage and cardiovascular prognosis. Recently, the authors compared the degree of sleep‐trough morning BP surge between a group of Japanese and a group of Western European untreated patients with hypertension and found that sleep‐trough morning BP surge in Japanese persons was significantly higher than that in Europeans. Although Asian persons have been known to have a higher incidence of stroke than heart disease, the difference in characteristics of BP indices assessed by ambulatory BP monitoring might be the cause of racial differences in stroke incidence between Asian and Western populations. This review focuses on Asian characteristics for the management of hypertension using ambulatory BP monitoring.