Short-term reproducibility of nocturnal non-dipping pattern in recently diagnosed essential hypertensives

Agreement Between Ambulatory and Home Blood Pressure Monitoring in Detecting Nighttime Hypertension and Nondipping Patterns in the General Population

BACKGROUND

Nighttime blood pressure (BP) and nondipping pattern are strongly associated with hypertensive end-organ damage. However, no previous studies have compared the diagnostic agreement between ambulatory and home monitoring in detecting these BP patterns in the general population.

METHODS

We studied a population-based sample of 180 persons aged 32-80 years. The study protocol included 24-hour ambulatory BP monitoring, home daytime measurements over 7 days, home nighttime measurements (6 measurements over 2 consecutive nights using a timer-equipped home device), and ultrasound measurements for left ventricular mass index (LVMI) and carotid intima-media thickness (IMT). We defined nondipping as a <10% reduction in nighttime BP compared with daytime BP, and nighttime hypertension as BP ≥ 120/70 mm Hg.

RESULTS

The agreement between ambulatory and home monitoring for detecting nighttime hypertension was good (80%, κ = 0.56, P < 0.001). However, their agreement in detecting nondipping status was poor (54%, κ = 0.12, P = 0.09). The magnitude of ambulatory systolic BP dipping percent was 1.7% higher than on home monitoring (P = 0.004), whereas no difference was observed for diastolic BP dipping (difference: 0.7%, P = 0.33). LVMI and IMT were significantly greater among individuals with nighttime hypertension than in normotensive individuals, irrespective of the measurement method. However, only ambulatory nondippers, but not home nondippers, had more advanced end-organ damage than dippers.

CONCLUSION

We observed a good agreement between ambulatory and home BP monitoring in detecting nighttime hypertension in the general population. Two-night home monitoring could offer an inexpensive and feasible method for the diagnosis of nighttime hypertension.

Reproducibility of ambulatory blood pressure values and circadian blood pressure patterns in untreated subjects in a 1-11 month interval

OBJECTIVE

To evaluate in untreated subjects the reproducibility of mean values and four circadian patterns between two ambulatory blood pressure monitoring (ABPM) recordings separated by 1-11 months.

METHODS

We performed a retrospective analysis of 481 individuals (59% women) evaluated by ABPM on two occasions, visit 1 (V1) and 2 (V2), separated by 5.5+0.2 months. Four circadian patterns were defined by night/day systolic blood pressure (SBP) ratios: reverse dippers (RD), ratio >1.0; non-dippers (ND), ratio 0.9-1.0; dippers (D), ratio 0.8-<0.9; and extreme dippers (ED), ratio <0.8. Coefficients of correlation and concordance between the ABPM values at V1 and V2 and the reproducibility of the RD, ND, D and ED patterns were calculated by the percentage of the same profile from V1 to V2.

RESULTS

Mean 24-h blood pressure (BP) at V1 and V2 was 126.8/75.9±0.5/0.5 vs. 126.5/75.7±0.5/0.4 mmHg (NS). Nighttime SBP fall was 9.8±0.4 (V1) and 9.6±0.3% (V2) (NS). The correlation coefficient of ABPM data at V1 vs. at V2 was 0.41-0.69 (p<0.001) and the concordance coefficient was 0.34-0.57 (p<0.01). At V1, 38 subjects were classified as ED (7.9%); D, n=216 (44.9%), 187 as ND (38.9%) and 40 as RD (8.3%). At V2 only 26.3% of ED, 44.9% of D, 54.5% of ND and 40% of RD maintained the same profile as at V1.

CONCLUSION

In untreated subjects ABPM has high reproducibility for mean values but only modest reproducibility for circadian profiles, thereby challenging the prognostic value of BP dipping patterns.

Both Low and High 24-Hour Diastolic Blood Pressure Are Associated With Worse Cognitive Performance in Type 2 Diabetes: The Maastricht Study

OBJECTIVE

Hypertension and diabetes are both risk factors for cognitive decline, and individuals with both might have an especially high risk. We therefore examined linear and nonlinear (quadratic) associations of 24-h blood pressure (BP) with cognitive performance in participants with and without type 2 diabetes. We also tested the association of nocturnal dipping status with cognitive performance.

RESEARCH DESIGN AND METHODS

This study was performed as part of the Maastricht Study, an ongoing population-based cohort study. Cross-sectional associations of 24-h BP (n = 713, of whom 201 had type 2 diabetes) and nocturnal dipping status (n = 686, of whom 196 had type 2 diabetes) with performance on tests for global cognitive functioning, information processing speed, verbal memory (immediate and delayed word recall), and response inhibition were tested using linear regression analysis and adjusted for demographics, vascular risk factors, cardiovascular disease, depression, and lipid-modifying and antihypertensive medication use.

RESULTS

After full adjustment, we found quadratic (inverted U-shaped) associations of 24-h diastolic blood pressure (DBP) with information processing speed (b for quadratic term = -0.0267, P < 0.01) and memory (immediate word recall: b = -0.0180, P < 0.05; delayed word recall: b = -0.0076, P < 0.01) in participants with diabetes, but not in those without. No clear pattern was found for dipping status.

CONCLUSIONS

This study shows that both low and high 24-h DBP are associated with poorer performance on tests of information processing speed and memory in individuals with type 2 diabetes.

The effect of non-dipper pattern of hypertension on erectile dysfunction

BACKGROUND

The purpose of this study was to evaluate the relationship between erectile dysfunction (ED) and non-dipper pattern in hypertensive patients.

METHODS

A total of 750 consecutive patients with essential hypertension, who had been evaluated with ambulatory BP monitoring, were screened for this study. One hundred and thirty-two male patients (age range 28-54 years) who had fulfilled the inclusion and exclusion criteria were included in the final analysis. Dipper and non-dipper patterns were detected and sexual function was assessed by the self-administered questionnaire of the International Index of Erectile Function (IIEF).

RESULTS

There was no significant difference between the two groups regarding the number of medications taken and the proportion of each class of antihypertensive medications. Mean age, body mass index, lipid profiles, rate of smoking were similar between the two groups. IIEF score was significantly higher in non-dippers than dippers (p= 0.009). Non-dipping was also found to be an independent determinant for ED.

CONCLUSION

The result of the present study further suggests that non-dipping is a risk indicator for early deterioration of erectile function in hypertensive patients.

Prognostic value of subdivisions of nighttime blood pressure fall in hypertensives followed up for 8.2 years. Does nondipping classification need to be redefined?

To evaluate the long-term prognostic significance of different ranges of the percentage fall in nighttime blood pressure (BP) of the nondipping pattern, 1200 hypertensive patients (645 women, age 51+/-12 years) underwent ambulatory BP monitoring under stabilized therapy. The occurrence of cardiovascular (CV) events was followed for 9833 patient-years and analyzed by the Cox hazard model. There were 152 CV fatal/nonfatal events (79 strokes, 51 coronary events, 22 others) during the 15.2 years of follow-up. According to nighttime BP fall (%) the authors noted: <0% (reverse-dippers [RD], n=83); 0%-4.9% (nondippers 1 [ND1], n=207); 5%-9.9% (nondippers 2 [ND2], n=311), 10%-19.9% (dippers [D], n=523); and > or =20% (extreme dippers [ED], n=76). After adjustment for confounding variables, hazard ratios (95% confidence interval) of CV event and stroke in RD vs D were 2.29 (1.31-3.99) and 2.46 (1.11-5.49); of ND1 vs D were 1.42 (1.12-1.79) and 1.62 (1.17-2.23); and of ND1 vs ND2 were 2.24 (1.33-3.75) and 2.30 (1.15-4.58). No differences were found in RD vs ND1 and ND2 vs D. Nondippers have a higher CV risk than dippers but only for a nighttime BP fall <5% suggesting that the limits for nondipping should be redefined for a stratification of CV risk.

Effect of dipping status on QRS morphology in patients with hypertension

BACKGROUND

Prolongation of the QRS complex on the surface electrocardiogram (ECG) has been shown to be predictive of cardiovascular outcomes in selected populations. A 'nondipper' blood pressure (BP) profile is currently regarded as a risk factor in its own right for cardiovascular events and target organ damage. The predictive value of ECG parameters in hypertensives with nondipper profile has not been established.

METHODS

A total of 750 consecutive patients with hypertension who had been evaluated with ambulatory BP monitoring were screened for this study. One hundred and thirty-six patients who had fulfilled the inclusion and exclusion criteria were included in the final analysis. Dipper and nondipper patterns were detected and the maximum QRS duration (QRSd) measured on a 12-lead ECG was recorded.

RESULTS

There were 70 nondipper and 66 dipper hypertensives. There was no significant difference between the two groups regarding the daytime systolic and diastolic mean BPs, number of medications taken, and the proportion of each class of antihypertensive medications. Other variables were similar between the two groups. QRSd was significantly higher in nondippers than dippers (P=0.006). Correlation analysis revealed that the systolic BP fall at night was inversely and significantly related with QRSd (r=-0.482, P<0.001). Regression analysis further showed that the systolic BP fall at night and age were independent correlates of QRSd.

CONCLUSION

QRSd on the standard-surface 12-lead ECG was increased in patients with nondipper pattern and furthermore the systolic BP fall at night was independent correlate of QRSd in patients with hypertension.

The impact of work on the night blood pressure dipping profile

OBJECTIVE

The purpose of this study was to elucidate whether ambulatory blood pressure (ABPM) performed during a work day and a non-work day had any impact on the night dipping profile.

STUDY DESIGN

A crossover randomized ABPM study in primary healthcare was retrospectively analysed for the occurrence of non-dipping (ND), dipping (D) or extreme (XD) nightly dipping. Non-dippers were defined as subjects with less than 10% and extreme dippers as subjects with more than 20% nightly blood pressure fall measured as mean arterial pressure (MAP).

SUBJECTS

Forty treated hypertensives and 40 normotensives (20 men and 20 women in each group), who had performed ABPM twice in a fortnight. They had been randomly allocated to perform a work day or a non-work day as the first period.

RESULT

Only one of the 16 subjects who at any time was a non-dipper remained so during both monitoring periods. Extreme dipping was more often reproduced in nine persons out of 29. Of all 80 subjects, 43.8% (35 persons) remained dippers during both periods. No one changed from a non-dipper to an extreme dipper or the reverse. The odds of being an ND were 3.8 times more common on a non-work day, p = 0.010. XDs were slightly more common (1.7 times) on a work day than on a non-work day, p = 0.040. There was no correlation as to the degree of MAP and the dipping profile, p = 0.629.

CONCLUSIONS

More subjects were non-dippers at the end than at the beginning of the work week. It is essential to consider this when attempting to identify a non-dipper by ABPM.

Different classifications of nocturnal blood pressure dipping affect the prevalence of dippers and nondippers and the relation with target-organ damage

OBJECTIVE

We assessed how different definitions of the awake and asleep periods and use of various blood pressure (BP) indices affect the extent of the nocturnal BP dip, the prevalence of dippers and nondippers, their respective reproducibilities and the relation of nondipping with target-organ damage.

METHODS

We performed 24-h ambulatory BP monitoring twice and determined the left ventricular mass index and urinary albumin excretion as indices of target-organ damage in 150 hypertensive patients (off-medication). Awake and asleep periods were assessed using fixed and diary time methods, covering all readings available (wide) or excluding morning and evening transition hours (narrow). Nondipping (BP dip < 10%) was established for systolic BP and diastolic BP, their combinations (and/or), and mean arterial pressure.

RESULTS

The different awake-asleep definitions caused significant variation in both the extent of the BP dip and the number of dippers and nondippers in comparison with the wide diary definition (i.e. use of actual awake and sleep periods). The prevalences of dippers and nondippers also varied significantly with the BP index. Reproducibility analyses of the BP dip and the dipping status yielded repeatability coefficients (expressed as percentages of nearly maximal variation) between 42.39 and 48.71%, and kappa values between 0.323 and 0.459, respectively. Some classifications, but not all, discriminated significantly between consistent dippers and nondippers in terms of left ventricular mass index or urinary albumin excretion.

CONCLUSIONS

Use of different definitions of awake-asleep and BP indices affects significantly the classification of nocturnal BP dipping and its relation with hypertensive target-organ damage.

Nocturnal hypertension defined by fixed cut-off limits is a better predictor of left ventricular hypertrophy than non-dipping

The classification of subjects as nocturnal hypertensives in accordance with non-dipping (i.e. systolic blood pressure - BP - fall <10%) is less reproducible as compared to the fixed cut-off limits method (nocturnal BP means >120/70 mm Hg). The present study was carried out to assess if nocturnal hypertension defined by fixed cut-off limits may be a better predictor of left ventricular hypertrophy (LVH) than to non-dipping. Echocardiography and 24-h ambulatory blood pressure monitoring were performed in 223 subjects. Logistic regression showed that nocturnal hypertension defined by fixed cut-off limits was a significant predictor of LVH (OR=11.1, 95%CI=3.0-40.1) whereas non-dipping was not (OR=1.4, 95%CI=0.4-5.5). No interaction was detected (p<.3). These results suggest that the definition of nocturnal hypertension based on fixed cut-off values is a better predictor of left ventricular hypertrophy than non-dipping.

Ambulatory blood pressure, asymptomatic cerebrovascular damage and cognitive function in essential hypertension

Prolonged exposure to elevated blood pressure (BP) can lead to both structural (white matter lesions (WML) or infarctions) and functional changes in the brain. We studied in previously diagnosed essential hypertensive individuals if diurnal BP variation and ambulatory BP (ABP) profile (daytime, night time and 24-h BP averages) were related to evidence of WML, the presence of 'silent' infarcts, and cognitive performance. A group of 86 patients (mean age 57.4+/-10 years, range 40-80) were first screened for hypertension-related organ damage and underwent 24-h ABP monitoring, magnetic resonance imaging (MRI) of the brain, and a comprehensive neurocognitive assessment. Age and ABP profile were related to more periventricular, but not subcortical, WML and to presence of lacunar infarctions on MRI. After correction for demographical group differences, no association was found between night time dipping of BP on the one hand and both WML load and cognitive parameters (verbal memory, sensorimotor speed, cognitive flexibility) on the other. The presence of lacunar infarctions, however, predicted lower performance on verbal memory. Furthermore, daytime and 24-h pulse pressure averages were associated with pWML, whereas systolic BP and mean arterial pressure (MAP) for daytime, night-time and 24-h periods were higher in patients with lacunar infarctions. Notwithstanding the large variability of WML in this sample, the evidence of a connection between diurnal BP variation and early target organ damage in the brain was not convincing. However, the ABP profile may be predictive of cerebral lesion type.

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.

Non-dipper treated hypertensive patients do not have increased cardiac structural alterations

BACKGROUND

Non-dipping pattern in hypertensive patients has been shown to be associated with an excess of target organ damage and with an adverse outcome. The aim of our study was to assess whether a reduced nocturnal fall in blood pressure (BP), established on the basis of a single 24-h BP monitoring, in treated essential hypertensives is related to more prominent cardiac alterations.

METHODS

We enrolled 229 treated hypertensive patients attending the out-patient clinic of our hypertension centre; each patient was subjected to the following procedures : 1) clinic BP measurement; 2) blood and urine sampling for routine blood chemistry and urine examination; 3) standard 12-lead electrocardiogram; 4) echocardiography; 5) ambulatory BP monitoring (ABPM). For the purpose of this study ABPM was carried-out in three subgroups with different clinic BP profile: 1) patients with satisfactory BP control (BP < 140/90 mmHg; group I, n = 58); 2) patients with uncontrolled clinic BP (clinic BP values > or = 140 and/or 90 mmHg) but lower self-measured BP (< 20 mmHg for systolic BP and/or 10 mmHg for diastolic BP; group II, n = 72); 3) patients with refractory hypertension, selected according to WHO/ISH guidelines definition (group III, n = 99). Left ventricular hypertrophy (LVH) was defined by two gender-specific criteria (LV mass index > or = 125/m2 in men and 110 g/m2 in women, > or = 51/gm2.7 in men and 47/g/m2.7 in women).

RESULTS

Of the 229 study participants 119 (51.9%) showed a fall in SBP/DBP < 10% during the night (non-dippers). The prevalence of non-dippers was significantly lower in group I (44.8%) and II (41.6%) than in group III (63.9%, p < 0.01 III vs II and I). The prevalence of LVH varied from 10.3 to 24.1% in group I, 31.9 to 43.1% in group II and from 60.6 to 67.7% in group III (p < 0.01, III vs II and I). No differences in cardiac structure, analysed as continuous variable as well as prevalence of LVH, were found in relationship to dipping or non-dipping status in the three groups.

CONCLUSIONS

In treated essential hypertensives with or without BP control the extent of nocturnal BP decrease is not associated with an increase in LV mass or LVH prevalence; therefore, the non-dipping profile, diagnosed on the basis of a single ABPM, does not identify hypertensive patients with greater cardiac damage.