Nocturnal Dipping Pattern Research Articles

PREVALENCE OF ARTERIAL HYPERTENSION AND CHARACTERISTICS OF NOCTURNAL BLOOD PRESSURE PROFILE OF ASTHMA PATIENTS ACCORDING TO THERAPY AND SEVERITY OF THE DISEASE: THE BADA STUDY

Objective: Several studies report an increased risk for asthmatic subjects to develop arterial hypertension and the relationship between these two diseases, frequently co-existing, still has some unclear aspects. Available data reports that asthmatics were 36 to 43 % more likely to have high blood pressure than non-asthmatics. None of these studies evaluated the event of an unrecognized hypertension and/or the 24-hours blood pressure profile of asthmatic patients through an Ambulatory Blood Pressure Monitoring (ABPM). Design and method: The BADA (Blood pressure levels, clinical features and markers of subclinical cArdiovascular Damage of Asthma patients) Study is aimed to evaluate the prevalence of the cardiovascular comorbidities of asthma and their impact on the clinical outcome. In this pilot study forty patients affected by asthma were consecutively recruited. Forty consecutive individuals referring for ambulatory examination due to medical reasons different from respiratory diseases served as the control group. Main exclusion criteria were the presence of other respiratory diseases, current smoking, any contraindication to ABPM. Results: The overall percentage of asthmatics having also hypertension was 75 % (30 patients) vs 45 % (18 patients) of the control group (p: 0,012). Reduced level of FEV1 (but neither inhaled steroid therapy or other asthma-related factors) was associated to newly-diagnosed hypertension (p: 0.0002), higher day SBP levels (p: 0.003), higher day DBP levels (p: 0.03), higher 24h-SBP levels (p: 0.005) and higher 24h-DBP levels (p: 0.03). A comparison of nocturnal dipping patterns between asthmatics and controls, do not found any statistically significant differences between the two groups. The regression analysis performed taking into account sex, age, diabetes, fasting glucose, Body Mass Index confirms the independent role played by asthma towards the overall hypertension (both already note adn newly diagnosed): Odds Ratio (OR): 3.66 (CI: 1.29–11.1). Conclusions: Arterial hypertension in asthma is more prevalent than how supposed before, emphasizing the need for a deeper cardiovascular screening for asthma patients. In particular, our data highlights the need for a more extensive use of ABPM.

Reproducibility study of nocturnal blood pressure dipping in patients with high cardiovascular risk.

It has been shown that in most people there is a physiological reduction in blood pressure during nighttime sleep, it falling by approximately 10% compared to daytime values (dippers). On the other hand, in some people, there is no nighttime reduction (non‐dippers). Various studies have found an association between being a non‐dipper and a higher risk of cardiovascular disease, but few have assessed whether the nocturnal pattern is maintained over time. From the database of the TAHPS study, data were available on 225 patients, each of whom underwent 24‐hour ambulatory blood pressure monitoring (ABPM) on four occasions over a period of 5 months. We studied the reproducibility of the nocturnal BP dipping pattern with mixed linear analysis and also calculated the concordance in the classification of patients as dippers or non‐dippers. The intraclass correlation coefficients between the different ABPM recordings were 0.482 and 0.467 for systolic and diastolic blood pressure, respectively. Two‐thirds (67%) and 70% of the patients classified, respectively, as dippers or non‐dippers based on systolic and diastolic blood pressure readings in the first ABPM recording were found to have the same classification based on the subsequent recordings. We conclude that the reproducibility of nocturnal dipping patterns and concordance of dipper vs non‐dipper status in individual patients is modest and therefore that we should be cautious about recommending treatments or interventions based on these patterns.

Association Between Nocturnal Blood Pressure Dipping and Chronic Kidney Disease Among Patients With Controlled Office Blood Pressure.

Although abnormal blood pressure (BP) patterns are associated with adverse cardiorenal outcomes, their associations are yet unquantified by nocturnal dipping status. We examined the association of nocturnal BP dipping pattern with albuminuria and kidney function among participants with controlled hypertension without prior advanced kidney disease. Ambulatory BP (ABP) measurements were collected from 995 middle-aged, cardiology clinic patients with controlled office BP (OBP) (<140/90 mm Hg). The magnitude of dipping was calculated as the difference between daytime and nighttime systolic BP (SBP) divided by daytime SBP. Accordingly, the participants were categorized as extreme-dipper (≥20%), dipper (10% to <20%), non-dipper (0% to <10%), or reverse-dipper (<0%). We analyzed the cross-sectional associations of dipping with albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g) and decreased estimated glomerular filtration rate (<60 ml/min/1.73 m2), adjusting for OBP/ABP, antihypertensive class, body mass index, total cholesterol, fasting glucose, socioeconomic status, and health behavior. The participants (mean age 60.2 years; 52.9% male) consisted of 13.5% extreme-dippers, 43.1% dippers, 34.7% non-dippers, and 8.7% reverse-dippers. In reference to dippers, odds ratios [95% confidence interval] for albuminuria were 1.73 [1.04-2.60] in reverse-dippers, 1.67 [1.20-2.32] in non-dippers, and 0.62 [0.38-1.04] in extreme-dippers. Likewise, abnormal dipping profile was associated with decreased kidney function: reverse-dipping, 2.02 [1.06-3.84]; non-dipping, 1.98 [1.07-3.08]; extreme-dipping, 0.69 [0.20-1.17]. The associations persisted among participants with more conservatively controlled OBP (<130/80 mm Hg). Monitoring diurnal and nocturnal BP may identify chronic kidney disease otherwise overlooked based on OBP.

Defining the nocturnal period in 24-h ambulatory blood pressure monitoring: a comparison of three methods.

The purpose of our study was to compare three definitions of ambulatory blood pressure (BP) nocturnal period and to assess their agreement in determining nocturnal BP dipping patterns. We investigated 69 subjects with metabolic syndrome, aged 50-55 years. In all subjects, we assessed 24-h BP monitoring, electrocardiogram and actigraphy profiles. The nocturnal period was defined in three ways: as a fixed narrow nighttime period from 01:00 to 06:00, as a self-reported sleeping period and as a disappearance and onset of physical activity recorded by the actigraph. Our study revealed a significant discrepancy between the self-reported and actigraphy-based nocturnal periods (P < 0.001). In addition, different definitions of the nighttime yielded significant differences in determining nondipping, extreme dipping and dipping BP patterns, the identification of the latter being affected the most. The actigraphy-based approach best aligned with the fixed-time determination of the nocturnal period: Cohen's kappa coefficient for the nondipping pattern was 0.78 (0.58-1), for the dipping pattern 0.75 (0.59-0.91) and for the extreme dipping pattern 0.81 (0.65-0.97). In comparison to the self-reported determination of the nocturnal period, using the actigraphy-based approach resulted in reclassifying the nocturnal BP pattern in 20.3% of subjects. The lack of agreement between fixed-time, self-reported and actigraphy-based determinations of the nighttime period affects the identification of the nocturnal BP patterns. In comparison to the self-reported nocturnal period estimation, the actigraphy-based approach results in the reclassification of BP dipping status in every fifth subject.

The cuffless SOMNOtouch NIBP device shows poor agreement with a validated oscillometric device during 24-h ambulatory blood pressure monitoring.

Repeated cuff‐based blood pressure (BP) measurements may cause discomfort resulting in stress and erroneous recording values. SOMNOtouch NIBP is an alternative cuff‐less BP measurement device that calculates changes in BP based on changes in pulse transit time (PTT) and a software algorithm. The device is calibrated with a single upper arm cuff‐based BP measurement. We tested the device against a validated 24‐h ambulatory BP monitoring (ABPM) device using both the previous (SomBP1) and the current software algorithm (SomBP2). In this study, 51 patients (mean age ± SD 61.5 ± 13.0 years) with essential hypertension underwent simultaneous 24‐h ABPM with the SOMNOtouch NIBP on the left arm and a standard cuff‐based oscillometric device on the right arm (OscBP). We found that mean daytime systolic BP (SBP) with OscBP was 140.8 ± 19.7 compared to 148.0 ± 25.2 (P = .008) and 146.9 ± 26.0 mmHg (P = .034) for SomBP1 and SomBP2, respectively. Nighttime SBP with OscBP was 129.5 ± 21.1 compared with 146.1 ± 25.8 (P < .0001) and 141.1 ± 27.4 mmHg (P = .001) for SomBP1 and SomBP2, respectively. Ninety‐five% limits of agreement between OscBP and SomBP1 were ± 36.6 mmHg for daytime and ± 42.6 mmHg for nighttime SBP, respectively. Agreements were not improved with SomBP2. For SBP, a nocturnal dipping pattern was found in 33% of the study patients when measured with OscBP but only in 2% and 20% with SomBP1 and ‐2, respectively. This study demonstrates that BP values obtained with the cuff‐less PTT‐based SOMNOtouch device should be interpreted with caution as these may differ substantially from what would be obtained from a validated cuff‐based BP device.

Impaired Daytime Urinary Sodium Excretion Impacts Nighttime Blood Pressure and Nocturnal Dipping at Older Ages in the General Population.

The circadian rhythm of urinary sodium excretion is related to the diurnal blood pressure regulation (BP) and the nocturnal dipping pattern. The renal sodium excretion expressed as daytime/nighttime ratio impacts BP, but a limited number of studies have investigated this topic to date. In this cross-sectional study, we aimed to investigate the impact of different daily patterns of sodium excretion (comparing low with high ratios) on BP and nocturnal dipping and to explore the relationship with age. Twenty-four-hour ambulatory BP monitoring and daytime and nighttime urinary sodium collections were used to assess 1062 subjects in Switzerland. Analyses were performed according to the day/night urinary sodium excretion ratio quartiles (Q1–Q4) and by age group (≤50 and ≥50 years). Subjects in Q1 can be considered low excretors of sodium during the daytime since the rate of sodium excretion during the daytime was 40% lower than that of subjects in Q4. Quartiles of the day/night urinary sodium excretion ratio showed that subjects in Q1 were 7 years older and had respectively 6 and 5 mmHg higher nighttime systolic and diastolic BP and a higher nocturnal dipping compared with subjects in Q4 (p-value ≤0.001). Associations found were significant only for subjects older than 50 years (all p < 0.05). The present results suggest that a decreased capacity to excrete sodium during daytime is more prevalent as age increases and that it impacts nighttime blood pressure and nocturnal dipping in older subjects.

P275 Uncontrolled post-clinic blood pressure readings can identify nocturnal non-dipping blood pressure pattern

Abstract Funding Acknowledgements Aga Khan University Faculty of Health Sciences Research Committee (#80096) On Behalf PC BP (Post Clinic Blood Pressure) Study Group Background Nocturnal non-dipping increases cardiovascular morbidity and mortality in both hypertensive and normotensive subjects. Ambulatory blood pressure monitoring(ABPM) can identify nocturnal blood pressure(BP) dipping patterns but clinic BP cannot. We previously showed that 15-minute post-clinic BP correlates well with 24- hour ABPM. Purpose We aimed to determine if 15-minute post-clinic BP reading helped to identify patients with nocturnal non-dipping pattern. Methods A cross-sectional study involving 150 participants, as part of the Post Clinic-Ambulatory Blood Pressure(PC-ABP) study, was conducted in cardiology clinics. Participants aged ≥18 years, with hypertension or those referred for its assessment, were included. Pregnant females were excluded. Post-clinic BP was taken 15 minutes after the patient-physician encounter in the clinic using an automated, validated BP device by a research assistant. All the participants were then referred for 24-hour ABPM. Patterns of nocturnal dipping were studied amongst groups of controlled(&amp;lt;140 mmHg) and uncontrolled(≥140mmHg) post-clinic systolic BP(SBP). Fischer exact test was used to determine the difference in dipping patterns amongst the two groups. Results The mean age of participants was 60.3 ± 11.9 years. Of 150 participants, 49% were male and of all, 76% were hypertensive. Mean nighttime SBP(±SD) was 121.9(±18) mmHg(p-value &amp;lt;0.001). Mean nighttime DBP(±SD) was 68.7(± 8.7) mmHg(p &amp;lt; 0.001). Patterns of nocturnal dipping amongst patients with mean post-clinic SBP &amp;lt;140mmHg versus ≥140mmHg has been shown in Table 1. The difference in nocturnal dipping patterns between the two groups was statistically insignificant(p-value 0.071). Pearson correlation coefficient between post-clinic SBP and nighttime SBP for patients with loss of dip was higher (0.64; p &amp;lt; 0.001) whereas it was 0.56(p-value &amp;lt;0.001) for those with preserved dip. Conclusion Uncontrolled post-clinic BP can help in identifying patients with nocturnal non-dipping. Larger studies can help determine the prognostic value of post-clinic BP amongst patients with nocturnal non-dipping. Nocturnal Dipping Amongst The Two Groups Controlled PC SBP &amp;lt;140mmHg (n = 80) Uncontrolled PC SBP ≥140mmHg (n = 70) Preserved Nocturnal Dipping (10 to 20% nocturnal drop in SBP) 61.2% (n = 49) 47.1% (n = 33) Loss of Dip (&amp;gt;0% to &amp;lt;10% of nocturnal drop in SBP) 33.8% (n = 27) 48.6% (n = 34) Reversed Dip (≤0% drop in SBP) 5% (n = 4) 1.4%(n = 1) Excessive Dip (&amp;gt;20% drop in SBP) 0 2.9% (n = 2) Table 1 shows the patterns of nocturnal dipping amongst patients with controlled (&amp;lt;140mmHg) and uncontrolled (≥140mmHg) 15-minute post-clinic systolic blood pressure (PC SBP).

Ambulatory blood pressure monitoring-based analysis of long-term outcomes for kidney disease progression

Non-dipping nocturnal blood pressure (BP) pattern is a predictor of the future decline of renal function; however, it is unclear whether it is still a risk for chronic kidney disease (CKD) patients with normal BP. To solve this question, a retrospective cohort study was conducted, and 1107 CKD patients who underwent ambulatory blood pressure monitoring (ABPM) were enrolled. We divided patients into 4 groups based on their nocturnal BP dipping pattern (dipper or non-dipper) and average 24-hour BP (hypertension or normotension). The cumulative incidence of composite renal outcomes, including a 40% reduction in eGFR, the induction of renal-replacement therapy, or death from renal causes, was analyzed. Overall, 86.1% of participants were non-dippers and 48.2% of them were normotensive. During the median follow-up period of 4.72 years, the incidence of renal composite outcomes was highest in hypertensive non-dipper patients, and was similar between normotensive dipper and non-dipper patients. Multivariate regression analysis revealed that the 24-hour systolic BP, amount of urinary protein, and hemoglobin values were associated with the incidence of renal outcomes. In conclusion, our ABPM-based analysis revealed that a non-dipping BP pattern with normotension does not predict the future incidence of composite renal outcomes in CKD patients.

Microvascular narrowing and BP monitoring: A single centre observational study.

IntroductionHalf of all hypertensive individuals have inadequately-controlled BP because monitoring methods are ineffective. This single centre study examined consecutive subjects undergoing 24 hour BP measurements for clinic and ambulatory BP levels, and for end-organ damage (retinal microvascular abnormalities and left ventricular hypertrophy, LVH, > 1.1 cm). Retinal images were graded for microvascular retinopathy (Wong and Mitchell classification), and vessel calibre using a semiautomated method. Features were compared using chi-squared, Fisher’s exact or the student’s t test.MethodsOne hundred and thirty-one individuals (59 male, 45.0%, mean age 61.7 ± 14.5 years) were studied. Ninety-nine (76.2%) had a clinic BP ≥ 140/90 mm Hg, 84 (64.6%) had a mean awake systolic BP ≥ 135 mm Hg, 100 (76.9%) had a mean sleeping systolic BP ≥ 120 mm Hg, and 100 (76.2%) had abnormal nocturnal BP dipping patterns. Sixty-nine individuals had undergone echocardiography and 23 (33.3%) had LVH.ResultsAll participants had a mild (88.5%) or moderate (11.5%) microvascular retinopathy. Moderate microvascular retinopathy was found in 86.7% of those with a mean awake systolic BP ≥135 mm Hg (p = 0.058) but was not associated with other abnormal BP measurements, abnormal dipping patterns or LVH. However retinal arteriole calibre was reduced in subjects with a mean 24 hour awake systolic BP ≥ 135 mm Hg (p = 0.05). Retinal arteriole calibre was smaller in subjects with LVH (128.1 ± 13.5 μm compared with 137.6 ± 14.1 μm in normals, p = 0.014). Venular calibre was also less in subjects with LVH (185.4 ± 24.6 μm compared with 203.0 ± 27.2 μm in normals, p = 0.016). Arteriole narrowing predicted an increased risk of LVH (AUC 0.69, 95%CI 0.55 to 0.83) that was comparable with 24 hour systolic BP ≥130 mm Hg (AUC 0.68, 95%CI 0.53 to 0.82) and mean awake systolic BP ≥135 mm Hg (AUC 0.68, 95%CI 0.54 to 0.83).ConclusionsThis study suggests that retinal arteriole narrowing may be equally accurate in predicting LVH as any clinic or ambulatory BP measurement. The convenience and accuracy of microvascular calibre measurement mean that it should be investigated further for a role in routine hypertension assessment and monitoring.

Night-time systolic blood pressure and subclinical cerebrovascular disease: the Cardiovascular Abnormalities and Brain Lesions (CABL) study.

Although ambulatory blood pressure (BP) is a better predictor of cardiovascular outcomes than office BP, its association with subclinical cerebrovascular disease is not clarified. We investigated the associations of office and ambulatory BP values with subclinical cerebrovascular disease in a population based, predominantly elderly cohort without prior stroke. Eight hundred and twenty-eight participants underwent 24-h ambulatory BP monitoring (ABPM), 2D echocardiography and brain magnetic resonance imaging in the Cardiac Abnormalities and Brain Lesion (CABL) study. Daytime, night-time, and 24-h BPs, nocturnal dipping pattern, morning surge (MS), and 24-h variability were assessed. Subclinical cerebrovascular disease was defined as silent brain infarcts (SBIs) and white matter hyperintensity volume (WMHV). The association of BP measures with the presence of SBI and upper quartile of log-WMHV (log-WMHV4) was analysed. SBIs were detected in 111 patients (13.4%). Mean log-WMHV was -0.99 ± 0.94. In multivariable analysis, only night-time systolic BP (SBP) was significantly associated with SBI [odds ratio (OR) 1.15 per 10 mmHg, P = 0.042], independent of cardiovascular risk factors, and pertinent echocardiographic parameters. Although daytime, night-time, 24-h BPs, and non-dipping pattern were all significantly associated with log-WMHV4 (all P < 0.05), night-time SBP showed the strongest association (OR 1.21 per 10 mmHg, P = 0.003) and was the sole independent predictor when tested against the other BP parameters. Office BP measures, MS, and BP variability were not associated with subclinical cerebrovascular disease in adjusted analyses. Elevated night-time SBP is strongly associated with subclinical cerebrovascular disease. Night-time SBP by ABPM allows to identify individuals at higher risk of hypertensive brain injury.

Evaluation of posttraumatic stress disorder diagnosis and therapy on diurnal blood pressure patterns from 24-hour ambulatory blood pressure monitoring.

IntroductionThe veteran population has a high incidence of posttraumatic stress disorder (PTSD), which is associated with increased risk of hypertension and cardiovascular death. Ambulatory blood pressure monitoring (ABPM) can identify abnormal diurnal blood pressure (BP) patterns, which are associated with increased risk of cardiovascular events. The intent of this evaluation was to examine prior ABPM studies to determine whether veterans with PTSD are more likely to have abnormal nocturnal dipping patterns compared with the general veteran population.MethodsRetrospective chart review was performed on all archived ABPM studies and classified by nocturnal dipping status and BP control rates. Pertinent patient demographics of age, sex, concomitant PTSD, and use of selected PTSD therapies were identified at the time of ABPM study. Association between dipping status, BP control rates, and patient demographics were analyzed using appropriate statistical tests.ResultsA total of 470 ABPM studies were determined to be valid and included. There were no differences in the distribution of nocturnal dipping patterns in veterans with or without PTSD. Likewise, rates of nocturnal, awake, and 24-hour hypertension were similar between groups. In patients with PTSD who were treated with evening PTSD therapy, there was a higher rate of normal dipping status compared with those without treatment (66.7% vs 29.7%, P = .03).DiscussionVeterans with PTSD had similar distributions of dipping patterns and rates of overall, awake, and nocturnal hypertension compared with the general veteran population. The association of nocturnal PTSD therapy prescription in patients with PTSD and higher rates of normal dipping status may warrant further investigation.

Association of Circadian Rhythm of Blood Pressure and Cerebral Small Vessel Disease in Community-Based Elderly Population.

Although it is accepted that the etiology of cerebral small vessel disease (CSVD) is associated with cardiovascular risk factors, the association between CSVD and the circadian rhythm of blood pressure (BP) is unclear. We aimed to determine if such an association existed in the elderly population. White matter hyperintensities (WMHs), lacunes, microbleeds, nocturnal dipping pattern (NDP), and morning surge in systolic blood pressure (SBP) were assessed in 2,091 participants ≥60 years of age. During an average of 63 months of follow-up, WMH and the WMH-to-intracranial volume ratio were significantly increased in extreme dippers, nondippers, and reverse dippers than those in dippers (p < .001). For new-incident Fazekas scale ≥2, the hazard ratios were 1.77 (95% confidence interval [CI], 1.09-2.86) for extreme dippers, 2.20 (95% CI, 1.48-3.28) for nondippers, and 2.43 (95% CI, 1.59-3.70) for reverse dippers compared with dippers, and 1.04 (95% CI, 0.81-1.35) for higher morning surge compared with lower morning surge. Nondippers and reverse dippers were associated with higher risks of new-incident lacunes and microbleeds than dippers (p < .05). Higher morning surge was associated with a higher risk of new-incident microbleeds than lower morning surge (p < .05). NDPs in SBP played an important role in CSVD, and the morning surge in SBP was associated with cerebral microbleeds in community-based elderly population beyond the average SBP level.

Morning Blood Pressure Surge Relates to Autonomic Neural Activity in Young Non-Dipping Adults: The African-PREDICT Study

It is well established that an exaggerated morning blood pressure surge (MBPS) is associated with an increased risk for cardiovascular disease development in hypertensive individuals. However, in non-dipping individuals, a lower surge was reportedly associated with increased cardiovascular risk. Sympathetic nervous system activity is involved in 24-hour blood pressure fluctuations, including night-time dipping and the MBPS. To better understand this interaction, we investigated associations of MBPS with heart-rate variability and baroreceptor sensitivity in young healthy dippers and non-dippers. We included black and white men and women (n=827), aged 20-30 years and determined the MBPS using two formulas: the sleep-trough and dynamic morning surge. For autonomic function we determined baroreceptor sensitivity and heart-rate variability. The majority of non-dippers in this population were black (70.4%), presenting lower sleep-trough and dynamic morning surge (all p<0.001). Heart-rate variability was comparable between dippers and non-dippers, whereas baroreceptor sensitivity was higher in non-dippers (p=0.021). Despite a suppressed MBPS profile in non-dippers, we found both sleep-trough (β=-0.25; p=0.039) and dynamic morning surge (β=-0.14; p=0.047) to be inversely and independently associated with 24-hour heart-rate variability (total power). These results were absent in dippers. In conclusion, we found a higher night-time blood pressure coupled with lower MBPS in young healthy non-dippers. Furthermore, this lower MBPS was independently and negatively associated with autonomic neural activity, suggesting increased autonomic function involvement in MBPS suppression of non-dippers. The predictive value of suppressed nocturnal dipping pattern should be investigated while taking autonomic neural activity into account.

Impact of Blunted Nocturnal Blood Pressure Dipping on Cardiac Systolic Function in Community Participants Not Receiving Antihypertensive Therapy.

Blunted nocturnal blood pressure (BP) dipping (nondipping) predicts cardiovascular morbidity and mortality, and is associated with heart failure (HF) independent of office BP. Whether nondipping is independently associated with cardiac systolic function prior to the development of HF is uncertain. We assessed whether nocturnal BP dipping pattern and nocturnal BP were associated with indexes of cardiac systolic function [endocardial fractional shortening (endFS), midwall FS (mFS), ejection fraction (EF)] independent of left ventricular mass index (LVMI) and relative wall thickness (RWT) in 491 randomly selected community participants not receiving antihypertensive therapy. Nocturnal BP and dipping pattern were determined from 24-hour BP monitoring where nighttime was defined from fixed-clock time intervals. BP dipping was defined as night-to-day BP ratio. Pulse wave velocity (PWV) was determined using SphygmoCor, and total peripheral resistance (TPR) was calculated from echocardiographic data. On bivariate analyses, nocturnal BP and BP dipping but not day BP were correlated with indexes of cardiac systolic function (P < 0.005). After adjustments for potential confounders including age, LVMI (or RWT) and 24 hour (or day) BP, endFS (P < 0.01), mFS (P < 0.05), and EF (P < 0.01) were associated with nocturnal BP and BP dipping. These relationships survived further adjustments for PWV, and the homeostasis model of insulin resistance. The decreased mFS in reverse dippers was in-part explained by an increased TPR. In an untreated community sample, blunted nocturnal BP dipping is independently and inversely associated with cardiac systolic function. Hence, nondipping is related to a reduced cardiac systolic function prior to the development of HF.

Morning surge and nocturnal dipping pattern: Two different entities or statistical gymnastics?

Morning surge and nocturnal dipping pattern: Two different entities or statistical gymnastics?

Changes of blood pressure patterns and target organ damage in patients with chronic kidney disease

Blood pressure (BP) control is the most established practice for preventing the progression of chronic kidney disease (CKD). We examined the BP control and nocturnal dipping pattern changes in hypertensive patients with CKD and their effects on target organ damages. We recruited 378 hypertensive CKD patients from four centers in Korea. The patients underwent clinic and ambulatory BP monitoring at the time of enrollment and 1 year later. The BP control states at the two time points were as follows: true controlled (16.5, 17.5%), white-coat (2.9, 0.4%), masked (50.0, 53.3%), and sustained uncontrolled (30.6, 28.8%) hypertension. The dipping states at two time points were as follows: extreme-dipping (11.4, 10.8%), dipping (22.2, 20.5%), nondipping (31.3, 34.7%), and reverse-dipping (35.0, 34.0%). When we divided the patients according to the median estimated glomerular filtration rate (eGFR) and proteinuria changes, more stable changes in eGFR and proteinuria were associated with better (to true controlled and white-coat) initial and follow-up BP control statuses. Moreover, better BP control and dipping (to dipper) changes were also associated with more stable eGFR and proteinuria changes. Good initial and follow-up BP control statuses were associated with less left ventricular hypertrophy. Also, masked and sustained uncontrolled hypertension was associated with more cardio-cerebrovascular events in the univariate analysis. A large majority of Korean hypertensive CKD patients had uncontrolled BP and abnormal dipping patterns. Furthermore, better BP control and dipping status changes were associated with better renal function and proteinuria, and also less cardio-cerebrovascular damages.

OS 19-06 CHANGE OF BLOOD PRESSURE PATTERN AND TARGET ORGAN DAMAGE IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Objective: Blood pressure (BP) control is the most established practice for preventing the progression of chronic kidney disease (CKD). We examined the BP control and nocturnal dipping pattern change in hypertensive patients with CKD and its effects on target organ damages. Design and Method: We recruited 378 hypertensive CKD patients from 4 centers in Korea. They underwent office and ambulatory BP monitoring at the time of enrollment and 1 year after. High office and ambulatory BP was defined as > 140/90 mmHg and > 135/85 mmHg (daytime)/> 120/70 mmHg (nighttime), respectively. Results: The BP control state at 2 time points were as follows: true controlled (14.8, 17.5%), white-coat (2.6, 0.4%), masked (45.0, 53.3%), and sustained uncontrolled (27.5, 28.8%) hypertension. The dipping state at 2 time points were as follows: extreme -dipping (11.4, 10.8%), dipping (22.2, 20.5%), non-dipping (31.3, 34.7%), and reverse -dipping (35.0, 34.0%). Better change (to true controlled and white-coat) of BP control status was associated with lower initial level of serum uric acid, urea nitrogen, and proteinuria and higher estimated GFR (eGFR). When we divided patients according to the median of eGFR and proteinuria change, more stable change of eGFR and proteinuria was associated with better initial and follow-up BP control status. And better BP control and dipping status (to dipper) change was also associated with more stable eGFR and proteinuria change. Good initial and follow-up BP control status was associated with less LVH. And masked and sustained uncontrolled hypertension was associated with more congestive heart failure and stroke. Conclusions: The large majority of Korean hypertensive CKD patients had uncontrolled BP and abnormal dipping pattern. And better BP control and dipping status change was associated with better renal function and proteinuria as well as less cardio-cerebrovascular damages.

Poor adoption of guideline recommendations about out-of-office blood pressure measurement in patients with resistant hypertension

Discussion: In this population of normotensive healthy medical residents, there was no influence of caffeine on their systolic pressure, diastolic pressure, pulse pressure, or dipping pattern while performing their night duty. The intake of caffeine also did not alter the normal circadian rhythm during sleep manifested by normal dipping pattern. The results of this study agree with Hartley et al in which his group found significant elevations in systolic and diastolic blood pressure due to caffeine in patients who were hypertensive at baseline, but not in patients who have normal blood pressure at baseline. Caffeine also did not significantly decrease the nocturnal dipping pattern in the healthy medicine residents suggesting that adverse effects of caffeine may be more profound in patients with hypertension at baseline. Further studies are needed in a greater number of patients to elucidate the effects of caffeine on nocturnal dipping patterns and in patients hypertensive at baseline. Terry R. Hartley, Bong Hee Sung et al. Hypertension Risk Status and Effect of Caffeine on Blood Pressure. Hypertension. 2000;36:137-141.

Male prairie voles display cardiovascular dipping associated with an ultradian activity cycle

Mammals typically display alternating active and resting phases and, in most species, these rhythms follow a circadian pattern. The active and resting phases often are accompanied by corresponding physiological changes. In humans, blood pressure decreases during the resting phase of the activity cycle, and the magnitude of that “nocturnal dipping” has been used to stratify patients according to the risk for cardiovascular disease. However, in contrast to most mammals, prairie voles (Microtus ochrogaster) have periods of activity and rest that follow an ultradian rhythm with period lengths significantly <24h. While rhythmic changes in blood pressure across a circadian activity cycle have been well-documented, blood pressure patterns in species that display ultradian rhythms in activity are less well-studied. In the current study, we implanted pressure-sensitive radiotelemetry devices in male prairie voles and recorded activity, mean arterial pressure (MAP), and heart rate (HR) continuously for 3days. Visualization of the ultradian rhythms was enhanced using a 1h running average to filter the dataset. Positive correlations were found between activity and MAP and between activity and HR. During the inactive period of the ultradian cycle, blood pressure decreased by about 15%, which parallels the nocturnal dipping pattern seen in healthy humans. Further, the duration of inactivity did not affect any of the cardiovascular measures, so the differences in blood pressure values between the active and inactive periods are likely driven by ultradian oscillations in hormones and autonomic function. Finally, specific behavioral patterns also were examined. Both the instrumented animal and his non-instrumented cagemate appeared to show synchronized activity patterns, with both animals displaying sleep-like behavior for more than 90% of the inactive period. We propose that the prairie vole ultradian rhythm in blood pressure is an analogue for circadian blood pressure variability and can be used to study the long-term effects of commonly prescribed drugs on blood pressure dipping.

Nocturnal blood pressure dipping in acute ischemic stroke.

We aim to assess the impact of early nocturnal blood pressure (BP) variation in the functional outcome of patients after an acute ischemic stroke. We included consecutive stroke patients treated with intravenous thrombolysis (IVrtPA) in a tertiary stroke center. BP measurements were performed at regular intervals throughout day and night during the first 48 h after stroke onset, and subjects were divided into four dipping categories (extreme dippers, dippers, non-dippers, and reverse dippers). Recanalization was assessed by transcranial color-coded Doppler and/or angiographic CT. Hemorrhagic transformation was evaluated at 24 h follow-up CT scan. Functional outcome was evaluated at 3 months after stroke using the modified Rankin Scale. A total of 304 patients were included, mean age 72.80 ± 11.10 years. After 24 h of systolic BP monitoring, 30.59% were classified as reverse dippers, 39.14% as non-dippers, 19.10% as dippers, and 11.18% as extreme dippers. Multivariate analysis did not show an independent association of any dipping class with 3-month functional outcome. Hemorrhagic transformation was not uniform between dipping classes: 25.81% for reverse dippers, 14.29% for non-dippers, 15.52% for dippers, and 5.88% for extreme dippers, P = 0.033. Nocturnal BP dipping pattern is not associated with functional outcome at 3 months in acute stroke patients treated with IVrtPA. Hemorrhagic transformation was more frequent in reverse dippers.