Dipper Status Research Articles

Examining Circadian Blood Pressure Patterns: Investigating the Interplay between Dipper Status and Arterial Stiffness Metrics

Examining Circadian Blood Pressure Patterns: Investigating the Interplay between Dipper Status and Arterial Stiffness Metrics

Identifying an acceptable number of ambulatory blood pressure measurements for accuracy of average blood pressure and nocturnal dipping status.

We aimed to identify the minimum number of ambulatory blood pressure (ABP) measures to accurately determine daytime and nighttime systolic blood pressure (BP) averages and nocturnal dipping status (i.e., relative daytime:nighttime change). A total of 43 midlife participants wore an ABP monitor for 24 h with measurements every 20/30 min during the daytime/nighttime, as identified by a sleep diary. We calculated daytime/nighttime systolic BP average and dipping status from all available measurements per participant (i.e., normative data). We then calculated daytime and nighttime BP per participant based on a random selection of 8-20 and 4-10 measurements and replicated random selections 1,000 times. We calculated accuracy by checking the proportion from 1,000 different randomly selected samples for a particular number of measurements that systolic BP was ±5 mmHg of normative data, and dipping status remained unchanged for each participant compared with the normative value. The best fit for the regression model estimated the minimal number of measurements for an accuracy of 95% in BP averages. For a 95% accuracy in estimating daytime and nighttime systolic BP, 11 daytime and 8 nighttime measurements were required. The highest accuracy for dipping status was 91.6 ± 13.4% using 20 daytime and 10 nighttime measures, while the lowest was (83.4 ± 15.1%) using 8 daytime and 4 nighttime measures. In midlife adults, 11 daytime and 8 nighttime measurements are likely enough to calculate average systolic BPs accurately. However, no minimum number is suggested to accurately calculate dipping status.NEW & NOTEWORTHY We found that a minimum of 11 blood pressure (BP) measures are necessary to calculate an accurate average daytime BP, and 8 nighttime measures are necessary to calculate an accurate nighttime average if 95% accuracy is acceptable. Regarding BP dipping status, the current recommendations (20 daytime/7 nighttime) inaccurately classified the dipping status 10.5% of the time, suggesting that guidelines may need to be updated to classify patients as nocturnal dippers or nondippers correctly.

Sleep Apnea, Autonomic Disturbances, and Blood Pressure Variability.

Augmented blood pressure variability has emerged as a quantity predictive of adverse cardiovascular outcomes. Among the range of intrinsic and extrinsic factors shown to increase night-time, circadian, short-term, and long-term blood pressure variations, the presence and severity of obstructive sleep apnea have emerged as one of the most prevalent and potent. Obstructive sleep apnea alters acutely the normal nocturnal equilibrium between sympathetic and parasympathetic tone, magnifying nocturnal blood pressure oscillations, and induces sustained autonomic aftereffects with the capacity to amplify short-term and intersessional blood pressure variabilities. The object of this brief review is to synthesize the current understanding of the potential interrelations between obstructive sleep apnea, the acute and sustained autonomic disturbances that it elicits, and beat-to-beat blood pressure fluctuation during sleep, nocturnal dipping status, and day-to-day blood pressure variability and the consequences of these perturbations for cardiovascular risk.

#1511 The immune cell ‘signature’ of incident hypertension

Abstract Background and Aims Hypertension results from complex genetic and environmental interactions, mediated by cardiac, vascular, endocrine, and renal systems. The immune system may modulate all of these, though the exact mechanisms linking immune activation with hypertension and organ damage remain poorly defined. We aimed to identify the immune cell ‘signature’ in patients with newly diagnosed, untreated hypertension (HTN; n=76) compared to normotensive controls (NTN; n=67), as well as in relation to nocturnal dipping status. Method Flow cytometry of peripheral blood mononuclear cells (Attune, Thermo Fisher) characterising B cell, T cell, monocyte and dendritic cells (DC) subsets, including activation signature with intracellular staining, in an exploratory comparative analysis. Results The proportion of CD4+ naïve T cells (CD45RA+CCR7+) was lower in hypertension, with CD45RO+CD62L+ cells attaining nominal statistical significance between NTN and HTN groups (1.3 ± 1.1 vs 1.2 ± 1.0, p=0.039). CD4+ T central memory cells were expanded (TCM, 23.1 ± 7.2 vs 27.7 ± 10.0, p=0.002, Figure) in HTN along with T effector memory (TEM) cells lacking CD62 in an adjusted model, (TEM, CD4+CD45RA-CCR7-CD62l-; 31.4 ± 7.5 vs 33.7 ± 10.3, p0.035; CD8+CD45RA-CCR7-CD45RO+CD62l− 48.9 ± 10.5 vs 52.2 ± 13.3, p=0.011). Hypertensive group had proportionally fewer CD4+CD28+ cells (95.1 ± 9.8 vs 92.0 ± 13.5, p=0.034) and CD8+CD28+ (68.0 ± 19.7 vs 62.0 ± 21.0, p=0.011), as well as CD8+ TEMRA cells (Figure). In a fully adjusted model, the CCR7-CD45RO-CD62L+ (52.2 ± 14.5 vs 50.2 ± 16.1, p=0.036), and CD8+CD28+CD45RA+CCR7- significantly differed between groups (23.1 ± 14.7 vs 25.0 ± 17.8, p=0.008). On the molecular level, T cells were polarised in HTN towards a Th1/Tc1 and Th17.1/Tc17.1 pro-inflammatory milieu (Figure). No differences were detected in B cell subsets. The innate immune ‘signature’ was characterised by intermediate monocytes with a differing pattern of CCR2 and CCR5 chemokine receptor expression (Table 1), and alterations in STAT1 and STAT6 phosphorylation cascades. NK cell CD56+Dim expression and fewer CD122-expressing NKT (0.13 ± 0.0 vs 0.08 ± 0.1, p=0.046) and CD122+ T lymphocytes (1.3 ± 3.4 vs 0.6 ± 0.4, p=0.019) further supported pro-inflammatory milieu in hypertension. Finally, in an exploratory nominal statistical analysis, nocturnal non-dipping was associated with particular changes in immune cell signature, including expanded CD4+TCM (CD4+CD45RO+CD62L-, 9.4 ± 4.3 vs 8.0 ± 3.3, p=0.04) and reduced CD4+TEM and TEMRA compartments; polarisation towards Th17 and Tc1; and altered Monocyte CCR2 and CCR5 expression. Additionally, non-dipping was linked to dendritic cell mannose receptor downregulation e.g. mDC non-dipper 10.9 ± 5.8 vs dipper 13.6 ± 9.7, p=0.03. Conclusion These exploratory data support alterations of circulating innate (monocytes) and adaptive (T cells) immune compartments in newly diagnosed untreated, and uncomplicated hypertension.

Sex difference in nocturnal blood pressure dipping in adolescents with varying degrees of adiposity

BackgroundFor adolescents, abnormal dipping patterns in blood pressure (BP) are associated with early-onset organ damage and a higher risk of cardiovascular disorders in adulthood. Obesity is one of the most common reasons for abnormal BP dipping in young people. However, it is unknown whether the severity of obesity is associated with BP dipping status and whether this association is sex-dependent.Methods499 participants between 12 and 17 years old with overweight or obesity underwent ambulatory blood pressure monitoring (ABPM) between April 2018 and January 2019 in Beijing and Baoding. Participants were grouped by body mass index (BMI) into overweight (BMI 85th–95th percentile), obese (BMI ≥ 95th percentile) and severely obese (BMI ≥ 120% of 95th percentile or ≥ 35 kg/m2) groups. Non-dipping was defined as a < 10% reduction in BP from day to night. The interaction effect between sex and obesity degree was also analyzed.Results326 boys and 173 girls were included, of whom 130 were overweight, 189 were obese, and 180 were severely obese. Girls with severe obesity had a higher prevalence of non-dipping, but boys showed no significant differences in BP dipping status between obesity categories. In addition, as obesity severity went up, a more evident increase in night-time SBP was observed in girls than in boys.ConclusionsSeverely obese is associated with a higher prevalence of non-BP dipping patterns in girls than in boys, which suggests that the relationship between the severity of obesity and BP dipping status might be sex-specific.

Comparison of choroidal thickness and choroidal vascular index in normotensive dippers and nondippers.

The aim of this study was to evaluate the choroidal thickness and choroidal vascular index in normotensive individuals with dipping and nondipping patterns. Patients who applied to the cardiology clinic for routine checkups and underwent 24-h blood pressure monitoring were included in our study. They were divided into two groups based on their dipper status. The patients in whom systolic blood pressure decreased during the nocturnal time by 10% or more of the daily blood pressure were defined as dippers. On the contrary, patients whose nocturnal systolic blood pressure decreased by less than 10% were defined as nondippers. Choroidal thickness and choroidal vascular index were measured by spectral-domain optical coherence tomography. Central macular thickness, retinal nerve fiber layer, and ganglion cell layer (GCL) analyses were also recorded. In total, 35 patients with dipper pattern and 34 patients with nondipper pattern were recruited. The mean subfoveal choroidal thickness was 349.72±90 μm in the dipper group and 358.54±132.5 μm in the nondipper group. The groups had no significant difference in choroidal thickness, central macular thickness, retinal nerve fiber layer, and ganglion cell layer analyses. However, the choroidal vascular index was statistically significantly lower in the nondipper group when compared to the dipper group (0.61±0.02 vs. 0.64±0.02; p<0.001). Also, the choroidal vascular index was negatively correlated with subfoveal choroidal thickness in the nondipper group (Spearman; r=-0.419; p=0.033). Our study showed that the choroidal vascular index was significantly lower in nondippers than in dippers. Nondipper individuals may be affected by vascular dysregulation, leading to alterations in the choroidal circulation.

Evaluation of the Diurnal Cycle of Blood Pressure and Sleep in Shift Workers.

Circadian misalignment of physiological factors in shift workers is poorly studied in the Indian population. In the present study, 24-hour blood pressuremeasurements were taken on the same subject twice, once during his morning and night shifts. Sleep was also monitored by a self-reported sleep diary, which was confirmed with an activity monitor, and the sleep quality was assessed using sleep questionnaires. This study aimed to discover the pattern of blood pressure variation, the dipping and non-dipping status, and its correlation with sleep. This observational study was conducted in the Department of Physiology, All India Institute of Medical Sciences (AIIMS), Rishikesh, from April 2019to September 2019, among security guards working rotating shifts in theRishikesh hospital premises. Participants were given an activity sheet with instructions to document their daily activities for a complete 24-hour period on the designated measurement day, including recording the time of waking up and going to sleep. A wrist-worn activity monitor was utilised to assess the self-reported sleep duration provided by each participant on the activity sheet. The present study showed the mean age of the participants as 27.03 ± 2.71 years, along with a mean body mass index (BMI) of 22.10 ± 1.64.Sleep duration was significantly higher during the morning shift (5.81 ± 1.08 hours) compared to the night shift (4.02 ± 1.70 hours) on the day of ambulatory blood pressure monitoring (ABPM) recording.The mean difference in systolic blood pressure between night shift workers between their awake and sleep periods was 15.91 ± 8.44 mmHg.However, no statistically significant disparity was seen when comparing the systolic blood pressure at the 24-hour mark during wakefulness and sleep between those working morning and night shifts(p >0.05). The current study's findings indicate that participation in shift work, particularly night shift work, could potentially play a role in the emergence of irregular circadian blood pressure patterns and potentially lead to a lack of nocturnal blood pressure decline.

A comparative analysis of ambulatory blood pressure characteristics in acute stroke and non-stroke Indian patients.

The objective of this study is to identify 24-h blood pressure (BP) characteristics after acute stroke in Indian hospitalized patients. In total, 769 patients [284 women (36.9%)] admitted at a hospital in South India were analyzed. Of these, 364 patients (47.3%) had recently experienced stroke. All patients underwent ambulatory blood pressure measurement (ABPM) so that ABPM patterns and ABPM risk parameters of stroke and non-stroke patients could be compared. Additionally, to investigate the relationship between ABPM parameters and stroke, a stepwise logistic regression analysis was employed. Stroke patients had significantly higher BP than non-stroke patients (24-h ABP: 145.0 ± 22.1 vs. 133.7 ± 20.5 mmHg, P < 0.001), with similar dipping status. ABPM parameters mostly associated with stroke (all P < 0.001) were: nighttime [odds ratios (OR): 1.587, 95% confidence interval (95% CI): 1.341-1.885], 24-h (1.584, 1.34-1.881), minimum nighttime (1.582, 1.339-1.879), daytime (1.540, 1.304-1.827), and morning SBP (1.517, 1.287-1.797). Non-dipping status was relatively more common in stroke patients (79% vs. 71%, P < 0.05) but dipping percentage did not show a significant linear relationship with stroke. Several ABPM characteristics were strongly associated with stroke in Indian hospitalized patients. Specifically, minimum nighttime and average morning SBP may be considered as important and practical parameters for its relationship with stroke.

0843 Identifying the Minimum Number of Ambulatory Blood Pressure Measurements to Classify a Reliable Blood Pressure Dipping Status

Abstract Introduction Ambulatory blood pressure monitoring (ABPM) is recommended over office BP assessment as it enables quantification of the degree of nocturnal BP dipping (classifications: “dipping” = nighttime/daytime BP of &amp;lt; 0.9; “non-dipping” = ≥0.9), a robust predictor of future adverse events. However, ABPM can cause discomfort jeopardizing adherence to the 24-hour assessment. Current guidelines recommend at least 20/7 daytime/nighttime BP measurements for reliable classification of nocturnal dipping status, but recent reports suggest 8/4 daytime/nighttime measurements may be sufficient. This threshold for classification can reduce patient burden and potentially enhance clinical practice. We aimed to identify the minimum number of ambulatory BP measurements to determine a reliable dipping status. Methods Forty-three ostensibly healthy participants (50±10 years [mean±SD]) wore an ambulatory BP monitor for 24 hours with measurements every 20/30 minutes during the daytime/nighttime, respectively (maximum 48/16 daytime/nighttime measurements). We calculated each participant's dipping status using all available systolic BP measurements. We randomly selected 20-daytime plus 8-nighttime measurements, identified dipper statuses from all possibilities of 1-20 daytime and 1-8 nighttime measurements separately, and calculated the proportion of participants whose dipping status remained unchanged. We then evaluated all possible combinations starting with a minimum of 8 daytime/5 nighttime for consistency with participants’ full data set using a second random selection of 20/8 measurements Results We found that using 8-daytime (plus all available nighttime) measurements was sufficient for unchanged dipper status in 90% of possible combinations, and using 5-nighttime (plus all available daytime) measurements was sufficient for unchanged dipper status in 92% of possible combinations. Confirmatory analyses revealed that 8/5 daytime/nighttime combinations correctly identified dipper status in 84% of the &amp;gt;7 million combinations. 10/8 daytime/nighttime combination improved this to 86%, similar to 87% returned from the guidelines’ recommended combination of 20/7 daytime/nighttime measurements. Conclusion In ostensibly healthy people, current thresholds for ambulatory BP monitoring recommendation could result in ~13% misclassifications of dipping status compared to full datasets. However, considering that this measurement can cause discomfort and that dipping statuses can be unstable in 30% of individuals, 10/8 daytime/nighttime measurements may be a reliable alternative. Support (if any) NIH F32HL131308, R01HL163232, R01HL125893, R35HL155681, OHSU MRF and OFDIR.

24-hour ambulatory blood pressure and cryptogenic ischemic stroke in young adults

Background In young patients, up to 40% of ischemic strokes remain cryptogenic despite modern-day diagnostic work-up. There are limited data on blood pressure (BP) behavior in these patients. Thus, we aimed to compare ambulatory blood pressure (ABP) profiles between young patients with a recent cryptogenic ischemic stroke (CIS) and stroke-free controls. Patients and Methods In this substudy of the international multicenter case–control study SECRETO (NCT01934725), 24-hour ambulatory blood pressure monitoring (ABPM) was performed in consecutive 18–49-year-old CIS patients and stroke-free controls. The inclusion criteria were met by 132 patients (median age, 41.9 years; 56.1% males) and 106 controls (41.9 years; 56.6% males). We assessed not only 24-hour, daytime, and nighttime ABP but also hypertension phenotypes and nocturnal dipping status. Results 24-hour and daytime ABP were higher among controls. After adjusting for relevant confounders, a non-dipping pattern of diastolic blood pressure (DBP) was associated with CIS in the entire sample (odds ratio, 3.85; 95% confidence interval, 1.20–12.42), in participants without antihypertensives (4.86; 1.07–22.02), and in participants without a patent foramen ovale (PFO) (7.37; 1.47–36.81). After excluding patients in the first tertile of the delay between the stroke and ABPM, a non-dipping pattern of DBP was not associated with CIS, but a non-dipping pattern of both systolic BP and DBP was (4.85; 1.37–17.10). In participants with a PFO and in those without hypertension by any definition, no associations between non-dipping patterns of BP and CIS emerged. Conclusions Non-dipping patterns of BP were associated with CIS in the absence of a PFO but not in the absence of hypertension. This may reflect differing pathophysiology underlying CIS in patients with versus without a PFO. Due to limitations of the study, results regarding absolute ABP levels should be interpreted with caution. Key Messages Nocturnal non-dipping patterns of blood pressure were associated with cryptogenic ischemic stroke except in participants with a patent foramen ovale and in those without hypertension by any definition, which may indicate differing pathophysiology underlying cryptogenic ischemic stroke in patients with and without a patent foramen ovale. It might be reasonable to include ambulatory blood pressure monitoring in the diagnostic work-up for young patients with ischemic stroke to detect not only the absolute ambulatory blood pressure levels but also their blood pressure behavior.

Defining the impact of continuous positive airway pressure therapy on diastolic function in adults with moderate-to-severe obstructive sleep apnea.

Although studies have shown that continuous positive airway pressure (CPAP) therapy to treat obstructive sleep apnea improves left ventricular diastolic function, modifiers of improvement are unknown. We explored race and pre-treatment 24-h non-dipping blood pressure status as modifiers of improved diastolic function. Participants (N=220) with obstructive sleep apnea (apnea-hypopnea index ≥15 events/h) and hypertension were recruited to a cohort study that examined effects of 3-month CPAP therapy on 24-h blood pressure. Those who completed echocardiogram at baseline and follow-up were included in this analysis. Diastolic function parameters (E, A, e', E/A, E/e') were assessed. Race was categorised to African American versus others. Participants were categorised as nocturnal dippers (night-time blood pressure decrease by ≥10%) versus non-dippers. We compared changes in parameters of diastolic function by race and nocturnal dipping status. A total of 92 participants were included. They were men (86%), African American (67.4%), and current smoker (29.5%). Mean apnea-hypopnea index was 32.9 events/h. Mean CPAP usage was 3.15 h/day. After 3 months of CPAP treatment, there were significant improvements in measures of diastolic function: a median (interquartile range [IQR]) increase in E velocity by 4.00(-5.75 to 13.75)cm/s, an increase in e' by 2.00(0-4.00)cm/s, and a decrease in the E/e' ratio by 1.74(-4.27 to 0.00) at follow-up (p < 0.05). These changes did not differ by race or nocturnal dipping status. Improvements in diastolic function after CPAP therapy did not differ by race or nocturnal dipping status. Further studies are needed to understand predictors of CPAP effects on diastolic function.

The association between frontal QRS-T angle and reverse dipper status in newly diagnosed hypertensive patients.

The frontal QRS-T angle (fQRS-T angle) in ECG is a new measure of myocardial repolarization, in which a higher fQRS-T angle is linked with worse cardiac outcomes. Reverse dipper hypertension is also linked to poor cardiac outcomes. The purpose of this study was to investigate the association between the fQRS-T angle and reverse dipper status in individuals newly diagnosed with hypertension who did not have left ventricular hypertrophy (LVH). The investigation recruited 171 hypertensive individuals without LVH who underwent 24-h ambulatory blood pressure monitoring (ABPM). On the basis of the findings of 24-h ABPM, the study population was categorized into the following three groups: patients with dipper hypertension, non-dipper hypertension, and reverse dipper hypertension. LVH was defined by echocardiography. The fQRS-T angle was measured using the 12-lead ECG. The fQRS-T angle in individuals with reverse dipper hypertension was substantially greater than in patients with and without dipper hypertension (51° ± 28° vs. 28° ± 22° vs. 39° ± 25°, respectively, P < 0.001). The fQRS-T angle (odds ratio: 1.040, 95% confidence interval: 1.016-1.066; P = 0.001) was independently associated with reverse dipper hypertension according to multivariate analysis. In receiver operating characteristic curve analysis, the fQRS-T angle to predict reverse dipper hypertension was 33.5° with 76% sensitivity and 71% specificity. This study showed that an increased fQRS-T angle was associated with reverse dipper hypertension in newly diagnosed hypertensive patients without LVH.

PS-BPC12-8: ASSOCIATION OF URIC ACID WITH BLOOD PRESSURE LEVEL IN ESSENTIAL HYPERTENSION: DIFFERENCES ACCORDING TO DIPPING PATTERN OF NOCTURNAL BLOOD PRESSURE

Objective: In essential hypertensive patients, independent of the degree of hypertension, a non-dipping blood pressure pattern is a risk factor for the development of cardiovascular diseases. Serum uric acid level was demonstrated to be an independent predictor of developing hypertension. The increase of uric acid promotes oxidative stress and inflammation, which then enhances endothelial dysfunction. In this study, the association of serum uric acid with 24 hour average blood pressure level was investigated from differences in patterns of circadian blood pressure in patients with essential hypertensive patients. Design and method: In 154 untreated essential hypertensive patients (86 males, average age 56 ± 12 years) without chronic kidney disease (urinary albumin excretion less than 300 mg/g of creatinine and estimated glomerular filtration rate 60 mL/min/1.73m2 or more), 24 hour ambulatory blood pressure monitoring and blood sampling were performed. In blood samples, biochemical parameters including highly sensitive CRP (hsCRP) and nitric oxide metabolites (NOx) were measured. Non-dipper status was defined as a decrease in nocturnal systolic blood pressure &lt; 10 %. The patients were divided into two groups according to their nocturnal systolic blood pressure status: 56 patients with non-dipper status and 98 patients with dipper status. Results: 24 hour systolic blood pressure was higher in the non-dipper patients than in the dipper group (148 ± 17 vs 139 ± 16 mmHg, p &lt; 0.001), whereas diastolic blood pressure and pulse rate did not differ between the two groups. The non-dipper group was characterized by increased serum uric acid and hsCRP and decreased plasma NOx level compared with the dipper group (6.0 ± 1.7 mg/dL, 0.10 ± 0.15 mg/dL, 41.4 ± 25.3 μmol/L in the non-dipper group vs 5.5 ± 1.5, 0.07 ± 0.11, 50.1 ± 31.3 in the dipper group, p &lt; 0.05, respectively). 24 hour systolic blood pressure correlated positively with serum uric acid and hsCRP and negatively with plasma NOx in the non-dipper group (r = 0.25, 0.32, -0.25, p &lt; 0.05, respectively), but did not so in the dipper group. Furthermore, in the non-dipper group, multiple regression analysis revealed that serum uric acid was an independent determinant for 24 hour systolic blood pressure level together with hsCRP, and plasma NOx (R2 0.25, p &lt; 0.01). Conclusions: These data indicate that the elevation of serum uric acid could associate with persistently elevated blood pressure accompanied with micro-inflammation and vascular endothelial dysfunction in essential hypertensive patients with an attenuated nocturnal blood pressure dipping.

PS-P03-7: 24 HR-AMBULATORY BLOOD PRESSURE PROFILE AND CLINICAL FEATURES OF HYPERTENSIVE AND PREHYPERTENSIVE HEALTH CARE WORKERS IN A PHILIPPINE TERTIARY CENTER

Background: Hypertension is a leading cause of cardiovascular morbidity, and its prevalence is increasing most rapidly in developing countries like the Philippines, where there is poor hypertension treatment and control ABPM is an important diagnostic tool among patients because it identifies hypertension phenotypes and circadian blood pressure profile that are known to be predictors for target organ damage and increased incidence of future cardiovascular event. Objectives: To determine the blood pressure profile and phenotypes of hypertensive and pre-hypertensive health care workers and its association to BP control and dipping status. Design and Methods: This is a cross-sectional study of hypertensive employees who underwent 24 hr ambulatory blood pressure monitoring (ABPM). Results: 181 patients were included with majority from 50–59 years old age group (33.3%), female (70.17%), non-shift workers (61.88%) with the most common comorbidity of obesity (60.22%) and suspected obstructive sleep apnea (60.22%). All the known hypertensives (100%) had uncontrolled blood pressure despite being on antihypertensive medication. The following hypertension phenotypes were identified: Sustained hypertension (64.7%), masked hypertension (13.26%), white coat hypertension (7.18%), and non-dippers (66%). Conclusion: There was high prevalence of sustained hypertension among healthcare workers included in this study. All those known hypertensives tested had uncontrolled blood pressure despite being on one or more antihypertensive therapy, while there were also newly diagnosed with masked hypertension. The overall prevalence of non-dippers and those with elevated mean 24- hour blood pressure levels was high, and there is significant association of working longer hours and nocturnal dipping pattern. However, there was no significant difference on nocturnal dipping status and blood pressure elevation among those with those with shift work, compared to usual office work hours. This study is one of the few local data on 24hr ambulatory blood pressure measurement of Filipino hypertensive and prehypertensive patients and is one of few data on use of ambulatory blood pressure monitoring among Asians. This also highlights the importance of 24-hour ABPM to identify ABPM parameters at high risk for cardiovascular outcomes and finally determine blood pressure control among known hypertensive patients according to the locally available maintenance medications.

The importance of frontal QRS-T angle for predicting reverse dipper status in newly diagnosed hypertensive patients

Abstract Background The frontal QRS-T angle (fQRS-T angle) in electrocardiography is a new measure of myocardial repolarization, in which a higher fQRS-T angle is linked with worse cardiac outcomes. Reverse dipper hypertension is also linked to poor cardiac outcomes. The purpose of this study was to investigate the association between the fQRS-T angle and reverse dipper status in individuals newly diagnosed with hypertension who did not have left ventricular hypertrophy (LVH). Methods The investigation recruited 171 hypertensive individuals without LVH who underwent 24h ambulatory blood pressure monitoring (ABPM). Based on the findings of 24h ABPM, the study population was categorized into the following three groups: patients with dipper hypertension, with non-dipper hypertension, and with reverse dipper hypertension. The frontal QRS-T angle was measured using 12-lead electrocardiography (ECG). Results The fQRS-T angle in individuals with reverse dipper hypertension was substantially greater than in patients with and without dipper hypertension (510±280 vs. 280±220 vs. 390±250 respectively, p&amp;lt;0.001). The fQRS-T angle (OR: 1.040, 95% CI: 1.016–1.066; p=0.001) was independently associated with reverse dipper hypertension according to multivariate analysis. In receiver operating characteristic curve analysis, the fQRS-T angle to predict reverse dipper hypertension was 33.5° with 76% sensitivity and 71% specificity. Conclusion This study showed that an increased fQRS-T angle was a predictor of reverse hypertension in newly diagnosed hypertensive patients without LVH. Funding Acknowledgement Type of funding sources: None.

Association between nocturnal blood pressure dipping and chronic kidney disease

Abstract Introduction Management of blood pressure (BP) in chronic kidney disease (CKD) is critical for preventing cardio-renal complications. While increasing attention has been given to discrepancies between office and ambulatory BP control in this population, information on nocturnal BP decrease patterns (dipping) in CKD is still scarce. Purpose We aimed at describing nocturnal BP dipping patterns and its predictors in patients with CKD. Methods We analysed data from patients with CKD stages 1 to 5 referred for kidney function testing from September 2006 to January 2022, including 24-hour urine collection, gold-standard measurement of glomerular filtration rate (GFR) using clearance of a radioisotopic tracer, as well as ambulatory BP measurement (ABPM) in a single tertiary hospital in Paris, France. A total of 1177 ABPM were available in 642 participants. The magnitude of dipping was calculated as the difference between day- and night-time systolic BP (SBP), in percentage of daytime SBP. Participants were then categorized as extreme-dippers (≥20%), dippers (10% to &amp;lt;20%), non-dippers (0% to &amp;lt;10%), or reverse-dippers (&amp;lt;0%). Factors associated with a less than 10% dipping were analysed with crude and adjusted logistic regression models including a random intercept to deal with clustering of measurements within patients. Results Participants (mean age 56±15 years; 35% female, mean GFR 49±21 mL/min per 1.73 m2) consisted of 8% extreme-dippers, 37% dippers, 40% non-dippers, and 15% reverse-dippers. The prevalence of non- or reverse-dipping increased with CKD severity, from 36% in CKD stage 1 to 65% in CKD stages 4–5 (Figure). In crude analyses, African origin, a lower measured GFR, a higher daytime SBP, diabetes, a higher number of antihypertensive medications and a higher 24-hour urinary sodium to potassium ratio (24h Na/K) were associated with abnormal dipping status. In the multivariable adjusted regression, non or reverse dipping was independently associated with measured GFR (odds ratio [OR, 95% confidence interval] per 10 ml/min/1.73 m2 decrease = 1.16 [1.06–1.26], p=0.001), daytime ambulatory SBP (OR per 10 mmHg decrease = 1.17 [1.06–1.28], p=0.001), African origin (OR= 1.56 [1.04–2.34], p=0.03) and 24h Na/K (OR per 1-unit increase = 1.20 [1.06–1.37], p=0.006). Conclusions The prevalence of nocturnal non-or reverse dipping BP profiles increases substantially across the spectrum of CKD. Measured GFR, ambulatory daytime SBP, African origin and 24-hour urinary sodium to potassium ratio are independent predictors of abnormal nocturnal BP decrease and thus may help in cardiovascular risk stratification in this population. More research is needed on whether nocturnal dipping may be a treatment target to reduce cardiorenal complications. Funding Acknowledgement Type of funding sources: None.

The Role of Ambulatory Blood Pressure Monitoring in Current Clinical Practice.

Hypertension continues to be the leading modifiable risk factor for stroke, kidney disease and cardiovascular disease, and it also plays a key role in a significant proportion of preventable deaths globally. Ambulatory blood pressure monitoring (ABPM) is an underutilised tool that augments the accurate diagnosis of hypertension. Out-of-office blood pressure measurements such as ABPM, permits the diagnosis of white coat hypertension and masked hypertension as well as determining a patient's nocturnal dipping status. These common clinical phenotypes have relevance with regard to clinical outcomes and may impact management. Overall, the diagnosis and management of hypertension presents numerous challenges, requiring the complementary use of multimodal blood pressure monitoring. Familiarity with the use of ABPM is important in the optimal management of patients, particularly as it becomes more accessible with the recent introduction of a Medicare Benefits Schedule item number.

GENDER DIFFERENCES IN THE REGULATION OF BLOOD PRESSURE ASSESSED BY AMBULATORY BLOOD PRESSURE MONITORING – A SINGLE-CENTER EXPERIENCE

Objective: It has been shown a significant difference in clinical characteristics of HTN and treatment response to antihypertensive therapy between males and females. The purpose of our article was to examine gender differences in the regulation of blood pressure (BP) by using ambulatory blood pressure monitoring (ABPM). Design and method: Two hundred seventy-five consecutive hypertensive patients were included in the study (146 females, mean age 64.11 ± 10.47 and 129 males, mean age 61.69 ± 13.59). All patients were on antihypertensive treatment for more than one year (average duration of HTN was 11.07 ± 8.24 years for women, and 10.31 ± 7.5 years for men). In all pts, AMBP was performed. The values obtained by AMBP were compared between the two groups. Results: There were no significant differences in the presence of coronary artery disease, obesity, diabetes mellitus, or heredity between the groups. There were more smokers among male patients (p = 0.007), while dyslipidemia was more present in female pts (p = 0.005). Male pts had higher values of systolic (124.05 ± 13.89 vs. 119.5 ± 16.58, p = 0.015) and diastolic BP (72.77 ± 8.42 vs. 69.24 ± 8.23, p = 0.001) and larger burden of high BP during the night (56.54 ± 35.52 vs. 33.11 ± 35.27, p = 0.000) compared to female pts. There were no significant differences in pulse pressure (PP) values between the male and female groups (51.17 ± 11.33 vs. 50.72 ± 10.38, p = 0.730). However, pathological values of PP (&lt;40 mmHg or &gt; 60 mmHg) were found in almost 1/3 of pts (34.92% in men and 28.57% in women). Also, there was no significant difference in dipping pattern but only 40 (31.01%) male and 50 (34.25%) female patients had dipper status. There was no statistically significant difference in antihypertensive therapy between the groups. The most commonly used drugs were the angiotensin-converting enzyme inhibitors (82.21% of all pts) and beta blockers (78.78%), while the angiotensin receptor blockers were the least used (15.98%). Conclusions: Results indicate that women have better BP control than men. However, a high frequency of pathological PP values and disturbed dipping status detected by ABPM, in women as well as men, should highlight the importance of better BP management in both genders.

Inflammation in Hypertensive Patients with Type 2 Diabetes on Stable Therapy with Non-dipper and Dipper Status

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

MO093: Dietary Sodium Restriction Reduces Nocturnal Blood Pressure in Treatment Resistant Hypertensive Patients

Abstract BACKGROUND AND AIMS High blood pressure (BP) is an essential contributor to the risk of cardiovascular disease (CVD) and death. Hence, diagnosing and treating patients with high BP is paramount if the number of cardiovascular related death should be reduced. High nocturnal BP and blunting of normal nocturnal BP decrease have stronger correlation to the risk of CVD than high day time BP. Lowering nocturnal BP is assumed to reduce the risk of CVD. Patients with treatment resistant hypertension (TRH) represent a subgroup of hypertensive patients characterized by lack of BP control despite antihypertensive treatment. These patients are at particular risk of CVD and target organ damage. Patients with TRH are more likely to experience BP increase as a response to sodium loading than other individuals. Lifestyle modification is an important treatment angle in hypertensive patients. It is, in particular, central to reduce sodium intake, as high sodium intake increases the risk of TRH. Thus, in this study we aimed to analyse if self-performed dietary sodium restriction could be implemented in patients with TRH. Moreover, we aimed to analyse the effect of this attempted restriction on nocturnal BP and 24 h BP, on plasma levels of BNP and nitric oxide, and on body water content. METHOD Patients with TRH from 20 to 70 years with normal renal function were invited for participation in this cross-over interventional study. Patients were screened with 24 h ambulatory BP monitoring initiated after observed intake of usual antihypertensive medication, and they were included if 24 h systolic BP/diastolic BP ≥ 130/80 mmHg. Study participation included two periods of 14 days; a standard period with usual diet and an interventional period with instructed dietary sodium restriction and handed-out sodium-reduced bread. For both periods, all antihypertensive medication was dosed and handed out and ingested in the morning. At the end of each period, patients were examined with 24 h BP monitoring, 24 h urine collection (sodium excretion), blood samples (nitric oxide and BNP) and bioimpedance measurement (body water content). RESULTS Baseline characteristics of the fifteen included patients are shown in Table 1. Eleven of the patients were male. Patients had been treated for hypertension for a mean of 12.5 (7) years and excreted a mean of 11.2 grams of salt at baseline [192 (86) mmol sodium]. All patients but one reduced sodium excretion at follow up. Table 2 shows the effect of sodium restriction on BP, nitric oxide, BNP and body water content. Sodium excretion was reduced to 91 mmol/24 h, which equals 5.3 g of salt. BP (24 h, day and nocturnal) decreased significantly as well as body water content and plasma levels of BNP. These changes were, however, not correlated. Plasma levels of nitric oxide increased, but it was not related to the changes in BP. Nocturnal fraction of 24 h sodium excretion increased after sodium restriction; however, this was not correlated to changes in nocturnal BP. Renal function and urinary potassium excretion both remained unchanged. Four patients experienced side effects; three reported newly onset dizziness at follow-up; two of them had 24 h BP reduction &amp;gt; 10 mmHg systolic. One patient had increased creatinine and potassium at follow-up. CONCLUSION In a population of 15 treatment resistant hypertensive patients, we demonstrated that self-performed dietary sodium restriction could be implemented. Urinary sodium excretion was reduced significantly to 5.3 g/24 h. Nocturnal BP was reduced significantly; dipping status was, however, unchanged. Increased plasma levels of nitric oxide may be evidence of improved endothelial function. Hence, by the local vasodilating effect, NO may be one of the involved mechanisms in BP decrease following a sodium restriction. Reduced extracellular water content and BNP may be other explainable effects of BP reduction after inducing sodium restriction.