Nocturnal Blood Pressure Dipping Research Articles

While You Are Sleeping: Marital Ambivalence and Blunted Nocturnal Blood Pressure.

Marital relationships offer health benefits, including a lower risk of cardiovascular disease (CVD). However, quality of the relationship matters; ambivalent behaviors may increase CVD risk by affecting blunted nocturnal blood pressure (BP) dipping. This study tracked daytime and nocturnal SBP and DBP in 180 normotensive individuals (90 couples; participant mean age 25.04; 91.58% white) over a 24 h period using ambulatory blood pressure monitors to explore the impact of martial quality. Results showed that perceptions of spousal ambivalence were associated with blunted nocturnal BP dipping. Perceptions of one's own behavior as ambivalent also showed blunted nocturnal dipping. When in an ambivalent relationship, a gender interaction was found such that women were most likely to have blunted SBP dipping, but men were more likely to have blunted nocturnal DBP dipping. Overall, this study found an association between ambivalence and BP dipping, thus uncovering one virtually unexplored pathway by which marital relationships may have adverse effects on health.

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.

Ambulatory Blood Pressure in Patients With Rheumatoid Arthritis: Association With Immune Activation.

The prevalence of hypertension, a major cardiovascular risk factor, is increased in patients with rheumatoid arthritis (RA) and may be driven by immune activation. The purpose of this study was to determine if ambulatory 24-hour blood pressure (BP) is elevated in RA vs control participants and whether it is associated with immune activation. We conducted a cross-sectional study of 46 patients with RA and 23 control participants. Participants wore an ambulatory BP monitor that obtained diurnal BP every 15-30 minutes and nocturnal BP every 30 minutes. Inflammatory mediators in plasma were measured using an inflammation proteomics panel. Differences in BP measurements were assessed by Mann-Whitney U test, and association with inflammatory mediators was assessed by Spearman correlation. Patients with RA and control participants had similar office BP, but median ambulatory systolic BP (SBP) measurements (24-hour [RA 121 mmHg vs control 116 mmHg; P = 0.01], diurnal [RA 128 mmHg vs control 120 mmHg; P = 0.003], and nocturnal [RA 112 mmHg vs control 103 mmHg; P = 0.002]) were higher in patients with RA. Patients with RA also had higher nocturnal diastolic BP (DBP; RA 63 mmHg vs control 57 mmHg; P = 0.02), but other DBP measurements were similar. Nocturnal BP dipping was less in patients with RA (12%) compared to control participants (16%; P = 0.02). In patients with RA, higher 24-hour and nocturnal SBPs and less nocturnal dipping were strongly correlated with a wide range of inflammatory mediators. Despite similar office measurements, 24-hour and nocturnal SBP measurements were higher in patients with RA than in control participants and were strongly associated with inflammation.

Habitual Sleep Duration and Sleep Effciency Do Not Mediate the Relationship Between Race and Nocturnal Blood Pressure Dipping in Young Black and White Women

Blunted nocturnal blood pressure (BP) dipping, defined as less than 10% reduction in BP during sleep as compared to wake, independently predicts cardiovascular disease. Short and disturbed sleep associate with less nocturnal BP dipping in young adults, and Black women (BLW) demonstrate less nocturnal BP dipping and poorer sleep health compared to White women (WHW) as early as young adulthood. However, not known is if habitual, objectively estimated sleep metrics mediate the relationship between race and BP dipping in young women. Thus, this study sought to evaluate the mediating effect of objectively estimated habitual sleep duration and sleep effciency on the relationship between race and nocturnal BP dipping in apparently healthy, young BLW and WHW. We hypothesized that BLW would have lower nocturnal systolic and diastolic BP dipping than WHW, but that the relationship between race and nocturnal BP dipping would be at least partly mediated by sleep duration and sleep effciency. Participants were 18-29 years, female, normotensive, nonobese, without evidence of clinical sleep disorders, and self-identified their race as Black or White. Systolic and diastolic BP dipping were each derived from 24-hour ambulatory BP monitoring by subtracting mean asleep BP from mean awake BP, divided by mean awake BP, *100. Sleep duration (total sleep time between sleep onset and offset) and sleep effciency (total sleep time divided by total time in bed dedicated to sleep, *100) were measured via wrist actigraphy for 14 consecutive nights, and means were generated. Race differences in BP dipping and habitual sleep metrics were assessed via independent-samples t-tests. The standard mediation model as proposed by Baron and Kenney (1986) was used to assess the mediating effect of habitual sleep duration and sleep effciency on the relationship between race and systolic and diastolic BP dipping. Participants included 20 BLW (22±3 years) and 17 WHW (25±3 years). Systolic BP dipping (BLW: 9.5±5.9%, WHW: 13.9±5.1%, p=0.02) and diastolic BP dipping (BLW: 16.3±7.3%, WHW: 21.9±5.5%, p=0.01) were lower among BLW. Sleep duration was not different between races (BLW: 6.7±0.5 hrs, WHW: 7.0±0.7 hrs, p=0.14), though sleep effciency was lower among BLW (BLW: 81.6±4.4%, WHW: 86.0±3.1%, p&lt;0.01). In contrast to our hypothesis, neither habitual sleep duration nor sleep effciency significantly mediated the relationship between race and BP dipping (all indirect effects p&gt;0.38). Habitual sleep metrics did not explain race differences in nocturnal BP dipping between young BLW and WHW; thus, future work should consider other physiological, social, or environmental determinants of BP dipping in young BLW. University of Delaware Research Foundation — Strategic Initiative Grant (MAW/FP) and AHA Award #831488 (EH). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Nocturnal blood pressure dipping, blood pressure variability, and cognitive function in early and middle-aged adults.

Higher nighttime blood pressure (BP), less BP dipping, and higher BP variability have been linked with worse cognitive function in the elderly. The goal of this study is to explore whether this relationship already exists in early and middle adulthood. We further examined whether ethnic differences between African Americans and European Americans in BP parameters can explain ethnic differences in cognitive function. 24-h ambulatory BP monitoring and cognitive function were obtained from 390 participants (average age: 37.2 years with a range of 25-50; 54.9% African Americans; 63.6% females). We observed that higher nighttime BP, decreased dipping, and higher variability were significantly associated with lower scores on the Picture Sequence Memory Test. Significant negative associations between variability and overall composite scores were also observed. No significant associations between average 24-h or daytime BP and cognitive function were observed. Ethnic differences in nighttime diastolic pressures and dipping can explain 6.81% to 10.8% of the ethnicity difference in the score of the Picture Sequence Memory Test (ps<.05). This study suggests that the associations of nighttime BP, dipping, and variability with cognitive function already exist in young and middle-aged adults. Ethnic differences in nighttime BP and dipping can at least partially explain ethnic differences in cognitive function. The stronger association of these parameters with cognitive function than daytime or average BP in this age range raises the importance of using ambulatory BP monitoring for more precise detection of abnormal BP patterns in young adulthood.

Nocturnal Systolic Blood Pressure Dipping and Progression of CKD

Nocturnal Systolic Blood Pressure Dipping and Progression of CKD

Etiology, risk factors and management of hypertension post liver transplantation.

Cardiovascular events are one of the most important causes of morbidity and mortality in the long-term follow-up of liver transplant recipients. Hypertension is a significant cardiovascular risk factor that occurs frequently after pediatric liver transplantation. Chronic use of immunosuppressants - mainly calcineurin inhibitors - plays a major role in the development of post-transplant hypertension and circadian disturbances such as flattening of the nocturnal blood pressure dip. This requires special attention in children given the long timeframe during which immunosuppressive therapy is necessary. Careful and structured blood pressure monitoring and adequate treatment of hypertension are essential to optimize the quality of life and life expectancy of pediatric liver transplant patients. However, evidence-based guidelines for monitoring and management of post-transplant hypertension and its complications are lacking. We conducted a comprehensive review of the current knowledge and practices concerning post-transplant hypertension. The databases Pubmed, Embase, Web of Science and Google Scholar were scanned with the following keywords: pediatric liver transplantation, immunosuppression, tacrolimus, cardiovascular effects, hypertension, heart function, kidney function, circadian rhythm, mechanism, monitoring, and management. In this review, we describe the incidence and etiology of hypertension in pediatric liver transplant recipients, the underlying mechanisms and characteristics of calcineurin inhibitor-induced hypertension, and the consequences of and risk factors for post-transplant hypertension. We hereby present an overview of the current practices in blood pressure monitoring and antihypertensive treatment as well as an algorithm for the evaluation and management of hypertension post liver transplantation. Finally, we discuss knowledge gaps and suggestions for future research.

Obstructive sleep apnea and non-dipper: epiphenomena or risks of Alzheimer's disease?: a review from the HOPE Asia Network.

Obstructive sleep apnea (OSA) and associated nocturnal blood pressure (BP) surges is associated with non-dipper. On the other hand, the relationship between neurodegenerative diseases and non-dipper hypertension has been reported. To date, few studies have evaluated the relationships of nocturnal BP dipping patterns and OSA in relation to neurodegenerative diseases, particularly Alzheimer's disease (AD). This review examines the etiology of the association between OSA and the non-dipper pattern of hypertension and how both are involved in the development of AD. To set the stage for this review, we first focus on the pathophysiology of AD, which is interrelated with sleep apnea and non-dipper through dysregulation of central autonomic network.

256 How prevalent are markers of blood pressure instability on Ambulatory Blood Pressure Monitoring of older people with falls, faints &amp; dizziness?

Abstract Background In older people with BP-related falls, the mechanisms that usually tightly control Blood Pressure (BP) may be less efficient, leading to BP instability. This may manifest as specific markers on Ambulatory Blood Pressure Monitoring (ABPM), including BP variability, BP dipping and absence of nocturnal dipping/reverse dipping. The aim of this study therefore is to ascertain the prevalence of APBM markers of BP Instability among older people with falls/faints/dizziness and examine if there is an age-gradient seen for these markers. Methods ABPM data (minimum 25 BP values measured across 24 hours) was collected for 83 consecutive patients aged ≥70 years attending a tertiary-referral Falls &amp; Syncope Unit with falls, fainting or dizziness. Data analysed included BP Variability (standard deviation (SD) of BP values, i.e. measurement of the oscillation of BP measurements); Nocturnal dipping (decrease in average night BP compared to average day BP) and BP dips (number of systolic BP values &amp;lt;100 mm Hg). Results: Of the analysed ABPMs(n = 83, mean age 78 years, 48% female), mean number of readings per device was 34.6 (33.7–35.5). The average SD for overall systolic BP was 15.9. Over 15% of patients had an average SD ≥20 for systolic BP based on the full ABPM, reflecting high levels of BP variability. There was a significant age gradient seen for nocturnal dipping with mean change −0.30 (−9.3–8.8) in those aged ≥85 years compared to +10.9(7.3–14.6) in the 70–74 years age group. The mean number of systolic BP values&amp;lt;100 mm Hg was 2.9 (1.7–4.0). Conclusion Older patients attending with falls/faints/dizziness demonstrate significant BP variability, aberrant nocturnal dipping profiles and frequent systolic BP values dipping below 100 mm Hg. Further work is required to establish if these ABPM aberrancies are reliable predictors of future falls and potentially modifiable targets to reduce falls burden among older people.

Ambulatory blood pressure monitoring in pheochromocytoma - paraganglioma: A single center experience.

Pheochromocytoma and paraganglioma (PPGL) are rare tumors, and data on ambulatory blood pressure monitoring (ABPM) in these patients and the effect of blocking on ABPM parameters is limited. We aimed to describe ABPM parameters in a cohort of PPGL at our center in western India. Retrospective study of patients with PPGL whose ABPM data was available. Demographic details, secretory status, and ABPM data were retrieved. Coefficient of variability (CV) was calculated as standard deviation/mean in percentage. In the 39 included patients, mean age at presentation was 39.3 ± 14.2 yr; 20 (51.3%) were males, 25 (64.1%) hypertensive, and mean tumor diameter was 5.3 cm. In 18 patients whose baseline ABPM was done without medications, those with nocturnal blood pressure dipping (6/18, 33%) had higher serum metanephrines (median 313.2 vs. 34.7 pg/ml, P = 0.028). Despite normal office blood pressure (BP), 8.9% of systolic BP readings were >140 mmHg, and 1.2% were >160 mmHg. Among 29 patients with both pre and post-block ABPM, mean BP (systolic 121.6 vs. 132.5 mmHg, P = 0.014; diastolic 68.9 vs. 76.4 mmHg, P = 0.005) and percentage of BP readings above 140 mmHg (median 9.4% vs. 24.4%, P = 0.016) were significantly lowered after the preoperative blockade in hypertensive ( n = 19) patients, whereas CV was similar. The post-blockade ABPM characteristics were similar in patients blocked with amlodipine or prazosin. ABPM provides additional information about BP characteristics in PPGL. The preoperative blocking decreases the magnitude of BP excursions but does not affect BP variability.

Nocturnal systolic blood pressure dipping and progression of chronic kidney disease.

The relationship between declining nocturnal blood pressure (BP) and adverse cardiovascular outcomes is well-recognized. However, the relationship between diurnal BP profile and the risk of chronic kidney disease (CKD) progression is unclear. Herein, we examined the association between nocturnal systolic SBP (SBP) dipping and CKD progression in 1061 participants at the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI). The main exposure was diurnal systolic BP (SBP) profile and diurnal SBP difference ([nighttime SBP-daytime SBP] × 100/daytime SBP). The primary outcome was CKD progression, defined as a composite of ≥ a 50% decline in the estimated glomerular filtration rate from baseline or the initiation of kidney replacement therapy. During 4749 person-years of follow-up (median, 4.8 years), the composite outcome occurred in 380 (35.8%) participants. Compared to dippers, the hazard ratios (HRs) for the risk of adverse kidney outcomes were 1.02 (95% confidence interval [CI], 0.64-1.62), 1.30 (95% CI, 1.02-1.66), and 1.40 (95% CI, 1.03-1.90) for extreme dipper, non-dipper, and reverse dipper, respectively. In a continuous modeling, a 10% increase in diurnal SBP difference was associated with a 1.21-fold (95% CI, 1.07-1.37) higher risk of CKD progression. Thus, decreased nocturnal SBP decline was associated with adverse kidney outcomes in patients with CKD. Particularly, patients with non-dipping and reverse dipping patterns were at higher risk for CKD progression than those with a dipping pattern.

Effects of a high salt diet on blood pressure dipping and the implications on hypertension.

High blood pressure, also known as hypertension, is a major risk factor for cardiovascular disease. Salt intake has been shown to have a significant impact on BP, but the mechanisms by which it influences the blood pressure dipping pattern, and 24-h blood pressure remains controversial. This literature review aims to both summarize the current evidence on high salt diet induced hypertension and discuss the epidemiological aspects including socioeconomic issues in the United States and abroad. Our review indicates that a high salt diet is associated with a blunted nocturnal blood pressure dipping pattern, which is characterized by a reduced decrease in blood pressure during the nighttime hours. The mechanisms by which high salt intake affects blood pressure dipping patterns are not fully understood, but it is suggested that it may be related to changes in the sympathetic nervous system. Further, we looked at the association between major blood pressure and circadian rhythm regulatory centers in the brain, including the paraventricular nucleus (PVN), suprachiasmatic nucleus (SCN) and nucleus tractus solitarius (nTS). We also discuss the underlying social and economic issues in the United States and around the world. In conclusion, the evidence suggests that a high salt diet is associated with a blunted, non-dipping, or reverse dipping blood pressure pattern, which has been shown to increase the risk of cardiovascular disease. Further research is needed to better understand the underlying mechanisms by which high salt intake influences changes within the central nervous system.

High plasma aldosterone concentration is associated with worse 24-h ambulatory blood pressure profile in patients with primary aldosteronism.

Patients with primary aldosteronism (PA) have a higher risk of cardiovascular disease (CVD) than essential hypertension due to underlying hyperaldosteronism. However, the association between high plasma aldosterone concentrations (PACs) and diurnal blood pressure (BP) variation has not been fully elucidated. Because abnormal ambulatory blood pressure monitoring (ABPM) profiles are associated with increased CVD risk, we investigated the association between PACs and the ABPM profile in 36 patients with PA diagnosed by confirmatory tests who underwent adrenal venous sampling (AVS). The clinical parameters were measured during hospitalization for AVS. The dietary salt intake of hospitalized patients was controlled at 6 g/day. During AVS, blood samples were collected from the inferior vena cava before and 1 h after adrenocorticotropic hormone (ACTH) stimulation to measure the PACs. The post-stimulation PAC had a significant negative correlation with nocturnal BP dipping rates (R = -0.387, p = 0.020), whereas pre-stimulation PAC did not (R = -0.217, p = 0.204). The nocturnal BP dipping rates were significantly lower in the high PAC group (PAC higher than the median) than low PAC group (PAC lower than the median) (p = 0.009). Multiple regression analysis revealed that high PAC was an independent factor contributing to low nocturnal BP dipping rates (β = -0.316, p = 0.038). In conclusion, in patients with PA, hyperaldosteronism is associated with nocturnal hypertension, which is an important risk factor for CVD. Additionally, ACTH stimulation may improve the sensitivity of PACs as a clinical indicator of nocturnal hypertension.

0290 Ambulatory blood pressure monitoring does not reduce the sleep of off-duty firefighters

Abstract Introduction Ambulatory blood pressure monitoring (ABPM) across 24 hours is recommended to confirm hypertension and, outside of a laboratory setting, is the only means to measure the extent of any nocturnal decrease in blood pressure (BP) i.e., nocturnal BP dipping. The ambulatory device is traditionally programmed to inflate every 20-30 minutes during awake and sleep. Despite diagnostic benefits, ABPM may disturb sleep and lead to reduced compliance in some individuals. Firefighters, an occupational group with a greater risk of developing cardiovascular disease, often note continued vigilance during sleep, possibly reflecting light sleep and/or frequent awakenings. This potential sleep disturbance may contribute to firefighters’ cardiovascular disease risk and may also impact ABPM data. Methods To assess the effect of ABPM on total sleep time (TST) and wake after sleep onset (WASO) in firefighters, we measured sleep using wrist actigraphy in 120 firefighters (91.3% male) from two different departments in Oregon. As part of a larger longitudinal study, participants’ sleep off-shift (as noted from daily survey) was recorded for up to 14 days at two different time points, two months apart. During two consecutive days off, participants completed 24-48 hours of ABPM with simultaneous actigraphy. Overall, there were 1273 measures of sleep, 206 with the cuff and 1067 without the cuff. Separate mixed models with cuff (on/off) as a fixed effect and participant as a random effect, were run for TST and WASO. Models were adjusted for total time in bed, department, and collection interval. Results Surprisingly, TST with the cuff on was significantly greater than nights without the cuff (marginal mean ± SE: 432.0±3.1 vs. 415.9±1.7 minutes respectively, p&amp;lt; 0.001). Increased TST was attributable to a lower WASO with the cuff than without the cuff (43.8±2.9 vs 59.8±1.7 minutes, respectively, p&amp;lt; 0.001). Conclusion Contrary to our expectations, ABPM was not associated with actigraphy measured disturbed sleep among firefighters. In fact, in these data, sleep appeared to be improved while wearing the cuff. Perhaps concerns around poor sleep when wearing the device may have led to improved sleep behaviors on those nights, but this hypothesis needs further investigation. Support (if any) U19OH010154, K01HL151745

0821 Nighttime Average and Dipping Blood Pressure Can Differ Based on the Temporal Distribution of Ambulatory Measurements at Nighttime

Abstract Introduction Ambulatory blood pressure (BP) monitoring is recommended in preference to office BP as it enables BP assessments across the night and quantification of the degree of nocturnal BP dipping (dipping” = nighttime/daytime BP of &amp;lt; 0.9; non-dipping = ≥0.9). Both nighttime BP and dipping% are independent predictors of adverse cardiovascular events. Standard guidelines recommend at least ≥20/7 daytime/nighttime measurements for reliable ambulatory BP monitoring, but newer reports suggest ≥8/4 daytime/nighttime measurements are sufficient. Considering BP oscillates across the night, the temporal distribution of measurements across the night may impact nighttime BP and dipping%. To test whether this new recommendation holds for extreme examples of temporal distribution, we compared average nighttime BP and dipping% when using BP measurements only in the first (1st-half) vs. only in the second half (2nd-half) of the night. Methods Seventeen females and twenty-six males (50±10 years [mean±SD]) without cardiovascular disease or severe sleep disorders wore an ambulatory BP monitor for 24 hours, programmed to measure BP every 20 minutes when awake and every 30 minutes during a self-selected 8-hour time-in-bed for nighttime. We compared the nighttime BP averages and the calculated dipping% when using the first four measurements from the 1st-half of the nighttime, from the 2nd-half of the nighttime, and all measurements during the nighttime (All nighttime, AN). Repeated measures ANOVA was conducted with significance set as p&amp;lt; 0.05. Results Systolic BP was higher using 1st-half than 2nd-half but similar to AN (111±9 vs.107±11 vs. 109±9 mmHg, p&amp;lt; 0.01), while systolic BP dipping% using 1st-half was lower than 2nd-half and AN (9.7±7.4 vs.13.0±7.6 vs. 11.4±6.7 %, p&amp;lt; 0.01, respectively). Diastolic BP and diastolic dipping% were similar among the 1st-half, 2nd-half, and AN segment (63±6 vs. 63±7 vs. 62±7 mmHg, p=0.19) and (17.2±7.6 vs. 17.2±8.8 vs. 18.4±8.8 %, p=0.16), respectively. Conclusion In adults without cardiovascular disease or severe sleep disorders, nighttime BP and dipping% may depend upon when BP measurements are taken. The minimum threshold of 4 measurements for a reliable nighttime BP readout should be used cautiously. Support (if any) NIH F32-HL131308, R01HL163232, R01HL125893, R35HL155681, Medical Research Foundation, and OHSU OFDIR fellowship.

Higher levels of vigorous physical activity are associated with enhanced nocturnal blood pressure dipping

Introduction: Nocturnal blood pressure (BP) dipping determined from 24-hour ambulatory blood pressure monitoring (ABPM) is associated with reduced cardiovascular disease (CVD) risk. Physical activity lowers the risk of CVD related, in part, to preserved endothelial function and lower aortic stiffness, however the relation between physical activity and nocturnal dipping remains unclear. The objective of our cross-sectional retrospective analysis was to assess the relation between physical activity and nocturnal BP dipping, and whether this relation was confounded by measures of vascular function. We hypothesized that higher levels of physical activity would be associated with greater nocturnal BP dipping. Methods: Healthy adults (n=172, age 19 to 65 years, 55% female) had 24-hour ABPM measured. BP recordings were taken every 30 min during the daytime and every 60 min during the nighttime. Nocturnal “dippers” had a 10-20% difference between their mean daytime and nighttime systolic BP and “non-dippers/inverse dippers” had &lt;10% difference. The modifiable activity questionnaire was used to assess physical activity levels via self-reported days/week with greater than 30 min of moderate activity (3.0-6.0 METs) and vigorous activity (&gt;6.0 METs). Endothelial function (brachial artery flow-mediated dilation, FMD), and aortic stiffness (carotid-femoral pulse wave velocity, cfPWV) were also assessed. Results: Nocturnal BP dippers performed more days/week of moderate and vigorous physical activity compared to non-dippers (P=0.007 and P=0.008, respectively). Both moderate (B=0.386, P=0.042) and vigorous physical activity (B=0.604, P=0.002) were associated with nocturnal BP dipping in univariate linear regression analyses. However, only vigorous activity (B=0.926, P=0.001) remained associated with nocturnal BP dipping after adjustment for age, BMI, 24-hr systolic BP and diastolic BP, brachial FMD and cfPWV. Conclusion: Vigorous physical activity may attenuate CVD risk in part from enhanced nocturnal BP dipping. Future studies should investigate additional mechanisms by which vigorous physical activity may enhance nocturnal BP dipping. This study was supported by grants from the National Institutes of Health (AG063790; HL014388, HL07121; AG043722). Dr. Pierce is supported by the Russell B. Day and Florence D. Day Endowed Chair in Liberal Arts and Sciences, University of Iowa. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Decentering and baroreflex sensitivity in adults with elevated blood pressure

Previous studies have linked the ability to decenter, a non-judgmental view of emotions, with lower arterial stiffness and better nocturnal blood pressure dipping in adults. It is unknown however if autonomic regulation of blood pressure is linked to decentering. Therefore, the purpose of this study was to determine if decentering ability is related to cardiovagal or sympathetic baroreflex sensitivity. Thirty-three adults (age 25±6 years; BMI 25±3 kg/m2) with resting blood pressure ≥120/80 mmHg volunteered for this study. All participants had a BMI &lt;30 kg/m2, and had no history of smoking, diabetes, or prescriptions for blood pressure or cardiac function. Participants completed an 11-item experiences questionnaire to evaluate decentering, and then were equipped for a supine autonomic evaluation. The autonomic evaluation included continuous recording of heart rate via 3-lead ECG, muscle sympathetic nerve activity (MSNA) via microneurography, and beat-to-beat blood pressure via finger photoplethysmography. Cardiovagal baroreflex sensitivity (n=33) included estimation of vagal activation by evaluating up-up relationships between systolic arterial pressure (SAP) and R-R intervals of the ECG. Vagal withdrawal was also estimated via the down-down relationships between SAP and R-R intervals. Spontaneous sympathetic baroreflex sensitivity (n=26) was evaluated by evaluating the relationship between changes in diastolic arterial pressure (DAP) in 3 mmHg bins vs. changes in MSNA burst incidence (i.e., bursts / 100 heart beats). Results from 2-tailed Pearson correlation analyses revealed that there was not a relationship between decentering and vagal activation (r=-0.07; p=0.71) or between decentering and vagal withdrawal (r=-0.28; p=0.12). Likewise, there was no relationship between decentering and sympathetic baroreflex sensitivity (r=0.10; p=0.64). Our findings suggest that there is not a clear link between decentering and autonomic regulation of blood pressure as estimated through both cardiovagal and baroreflex sensitivity. NIH (1R15HL140596-01); Nils K. Nelson Endowment Fund This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Influence of Hydration Status and Plasma Copeptin on Ambulatory Blood Pressure in Healthy Young Adults

BACKGROUND: Adequate hydration is essential for regulating various physiological systems and may influence blood pressure (BP). Hypohydration is linked with elevated copeptin (surrogate of arginine vasopressin), which is associated with elevated cardiovascular disease risk. However, there is limited information on the influence of hydration and copeptin on ambulatory BP measures in young adults. Therefore, we sought to investigate associations between hydration, copeptin, and ambulatory BP. METHODS: We studied 41 participants (19 M/22 F, 24 White/17 Black, age 21±1 years, body mass index 26±5 kg/m 2 , screening BP 111± 10/67±8 mmHg; Mean ± SD) who provided a 24-hour urine sample. We measured urine specific gravity (USG), urine osmolality (OSM), and plasma copeptin as biomarkers of hydration. We used ambulatory BP monitoring (Suntech Oscar2) to assess BP during daytime (1000-2000) and nighttime (0000-0600). Our primary outcomes were plasma copeptin (pmol/L) and night-to-day BP dip ratio (nighttime/daytime BP) in dehydrated (USG &gt;1.020 or OSM &gt;800 mOsm/kg) vs euhydrated participants. Statistical procedures included Student’s t-tests and Mann-Whitney U tests. We also used Spearman’s rho correlation (controlling for BMI, sex, and race). We set α at ≤0.05. RESULTS: Copeptin concentration was elevated in dehydrated compared with euhydrated participants (USG: 6.6±2.9 vs 4.3±2.0 pmol/L, p&lt;0.005; OSM: 6.6±2.7 vs 4.1±2.0 pmol/L, p&lt;0.001). After controlling for BMI, sex, and race, copeptin was associated with USG (rho=0.44, p=0.005) and OSM (rho=0.51, p=0.001). Systolic and diastolic BP dip ratios did not differ by hydration status for either USG or OSM ( ps&gt;0.179). Additionally, adjusted BP dip ratios were not correlated with OSM or USG ( ps&gt;0.149). Plasma copeptin was not associated with BP dip ratios ( ps&gt;0.155) but was associated with absolute nocturnal systolic (rho=-0.34, p=0.036) and diastolic BP dip (rho=-0.33, p=0.041). When we split participants by low and high copeptin concentration (median split), higher copeptin was associated with a lower (i.e., worse) systolic BP dip ratio (0.87±0.06 vs 0.90±0.06, p=0.048) and lower absolute nocturnal systolic and diastolic BP dip ( ps&lt;0.01). CONCLUSIONS: Hydration biomarkers were correlated with plasma copeptin, but not ambulatory BP. The significance of our findings are that higher copeptin was associated with blunted nocturnal BP dipping in younger adults, which could predispose them to increased future cardiovascular disease risk. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Office blood pressure versus ambulatory blood pressure measurement in childhood obesity

BackgroundThe prevalence of obesity-related co-morbidities is rising parallel to the childhood obesity epidemic. High blood pressure (BP), as one of these co-morbidities, is detected nowadays at increasingly younger ages. The diagnosis of elevated BP and hypertension, especially in the childhood population, presents a challenge to clinicians. The added value of ambulatory blood pressure measurement (ABPM) in relation to office blood pressure (OBP) measurements in obese children is unclear. Furthermore, it is unknown how many overweight and obese children have an abnormal ABPM pattern. In this study we evaluated ABPM patterns in a population of overweight and obese children and adolescents, and compared these patterns with regular OBP measurements.MethodsIn this cross-sectional study in overweight or obese children and adolescents aged 4–17 years who were referred to secondary pediatric obesity care in a large general hospital in The Netherlands, OBP was measured during a regular outpatient clinic visit. Additionally, all participants underwent a 24-hour ABPM on a regular week-day. Outcome measures were OBP, mean ambulatory SBP and DBP, BP load (percentage of readings above the ambulatory 95th blood pressure percentiles), ambulatory BP pattern (normal BP, white-coat hypertension, elevated BP, masked hypertension, ambulatory hypertension), and BP dipping.ResultsWe included 82 children aged 4–17 years. They had a mean BMI Z-score of 3.3 (standard deviation 0.6). Using ABPM, 54.9% of the children were normotensive (95% confidence interval 44.1–65.2), 26.8% had elevated BP, 9.8% ambulatory hypertension, 3.7% masked hypertension, and 4.9% white-coat hypertension. An isolated night-time BP load > 25% was detected in almost a quarter of the children. 40% of the participants lacked physiologic nocturnal systolic BP dipping. In the group of children with normal OBP, 22.2% turned out to have either elevated BP or masked hypertension on ABPM.ConclusionsIn this study a high prevalence of abnormal ABPM patterns in overweight or obese children and adolescents was detected. Additionally, OBP poorly correlated with the child’s actual ABPM pattern. Herewith, we emphasized the usefulness of ABPM as an important diagnostic tool in this population.

The circadian clock remains intact, but with dampened hormonal output in heart failure

Circadian (24-h) rhythms are important regulators in physiology and disease, but systemic disease may disrupt circadian rhythmicity. Heart failure (HF) is a systemic disease affecting hormonal regulation. We investigate whether HF affects the rhythmic expression of melatonin and cortisol, main endocrine products of the central clock, and cardiac-specific troponin in patients. We corroborate the functionality of the peripheral clock directly in the organs of translational models, inaccessible in human participants. We included 46 HF patients (71.7% male, median age of 60 years, NYHA class II (32.6%) or III (67.4%), ischemic cardiomyopathy (43.5%), comorbidities: diabetes 21.7%, atrial fibrillation 30.4%), and 24 matched controls. Blood was collected at seven time-points during a 24-h period (totalling 320 HF and 167 control samples) for melatonin, cortisol, and cardiac troponin T (cTnT) measurements after which circadian rhythms were assessed through cosinor analyses, both on the individual and the group level. Next, we analysed peripheral circadian clock functionality using cosinor analysis in male animal HF models: nocturnal mice and diurnal zebrafish, based on expression of core clock genes in heart, kidneys, and liver, every 4h during a 24-h period in a light/darkness synchronised environment. Melatonin and cortisol concentrations followed a physiological 24-h pattern in both patients and controls. For melatonin, acrophase occurred during the night for both groups, with significantly decreased amplitude (median 5.2 vs 8.8, P=0.0001) and circadian variation ([maximum]/[minimum]) in heart failure patients. For cortisol, mesor showed a significant increase for HF patients (mean 331.9 vs 275.1, P=0.017) with a difference of 56.8 (95% CI 10.3-103.3) again resulting in a relatively lower variation: median 3.9 vs 6.3 (P=0.0058). A nocturnal blood pressure dip was absent in 77.8% of HF patients. Clock gene expression profiles (Bmal, Clock, Per, Cry) were similar and with expected phase relations in animal HF models and controls, demonstrating preserved peripheral clock functionality in HF. Furthermore, oscillations in diurnal zebrafish were expectedly in opposite phases to those of nocturnal mice. Concordantly, cTnT concentrations in HF patients revealed significant circadian oscillations. Central clock output is dampened in HF patients while the molecular peripheral clock, as confirmed in animal models, remains intact. This emphasises the importance of taking timing into account in research and therapy for HF, setting the stage for another dimension of diagnostic, prognostic and therapeutic approaches. Hartstichting.