Sex differences in ambulatory blood pressure monitoring

Stressing out! Effects of acute stress on prepulse inhibition and working memory

Prepulse inhibition (PPI) of the startle reflex serves as a pre-cognitive marker of sensorimotor gating, and its deficit may predict cognitive impairments. Startle reflex is modulated by many factors. Among them, stress has been a topic of interest, but its effects on both pre-cognitive and cognitive variables continue to yield divergent results. This study aims to analyze the effect of acute stress on PPI of the startle reflex and cognitive function (working memory, attention, inhibition, and verbal fluency). Participants were exposed to the MAST stress induction protocol or a stress-neutral task: stress group (n = 54) or control group (n = 54). Following stress induction, participants' startle responses were recorded, and cognition was assessed. The results revealed that participants in the stress group exhibited greater startle magnitude, lower PPI, and lower scores in working memory tests compared with the control group. Additionally, a correlation was found between working memory and PPI across all the participants, independent of stress group. These findings support the notion that after stress, both greater startle magnitude and diminished PPI could play an adaptive role by allowing for increased processing of stimuli potentially dangerous and stress-related. Similarly, our results lend support to the hypothesis that lower PPI may be predictive of cognitive impairment. Considering the impact of stress on both pre-cognitive (PPI) and cognitive (working memory) variables, we discuss the possibility that the effect of stress on PPI occurs through motivational priming and emphasize the relevance of considering stress in both basic and translational science.

Effect of Liuzijue exercise in different periods on circadian rhythm of blood pressure in patients with essential hypertension: A randomized trial

BACKGROUND

Exercising at different times of the day is a widely employed strategy for treating essential hypertension, aimed at enhancing the circadian rhythm of blood pressure. This study aimed to investigate the effects of Liuzijue exercise in the morning and afternoon on the circadian rhythm of blood pressure in patients with essential hypertension.

METHODS

This clinical randomized trial recruited 36 patients. They were randomly divided into 3 groups: morning exercise, afternoon exercise, and waiting treatment group. Randomization was performed at a ratio of 1:1:1, ensuring an equal distribution of participants among the 3 groups. Based on maintaining routine work and rest and continuing the original drug treatment, the exercise performed Liuzijue exercise for 12 weeks. The exercise time was 9:00 to 10:00 in the morning exercise group and 14:00 to 15:00 in the afternoon exercise group. The waiting treatment group did not perform any form of fitness exercise. The subjects in the 3 groups were monitored by 24-hour ambulatory blood pressure on the day before and after the first day.

RESULTS

After the 12-week Liuzijue exercise intervention, mean systolic blood pressure during the night significantly decreased in the morning exercise group (P < .01). In contrast, the waiting group experienced substantial increases in 24-hour mean systolic blood pressure (24hSBP), 24-hour mean diastolic blood pressure (24hDBP), mean systolic blood pressure during the daytime (dSBP), and mean diastolic blood pressure during the daytime (dDBP) (P < .01). Further analysis showed that the morning exercise group had significantly lower 24hSBP, 24hDBP, dSBP, dDBP, and mean systolic blood pressure during the night than the waiting group (P < .05). Additionally, the morning exercise group had lower 24hSBP and dSBP levels than the afternoon exercise group (P < .05). In contrast, the afternoon exercise group had lower 24hDBP and dDBP than the waiting treatment group (P < .05).

CONCLUSIONS

The 12-week Liuzijue exercise in the morning regimen demonstrated superior efficacy in reducing 24-hour ambulatory blood pressure levels among patients with essential hypertension. Moreover, it facilitates the transition of non-dipper blood pressure patterns to dippers, thereby rectifying aberrant circadian rhythms.

Sex Differences in Ambulatory Blood Pressure Levels and Subtypes in a Large Italian Community Cohort

BACKGROUND

Sex differences in blood pressure control are recognized. We systematically investigated sex differences in specific components of ambulatory blood pressure (ABP), including variability, day-night changes, morning surge, and hypertension types.

METHODS

We analyzed ABPs of 52 911 participants (45.6% male, 54.4% female, 37.0% treated for hypertension) visiting 860 Italian community pharmacies. Sex differences in ABP levels and patterns were evaluated in the whole group and 4 risk groups (antihypertensive-treated patients, patients with diabetes, dyslipidemia, or cardiovascular disease).

RESULTS

Average 24-hour, day-time, and night-time blood pressure values were consistently higher in males than females (P<0.001). Variability in ABP was higher in females, except during the night. Nondippers and an abnormal morning surge were more common among males (odds ratio and 95% CI, 1.282 [1.230-1.335] and 1.244 [1.159-1.335]; P<0.001). The prevalence of 24-hour and masked hypertension was higher in males (odds ratio and 95% CI, 2.093 [2.019-2.170] and 1.347 [1.283-1.415]; P<0.001) and that of white-coat hypertension in females (0.719 [0.684-0.755]; P<0.001). Ambulatory heart rate mean values were higher (P<0.001) in females. Day-time HR variability was higher and night-time heart rate variability lower in females (P<0.001). Sex differences in ABP levels and patterns detected in the whole population were replicated in all risk groups, except for the prevalence of abnormal morning surge (between sexes difference in antihypertensive-treated participants only).

CONCLUSIONS

Females show better ABP control than males, but with an increased blood pressure variability and a greater prevalence of white-coat hypertension. These findings support tailored management of hypertension.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03781401.

Sex Differences in Circadian Rhythms

Sex as a biological variable is the focus of much literature and has been emphasized by the National Institutes of Health, in part, to remedy a long history of male-dominated studies in preclinical and clinical research. We propose that time-of-day is also a crucial biological variable in biomedical research. In common with sex differences, time-of-day should be considered in analyses and reported to improve reproducibility of studies and to provide the appropriate context to the conclusions. Endogenous circadian rhythms are present in virtually all living organisms, including bacteria, plants, invertebrates, and vertebrates. Virtually all physiological and behavioral processes display daily fluctuations in optimal performance that are driven by these endogenous circadian clocks; importantly, many of those circadian rhythms also show sex differences. In this review, we describe some of the documented sex differences in circadian rhythms.

Sex difference in ambulatory blood pressure control associates with risk of ESKD and death in CKD patients receiving stable nephrology care

BACKGROUND

It is unknown whether faster progression of chronic kidney disease (CKD) in men than in women relates to differences in ambulatory blood pressure (ABP) levels.

METHODS

We prospectively evaluated 906 hypertensive CKD patients (553 men) regularly followed in renal clinics to compare men versus women in terms of ABP control [daytime <135/85 and nighttime blood pressure (BP) <120/70 mmHg] and risk of all-cause mortality and end-stage kidney disease (ESKD).

RESULTS

Age, estimated glomerular filtration rate and use of renin-angiotensin system inhibitors were similar in men and women, while proteinuria was lower in women [0.30 g/24 h interquartile range (IQR) 0.10-1.00 versus 0.42 g/24 h, IQR 0.10-1.28, P = 0.025]. No sex-difference was detected in office BP levels; conversely, daytime and nighttime BP were higher in men (134 ± 17/78 ± 11 and 127 ± 19/70 ± 11 mmHg) than in women (131 ± 16/75 ± 11, P = 0.005/P < 0.001 and 123 ± 20/67 ± 12, P = 0.006/P < 0.001), with ABP goal achieved more frequently in women (39.1% versus 25.1%, P < 0.001). During a median follow-up of 10.7 years, 275 patients reached ESKD (60.7% men) and 245 died (62.4% men). Risks of ESKD and mortality (hazard ratio and 95% confidence interval), adjusted for demographic and clinical variables, were higher in men (1.34, 1.02-1.76 and 1.36, 1.02-1.83, respectively). Adjustment for office BP at goal did not modify this association. In contrast, adjustment for ABP at goal attenuated the increased risk in men for ESKD (1.29, 0.98-1.70) and death (1.31, 0.98-1.77). In the fully adjusted model, ABP at goal was associated with reduced risk of ESKD (0.49, 0.34-0.70) and death (0.59, 0.43-0.80). No interaction between sex and ABP at goal on the risk of ESKD and death was found, suggesting that ABP-driven risks are consistent in males and females.

CONCLUSIONS

Our study highlights that higher ABP significantly contributes to higher risks of ESKD and mortality in men.

Prevalence and Predictors of White Coat Hypertension among Newly-Diagnosed Hypertensive Patients in a Tertiary Health Centre in Nigeria

Background

Failure to diagnose and adequately classify newly-diagnosed hypertensive patients may lead to non-recognition of White Coat Hypertension (WCH) and inappropriate use of antihypertensive medications. This study determined the prevalence and predictors of white coat hypertension among newly-diagnosed hypertensive patients in a tertiary health centre in Nigeria.

Methods

One hundred and twenty newly-diagnosed hypertensive patients and 120 controls were recruited for the study. All the participants had 24-hour Ambulatory Blood Pressure Monitoring (ABPM) using an oscillometric device (CONTEC®). Data were analyzed using SPSS version 20.0.

Results

Out of 120 patients, 52 were males and the mean age was 44.2 ± 9.7 years whereas of the 120 controls, 53 were males and the mean age was 44.0 ± 7.5 years. The mean body mass index of the patients, BMI (27.0 ± 4.5kg/m²) was higher than control (24.1 ± 4.5kg/m²), p-value <0.001. The prevalence of WCH was 36.7%. The mean age and BMI of those with WCH were 43.3 ± 11.4 years and 26.4 ± 4.5kg/m2 respectively. Females constituted a greater proportion (70.5%). In multivariate analysis, high level of education and being overweight or obese were significant determinants of WCH.

Conclusion

High prevalence of WCH existed among participants studied. High level of education and being obese were predictors of white coat hypertension. Hence, ambulatory blood pressure monitoring should be included as part of routine work-up for newly-diagnosed hypertensive patients in order to limit the number of those who may be committed to lifelong antihypertensive medications with its unwanted side effects.

Ambulatory Blood Pressure Monitoring (ABPM) as the reference standard for diagnosis of hypertension and assessment of vascular risk in adults

New information has become available since the ISC, AAMCC, and SECAC released their first extensive guidedelines to improve the diagnosis and treatment of adult arterial hypertension. A critical assessment of evidence and a comparison of what international guidelines now propose are the basis for the following statements, which update the recommendations first issued in 2013. Office blood pressure (BP) measurements should no longer be considered to be the "gold standard" for the diagnosis of hypertension and assessment of cardiovascular risk. Relying on office BP, even when supplemented with at-home wake-time self-measurements, to identify high-risk individuals, disregarding circadian BP patterning and asleep BP level, leads to potential misclassification of 50% of all evaluated persons. Accordingly, ambulatory BP monitoring is the recommended reference standard for the diagnosis of true hypertension and accurate assessment of cardiovascular risk in all adults ≥18 yrs of age, regardless of whether office BP is normal or elevated. Asleep systolic BP mean is the most significant independent predictor of cardiovascular events. The sleep-time relative SBP decline adds prognostic value to the statistical model that already includes the asleep systolic BP mean and corrected for relevant confounding variables. Accordingly, the asleep systolic BP mean is the recommended protocol to diagnose hypertension, assess cardiovascular risk, and predict cardiovascular event-free interval. In men, and in the absence of compelling clinical conditions, reference thresholds for diagnosing hypertension are 120/70 mmHg for the asleep systolic/diastolic BP means derived from ambulatory BP monitoring. However, in women, in the absence of complicating co-morbidities, the same thresholds are lower by 10/5 mmHg, i.e., 110/65 mmHg for the asleep means. In high-risk patients, including those diagnosed with diabetes or chronic kidney disease, and/or those having experienced past cardiovascular events, the thresholds are even lower by 15/10 mmHg, i.e., 105/60 mmHg. Bedtime treatment with the full daily dose of ≥1 hypertension medications is recommended as a cost-effective means to improve the management of hypertension and reduce hypertension-associated risk. Bedtime treatment entailing the full daily dose of ≥1 conventional hypertension medications must be the therapeutic regimen of choice for the elderly and those with diabetes, resistant and secondary hypertension, chronic kidney disease, obstructive sleep apnea, and medical history of past cardiovascular events, among others, given their documented high prevalence of sleep-time hypertension.

Sex differences in salt-sensitivity risk approximated from ambulatory blood pressure monitoring and mortality

BACKGROUND

Salt-sensitivity is difficult to assess with salt diet.

METHODS

: Salt-sensitivity risk was estimated from ambulatory blood pressure monitoring indices, patient data, and 20-year all-cause mortality. Tracings of 2064 untreated patients from our clinical monitoring service were evaluated for the prevalence and associations of salt-sensitivity risk, which was considered low in patients with both mean arterial pressure dipping more than 10% and 24-h heart rate less than 70  bpm; high in patients with dipping 10% or less and 24-h heart rate at least 70  bpm; and intermediate in patients with the other combinations.

RESULTS

Low, intermediate, and high salt-sensitivity categories were predicted for 33% (366/1099), 57% (624/1099), and 10% (109/1099) of men and 18% (177/965), 67% (630/965), and 16% (158/965) of women, respectively (χ(2) < 0.0001). Positive linear trends were noted between salt-sensitivity and BMI, clinic and 24-h ambulatory blood pressure, awake and sleep ambulatory heart rate and awake and sleep blood pressure variability, and negative trend with heart rate dipping (all P < 0.005). Kaplan-Meier analyses revealed increased mortality in association with salt-sensitivity in men but not in women (P < 0.02). With low and intermediate salt-sensitivity as reference, adjusted Cox proportional hazard ratios for all-cause mortality associated with high sensitivity were 1.96 (95% confidence interval 1.07-3.62) in men and 1.02 (0.51-2.07) in women.

CONCLUSION

To the extent that ambulatory blood pressure-derived estimation of salt-sensitivity is feasible, analysis of our database suggests increased mortality risk in men but not in women, in whom salt-sensitivity was more common.

Use of ambulatory blood pressure monitoring to guide hypertensive therapy

OPINION STATEMENT

With the advent of noninvasive 24-hour ambulatory blood pressure monitoring (ABPM), clinicians have access to a wealth of individualized data for the hypertensive patient. This has led to a greater understanding of the pathophysiology of hypertension and its complications. This tool has provided more precise diagnostic criteria for hypertension and helped discover those with white coat and masked hypertension. Patterns noted on ABPM and correlated with outcomes have allowed for more accurate identification of patients at high risk of cardiovascular (CV) events, and have offered an additional prognostic tool. In addition, ABPM allows for the assessment of the efficacy and adequacy of blood pressure treatment. In the current paper, we will describe the essential components of ABPM, review the evidence detailing the prognostic information that can be derived from its use, highlight clinical scenarios wherein ABPM can offer invaluable diagnostic information, and describe applications of ABPM that evaluate the efficacy of treatment of the hypertensive patient.

Differences between men and women in ambulatory blood pressure thresholds for diagnosis of hypertension based on cardiovascular outcomes

Previous studies have reported sex differences in the pathophysiology of hypertension and responses to blood pressure (BP)-lowering medications. Moreover, men exhibit typically higher BP than women, the differences being greater for systolic (SBP) than diastolic (DBP) BP. These differences become apparent during adolescence and remain significant at least until 55-60 yrs of age. Despite such significant sex-related differences in BP regulation, the current recommended ambulatory BP monitoring (ABPM) thresholds for diagnosis of hypertension do not differentiate between men and women. We aimed to derive separate male and female diagnostic thresholds for the awake and asleep SBP and DBP means based upon cardiovascular disease (CVD) outcome. We prospectively studied 3344 subjects (1718 men/1626 women), 52.6 ± 14.5 yrs of age, during a median follow-up of 5.6 yrs. Those with hypertension at baseline were randomized to ingest all their prescribed hypertension medications upon awakening or the entire daily dose of ≥1 of them at bedtime. At baseline, BP was measured at 20-min intervals from 07:00 to 23:00 h and at 30-min intervals at night for 48 h, and physical activity was simultaneously monitored every minute by wrist actigraphy to accurately derive the awake and asleep BP means. Identical assessment was scheduled annually and more frequently (quarterly) if treatment adjustment was required. Cox regression analysis was used to derive outcome-based reference thresholds for ABPM in men and women. Men exhibited greater event rates than women of CVD death, myocardial infarction, angina pectoris, coronary revascularization, and heart failure; however, event rates of non-CVD death and cerebrovascular events were comparable. The relationship between progressively higher ambulatory BP and CVD risk increased more rapidly in women than men for awake SBP/DBP means ≥125/75 mm Hg and asleep means ≥110/70 mm Hg. The derived outcome-based reference thresholds for men were 135/85 mm Hg for the awake and 120/70 mm Hg for the asleep SBP/DBP means. In terms of CVD outcome, the equivalent cutoff threshold values for women were 125/80 mm Hg for the awake and 110/65 mm Hg for the asleep SBP/DBP means. Outcome-based reference thresholds for the diagnosis of hypertension were 10/5 mm Hg lower for ambulatory SBP/DBP in women than men. This marked sex difference indicates the need for revision of current guidelines that propose diagnostic thresholds for ambulatory BP without differentiation between men and women.

Relationship between resting blood pressure and laboratory-induced pain among healthy children

BACKGROUND

Adult studies have demonstrated that increased resting blood pressure (BP) levels correlate with decreased pain sensitivity. However, few studies have examined the relationship between BP and experimental pain sensitivity among children.

OBJECTIVES

This study investigated the association between resting BP levels and experimental pain tolerance, intensity, and unpleasantness in healthy children. We also explored whether these BP-pain relationships were age and gender dependent.

METHODS

Participants underwent separate 4-trial blocks of cutaneous pressure and thermal pain stimuli, and 1 trial of a cold pain stimulus in counterbalanced order.

RESULTS

A total of 235 healthy children (49.6% female; mean age 12.7 [2.9] years; age range 8-18 years) participated. The study revealed specific gender-based BP-pain relationships. Girls with higher resting systolic BP levels were found to have lower thermal intensity ratings than girls with lower resting systolic BP levels; this relationship was stronger among adolescent girls than among younger girls. Among young girls (8-11 years), those with higher resting diastolic BP (DBP) levels were found to have lower cold intensity and unpleasantness as well as lower thermal intensity ratings than did young girls with lower resting DBP levels; these DBP-pain response relationships were not seen among adolescent girls.

CONCLUSIONS

Age, rather than resting BP, was predictive of laboratory pain ratings in boys. The findings suggest that the relationship between BP and experimental pain is age and gender dependent. These aspects of cardiovascular relationships to pain in males and females need further attention to understand their clinical importance.

Masked hypertension: different blood pressure measurement methodology and risk factors in a working population

OBJECTIVES

To estimate the prevalence of masked hypertension when the same ambulatory device is used for both manual and ambulatory blood pressure measurements and to measure associations with lifestyle risk factors in a working population.

METHODS

White-collar workers were recruited from three public organizations. Blood pressure was measured at the workplace using Spacelabs 90207 for manual measurements (mean of the first three readings taken by a trained assistant) followed by ambulatory measurements (mean of every other reading obtained during the working day). Masked hypertension was defined as manual blood pressure measurement of less than 140/90 mmHg and ambulatory blood pressure measurement of at least 135/85 mmHg. Smoking, alcohol intake, BMI and leisure physical activity were also assessed.

RESULTS

Blood pressure measurements were obtained from 2370 workers (80% participation, 61% women; mean age = 44 years). Masked hypertension was diagnosed in 15.02% of the participants. The prevalence was higher in men [adjusted odds ratio (OR) = 2.38, 95% confidence interval (CI) = 1.86-3.05]. The prevalence in men increased with age (adjusted OR = 2.08 for 40-49 years, 95% CI = 1.33-3.26 and adjusted OR = 1.91 for > or =50 years, 95% CI = 1.20-3.04) and BMI (adjusted OR = 1.78 for BMI > or = 27, 95% CI = 1.21-2.64). The prevalence in women increased with BMI (adjusted OR = 1.65 for BMI > or =27, 95% CI = 1.14-2.39) and alcohol intake (adjusted OR = 2.12 for at least six drinks per week, 95% CI = 1.34-3.35).

CONCLUSION

Masked hypertension is frequent and still present when blood pressure is measured out of the office, using the same device for manual and ambulatory measurements. Sex, age, BMI and alcohol intake are associated with masked hypertension.