Diurnal cortisol variation is associated with nocturnal blood pressure dipping

The association between depressive symptoms and masked hypertension in participants with normotension measured at research center

Masked hypertension is a risk factor for cardiovascular diseases. However, masked hypertension is sometimes overlooked owing to the requirement for home blood pressure measurements for diagnosing. Mental status influences blood pressure. To reduce undiagnosed masked hypertension, this study assessed the association between depressive symptoms and masked hypertension. This cross-sectional study used data from the Tohoku Medical Megabank Project Community-Based Cohort Study (conducted in Miyagi Prefecture, Japan, from 2013) and included participants with normotension measured at the research center (systolic blood pressure<140 mmHg and diastolic blood pressure <90 mmHg). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (Japanese version). Masked hypertension was defined as normotension measured at the research center and home hypertension (home systolic blood pressure ≥135 mmHg or home diastolic blood pressure ≥85 mmHg). The study comprised 6705 participants (mean age: 55.7 ± 13.7 years). Of these participants, 1106 (22.1%) without depressive symptoms and 393 (23.2%) with depressive symptoms were categorized to have masked hypertension. Sex-specific and age-adjusted least mean squares for home blood pressure, not for research blood pressure were significantly higher in the group with depressive symptoms in both sex categories. The multivariate odds ratio for masked hypertension in the patients with depressive symptoms was 1.72 (95% confidence interval: 1.26-2.34) in male participants and 1.30 (95% confidence interval: 1.06-1.59) in female ones. Depressive symptoms were associated with masked hypertension in individuals with normotension measured at the research center. Depressive symptoms may be one of the risk factors for masked hypertension. Depressive symptoms were associated with masked hypertension in individuals with normotension measured at research center.

Familiarization with ambulatory sleep and blood pressure monitoring is necessary for representative data collection

Ambulatory sleep and blood pressure monitoring are gaining popularity as these can be completed in an individual's home. Little is known regarding the reliability of data and the time it takes to acclimate to the equipment. This study aimed to determine how many nights of wearing the monitoring equipment were required to restore sleep architecture and blood pressure data to baseline. It was hypothesized familiarization would be demonstrated by night 3. Ten male and 10 female subjects completed three nights of sleep and blood pressure recordings. At visit 1, the subjects were familiarized with the equipment and instructed to wear the Sleep Profiler{trade mark, serif} and SunTech Medical Oscar2 ambulatory blood pressure cuff simultaneously for three consecutive nights, then subjects returned the equipment. The percent of time spent in rapid eye-movement (REM) sleep was statistically different on night 3 when compared to night 1. Wake-after-sleep onset and sleep latency were not statistically different between nights 1, 2, and 3. Systolic, diastolic, and pulse pressure were all significantly lower on night 3 compared to night 1. Cortical and autonomic arousals were statistically different on night 3. Ambulatory sleep and blood pressure monitoring need at least 3 nights for familiarization. The percent of time spent in REM sleep was statistically different on night 3 when compared to night 1. Systolic blood pressure, diastolic blood pressure, and pulse pressure were all significantly lower on night 3 compared to night 1. Cortical and autonomic arousals were statistically different on nights 3 and 2, respectively compared to night 1. Based on these findings, ambulatory sleep and blood pressure monitoring takes three nights before the data are reliable and the person is familiarized with the mode of measurement. Therefore, it is recommended to use at least three nights of data collection when using the Sleep Profiler and Oscar2 ambulatory blood pressure cuff in order for results to be valid and reliable.

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

BACKGROUND

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.

METHODS

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 4 h during a 24-h period in a light/darkness synchronised environment.

FINDINGS

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.

INTERPRETATION

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.

FUNDING

Hartstichting.

Dysregulated diurnal cortisol patterns are associated with cardiovascular mortality: Findings from the KORA-F3 study

Psychosocial stress has been associated with an increased risk for cardiovascular disease and death. Dysregulated diurnal cortisol slopes, which have also been associated with stress, might mediate this association. However, existing evidence on the cardiovascular health consequences of dysregulated cortisol slopes remains limited and inconclusive. To elucidate whether dysregulated diurnal cortisol slopes are related to cardiovascular mortality, we assessed salivary cortisol and cardiovascular morbidity and mortality in 1090 participants from the KORA-F3 study, a prospective, observational cohort study of a random representative sample from the general population. Eighty-seven deaths were registered during the mean follow-up period of approximately 11 years, 31 of which were classified as cardiovascular deaths. A more pronounced cortisol awakening response was associated with a lower risk of cardiovascular mortality in the adjusted Cox proportional hazards analysis (HR 0.59 [95-%-CI 0.36-0.96], p = 0.03). A greater diurnal cortisol peak-to-bedtime ratio at baseline also predicted a decreased risk of cardiovascular mortality (HR 0.50 [95-%-CI 0.34-0.73], p 0.01) and a decreased risk of stroke (HR 0.71 [95-%-CI 0.55-0.92], p 0.01). Increased levels of late night salivary cortisol predicted a higher risk of cardiovascular mortality (HR 1.49 [95-%-CI 1.13-1.97], p 0.01) and an increased risk of stroke (HR 1.24 [95-%-CI 1.01-1.52], p = 0.04). There was no association between measures of cortisol and non-cardiovascular related mortality. In conclusion, dysregulated diurnal cortisol patterns are associated with cardiovascular mortality, while greater diurnal cortisol variation seems to have a protective effect. This adds evidence to suggest a pathophysiological role of diurnal cortisol secretion patterns in cardiovascular health.

The association of actigraphy-assessed sleep duration with sleep blood pressure, nocturnal hypertension, and nondipping blood pressure: the coronary artery risk development in young adults (CARDIA) study

OBJECTIVE

Nocturnal hypertension and nondipping systolic blood pressure (SBP) are associated with increased cardiovascular disease (CVD) risk. Short and long sleep duration (SSD and LSD) are also associated with increased CVD risk and may be risk factors for nocturnal hypertension and nondipping SBP. We examined the association between SSD and LSD with sleep BP, nocturnal hypertension, and nondipping SBP among 647 white and African American Coronary Artery Risk Development in Young Adults (CARDIA) study participants who completed 24-h ambulatory BP monitoring, wrist actigraphy, and sleep diaries in 2015-2016.

METHODS

The times when participants were asleep and awake were determined from actigraphy complemented by sleep diaries. Nocturnal hypertension was defined as sleep BP ≥120/70 mmHg and nondipping SBP as mean sleep-to-awake SBP ratio >0.90. Sleep duration was categorized as SSD (<6 h), normal sleep duration (NSD: 6-8.9 h), and LSD (≥9 h).

RESULTS

The prevalence of SSD and LSD were 13.9 and 21.1%, respectively. Compared to participants with NSD, participants with LSD had higher mean sleep SBP (2.1 mmHg, 95% confidence interval [CI] 0.2, 4.1 mmHg) and diastolic BP (1.7 mmHg, 95% CI 0.5, 3.0 mmHg). Participants with LSD had a higher prevalence of nocturnal hypertension (prevalence ratio [PR]: 1.26, 95% CI 1.03-1.54) and nondipping SBP (PR 1.33, 95% CI 1.03-1.72) compared to participants with NSD. There was no evidence of an association between SSD and sleep SBP or DBP, nocturnal hypertension, or nondipping SBP.

CONCLUSIONS

These findings suggest that LSD may be associated with nocturnal hypertension and nondipping SBP.

Diurnal Cortisol Slope and Nighttime Blood Pressure: A Study in European Americans and African Americans

Objectives

African Americans (AAs) have higher nighttime blood pressure (BP) than European Americans (EAs). Stress has been suggested to play a role in this difference, but the mechanism is not well-understood. Flatter diurnal cortisol slope (DCS) is a well-known biological marker of stress. The objectives of this study were to: 1) examine ethnic differences in DCS; 2) evaluate the association between DCS and nighttime BP; and 3) determine the extent to which ethnic differences in nighttime BP can be explained by ethnic differences in DCS.

Methods

A total of 510 participants (age range: 14-35 years; 49.6% AAs, 54.5% females) provided four salivary cortisol samples at bedtime, wakeup, 30-minutes post-wakeup, and 60-minutes post-wakeup. Additionally, participants wore an ambulatory BP monitor for 24 hours. DCS was calculated as the average of the three morning samples minus the bedtime measurement.

Results

After adjustment for age, sex, BMI, and smoking, AAs had blunted DCS (P=.018) and higher nighttime systolic BP (SBP) and diastolic BP (DBP) (Ps<.001) compared with EAs. The DCS was inversely related to nighttime SBP and this relationship did not depend on ethnicity. The ethnic difference of nighttime SBP was significantly attenuated upon addition of DCS to the model. Mediation test showed that 9.5% of ethnic difference in nighttime SBP could be explained by DCS (P=.039).

Conclusion

This study confirms ethnic differences in DCS and nighttime BP and further demonstrates that the ethnic differences in DCS can, at least partially, explain the ethnic differences found in nighttime BP.

Effect of Dog Presence on Stress Levels in Students under Psychological Strain: A Pilot Study

As university students face many stressful situations, especially during the examination period, this study focused on the use of animal-assisted activities (AAAs) with a dog as a means of relieving students’ stress before a final exam. The aim was to determine whether a 10-min interaction with a dog affected subjectively evaluated stress and mood, objective blood pressure, and heart rate. Ninety-three female students (mean age = 22.5 years; standard deviation = 3.8 years) were divided into three groups according to their preference. The first group underwent AAAs (n = 26), the second group chose a relaxation technique (n = 28), and the last one was a control group (n = 39). Physiological values were measured using a pressure gauge and the subjective feelings of stress and mood were evaluated by the Likert scale 1–5. The AAA group showed significant improvement after 10 min of interaction in both mood and stress, with no change in heart rate and blood pressure. The remaining groups showed a significant decrease in blood pressure, but not in heart rate, with different evaluations of mood and stress. AAAs with a dog appear to be effective in improving students’ mood and stress without affecting their physiological parameters.

The effects of stress on cardiovascular disease and Alzheimer's disease: Physical exercise as a counteract measure

AD is a complicated multi-systemic neurological disorder that involves different biological pathways. Several risk factors have been identified, including chronic stress. Chronic stress produces an alteration in the activity of the hypothalamic pituitary adrenal (HPA) system, and the autonomic nervous system (ANS), which over time increase the risk of AD and also the incidence of cardiovascular disease (CVD) and risk factors, such as hypertension, obesity and type 2 diabetes, associated with cognitive impairment and AD. Considering the multi-factorial etiology of AD, understanding the complex interrelationships between different risk factors is of potential interest for designing adequate strategies for preventing, delaying the onset or slowing down the progression of this devastating disease. Thus, in this review we will explore the general mechanisms and evidence linking stress, cardiovascular disease and AD, and discuss the potential benefits of physical activity for AD by counteracting the negative effects of chronic stress, CVD and risk factors.

Sleep, a Governor of Morbidity in PTSD: A Systematic Review of Biological Markers in PTSD-Related Sleep Disturbances

BACKGROUND

Sleep disturbances (SD) are the most impactful and commonly reported symptoms in post-traumatic stress disorder (PTSD). Yet, they are often resistant to primary PTSD therapies. Research has identified two distinct SDs highly prevalent in PTSD; insomnia and nightmares. Those who report SDs prior to a traumatic event are at greater risk for developing PTSD; highlighting that sleep potentially plays a role in PTSD's pathology. To further understand the pathobiological mechanisms that lead to the development of PTSD, it is first imperative to understand the interplay which exists between sleep and PTSD on a biological level. The aim of this systematic review is to determine if biological or physiological markers are related to SD in PTSD.

METHODS

A systematic literature search was conducted on the electronic databases; Medline, Embase, AMED and PsycINFO, using Medical Subject Headings and associated keywords.

RESULTS

Sixteen studies were included in the final analyses. Physiological makers of autonomic function, and biochemical markers of HPA-axis activity; inflammatory processes; and trophic factor regulation were related to the severity of SDs in PTSD.

CONCLUSION

These findings add to the growing literature base supporting a central focus on sleep in research aiming to define the pathophysiological processes which result in PTSD, as well as emphasising the importance of specifically targeting sleep as part of a successful PTSD intervention strategy. Resolving SDs will not only reduce PTSD symptom severity and improve quality of life but will also reduce all-cause mortality, hospital admissions and lifetime healthcare costs for those with PTSD. Limitations of the current literature are discussed, and key recommendations future research must adhere to are made within.

Acute Physiologic Stress and Subsequent Anxiety Among Family Members of ICU Patients

Supplemental Digital Content is available in the text.

Objectives:

The ICU is a complex and stressful environment and is associated with significant psychologic morbidity for patients and their families. We sought to determine whether salivary cortisol, a physiologic measure of acute stress, was associated with subsequent psychologic distress among family members of ICU patients.

Design:

This is a prospective, observational study of family members of adult ICU patients.

Setting:

Adult medical and surgical ICU in a tertiary care center.

Subjects:

Family members of ICU patients.

Interventions:

Participants provided five salivary cortisol samples over 24 hours at the time of the patient ICU admission. The primary measure of cortisol was the area under the curve from ground; the secondary measure was the cortisol awakening response. Outcomes were obtained during a 3-month follow-up telephone call. The primary outcome was anxiety, measured by the Hospital Anxiety and Depression Scale-Anxiety. Secondary outcomes included depression and posttraumatic stress disorder.

Measurements and Main Results:

Among 100 participants, 92 completed follow-up. Twenty-nine participants (32%) reported symptoms of anxiety at 3 months, 15 participants (16%) reported depression symptoms, and 14 participants (15%) reported posttraumatic stress symptoms. In our primary analysis, cortisol level as measured by area under the curve from ground was not significantly associated with anxiety (odds ratio, 0.94; p = 0.70). In our secondary analysis, however, cortisol awakening response was significantly associated with anxiety (odds ratio, 1.08; p = 0.02).

Conclusions:

Roughly one third of family members experience anxiety after an ICU admission for their loved one, and many family members also experience depression and posttraumatic stress. Cortisol awakening response is associated with anxiety in family members of ICU patients 3 months following the ICU admission. Physiologic measurements of stress among ICU family members may help identify individuals at particular risk of adverse psychologic outcomes.

Circadian and ultradian cardiovascular rhythmicity in obese children

Altered circadian and ultradian blood pressure (BP) and heart rate (HR) rhythmicity have been described in diseases with increased cardiovascular risk. We analyzed cardiovascular rhythmicity in obese children. BP and HR rhythmicity was assessed with Fourier analysis from 24-h ambulatory BP measurements in 75 obese children and compared with an age- and gender-matched, lean healthy reference group of 150 subjects. Multivariate regression analysis was applied to identify significant independent factors explaining variability of rhythmicity. Prevalence of 24- and 6-h BP rhythmicity in the obese group was lower (p = 0.03 and p = 0.02), whereas the prevalence of HR rhythmicity was comparable in both groups. Excluding hypertensive participants, the results remained similar. Twenty-four-hour BP and HR acrophase were delayed in obese children (p = 0.004, p < 0.0001), 24-h BP amplitude did not differ (p = 0.07), and 24-h HR amplitude was blunted (p = < 0.0001). BP Mesor in the obese group was higher (p = 0.02); HR Mesor did not differ (p = 0.1). Multivariate regression analysis failed to identify a single anthropometric or blood pressure parameter explaining the variability of BP and HR rhythmicity.

CONCLUSION

Prevalence and parameters of circadian and ultradian BP and HR rhythmicity in obese children are altered compared to a healthy reference group, independent of preexisting hypertension.

WHAT IS KNOWN

• Altered cardiovascular rhythmicity has been described in children with different diseases such as primary hypertension or chronic renal failure. What is New: • This study reveals altered cardiovascular rhythmicity in obese children compared to an age and gender-matched healthy reference group independent from preexisting hypertension.

Breastfeeding, Bed-Sharing, and Maternal Cortisol

Prior studies have found that close mother-child sleep proximity helps increase rates of breastfeeding, and breastfeeding itself is linked to better maternal and infant health. In this study, we examine whether breastfeeding and infant bed-sharing are related to daily rhythms of the stress-responsive hormone cortisol. We found that bed-sharing was related to flatter diurnal cortisol slopes, and there was a marginal effect for breastfeeding to predict steeper cortisol slopes. Furthermore, mothers who breastfeed but do not bed-share had the steepest diurnal cortisol slopes, whereas mothers who bed-shared and did not breastfeed had the flattest slopes (P < .05). These results were significant after controlling for subjective sleep quality, perceived stress, depression, socioeconomic status, race, and maternal age. Findings from this study indicate that infant parenting choices recommended for infants (breastfeeding and separate sleep surfaces for babies) may also be associated with more optimal stress hormone profiles for mothers.

Blood pressure variability: assessment, predictive value, and potential as a therapeutic target

A large body of evidence has consistently supported the relationship between blood pressure (BP) levels and the risk of cardiovascular complications. In recent years, several independent studies have also indicated that this risk may not only depend on the magnitude of the blood pressure elevation per se but also on the presence of other associated conditions such as increased blood pressure variability. This concept has been supported by a series of reports, most of which post hoc analyses of clinical trials in hypertension, showing that increasing values of BP variability (BPV) (either in the short term, in the midterm, or in the long term) may predict development, progression, and severity of cardiac, vascular, and renal organ damage, as well as cardiovascular events and mortality. Remarkably, studies conducted in populations at high cardiovascular risk have shown increasing values of BPV in the individual subjects (so-called intra- or within-individual BPV) to be strong predictors of cardiovascular morbidity and mortality, even to a larger extent than average BP values. However, in subjects at low to moderate cardiovascular risk, the contribution of BPV to cardiovascular risk prediction over and beyond average BP values has been shown to be only moderate. The aim of this paper is to critically review the evidence addressing the prognostic relevance of different components of BPV addressing a yet open question, i.e., whether routine assessment of BPV in clinical practice should be regarded as an additional target of antihypertensive treatment to improve cardiovascular protection.

Salivary testosterone and cortisol are jointly related to pro-environmental behavior in men

Recently, cortisol has been suggested to moderate the positive relationship between testosterone and antisocial behavior. More precisely, high testosterone levels have been found to be related to aggressive or dominant behavior especially when cortisol levels were low. In the present study, we aimed to extend these findings to pro-environmental behavior as an indicator of prosocial behavior. In a first step, 147 male participants provided information on their everyday pro-environmental behavior by completing an online questionnaire on various energy-saving behaviors. In a second step, subjects provided two saliva samples for the assessment of testosterone and cortisol on two subsequent mornings after awakening. We found that testosterone was negatively related to pro-environmental behavior, but only in men with low cortisol. In conclusion, our findings provide first evidence for the joint association of testosterone and cortisol with everyday pro-environmental behavior. These results further reinforce the importance of considering interdependent hormone systems simultaneously rather than focusing on a single hormone.

Systemic and Ocular Hemodynamic Risk Factors in Glaucoma

Primary open angle glaucoma (POAG) is a multifactorial disease characterized by progressive retinal ganglion cell death and visual field loss. It is known that alterations in intraocular pressure (IOP), blood pressure (BP), and ocular perfusion pressure (OPP) can play a significant role in the pathogenesis of the disease. Impaired autoregulatory capacity of ocular blood vessels may render tissues vulnerable to OPP changes and potentially harmful tissue ischemia-reperfusion damage. Vascular risk factors should be considered more important in a subgroup of patients with POAG, and especially in patients with normal tension glaucoma (NTG) with evidence of unphysiological BP response. For example, reduction of BP during the nighttime has an influence on OPP, and increased circadian OPP fluctuation, which might stand for unstable ocular blood flow, has been found to be the consistent risk factor for NTG development and progression. Central visual field may be affected more severely than peripheral visual field in NTG patients with higher 24-hour fluctuation of OPP. This review will discuss the current understanding of allegedly major systemic and ocular hemodynamic risk factors for glaucoma including systemic hypertension, arterial stiffness, antihypertensive medication, exaggerated nocturnal hypotension, OPP, and autonomic dysregulation.

Developmental origins of flatter cortisol rhythms: socioeconomic status and adult cortisol activity

OBJECTIVE

Low socioeconomic status (SES) is associated with increased psychosocial stress among low-income persons, which could contribute to differences in activity of the HPA axis (assessed by diurnal cortisol profiles). The current article investigates associations of SES from different developmental stages with cortisol profiles.

METHODS

Using data from a large, socioeconomically diverse birth cohort (N = 1,490) in Cebu, Philippines, the current study compares the relative and joint contributions of SES from five developmental periods, between the prenatal/birth period and early adulthood, to adult cortisol, and examines the effects of chronic exposure to low SES.

RESULTS

Chronically low SES from infancy through early adulthood predicts the highest bedtime cortisol levels, lowest cortisol awakening responses (CARs), lowest total cortisol levels across the day (area under curve or AUC), and the flattest cortisol rhythms between wake up and bedtime, a profile associated with poorer health. Results indicate that cumulative economic strain (between the prenatal period and early adulthood) predicts flatter cortisol rhythms more consistently than SES from any particular period.

CONCLUSION

Interventions focusing on the psychosocial stressors associated with economic deprivation during any period from infancy to adulthood may be helpful, but targeting interventions across multiple periods may have the greatest impact. Interventions aimed at improving economic conditions between infancy and early adulthood may have implications for long-term changes in HPA axis functioning.

Racial and ethnic differences in diurnal cortisol rhythms: are they consistent over time?

BACKGROUND

Prior research indicates that blacks and Hispanics/Latinos have flatter diurnal cortisol declines across the day, a profile associated with poorer health. The stability of racial and ethnic differences in cortisol levels over time is not well understood, and additional research is needed to establish racial and ethnic differences in psychosocial stress levels as related to changes in cortisol levels.

METHODS

With data from a community-based study of 152 adults (mean age = 58 years; 53% women; 34% black, 26% Hispanic/Latino), we examined the magnitude of racial and ethnic differences over a 5-year period. Salivary cortisol samples were obtained 3 times per day for 3 days in Years 1, 3, 4, and 5. Life events and chronic stress were assessed by questionnaires in which participants reported on whether they had experienced specific types of events or stress within the past year. Depressive symptoms scales (Center for Epidemiologic Studies of Depression Scale) were also administered annually. Daily cortisol slopes were calculated by subtracting wakeup cortisol from bedtime levels and dividing by hours awake.

RESULTS

Increases in psychosocial stress were associated with flatter cortisol slopes among blacks (β = 0.010) and Hispanics/Latinos (β = 0.014), although including cardiovascular disease risk factors attenuates associations in blacks (β = 0.007; p = .125). Higher income predicts a steepening of cortisol rhythms across the study (β = -0.003; p = .019).

CONCLUSIONS

Racial and ethnic differences in diurnal cortisol rhythms are stable over time. However, the magnitude of changes in cortisol levels associated with chronic stress levels may vary by racial and ethnic subgroups.

Neighborhood problems and nocturnal blood pressure dipping

OBJECTIVE

Living in adverse neighborhood conditions has been linked with greater prevalence of cardiovascular disease (CVD). We aimed to learn whether perceived neighborhood problems are related to attenuated nocturnal blood pressure (BP) dipping, a risk factor for CVD morbidity.

METHOD

A sample of 133 adults (71 male, 62 female; 80 White, 53 Black) underwent 24-hr ambulatory blood pressure monitoring. The neighborhood problem scale (NPS) was used to assess neighborhood environmental stressors.

RESULTS

Nocturnal dipping in systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure was reduced in individuals with higher NPS scores (p < .05). Hierarchical regression analyses revealed that neighborhood problems explained 4%-6% of the variance in SBP, DBP, and MAP dipping (p < .05) even after adjusting for several theoretical confounders such as social status, age, gender, race, body mass index (BMI), smoking, exercise, depression and discrimination.

CONCLUSION

Neighborhood problems may contribute to attenuated BP dipping beyond the effect of known risk factors.

Blunted nocturnal cortisol rise is associated with higher carotid artery intima-media thickness (CIMT) in overweight African American and Latino youth

BACKGROUND

Blunted diurnal cortisol variation has been associated with overt cardiovascular disease in adults. The relationship between the diurnal cortisol variation and subclinical atherosclerosis in youth has yet to be investigated. The objectives of this study were to (1) determine the relationship between overnight cortisol measures and CIMT in overweight and obese, African-American and Latino children; (2) assess ethnic differences in these relationships; and (3) explore whether overnight cortisol and CIMT relationships were independent of inflammatory markers, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-∝ (TNF-∝).

METHODS

One hundred fifty-six overweight and obese African-American and Latino children (ages 8-17, 86 M/70 F, 55 African-American/101 Latino) underwent measures of CIMT by B-mode ultrasound, nocturnal cortisol rise (NCR = salivary cortisol rise from 2200 h to awakening at 0530 h), cortisol awakening response (CAR = salivary cortisol from time of awakening to 30 min later), fasting serum cortisol and overnight urinary free cortisol.

RESULTS

Using linear regression, salivary cortisol(0530 h) and NCR were negatively associated with CIMT (β(standardized) = -0.215 and -0.220, p < 0.01) independent of age, height, percent body fat, ethnicity and systolic blood pressure. Nocturnal salivary cortisol(2200 h), morning serum cortisol, and overnight urinary free cortisol were not associated with CIMT. Using ANCOVA, participants with LOW NCR (NCR < 0.44 μg/dL, n = 52) had significantly greater CIMT than those with HIGH NCR (NCR ≥ 0.91 μg/dL, n = 52; 0.632 ± 0.008 vs. 0.603 ± 0.008 mm, p=0.01) after controlling for covariates. Ethnicity was independently associated with CIMT, whereby African-American children had greater CIMT than Latino children (-0.028 ± 0.009, p=0.006). The relationships between cortisol measures and CIMT did not differ between the two ethnic groups (all p(interaction) = 0.28-0.97). CRP, IL-6 and TNF-∝ were not associated with CIMT (p > 0.05). IL-6 was inversely related to NCR (r = -0.186, p = 0.03), but it did not explain the relationship between NCR and CIMT.

CONCLUSIONS

Salivary cortisol(0530 h) and NCR, but not CAR, nocturnal salivary cortisol(2200 h), morning serum cortisol or overnight urinary free cortisol were associated with CIMT, independent of relevant covariates, including inflammatory factors. A low awakening salivary cortisol or a blunted NCR may be related to increased atherosclerosis risk in overweight and obese minority youth. These findings support adult studies suggesting flattened daytime diurnal cortisol variation impacts cardiovascular disease risk.

Examining the association between salivary cortisol levels and subclinical measures of atherosclerosis: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To investigate the association between salivary cortisol and two markers of subclinical cardiovascular disease (CVD), coronary calcification (CAC), and ankle-brachial index (ABI).

METHODS

Data from an ancillary study to the Multi-Ethnic Study of Atherosclerosis (MESA), the MESA Stress Study, were used to analyze associations of salivary cortisol data collected six times per day over three days with CAC and ABI. The authors used mixed models with repeat cortisol measures nested within persons to determine if specific features of the cortisol profile were associated with CAC and ABI.

RESULTS

A total of 464 participants were included in the CAC analysis and 610 in the ABI analysis. The mean age of participants was 65.6 years. A 1-unit increase in log coronary calcium was associated with a 1.77% flatter early decline in cortisol (95% CI: 0.23, 3.34) among men and women combined. Among women low ABI was associated with a steeper early decline (-13.95% CI: -25.58, -3.39) and a marginally statistically significant flatter late decline (1.39% CI: -0.009, 2.81). The cortisol area under the curve and wake to bedtime slope were not associated with subclinical CVD.

CONCLUSIONS

This study provides weak support for the link between cortisol and measures of subclinical atherosclerosis. We found an association between some features of the diurnal cortisol profile and coronary calcification and ABI but associations were not consistent across subclinical measures. There are methodological challenges in detecting associations of cortisol measures at a point in time with health outcomes that develop over a lifetime. Studies of short-term mechanisms linking stress to physiological processes related to the development of early atherosclerosis may be more informative.

Dysregulation of diurnal cortisol secretion affects abstinence induction during a lead-in period of a clinical trial for depressed cocaine-dependent patients

BACKGROUND AND OBJECTIVE

Hypothesizing that stress dysregulation may worsen cocaine dependence, we investigated the effect of diurnal cortisol secretion profile, suppression of cortisol secretion, and total cortisol secretion on retention, abstinence-based voucher earnings, days of cravings, and mood status of participants at the end of a 2-week medication-free lead-in prior to randomization in a clinical trial of mirtazapine (60 mg vs. placebo) for depressed cocaine-dependent patients.

METHODS

We measured saliva cortisol levels at 9 AM, 2 PM, and 5 PM on the first two consecutive days of a 2-week medication-free lead-in period. Results from saliva samples were used to estimate the total daily level of cortisol, the diurnal profile of secretion (typical vs. atypical), and response to dexamethasone suppression (.1 mg). Seventy-seven patients collected saliva samples at baseline, and 65 (85%) were suitable for profile analysis.

RESULTS

Patients with typical profiles (52%) collected significantly more abstinence-based voucher earnings during the lead-in (U = 299.50, p = .025). Diurnal secretion profile did not significantly affect mood status, days of craving, or retention. There were no significant effects of suppression of cortisol secretion or of total cortisol levels on any outcome measures.

CONCLUSION

In a subgroup of cocaine-dependent patients, deviation of cortisol secretion away from the homeostatic diurnal pattern was associated with reduced success at achieving early abstinence, an important determinant of treatment success.

Assessment and management of blood-pressure variability

Blood pressure (BP) is characterized by marked short-term fluctuations occurring within a 24 h period (beat-to-beat, minute-to-minute, hour-to-hour, and day-to-night changes) and also by long-term fluctuations occurring over more-prolonged periods of time (days, weeks, months, seasons, and even years). Rather than representing 'background noise' or a randomly occurring phenomenon, these variations have been shown to be the result of complex interactions between extrinsic environmental and behavioural factors and intrinsic cardiovascular regulatory mechanisms. Although the adverse cardiovascular consequences of hypertension largely depend on absolute BP values, evidence from observational studies and post-hoc analyses of data from clinical trials have indicated that these outcomes might also depend on increased BP variability (BPV). Increased short-term and long-term BPV are associated with the development, progression, and severity of cardiac, vascular, and renal damage and with an increased risk of cardiovascular events and mortality. Of particular interest are the findings from post-hoc analyses of large intervention trials in hypertension, showing that within-patient visit-to-visit BPV is strongly prognostic for cardiovascular morbidity and mortality. This result has prompted discussion on whether antihypertensive treatment should be targeted not only towards reducing mean BP levels but also to stabilizing BPV with the aim of achieving consistent BP control over time, which might favour cardiovascular protection.

Nocturnal blood pressure non-dipping, posttraumatic stress disorder, and sleep quality in women

Women with posttraumatic stress disorder (PTSD) have poor sleep quality and increased risk of cardiovascular disease (CVD). Non-dipping of nocturnal blood pressure may be an explanatory factor for the relationship between sleep and CVD found in previous research. The current study was designed to determine if non-dipping nocturnal blood pressure was associated with trauma exposure, PTSD diagnosis, PTSD symptoms, and sleep quality in a sample of women. Participants completed 24 hours of ABPM and self-report questionnaires. Non-dipping was defined as less than 10% reduction in blood pressure during sleep. The frequency of non-dippers did not differ by diagnostic status (d = .15). However, non-dippers endorsed more traumatic event categories (d = .53), more PTSD hyperarousal symptoms (d = .53), poorer overall sleep quality (d = .59), more frequent use of sleep medication (d = .62), greater sleep-related daytime dysfunction (d = .58), and longer sleep onset latencies (d = .55) than dippers. Increased attention to nocturnal blood pressure variation may be needed to improve blood pressure control in trauma-exposed women.

Socioeconomic status, nocturnal blood pressure dipping, and psychosocial factors: a cross-sectional investigation in Mexican-American women

BACKGROUND

Despite established links between reduced nocturnal blood pressure (BP) dipping and cardiovascular disease, BP dipping research in Hispanics is limited.

PURPOSE

This study investigated socioeconomic status (SES) as a predictor of BP dipping and the contributions of psychosocial factors to this relationship. Analyses were conducted for the overall sample and separately for higher and lower acculturated women.

METHODS

Mexican-American women (N = 291; 40-65 years) reported demographics and completed psychosocial assessments and 36-h ambulatory BP monitoring.

RESULTS

Lower SES related to reduced BP dipping in the overall sample and in more US-acculturated women (r's = .17-.30, p's < .05), but not in less-acculturated women (r's = .07, p's > .10). An indirect effect model from SES to BP dipping via psychosocial resources/risk fits well across samples.

CONCLUSIONS

In Mexican-American women, the nature of SES gradients in BP dipping and the roles of psychosocial resources/risk differ by acculturation level.

Salivary cortisol in ambulatory assessment--some dos, some don'ts, and some open questions

The impact of stress on health and disease is an important research topic in psychosomatic medicine. Because research on hypothalamic-pituitary-adrenal (HPA) axis regulation under controlled laboratory studies lacks ecological validity, it needs to be complemented by a research program that includes momentary ambulatory assessment. The measurement of salivary cortisol offers the possibility to trace the free steroid hormone concentrations in ambulant settings. Therefore, in this article, we first discuss the role of salivary cortisol in ambulatory monitoring. We start with a brief description of HPA axis regulation, and we then consider cortisol assessments in other organic materials, followed by a presentation of common salivary markers of HPA axis regulation suitable for ambulatory assessment. We further provide an overview on assessment designs and sources of variability within and between subjects (intervening variables), acknowledge the issue of (non)compliance, and address statistical aspects. We further give an overview of associations with psychosocial and health-related variables relevant for ambulatory assessment. Finally, we deal with preanalytical aspects of laboratory salivary cortisol analysis. The relative simplicity of salivary cortisol assessment protocols may lead to an overoptimistic view of the robustness of this method. We thus discuss several important issues related to the collection and storage of saliva samples and present empirical data on the stability of salivary cortisol measurements over time.

Disruption of Transitional Stages in 24-h Blood Pressure Recording in Renal Transplant Recipients

Patients with kidney replacement exhibit disrupted circadian rhythms. Most studies measuring blood pressure use the dipper/non-dipper classification, which does not consider analysis of transitional stages between low and high blood pressure, confidence intervals nor shifts in the time of peak, while assuming subjective onsets of night and day phases. In order to better understand the nature of daily variation of blood pressure in these patients, we analyzed 24 h recordings from 41 renal transplant recipients using the non-symmetrical double-logistic fitting assessment which does not assume abruptness nor symmetry in ascending and descending stages of the blood pressure profile, and a cosine best-fitting regression method (Cosinor). Compared with matched controls, double-logistic fitting showed that the times for most transitional stages (ascending systolic and descending systolic, diastolic, and mean arterial pressure) had a wider distribution along the 24-h. The proportion of individuals without daily blood pressure rhythm in the transplanted group was larger only for systolic arterial pressure, and the amplitude showed no significant difference. Furthermore, the transplant recipient group had a less pronounced slope in descending systolic and ascending mean blood pressure. Cosinor analysis confirmed this phase-related changes, showing a wider distribution of times of peak (acrophases). We conclude that daily disruptions in renal transplant recipients can be explained not necessarily by an absence in diurnal variation, but also by changes in waveform-related parameters of the rhythm, and that alterations in the phase of the rhythm are the most consistent finding in these patients.

Associations of salivary cortisol levels with metabolic syndrome and its components: the multi-ethnic study of atherosclerosis

CONTEXT

Prior research has identified associations between social-environmental factors and metabolic syndrome (MetS) components. The physiological mechanisms underlying these associations are not fully understood, but alterations in activity of the hypothalamic-pituitary-adrenal axis, a stress-responsive biological system, have been hypothesized to play a role.

OBJECTIVE

The aim of the study was to determine whether MetS diagnosis and specific clusters of MetS components (waist circumference, high-density lipoproteins, glucose, and blood pressure) are associated with cortisol levels.

DESIGN AND SETTING

We conducted cross-sectional analyses of data from the Multi-Ethnic Study of Atherosclerosis (MESA) study in the general community.

PATIENTS OR OTHER PARTICIPANTS

We studied a population-based sample of 726 adults (ages 48 to 89 yr) who do not have clinical diabetes.

INTERVENTION(S)

There were no interventions.

MAIN OUTCOME MEASURE(S)

Cortisol awakening response, cortisol decline across the waking day, and total cortisol output were analyzed (using 18 timed measures of salivary cortisol over 3 d).

RESULTS

Overall, we found little evidence that the presence of MetS or its components is related to cortisol output or patterns. Contrary to expectation, the presence of MetS was associated with lower rather than higher area under the curve, and no consistent pattern was observed when MetS components or subsets of components were examined in relation to cortisol.

CONCLUSIONS

Our findings do not support the hypothesis that differences in level or diurnal pattern of salivary cortisol output are associated with MetS among persons without clinical diabetes.

Overnight changes of immune parameters and catecholamines are associated with mood and stress

OBJECTIVES

To test the hypothesis that a nocturnal decrease of secretion of inflammation markers and catecholamines would be associated with mood and stress variables even after controlling for objective sleep variables.

METHODS

A total of 130 healthy volunteers participated in this study, spending 2 nights in the Gillin Laboratory of Sleep and Chronobiology at the University of California, San Diego, General Clinical Research Center. Blood samples were obtained before sleep (10:30 PM) and after awakening (6:30 AM) on the first day, and these samples were assayed for inflammatory biomarkers and catecholamines. On the second night, polysomnographic records were scored for objective sleep variables, e.g., total sleep time and wake after sleep onset. Self-rating scales for mood, stress, depression, and daily hassles were administered the second day.

RESULTS

The nocturnal decrease in interleukin-6 was smaller in people who reported more negative mood or fatigue and greater in those who reported more uplift events (e.g., with Profile of Mood States fatigue r(p) = -.25 to -.30). People with high stress or high depression levels had smaller nocturnal decreases of epinephrine. That relationship was even stronger when partial correlations were used to control for morning level and sleep variables. The associations between nocturnal changes of C-reactive protein, soluble tumor necrosis factor-receptor I, and norepinephrine with psychological states were nonremarkable.

CONCLUSIONS

The analyses of nocturnal change scores (difference scores) add substantial information compared with the traditional analyses of morning levels of immune variables and catecholamines alone. Subjective well-being is significantly associated with a greater nocturnal decrease of interleukin-6 and epinephrine. More research on nocturnal adaptation processes is warranted.

Low life purpose and high hostility are related to an attenuated decline in nocturnal blood pressure

OBJECTIVE

An attenuation of the nighttime decline in blood pressure (BP) predicts cardiovascular disease and cardiovascular-related mortality, beyond daytime BP levels. We investigated whether positive and negative psychological attributes were associated with sleep-wake BP ratios and examined sleep parameters as potential mediators of these relationships.

DESIGN

Two hundred twenty-four participants (50% men; 43% Black; mean age = 60 years) underwent ambulatory BP monitoring for 2 days and nights. Self-reports of positive and negative psychological attributes were collected. In-home polysomnography was conducted for 2 nights, and a wrist actigraph was worn for 9 nights.

MAIN OUTCOME MEASURES

Sleep-wake mean arterial pressure (MAP) ratios.

RESULTS

After adjustment for demographics, body mass index, and hypertensive status, low life purpose and high hostility were associated with high sleep-wake MAP ratios. Depression, anxiety, and optimism were not related to MAP ratios. Sleep latency, fragmentation, architecture, and the apnea-hypopnea index were examined as potential mediators between psychological attributes and MAP ratios; only long sleep latency mediated the relationship between hostility and MAP ratios.

CONCLUSION

Low life purpose and high hostility are associated with high sleep-wake BP ratios in Black and White adults, and these relationships are largely independent of sleep.

Everyday discrimination and nocturnal blood pressure dipping in black and white americans

OBJECTIVE

To investigate whether an association exists between experiences of everyday discrimination and blood pressure (BP) dipping in a biracial sample of black and white adults. Attenuated nocturnal BP dipping is closely linked to cardiovascular morbidity and mortality. Self-reported experiences of everyday discrimination have also been associated with negative cardiovascular health outcomes.

METHODS

Seventy-eight hypertensive and normotensive women and men (n = 30 black and 48 white) reported on their experiences of everyday discrimination (Everyday Discrimination Scale) and underwent two separate 24-hour ambulatory BP monitoring (ABPM) sessions approximately 1 week apart.

RESULTS

Correlation analysis revealed that higher endorsement of everyday discrimination was significantly associated with less diastolic BP (DBP) and systolic BP (SBP) dipping (p < .05). Subsequent hierarchical regression analyses indicated that everyday discrimination explained 8% to 11% of the variance in SBP and DBP dipping above and beyond other demographic and life-style-related factors, including race, age, 24-hour BP, body mass index, and current socioeconomic status. The relationship between discrimination and dipping was significantly stronger on the second night of monitoring. Finally, analyses revealed that everyday discrimination mediated the relationship between race and BP dipping.

CONCLUSIONS

These findings suggest that experiences of everyday discrimination are associated with less nocturnal SBP and DBP dipping above and beyond the effect of known covariates. The use of multiple ABPM sessions may facilitate the detection of relationships between psychological variables and BP dipping.

Social integration, social contacts, and blood pressure dipping in African-Americans and whites

OBJECTIVE

Both the size and diversity of an individual's social network are strongly and prospectively linked with cardiovascular morbidity and mortality. Social relationships may influence cardiovascular outcomes, at least in part, via their impact on physiologic pathways influenced by stress, such as daytime blood pressure (BP) levels. However, scant research has examined whether social relationships influence key nocturnal pathways, such as nocturnal BP dipping.

METHODS

The current study examined the degree to which social integration, as measured by participants' reported engagement in a range of different types of social relationships, and the frequency of daily social contacts influence the ratio of night/day mean arterial pressure (MAP) in a community sample of African-American and white men and women (N = 224). In addition, we examined the degree to which observed associations persisted after statistical adjustment for factors known to covary with nocturnal BP, including objective measures of sleep, catecholamines, health behaviors, and comorbidities.

RESULTS

In fully adjusted models, there was a significant association between both social integration and frequency of social contacts and the ratio of night/day MAP, indicating that socially isolated individuals were more likely to have blunted nocturnal BP-dipping profiles. There was also a significant interaction between social contact frequency and ethnicity, suggesting that the benefits of social relationships were particularly evident in African-Americans.

CONCLUSIONS

These findings contribute to our understanding of how social integration or conversely, social isolation, influences cardiovascular risk.

The effect of massage on immune function and stress in women with breast cancer--a randomized controlled trial

OBJECTIVES

To examine the short-term effects of light pressure effleurage on circulating lymphocytes by studying the number and activity of peripheral blood natural killer (NK) cells in patients with breast cancer compared to a control group. Furthermore, the effect of light pressure effleurage on salivary cortisol levels, heart rate and blood pressure was studied.

DESIGN

Single centre, prospective, randomized and controlled study.

METHODS

Thirty women, aged 50 to 75 years (mean 61 sd=7.2) with breast cancer undergoing radiation therapy in a hospital in southwestern Sweden were enrolled in the study. They were allocated to either receive massage in the form of a full-body light pressure effleurage treatment, or a control visit where they were given an equal amount of attention. Blood samples, saliva, notation of heart rate and blood pressure were collected before and after massage/control visit. Differences in change over time between groups were analyzed by Student's t-test.

RESULTS

Light pressure effleurage massage decreased the deterioration of NK cell activity occurring during radiation therapy. Furthermore it lowered heart rate and systolic blood pressure. No effects were demonstrated on cortisol and diastolic pressure.

CONCLUSIONS

A single full-body light pressure effleurage massage has a short-term effect on NK cell activity, systolic blood pressure and heart rate in patients with breast cancer. However, the long-term clinical importance of these findings needs to be further investigated.

Hall M, Strollo PJ, Owens JF, Buysse DJ, Lee L, Reis SE. Blood pressure dipping and sleep disturbance in African-American and Caucasian men and women

BACKGROUND

Elevated night time/daytime blood pressure (BP) ratios are associated with cardiovascular morbidity and mortality. We evaluated the associations between sleep/awake BP ratios and sleep disturbances.

METHODS

Sleep disturbances were assessed by in-home actigraphy and diary measures for nine nights, and polysomnography (PSG) for two nights; ambulatory BP was measured for at least 48 h. Participants were 186 middle-aged African-American and Caucasian men and women who were free from prevalent myocardial infarction, stroke, history of interventional cardiology procedures, diabetes, and diagnosed apnea or other sleep disorders.

RESULTS

Results showed that the greater the sleep/wake ratios of BP, the more fragmented the sleep, the greater the proportion in stage 1 (light) sleep and the smaller the proportion in rapid eye movement (REM) sleep, and the greater the number of arousals from sleep. These results were independent of age, race, gender, Framingham Risk status, cardiovascular medications, body mass index, and apnea/hypopnea index. Indicators of psychosocial stress were not greater among those with higher sleep/wake BP ratios.

CONCLUSIONS

Findings are consistent with the hypothesis that elevated night time/daytime pressure may be a consequence of poor sleep.

The cortisol awakening response in relation to objective and subjective measures of waking in the morning

Studies of the salivary cortisol awakening response (CAR) may be confounded by delays between waking in the morning and obtaining the 'waking' salivary sample. We used wrist actigraphy to provide objective information about waking time, and studied the influence of delays in taking the waking sample on the CAR. Eighty-three men and women (mean age 61.30 years) who were referred to hospital with suspected coronary artery disease were studied. Saliva samples were obtained on waking and 15 and 30 min later. The mean interval between waking defined by actigraphy and reported waking time was 6.12+/-(S.D.) 14.8 min, with 55.4% having no delay. The waking saliva sample was obtained an average 5.78+/-15.0 min after self-reported waking, and 12.24+/-20.3 min after objective waking. The waking cortisol value was significantly higher in participants who had a delay between waking and sampling >15 min (mean 14.46+/-6.34 nmol/l) than in those with zero (mean 10.45+/-6.41 nmol/l) or 1-15 min delays (mean 11.51+/-5.99 nmol/l, p=0.043). Cortisol did not increase between 15 and 30 min after waking in those who delayed >15 min. There were no differences in CAR between participants with zero and 1-15 min delays from objectively defined waking to reported sample times. A small proportion (14.7%) of participants who did not delay saliva sampling showed no increase in cortisol over the 30 min after waking. These CAR nonresponders did not differ from the remainder on sleep patterns, waking time, clinical or medication characteristics, but were more likely to be of higher socioeconomic status (p=0.009). We conclude that long delays between waking and obtaining 'waking' cortisol samples will lead to misleading CAR results, but that delays up to 15 min may not be problematic. A small minority of individuals do not show a positive CAR despite not delaying saliva sampling after waking.