Andrew Sherwood - Academia.edu (original) (raw)

Papers by Andrew Sherwood

Menopause, Aug 1, 2015

Objective-Hypertension becomes more prevalent in women during their postmenopausal years. Nightti... more Objective-Hypertension becomes more prevalent in women during their postmenopausal years. Nighttime systolic blood pressure (SBP) is especially predictive of adverse cardiac events and the relationship between rising nighttime SBP and cardiovascular risk increases more rapidly in women compared to men. The reasons for the prognostic significance of nighttime SBP are not completely known, but may involve vascular endothelial dysfunction. The purpose of this study was to examine the relationship of nighttime SBP and endothelial function, assessed by brachial artery flow-mediated dilation (FMD) and to determine whether postmenopausal women with nighttime hypertension (SBP≥120 mm Hg) evidenced greater endothelial dysfunction compared to women with normal nighttime SBP. Methods-One-hundred postmenopausal women (mean age: 65.8 ± 7.5 years, body mass index: 28.3 ± 4.7 kg/m 2 , hypertension: 47%, coronary artery disease: 51%, mean clinic BP 137 ± 17/67 ± 11 mm Hg, 34 with nighttime hypertension) underwent 24-hour ambulatory BP monitoring, actigraphy, and brachial artery FMD assessments. Results-Multivariate regression models showed that higher nighttime SBP and larger baseline artery diameter were inversely related to FMD. Nighttime SBP and baseline artery diameter accounted for 23% of the variance in FMD. After adjusting for baseline artery diameter, women with nighttime hypertension had lower FMD than women with normal nighttime SBP (2.95% ±0.65 vs 5.52%±0.46, p = .002). Conclusions-In postmenopausal women, nighttime hypertension was associated with reduced endothelial function. Research examining the therapeutic benefits of treating nighttime hypertension on endothelial function and future cardiovascular risk in postmenopausal women is warranted.

American Journal of Hypertension, 2002

In their recent article, Sherwood et al 1 reported that nighttime blood pressure (BP) dipping was... more In their recent article, Sherwood et al 1 reported that nighttime blood pressure (BP) dipping was attenuated in postmenopausal women and that this finding may contribute to increased cardiovascular disease risk. I would like to focus the attention on circadian changes of ambulatory BP in an unselected population. In 1995 we published a study 2 on a group of 186 subjects, split into quartiles by age, to assess the age related changes in 24-h BP profile. In the women aged 55 to 72 years, the nighttime mean BP decline was 10.4% systolic and 10.7% diastolic, whereas in the women aged 37 to 54 years it was 14.1% systolic and 12.1% diastolic. This finding is even more striking in elderly men and is associated with a diffuse arterial damage. A diminished nocturnal decline in BP was found in elderly hypertensive patients with left ventricular hypertrophy. 3 Nocturnal BP drop can, therefore, be influenced by age, sex, and hypertension, in addition to an easily intelligible series of methodologic parameters such as the number of BP measurements and the definition of daytime and nighttime subperiods.

Journal of Hypertension, 2017

Objective-The 'nondipping' pattern of circadian blood pressure (BP) variation is an established i... more Objective-The 'nondipping' pattern of circadian blood pressure (BP) variation is an established independent predictor of adverse cardiovascular outcomes. Although this phenomenon has been widely studied, its underlying circadian hemodynamics of cardiac output and systemic vascular resistance (SVR) have not been well characterized. We evaluated the hypothesis that BP nondipping would be associated with a blunted night-time reduction in SVR in a biracial sample of 140 (63 African-American and 77 white) men and women with elevated clinic BP (130-159/85-99 mmHg). Methods and results-Twenty-four-hour ambulatory hemodynamics were assessed using standard ambulatory BP monitoring coupled with synchronized ambulatory impedance cardiography. Using the criterion of less than 10% dip in SBP, there were 51 nondippers (SBP dip =7.3 ± 2.6%) and 89 dippers (SBP dip =15.5 ± 3.4%). There was minimal change in cardiac output from daytime to night-time in both dippers and nondippers. However, SVR decreased from daytime to night-time, but nondippers compared with dippers exhibited a significantly attenuated decrease in SVR from daytime to night-time (7.8 vs. 16.1%, P <0.001). Relative to their white counterparts, African-Americans also exhibited blunted SBP dipping (10.9 vs. 14.6%, P <0.001) as well as an attenuated decrease in SVR (10.8 vs. 15.6%, P <0.001). Conclusion-Overall, these findings indicate that blunted night-time BP dipping is associated with impairment of the systemic vasodilation that is characteristic of the night-time sleep period and is especially prominent among African-Americans. In the context of high BP, these findings suggest that nondipping may be a manifestation, or marker, of more advanced vascular disease.

Health Psychology, 1993

In 148 Black and White men and women, laboratory measures of blood pressure (BP), heart rate, str... more In 148 Black and White men and women, laboratory measures of blood pressure (BP), heart rate, stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) during baseline and 5 stressors were examined in relationship to ambulatory systolic (SBP) and diastolic (DBP) blood pressures at work. Baseline BP strongly predicted mean work levels in all groups. For White men and Black women, higher SV and CO responses to the active speech and averaged across all tasks predicted higher work SBP individually and also when added to a model based on baseline SBP, age, and diary information. For White women, higher SBP increases to the passive speech similarly predicted mean work SBP. For Black men, higher TPR response to the cold pressor test correlated with higher work SBP but did not improve a predictor model involving baseline SBP and age. Reactivity measures did not consistently contribute to prediction of work DBP.

Psychophysiology, Sep 1, 1986

ABSTRACTThe relationships among a variety of cardiovascular and respiratory measures were examine... more ABSTRACTThe relationships among a variety of cardiovascular and respiratory measures were examined in young college males subjected to a cold pressor task, reaction‐time shock avoidance task, and three levels of graded exercise. As expected, the relationships between cardiovascular (e.g., heart rate and cardiac output) and respiratory (e.g., oxygen uptake and minute ventilation) variables were tightly linear when considering rest and exercise values. However, the range of individual cardiopulmonary responses during cold pressor and reaction time was considerable, often leading to disruptions in the cardiovascular/respiratory interactions. Analyses of extreme high and low ventilation reactors during both reaction time and cold pressor revealed that the excessive ventilation responders in cold pressor showed clear signs of hyperventilation. Increases in ventilation by the high reactors during reaction time were of smaller magnitude than during cold pressor, with potential hyperventilation much less clear. Increases in minute ventilation by reactors during the cold pressor task were primarily due to large increases in tidal volume, with only modest increases in respiratory rate. For reaction time, however, the increases in ventilation by reactive individuals stemmed from rate increases with tidal volume remaining essentially unchanged.

Journal of Psychosomatic Research, 1989

Cardiovascular activity recorded at rest and during mental stress in the laboratory was studied i... more Cardiovascular activity recorded at rest and during mental stress in the laboratory was studied in relation to ambulatory recorded cardiovascular activity at work and at home. Fifty-five Type A men (M = 42.4 years) underwent a standardized laboratory mental stress protocol in which systolic blood pressure, diastolic blood pressure, and heart rate were recorded at baseline and during a 15 min mental arithmetic task (MAT). On a subsequent day, ambulatory blood pressure and heart rate were recorded at 20 minute intervals for 12-14 hr during normal activities at home and at work. Subjects completed a behavioral diary concurrently with each cuff inflation. High and Low groups were identified based upon a median split of their cardiovascular response levels at baseline and during the MAT. Subjects with high systolic blood pressure levels during the MAT had high systolic blood pressure at home, at work, during physical activity, and when they reported being 'stressed'. Baseline systolic blood pressure in the laboratory was less consistently related to ambulatory systolic pressure across ambulatory conditions. Diastolic blood pressure at baseline was related to ambulatory diastolic blood pressure at work, at home, and when resting. Diastolic blood pressure during the MAT was associated with higher diastolic pressure at work and at home. Heart rate at baseline and during the MAT was related to heart rate at work and during physical activity. Change scores derived by subtracting mean values during the MAT from baseline resting levels were not associated with ambulatory blood pressures or heart rates under any daily conditions. In the best case, systolic blood pressure measured during the MAT was related to systolic blood pressure during physical activity, to systolic blood pressure and heart rate during mental stress, to systolic and diastolic blood pressure at rest, and to systolic blood pressure and heart rate at work but not at home. We conclude that levels of blood pressure and heart rate measured in the laboratory, but not reactivity (i.e., change scores) during the MAT, are related to blood pressure and heart rate levels recorded in the natural environment, especially in the work setting.

Psychophysiology, May 1, 1993

Laboratory stress testing is typically conducted while subjects are seated, whereas real-life str... more Laboratory stress testing is typically conducted while subjects are seated, whereas real-life stressors may often be encountered while standing. The present study of 20 healthy young men evaluated blood pressure and underlying hemodynamic adjustments to a standardized mental arithmetic task performed twice while seated and twice while standing. Blood pressure increased during mental arithmetic in both postures, but the underlying hemodynamic determinants of the pressor responses were different for the two postures. Augmented cardiac output was responsible for increasing blood pressure during seated task performance, whereas increased vascular resistance was the mechanism for the pressor response to the task performed while standing. Blood pressure and hemodynamic responses were reproducible subject characteristics for a given posture; test-retest correlations were significant for all cardiovascular measures. However, seated blood pressures responses were not significantly correlated with standing blood pressure responses. In contrast, significant between-posture correlations were found for cardiac output and vascular resistance responses. This preliminary evidence of postural stability of the hemodynamic determinants of blood pressure responses during stress is consistent with growing evidence that hemodynamic response tendencies are robust characteristics of reactivity. Ambulatory monitoring of hemodynamic response patterns during real-life stress may reveal more idiosyncratic profiles of stress reactivity than are displayed by blood pressure responses alone.

International Journal of Behavioral Medicine, Sep 1, 1995

Investigation of the physiological correlates of psychological stress is of interest in relation ... more Investigation of the physiological correlates of psychological stress is of interest in relation to the putative impact of stress in the etiology of cardiovascular disease, Although the assessment of blood pressure and heart rate responses to psychological stress has been very informative, the addition of cardiac output measurement has added a further dimension to this research field, In recent studies, a more complete hemodynamic picture of the stress response has been documented in terms ~fcardiac output and systemic vascular resistance components of blood pressure changes. Different stressors have been shown to produce similar blood pressure increases due to quite different hemodynamic mechanisms. Furthermore. when faced with the same stressor, different individuals may exhibit pressor responses that are very different hemodynamically. There is growing evidence that these hemodynamic response patterns to psychological stress are stable individual traits. Response stability is a prerequisite for considering how stress-related hemodynamic changes may be implicated i n the pathophysio logy of cardiovascular diseases. Observations that hemodyrtamic resporme patterns in indWiduals at higher risk for the development ot' hypertension differ from those of lower risk individuals show that specific patterns of hemodynamic response are associated with disease processes, although it is 'as yet unclear whether they represent markers or mechanisms, Overall. hemodynamic studies appear to be helping to refine our understanding of how stress can impact cardiovascular disease processes.

International Journal of Psychophysiology, Nov 1, 1990

Cardiovascular responses to a competitive reaction-time task were monitored in 13 male subjects t... more Cardiovascular responses to a competitive reaction-time task were monitored in 13 male subjects tested twice, 3 months apart. The temporal stability of blood pressure responses was in line with previous reports. However, in this study impedance cardiography permitted the investigation of the hemodynamic adjustments underlying the observed blood pressure responses. Analyses revealed that cardiac output and total peripheral resistance responses displayed temporal stability, indicating that subjects' blood pressure responses on the two occasions were the result of similar hemodynamic responses. These data thus extend the literature by demonstrating that the hemodynamic response pattern itself represents a stable individual difference variable.

Medicine and Science in Sports and Exercise, Oct 1, 2001

The objective of this study was to investigate the effects of exercise training and weight loss o... more The objective of this study was to investigate the effects of exercise training and weight loss on blood pressure (BP) associated with physical activity and emotional stress during daily life. Methods: One hundred twelve participants with unmedicated high normal or stage 1 to stage 2 hypertension were randomized to one of three conditions: a combined exercise and behavioral weight management group (WM), an exercise-only group (EX), or a wait list control group (CON). BP was assessed in the clinic and during 15 h of daytime ambulatory BP monitoring at baseline and after 6 months of treatment. Results: Increased levels of physical activity and emotional distress measured during daily life were associated with increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and rate pressure product (RPP). After treatment, the WM group had significantly lower DBP, HR, and RPP responses during both high and low levels of physical activity and emotional distress compared with the CON group. The EX group had similar BP levels as the WM group, although the EX group had significantly lower BP than the CON group during low but not high levels of physical activity and emotional distress. Conclusion: These findings indicate that exercise, especially when combined with weight loss, reduces BP levels at rest and in situations that typically elevate BP such as intense physical activity and emotional distress.

Archives of internal medicine, Jun 24, 2002

Hypertension, Dec 1, 1987

A total of 228 men, aged 18 to 22 years (109 black and 119 white), underwent monitoring of heart ... more A total of 228 men, aged 18 to 22 years (109 black and 119 white), underwent monitoring of heart rate (HR) and systolic (SBP) and diastolic blood pressure (DBP) responses during several stressor conditions and a 30-minute posttask rest period. Stressors included the cold pressor test and three reaction-time tasks: noncompetitive, competitive, and competitive plus money incentive. Substantial within-subject variations in blood pressure and heart rate were induced, varying from 119/70 to 148/94 mm Hg and from 63 to 91 beats/min on the average. Men (25 black and 39 white) with marginal SBP elevations during initial casual determinations had higher SBP under all conditions compared with men whose casual SBP levels were normal, and they also showed greater elevations over baseline levels in heart rate, SBP, and DBP during the stressors and the initial casual determination. Black and white subjects did not differ in their blood pressures at baseline or during the initial casual determinations, although blacks had slightly lower heart rates. Blacks did show greater SBP elevations over baseline levels than whites during the stressors, primarily because the blacks with marginally elevated SBP showed substantially greater stress-induced increases than whites with marginally elevated SBP. This enhanced pressor response to stress in blacks with marginal blood pressure elevations may be due to higher vascular resistance during enhanced sympathetic activity and could contribute to the higher incidence of hypertension among blacks.

Journal of the American College of Cardiology, Aug 1, 2005

OBJECTIVES The purpose of this study was to assess whether depressive symptomatology was associat... more OBJECTIVES The purpose of this study was to assess whether depressive symptomatology was associated with vascular endothelial dysfunction in patients with coronary heart disease (CHD). BACKGROUND In patients with CHD, the presence of depression is associated with a two to four times increased risk of mortality, but the disease pathways involved are uncertain. Endothelial dysfunction is an established risk factor for cardiovascular events in patients with CHD. METHODS Flow-mediated dilation (FMD) of the brachial artery, a measure of endothelial function, was assessed in 143 patients (99 men, 44 women), ages 40 to 84 years (mean age, 63 Ϯ 10 years), with documented CHD. RESULTS Patients with significant depressive symptomatology, as indicated by a Beck Depression Inventory (BDI) score Ն10 (n ϭ 47) showed attenuated FMD (p ϭ 0.001) compared with patients that were not depressed (BDI Ͻ10; n ϭ 96). The use of antidepressant medication was associated with improved FMD (p Ͻ 0.05). CONCLUSIONS The increased risk of cardiovascular events in CHD patients with elevated symptoms of depression may be mediated, in part, by endothelial dysfunction.

Psychosomatic Medicine, Sep 1, 2007

Objective-To assess whether patients receiving aerobic exercise training performed either at home... more Objective-To assess whether patients receiving aerobic exercise training performed either at home or in a supervised group setting achieve reductions in depression comparable to standard antidepressant medication (sertraline) and greater reductions in depression compared to placebo controls. Methods-Between October 2000 and November 2005, we performed a prospective, randomized controlled trial (SMILE study) with allocation concealment and blinded outcome assessment in a tertiary care teaching hospital. A total of 202 adults (153 women; 49 men) diagnosed with major depression were assigned randomly to one of four conditions: supervised exercise in a group setting; home-based exercise; antidepressant medication (sertraline, 50-200 mg daily); or placebo pill for 16 weeks. Patients underwent the structured clinical interview for depression and completed the Hamilton Depression Rating Scale (HAM-D). Results-After 4 months of treatment, 41% of the participants achieved remission, defined as no longer meeting the criteria for major depressive disorder (MDD) and a HAM-D score of <8. Patients receiving active treatments tended to have higher remission rates than the placebo controls: supervised exercise = 45%; home-based exercise = 40%; medication = 47%; placebo = 31% (p =. 057). All treatment groups had lower HAM-D scores after treatment; scores for the active treatment groups were not significantly different from the placebo group (p = .23). Conclusions-The efficacy of exercise in patients seems generally comparable with patients receiving antidepressant medication and both tend to be better than the placebo in patients with MDD. Placebo response rates were high, suggesting that a considerable portion of the therapeutic response is determined by patient expectations, ongoing symptom monitoring, attention, and other nonspecific factors.

SLEEP

Study Objectives Prior work has established associations between post-traumatic stress disorder (... more Study Objectives Prior work has established associations between post-traumatic stress disorder (PTSD), disrupted sleep, and cardiovascular disease (CVD), but few studies have examined health correlates of nightmares beyond risks conferred by PTSD. This study examined associations between nightmares and CVD in military veterans. Methods Participants were veterans (N = 3468; 77% male) serving since September 11, 2001, aged 38 years (SD = 10.4); approximately 30% were diagnosed with PTSD. Nightmare frequency and severity were assessed using the Davidson Trauma Scale (DTS). Self-reported medical issues were assessed using the National Vietnam Veterans Readjustment Study Self-report Medical Questionnaire. Mental health disorders were established using the Structured Clinical Interview for DSM-IV. The sample was stratified by the presence or absence of PTSD. Within-group associations between nightmare frequency and severity and self-reported CVD conditions, adjusting for age, sex, race, ...

Psychosomatic Medicine, 2018

Objective-Racial discrimination is increasingly recognized as a contributor to increased cardiova... more Objective-Racial discrimination is increasingly recognized as a contributor to increased cardiovascular disease risk among African Americans. Previous research has shown significant overlap between racial discrimination and hostility, an established predictor of CVD risk including alterations in adrenergic receptor functioning. The present study examined the associations of racial discrimination and hostility with adrenergic receptor responsiveness. Methods-In a sample (N=57) of young to middle-aged African American adults (51% female) with normal and mildly elevated blood pressure (BP), a standardized isoproterenol sensitivity test (CD 25) was used to evaluate β-AR responsiveness, while the dose of phenylephrine required to increase mean arterial pressure (MAP) by 25 mmHg (PD 25) was used to assess α 1-AR responsiveness. Racial discrimination was measured using the Perceived Racism Scale and hostility was assessed using the Cook-Medley Hostility scale. Results-In hierarchical regression models, greater racial discrimination, but not hostility, emerged as a significant predictor of decreased β-adrenergic receptor responsiveness (β = .38, p =. 004). However, moderation analysis revealed that the association between racial discrimination and blunted β-adrenergic receptor responsiveness was strongest among those with higher hostility (β = .49, 95% CI [.17, .82], p =.004). In addition, hostility, but not racial discrimination, significantly predicted α 1-AR responsiveness. Conclusions-These findings suggest racial discrimination was associated with blunted βadrenergic receptor responsiveness, providing further evidence of the potential contribution of racial discrimination to increased CVD risk among African Americans. The adverse effects of discrimination on cardiovascular health may be enhanced in individuals with higher levels of hostility.

Psychosomatic medicine, Jan 21, 2017

To determine the relationship of lifestyle factors and neurocognitive functioning in older adults... more To determine the relationship of lifestyle factors and neurocognitive functioning in older adults with vascular risk factors and cognitive impairment, without dementia (CIND). One hundred sixty adults (Mean = 65.4±6.8 years) with CIND completed neurocognitive assessments of executive function, processing speed, and memory. Objective measures of physical activity using accelerometry, aerobic capacity determined by exercise testing, and dietary habits quantified by the Food Frequency Questionnaire and 4-Day Food Diary to assess adherence to the Mediterranean and DASH diets were obtained to assess direct effects with neurocognition. Potential indirect associations of high sensitivity C-Reactive Protein (hsCRP) and the Framingham Stroke Risk Profile (FSRP) also were examined. Greater aerobic capacity (β =0.24) and daily physical activity (β = 0.15) were associated with better Executive Functioning/Processing Speed and Verbal Memory (βs = 0.24; 0.16). Adherence to the DASH diet was assoc...

Psychosomatic Medicine, 2017

Objective Posttraumatic stress disorder (PTSD) has been linked to elevated heart rate (HR) and re... more Objective Posttraumatic stress disorder (PTSD) has been linked to elevated heart rate (HR) and reduced heart rate variability (HRV) in cross-sectional research. Recent evidence suggests that this link may be driven by individual differences in autonomic arousal associated with momentary negative affect (NA). Using ecological momentary assessment (EMA) of NA and minute-to-minute HR/HRV monitoring, we examined whether NA-related HR/HRV mediated the association of PTSD symptom severity with 24-hour HRV and endothelial functioning. Methods One hundred ninety-seven young adults (18–39 years), 93 with PTSD, underwent 1 day of Holter monitoring while concurrently reporting NA levels via EMA. Two noninvasive measures of endothelial functioning—flow-mediated dilation and hyperemic flow—were also collected. Multilevel modeling was used to assess the associations of momentary NA with HR and low- and high-frequency HRV during the 5-minute intervals after each EMA reading. Latent variable modeli...

Psychosomatic medicine, Sep 7, 2016

Posttraumatic stress disorder (PTSD) has been linked to elevated heart rate (HR) and reduced hear... more Posttraumatic stress disorder (PTSD) has been linked to elevated heart rate (HR) and reduced heart rate variability (HRV) in cross-sectional research. Using ecological momentary assessment and minute-to-minute HRV/HR monitoring, we examined whether cross-sectional associations between PTSD symptom severity and HRV/HR were due to overall elevations in distress levels or to attenuated autonomic regulation during episodes of acute distress. Two hundred nineteen young adults (18-39 years old), 99 with PTSD, underwent 1 day of Holter monitoring and concurrently reported distress levels via ecological momentary assessment. Using multilevel modeling, we examined the associations between momentary distress and the 5-minute means for low-frequency (LF) and high-frequency (HF) HRV and HR immediately following distress ratings, and whether PTSD symptom severity moderated these associations. Compared with the controls, participants with PTSD recorded higher ambulatory distress (mean [standard d...

Circulation, 2021

Background: Although lifestyle modifications generally are effective in lowering blood pressure (... more Background: Although lifestyle modifications generally are effective in lowering blood pressure (BP) among patients with unmedicated hypertension and in those treated with 1 or 2 antihypertensive agents, the value of exercise and diet for lowering BP in patients with resistant hypertension is unknown. Methods: One hundred forty patients with resistant hypertension (mean age, 63 years; 48% female; 59% Black; 31% with diabetes; 21% with chronic kidney disease) were randomly assigned to a 4-month program of lifestyle modification (C-LIFE [Center-Based Lifestyle Intervention]) including dietary counseling, behavioral weight management, and exercise, or a single counseling session providing SEPA (Standardized Education and Physician Advice). The primary end point was clinic systolic BP; secondary end points included 24-hour ambulatory BP and select cardiovascular disease biomarkers including baroreflex sensitivity to quantify the influence of the baroreflex on heart rate, high-frequency ...