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Changes in Heart Rate Variability during Vasomotor Symptoms among Midlife Women

Objective
Most midlife women report vasomotor symptoms, yet their physiology remains poorly understood. This study tested whether acute decreases in cardiac vagal control would occur with vasomotor symptoms in a large sample of women monitored during wake and sleep.

Methods
215 nonsmoking women ages 40–60 with evidence of vasomotor symptoms were included. Women were free of a history of clinical cardiovascular disease or arrhythmia; or use of insulin, beta blockers, calcium channel blockers, or medications impacting vasomotor symptoms. Women underwent 24 hours of ambulatory monitoring for physiological (sternal skin conductance) and self-report (electronic diary) measurement of vasomotor symptoms; heart rate variability (electrocardiogram); and respiratory rate. Changes in cardiac vagal control as assessed by respiratory sinus arrhythmia during vasomotor symptoms relative to periods preceding and following vasomotor symptoms were tested in linear mixed models.

Results
Significant decreases in respiratory sinus arrhythmia were observed during physiologically-measured vasomotor symptoms relative to periods preceding (b(SE)=.13(.004), p<.0001) and following the VMS (b(SE)=.13(.004), p<.0001), adjusted for age, race, body mass index, sleep/wake. Decreases were observed for women not aware of their vasomotor symptoms, and persisted controlling for respiration rate. Interactions indicated that respiratory sinus arrhythmia decreases were most pronounced during sleep and for younger women.

Conclusions
Physiologically-measured vasomotor symptoms were accompanied by an inhibition of cardiac vagal control in a large sample of women. Changes were observed irrespective of whether the vasomotor symptoms were reported, were most pronounced during sleep, and were greatest among younger women. These findings contribute to the understanding of vasomotor symptom physiology.

Child Abuse and Neglect and Subclinical Cardiovascular Disease among Midlife Women

Objective
A childhood history of abuse or neglect may be associated with elevated adult cardiovascular disease (CVD) risk. No studies have examined associations between child abuse/neglect and subclinical CVD using a validated measure of abuse and neglect. We hypothesized that midlife women with a childhood abuse or neglect history would have increased subclinical CVD beyond standard CVD risk factors. We tested moderation of associations by sleep, hot flashes, and race/ethnicity.

Methods
295 midlife women completed the Child Trauma Questionnaire, physiologic hot flash and actigraphic sleep monitoring, blood draw, and carotid ultrasound (intima media thickness, IMT; plaque). Relations between abuse/neglect and outcomes were tested in linear regression models adjusting for demographic, psychosocial, and CVD risk factors. Interactions with sleep, hot flashes, and race/ethnicity were tested.

Results
45% of women reported a history of child abuse or neglect. Women with any child abuse or neglect had higher IMT [b(SE)=.039(.011), p<.01] and carotid plaque [OR(95%CI= 1.95 (1.15–3.33), p<.05] than non-abused/neglected women. Further, physical abuse, emotional abuse, or emotional neglect were associated with higher subclinical CVD. Sexual abuse was associated with higher IMT among nonwhite women. Interactions with sleep time and sleep hot flashes (p values <.05) indicated that higher subclinical CVD with an abuse/neglect history was observed primarily among women sleeping <6 hours/night or with sleep hot flashes.

Conclusions
A history of child abuse or neglect is associated with higher subclinical CVD in women, particularly when paired with short sleep or hot flashes. Findings underscore the importance of childhood adversity in midlife women’s CVD risk.

Sleep Characteristics and Carotid Atherosclerosis Among Midlife Women

Midlife, which encompasses the menopause transition in women, can be a time of disrupted sleep and accelerated atherosclerosis accumulation. Short or poor sleep quality has been associated with cardiovascular disease (CVD) risk; few studies have investigated relations among midlife women. We tested whether shorter actigraphy sleep time or poorer subjective sleep quality was associated with carotid atherosclerosis among midlife women.Two hundred fifty-six peri- and postmenopausal women aged 40–60 years completed 3 days of wrist actigraphy, hot flash monitoring, questionnaires (Pittsburgh Sleep Quality Index [PSQI], Berlin), a blood draw, and carotid ultrasound [intima media thickness (IMT), plaque]. Associations of objective (actigraphy) and subjective (PSQI) sleep with IMT/plaque were tested in regression models (covariates: age, race, education, body mass index, blood pressure, lipids, insulin resistance, medications, snoring, depressive symptoms, sleep hot flashes, and estradiol).Shorter objective sleep time was associated with higher odds of carotid plaque (for each hour shorter sleep, plaque score ≥ 2, odds ratio (OR) [95% confidence interval, CI] = 1.58 [1.11–2.27], p = .01; plaque score = 1, OR [95% CI] = 0.95 [0.68–1.32], p = .75, vs. no plaque, multivariable). Poorer subjective sleep quality was associated with higher mean IMT [β, b (standard error, SE) = 0.004 (0.002), p = .03], maximal IMT [b (SE) = 0.009 (0.003), p = .005], and plaque [plaque score ≥ 2, OR (95% CI) = 1.23 (1.09–1.40), p = .001; score = 1, OR (95% CI) = 1.06 (0.93–1.21), p = .37, vs. no plaque] in multivariable models. Findings persisted additionally adjusting for sleep hot flashes and estradiol.Shorter actigraphy-assessed sleep time and poorer subjective sleep quality were associated with increased carotid atherosclerosis among midlife women. Associations persisted adjusting for CVD risk factors, hot flashes, and estradiol.