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L A Lipsitz

Publications and source records attributed to L A Lipsitz.

At least 55 records · Page 3Linked to original sources
PubMed1996

Restrictive left ventricular filling patterns in very old patients with congestive heart failure: clinical correlates and prognostic significance.

OBJECTIVES: In certain younger patients with congestive heart failure (CHF), Doppler/echocardiography has identified a "restrictive" pattern of early diastolic ventricular filling characterized by very rapid early filling and a steep deceleration slope. We asked whether a similar restrictive pattern can be identified in very old patients with CHF, and if so, what are its clinical correlates and prognostic implications. DESIGN: Retrospective cohort with prospective follow-up. SETTING: Academic long-term care facility. PARTICIPANTS: Thirty-nine residents with clinical CHF (age 89 +/- 5 (SD) years) MEASUREMENTS: Transmitral Doppler flow, clinical characteristics, recurrent CHF episodes, hospitalizations, and mortality were measured. RESULTS: Fifteen (38%) of the subjects had restrictive filling patterns, characterized by a ratio of early to late flow (E/A) > 1.00 and 24 (62%) had nonrestrictive patterns. The restrictive pattern was associated with a longer duration of CHF, more angina, and higher rate of symptomatic recurrences of CHF. CONCLUSION: A restrictive diastolic filling pattern may represent a late stage in the evolution of congestive heart failure when left ventricular filling pressure is markedly increased. The treatment of CHF in older patients may need to account for different patterns of diastolic filling.

Age Factors↗
PubMed1996

Intraindividual reproducibility of postprandial and orthostatic blood pressure changes in older nursing-home patients: relationship with chronic use of cardiovascular medications.

OBJECTIVES: Although postprandial and orthostatic hypotension are commonly observed in nursing home residents, their reproducibility, relationship to each other, and association with chronic use of cardiovascular medications are poorly understood. DESIGN: We examined blood pressure (BP) and heart rate (HR) before and after postural change, and before and after a 419-kcal meal in 22 nursing home residents (mean age 89 +/- 5 (SD) years), each on two occasions, to determine reproducibility changes. These studies were repeated in 17 residents, with and without previous administration of cardiovascular medications, in random order. SETTING: Hebrew Rehabilitation Center for the Aged, an academic long-term care facility. RESULTS: Systolic BP declined an average (+/- SE) of 16 +/- 4 mm Hg and 12 +/- 4 mm Hg during the first and second meal studies, respectively. Mean intra-class correlation of postprandial systolic BP values during the two studies was 0.88 (95% CI 0.85-0.97). Systolic BP increased significantly during the first posture test to a maximum of 8 +/- 6 mm Hg at 6 minutes. There was no significant difference over time in postural systolic BP between the two tests. Repeated postural studies showed a mean intra-class correlation of 0.72 (95% CI 0.62-0.92) for changes in systolic BP. Cardiovascular medications had no additional effect on postprandial or orthostatic BP and HR changes. During the first studies, 10 subjects had postprandial hypotension, and three subjects had orthostatic hypotension, but only two of 22 subjects had both. CONCLUSIONS: Patterns of systolic BP response to meals or postural change are reproducible. BP responses to meals and postural change seem to be unaffected by potentially hypotensive medications in chronic users. Postprandial hypotension is distinct from orthostatic hypotension, occurring more commonly than orthostatic hypotension and infrequently together in the same patients.

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PubMed1996

The epidemiology, clinical characteristics, and natural history of older nursing home residents with a diagnosis of Parkinson's disease.

OBJECTIVE: To determine the epidemiology, clinical characteristics and natural history of nursing home residents with a diagnosis of Parkinson's disease (PD). DESIGN: A cohort study with 18-month follow-up utilizing resident assessments from the National HealthCorp 1991-1992 dataset. SETTING: Seventy-one National HealthCorp nursing homes. PARTICIPANTS: A total of 5020 nursing home residents older than age 55 were studied. Residents with primary and secondary diagnoses of PD were identified from the population using the International Classification of Diseases, Ninth Revision, Clinical Modification code 332.0. MEASUREMENTS: Baseline demographic and clinical characteristics were compared for residents with and those without Parkinson's disease. Outcome measures over the course of 18 months included death and functional status. RESULTS: The prevalence of a diagnosis of PD was 6.8%. Significant factors associated independently with PD included: younger age (79 +/- 7 vs 81 +/- 9 years; P < .001), male sex (32% vs 23%; P < .001), severe dependence in activities of daily living (OR = 1.26; 95% CI 1.08-1.46), impared body control (OR = 1.38; 95% CI 1.03-1.68), symptoms of depression (OR = 1.29; 95% CI 1.02-1.64), and the number of daily medications (OR = 1.23; 95% CI 1.08-1.44). Residents with a diagnosis of PD had a faster rate of functional decline over 18 months (P < .001) but did not have a higher mortality rate than residents without PD. CONCLUSIONS: Parkinson's disease is a relatively common diagnosis among nursing home residents and is associated with increased functional disability. There are several potentially modifiable conditions associated with PD that may offer an opportunity to design specific interventions and health services to improve the quality of life and slow functional decline in this frail population.

Activities of Daily Living↗
PubMed1996

Age-related alterations in the fractal scaling of cardiac interbeat interval dynamics.

We postulated that aging is associated with disruption in the fractallike long-range correlations that characterize healthy sinus rhythm cardiac interval dynamics. Ten young (21-34 yr) and 10 elderly (68-81 yr) rigorously screened healthy subjects underwent 120 min of continuous supine resting electrocardiographic recording. We analyzed the interbeat interval time series using standard time and frequency domain statistics and using a fractal measure, detrended fluctuation analysis, to quantify long-range correlation properties. In healthy young subjects, interbeat intervals demonstrated fractal scaling, with scaling exponents (alpha) from the fluctuation analysis close to a value of 1.0. In the group of healthy elderly subjects, the interbeat interval time series had two scaling regions. Over the short range, interbeat interval fluctuations resembled a random walk process (Brownian noise, alpha = 1.5), whereas over the longer range they resembled white noise (alpha = 0.5). Short (alpha s)- and long-range (alpha 1) scaling exponents were significantly different in the elderly subjects compared with young (alpha s = 1.12 +/- 0.19 vs. 0.90 +/- 0.14, respectively, P = 0.009; alpha 1 = 0.75 +/- 0.17 vs. 0.99 +/- 0.10, respectively, P = 0.002). The crossover behavior from one scaling region to another could be modeled as a first-order autoregressive process, which closely fit the data from four elderly subjects. This implies that a single characteristic time scale may be dominating heartbeat control in these subjects. The age-related loss of fractal organization in heartbeat dynamics may reflect the degradation of integrated physiological regulatory systems and may impair an individual's ability to adapt to stress.

Adult↗
PubMed1995

Open-loop and closed-loop postural control mechanisms in Parkinson's disease: increased mediolateral activity during quiet standing.

Stabilogram-diffusion analysis was used to gain insights into how idiopathic Parkinson's disease (IPD) affects the postural control mechanisms involved in maintaining erect stance. Twenty-two subjects with IPD and twenty-four healthy elderly subjects were studied under eyes-open, quiet-standing conditions. The postural control mechanisms in the parkinsonian subjects, compared to the healthy elderly, were characterized by an increase in the effective stochastic activity in the mediolateral direction. Mediolateral posturographic measures were also associated with a history of falls and poor performance on clinical measures of balance. It is hypothesized that the increase in mediolateral activity in subjects with IPD may reflect an attempt to maintain potentially stabilizing movements during quiet standing in the face of impaired movement in the anteroposterior direction. This study supports the notion that mediolateral instability is an important posturographic marker of functional balance impairment in the elderly.

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PubMed1995

Postprandial hypotension in elderly patients with unexplained syncope.

BACKGROUND: Syncope in older patients may be caused by a variety of disorders, including hypotension, but frequently remains unexplained. Postprandial hypotension is a common disorder of blood pressure regulation in the elderly. OBJECTIVE: To determine the pathogenic mechanisms and potential role of postprandial hypotension in elderly patients with otherwise unexplained syncope. METHODS: We studied 16 elderly patients with unexplained syncope and nine elderly controls. Blood pressure, heart rate, forearm vascular resistance, plasma norepinephrine level, and cardiac and splanchnic blood volumes were measured before and after a 1680-kJ meal. RESULTS: Eight elderly patients with syncope had postprandial hypotension, with a decline in supine mean arterial blood pressure of 17 +/- 2 mm Hg after a meal (P < .001). The blood pressure remained unchanged after the meal in the other patients with syncope and the controls. In patients with postprandial hypotension, systemic vascular resistance fell after the meal, while it remained unchanged in the other groups. Heart rate and plasma norepinephrine level increased to a similar extent in all three groups. Forearm vascular resistance increased only in the control subjects. Splanchnic blood volume increased by 26% (P < .01) in patients with syncope who had postprandial hypotension and by 22% (P < .01) in control subjects. Splanchnic blood volume remained unchanged in the patients with syncope without postprandial hypotension. CONCLUSIONS: Postprandial hypotension may be an important causative factor in elderly patients with unexplained syncope. The evaluation of syncope in elderly patients should therefore include blood pressure measurements surrounding a meal. Elderly patients with syncope who have postprandial hypotension fail to maintain systemic vascular resistance, probably because of splanchnic blood pooling without a compensatory increase in peripheral vascular resistance.

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PubMed1995

The effects of exercise on falls in elderly patients. A preplanned meta-analysis of the FICSIT Trials. Frailty and Injuries: Cooperative Studies of Intervention Techniques.

OBJECTIVE: To determine if short-term exercise reduces falls and fall-related injuries in the elderly. DESIGN: A preplanned meta-analysis of the seven Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT)--independent, randomized, controlled clinical trials that assessed intervention efficacy in reducing falls and frailty in elderly patients. All included an exercise component for 10 to 36 weeks. Fall and injury follow-up was obtained for up to 2 to 4 years. SETTING: Two nursing home and five community-dwelling (three health maintenance organizations) sites. Six were group and center based; one was conducted at home. PARTICIPANTS: Numbers of participants ranged from 100 to 1323 per study. Subjects were mostly ambulatory and cognitively intact, with minimum ages of 60 to 75 years, although some studies required additional deficits, such as functionally dependent in two or more activities of daily living, balance deficits or lower extremity weakness, or high risk of falling. INTERVENTIONS: Exercise components varied across studies in character, duration, frequency, and intensity. Training was performed in one area or more of endurance, flexibility, balance platform, Tai Chi (dynamic balance), and resistance. Several treatment arms included additional nonexercise components, such as behavioral components, medication changes, education, functional activity, or nutritional supplements. MAIN OUTCOME MEASURES: Time to each fall (fall-related injury) by self-report and/or medical records. RESULTS: Using the Andersen-Gill extension of the Cox model that allows multiple fall outcomes per patient, the adjusted fall incidence ratio for treatment arms including general exercise was 0.90 (95% confidence limits [CL], 0.81, 0.99) and for those including balance was 0.83 (95% CL, 0.70, 0.98). No exercise component was significant for injurious falls, but power was low to detect this outcome. CONCLUSIONS: Treatments including exercise for elderly adults reduce the risk of falls.

Accidental Falls↗
PubMed1995

Postprandial hypotension: epidemiology, pathophysiology, and clinical management.

OBJECTIVE: To show the clinical relevance of postprandial hypotension and to review its pathophysiology and management. DATA SOURCES: Articles on postprandial hypotension were identified through MEDLINE and bibliographies of relevant articles. STUDY SELECTION: All articles and case reports describing meal-related hypotension in the elderly and in patients with autonomic failure. DATA SYNTHESIS: Postprandial hypotension, defined as a decrease in systolic blood pressure of 20 mm Hg or more, may result in syncope, falls, dizziness, weakness, angina pectoris, and stroke. Postprandial hypotension is distinct from and probably more common than orthostatic hypotension. Because meal-related hypotension is particularly common in older hypertensive patients, it has important implications for the evaluation and management of hypertension. The mechanism of postprandial hypotension is not fully understood. Possible contributors include inadequate sympathetic nervous system compensation for meal-induced splanchnic blood pooling; impairments in baroreflex function; inadequate postprandial increases in cardiac output; and impaired peripheral vasoconstriction, insulin-induced vasodilation, and release of vasodilatory gastrointestinal peptides. Although caffeine is often recommended as treatment for postprandial hypotension, available data do not support its use. Octreotide, a somatostatin analog, has been shown to be effective, but it is expensive and must be given parenterally. CONCLUSION: All physicians caring for elderly patients should be aware of the hypotensive effects of food intake and should consider postprandial hypotension in the evaluation of syncope, falls, dizziness, and other cerebral ischemic symptoms.

Age Factors↗
PubMed1995

Age-related changes in open-loop and closed-loop postural control mechanisms.

In an earlier posturographic investigation (Collins and De Luca 1993) it was proposed that open-loop and closed-loop control mechanisms are involved in the regulation of undisturbed, upright stance. In this study, stabilogram-diffusion analysis was used to examine how the natural aging process affects the operational characteristics of these control mechanisms. Stabilogram-diffusion analysis leads to the extraction of repeatable center-of-pressure (COP) parameters that can be directly related to the steady-state behavior and functional interaction of the neuromuscular mechanisms underlying the maintenance of erect posture. Twenty-five healthy young males (aged 19-30 years) and twenty-five elderly males (aged 71-80 years) who were free of major gait and postural disorders were included in the study. An instrumented force platform was used to measure the time-varying displacements of the COP under each subject's feet during quiet standing. The COP trajectories were analyzed as one-dimensional and two-dimensional random walks, according to stabilogram-diffusion analysis. Using this technique, it was demonstrated cross-sectionally that healthy aging is associated with significant changes in the 'quasi-static' dynamics of the postural control system. (It was also shown that more traditional posturographic analyses, i.e., summary statistics, were not sensitive enough to detect these age-related differences.) It was found that the steady-state behavior of the open-loop postural control mechanisms in the elderly is more positively correlated and therefore perhaps more unstable, i.e., the output of the overall system has a greater tendency to move or drift away from a relative equilibrium point over the short term. In contrast with this result, it was also found that the steady-state behavior of the closed-loop postural control mechanisms in the elderly is more negatively correlated and therefore perhaps more stable, i.e., over the longer term, there is an increased probability that movements away from a relative equilibrium point will be offset by corrective adjustments back towards the equilibrium position. In addition, it was demonstrated that the elderly utilize open-loop control schemes for longer time intervals and correspondingly larger COP displacements during periods of undisturbed stance. This result suggests that in the elderly there is a greater delay, on average, before closed-loop feedback mechanisms are called into play. Finally, it was shown that there is an increased heterogeneity of postural control abilities in healthy older adults.

Adult↗
PubMed1995

Whether to transfer? Factors associated with hospitalization and outcome of elderly long-term care patients with pneumonia.

OBJECTIVE: To determine factors associated with the decision to treat elderly long-term care patients with pneumonia in the hospital vs in the long-term care facility (LTCF) and factors associated with patient outcomes. DESIGN: Retrospective cohort study. SETTING: Hebrew Rehabilitation Center for Aged. PATIENTS: Nursing home residents who had an episode of pneumonia, defined as a new respiratory sign or symptom and a new infiltrate. MEASUREMENTS AND MAIN RESULTS: The majority of the 316 pneumonia episodes (78%) were managed in the LTCF, most (77%) with oral antibiotics. Both patient-related factors, such as elevated respiratory rate, and non-patient-related factors, such as evening evaluation, were associated with hospitalization. No patient who had a do-not-hospitalize (DNH) order was hospitalized. Equal proportions of patients given LTCF therapy (87%) and hospital therapy (88%) survived. Elevated respiratory rate was associated with dying from pneumonia in the LTCF but not in the hospital. Dependent functional status was associated with dying from pneumonia in both sites. CONCLUSIONS: Many episodes of pneumonia can be managed in the LTCF with oral antibiotics. Because, in the absence of DNH orders, both patient-related and non-patient-related factors are associated with hospital transfer, discussion regarding preferences for hospitalization should occur prior to the development of an acute illness. A high respiratory rate may be a good marker for those LTCF patients requiring hospitalization. Dependent functional status may be a good marker for those LTCF patients unlikely to benefit from hospital transfer.

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PubMed1995

Depression in a long-term care facility: clinical features and discordance between nursing assessment and patient interviews.

OBJECTIVE: Nurses commonly observe more depression than is diagnosed and treated in nursing homes. Accordingly, we aimed to describe the clinical features of untreated nursing home residents whom nurses identify as depressed and to compare nurse ratings of depressed nursing home residents with ratings from direct interviews and patient self-reports. DESIGN: Cross-sectional survey followed by semi-structured diagnostic interviews of depressed patients and their nurses. SETTING: A large academic, multi-level, long-term care facility. PARTICIPANTS: Thirty-seven patients aged 74-99 (mean age 88.4) whom nurses identified as having daily symptoms of depression. Subjects had Mini-Mental State Exam (MMSE) scores > 10 (mean score 21.2), were not acutely or terminally ill, and were able to participate in an interview. MEASUREMENTS: DSM-III-R mood diagnoses and separate ratings of interviews with nurses and patients using the Cornell Scale for Depression. RESULTS: Nurses observed daily symptoms of depression in 110 of 495 (22%) long-term care residents on units not reserved for advanced dementia. Of these 110 patients, 58 (53%) were not receiving antidepressants. Of 37 patients eligible for interviews, nine met criteria for major depression, 20 met criteria for another non-major depression diagnosis, and eight did not have a diagnosable mood disorder. Cornell scale ratings derived exclusively from interviews of nurses were similar across the three diagnostic groups (12.5, 9.9, and 9.5, respectively; P = .31; mean 10.5), whereas Cornell scale ratings from patient interviews differed among groups (15.9, 6.9, and 4.1, respectively; P < .001; mean 8.4). Correlation between nurse Cornell ratings and patient Cornell ratings was poor (r = .27), especially for patients with non-major forms of depression (r = -.20). MMSE and Cumulative Illness Rating Scale (CIRS-G) scores were similar in the three groups. CONCLUSIONS: Nurses frequently observed symptoms of depression in a long-term care setting, and many symptomatic patients were not being treated with antidepressants. In these patients, nurse-derived symptom ratings did not vary across DSM-III-R diagnostic categories and correlated poorly with ratings from direct patient interviews. These findings suggest that nurse caregivers may contribute important diagnostic information about non-major depression and raise questions about the application of standard diagnostic categories to late-life depression in the nursing home.

Aged↗
PubMed1995

Epidemiologic and diagnostic aspects of bacteriuria: a longitudinal study in older women.

OBJECTIVE: To examine month-by-month variability of bacteriuria in a cohort of older women and to evaluate the performance of rapid diagnostic tests commonly used to indicate the presence of significant bacteriuria. DESIGN: Prospective, observational study. SETTING: Community housing sites and a long-term care institution. PARTICIPANTS: Sixty-one women, mean age 77.6, took part in the study. MEASUREMENTS: Midstream clean-catch urine samples and medical information on subjects were collected at baseline, and then monthly for 6 months. RESULTS: Bacteriuria alone (> or = 10(5) organisms per mL) occurred in 17% of all urine samples (28% of patients), bacteriuria with pyuria in 15% (26% of patients), and bacteriuria with symptoms in 3% (10% of patients). Spontaneous clearance of bacteriuria with pyuria was common (P = .30), as were new occurrences (P = .12) over 6 months of follow-up. For the outcome of bacteriuria with symptoms, sensitivity of urinary diagnostic tests such as bacteria and pyuria on microscopic analysis, and leukocyte esterase on dipstick testing, ranged from 79 to 93%. Negative predictive values of these tests approached 100%. CONCLUSIONS: Bacteriuria was a very common event, occurring in almost one-fifth of all urine samples and one-third of all subjects during 6 months of follow-up. Month-by-month follow-up indicates that the natural history of bacteriuria is marked by frequent spontaneous alternation between positive and negative events. The high negative predictive value of many simple diagnostic tests commonly used for urinary tract disease suggests that they can quickly and cost-effectively rule out bacteriuria in the older female patient.

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PubMed1995

Older community-dwelling adults' attitudes toward and practices of health promotion and advance planning activities.

OBJECTIVE: To describe the attitudes toward and practice of health prevention and advance planning measures by a group of community-dwelling older adults and to examine the effect of age on these practices. DESIGN: A descriptive study performed by mail survey. PARTICIPANTS: Members of a research registry who were 65 years of age or older. MEASUREMENTS: By means of a written questionnaire, we asked about knowledge of various health prevention and advance planning topics, including exercise, cholesterol screening, rectal examination, influenza vaccination, sigmoidoscopy, mammography, prostate cancer screening, organ donation, autopsy, health care proxy, and advance directives. Of those who knew about the topic, we asked if the respondent had discussed it with a physician, who initiated the conversation, and if the respondent participated in the activity. We also asked how important the topic was to the respondent. RESULTS: We received 598 completed surveys, a response rate of 83%. Respondents had a mean age of 74 years, were predominately white (96%), and were well educated, with 44% having completed college. The respondents were all knowledgeable about the topics, and, with the exception of sigmoidoscopy, organ donation, and autopsy, more than 70% thought these topics were important. In the case of health screening and prevention activities, a large percentage of respondents reported having discussed the topic with a physician, and a slightly smaller percentage reported regular participation. In the case of health care proxies and advance directives, however, only about one-half of those who had made these arrangements said they had discussed them with a physician. When discussion did occur, it was much more likely to have been initiated by the respondent. Controlling for level of education, age was inversely associated with the likelihood of a woman reporting she had undergone mammography (P < .05). Age, however, was not associated with decreased frequency of undergoing other screening tests. CONCLUSIONS: Among a group of well educated older adults, reported interest in and compliance with health screening, health promotion, and advance planning activities were high. However, sigmoidoscopy, a relatively more invasive procedure that is generally recommended as a screening tool, is reported less likely to be practiced than prostate cancer screening, a less invasive procedure without such recommendation. Older adults state they are pursuing health care proxies and advance directives, often without the involvement of their physicians. Of the screening tests about which we asked, age was associated only with less frequent practice of mammography.

Advance Directives↗
PubMed1995

Heart rate and respiratory rhythm dynamics on ascent to high altitude.

OBJECTIVE: To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS: 11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES: 24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS: All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS: These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress.

Adult↗
PubMed1995

Effects of chronic estrogen replacement therapy on beat-to-beat blood pressure dynamics in healthy postmenopausal women.

Recent data showing gender differences in autonomic control of heart rate and acute estrogen effects on vasodilatation suggest that estrogen may influence autonomic regulation of heart rate and blood pressure. We aimed to determine the effect of postmenopausal estrogen replacement therapy on autonomic control of beat-to-beat heart rate and blood pressure dynamics. Subjects included 20 healthy postmenopausal women aged 60 to 75 years with normal exercise tolerance tests, 10 of whom were taking oral estrogen for 13 +/- 3 (+/- SEM) years. Six healthy premenopausal women were also studied. Continuous electrocardiographic and noninvasive radial artery blood pressure measurements and intermittent forearm blood flow recordings (by venous-occlusion plethysmography) were obtained before and after a 20-minute, 60 degrees head-up tilt and a 420-kcal meal during periods of spontaneous and metronomic breathing (at 0.25 Hz). Low-frequency (0.01- to 0.15-Hz) and high-frequency (0.15- to 0.50-Hz) heart rate and blood pressure spectral powers were compared with a fast Fourier transform. Cardiovascular and heart rate spectral power responses to upright tilt and meal digestion were the same in postmenopausal estrogen users and nonusers. However, during spontaneous breathing the blood pressure spectral power responses to upright tilt and meal ingestion were significantly different between the two groups of women. The low-frequency systolic pressure power response to upright tilt was smaller in estrogen users than nonusers (P = .01). After meal ingestion nonusers had an early postprandial fall (20 to 30 minutes after the meal) and late rise (50 to 60 minutes) in low-frequency systolic and diastolic pressure powers, which were significantly attenuated in estrogen users (P < .02).(ABSTRACT TRUNCATED AT 250 WORDS)

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