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Biomedical subjects

H S Miller

Publications and source records attributed to H S Miller.

At least 19 recordsLinked to original sources
PubMed1995

Long-term (5-year) changes in HDL cholesterol in cardiac rehabilitation patients. Do sex differences exist?

BACKGROUND: It is unknown whether the benefits of a cardiac rehabilitation program on HDL cholesterol (HDL-C) are equally achieved in men and women. To study this, we compared changes in HDL-C and other lipids in a large group of men and women participating in a cardiac rehabilitation program for up to 5 years. METHODS AND RESULTS: We compared changes in HDL-C and other fasting lipids in 553 men and 166 women participating in a cardiac rehabilitation program at baseline and then annually for up to 5 years. Patients exercised 3 days a week at 70% to 85% of their maximum heart rate predetermined by a symptom-limited treadmill test. Aerobic capacity was estimated in metabolic equivalents (METs), and percent body fat was determined by skin-fold measurements. Baseline HDL-C, LDL cholesterol (LDL-C), and total cholesterol were significantly higher in women, whereas the ratio of total cholesterol to HDL-C was lower. Although both men and women showed an increase in HDL-C after 1 year (10% and 7%, respectively), only the women's level continued to increase over 5 years (20% versus 5% for men, P = .03). The sex difference in change in HDL-C remained after adjustment for age and smoking. A nonsignificant trend toward a greater change in HDL-C in women existed after adjustment for baseline percent body fat and estimated METs. The change in the ratio of total cholesterol to HDL-C was also more favorable in women, with a 38% decrease over 5 years compared with a 14% decrease in men (P = .01). Total cholesterol decreased by 20% in women and 8% in men (P = .001), whereas LDL-C dropped by 34% in women and 15% in men (P = .0001). There was no sex difference in change in triglycerides. CONCLUSIONS: Women with heart disease who participate in a cardiac rehabilitation program may achieve greater lipid benefits over longer periods of time than previously demonstrated in men.

Aged↗
PubMed1994

Effects of captopril on ischemic events after myocardial infarction. Results of the Survival and Ventricular Enlargement trial. SAVE Investigators.

BACKGROUND: In the Survival and Ventricular Enlargement (SAVE) trial, recurrent myocardial infarction (MI) was the most important predictor of a poor outcome and conferred a sevenfold increase in risk of death. The purpose of this study was to determine the predictors of recurrent MI in study participants and to examine the influence of the angiotensin-converting enzyme inhibitor captopril on this and other myocardial ischemic events. METHODS AND RESULTS: The 2231 patients had survived the acute phase of MI (3 to 16 days) and had a radionuclide ventricular ejection fraction < or = 40%. Patients were randomly assigned to receive double-blind treatment with either placebo or captopril and were followed for an average of 42 months. The influence of captopril on recurrent MI, cardiac revascularization procedures, and hospitalization with unstable angina was examined. The likelihood of recurrent MI was greater in patients with an MI or functional disability before the index infarction and higher systolic pressure (all P < .001) but was not influenced by baseline left ventricular ejection fraction. Therapy with captopril reduced the risk of development of recurrent MI by 25% (95% confidence intervals, 5% to 40%; P = .015) and the risk of death after recurrent MI by 32% (95% confidence intervals, 4% to 51%; P = .029). Captopril-assigned patients were also less likely to require cardiac revascularization procedures (P = .010), but hospitalization for unstable angina was unaltered. When all three of these major coronary ischemic events were considered together, captopril therapy reduced the risk (14% risk reduction; 95% confidence intervals, 0% to 26%; P = .047). CONCLUSIONS: In post-MI patients with asymptomatic left ventricular dysfunction, long-term administration of captopril reduced recurrence of MI and the need for cardiac revascularization but had no influence on the rate of hospitalization with a discharge diagnosis of unstable angina. The finding that the recurrence of MI was independent of left ventricular ejection fraction suggests that captopril could be useful in preventing recurrent MI in patients with more preserved left ventricular function. The need for cardiac revascularization was reduced in patients receiving long-term captopril therapy, suggesting either an anti-ischemic effect or the ability of the angiotensin-converting enzyme inhibitor to modify the atherosclerotic process in survivors of MI.

Angina, Unstable↗
PubMed1992

Acute exercise: buffering psychosocial stress responses in women.

We evaluated the experimental hypothesis that an acute bout of aerobic exercise (AE) serves as a buffer to psychosocial stress responses in low to moderate physically fit women. Forty-eight (24 White, 24 Black) 25- to 40-year-old women participated in two counterbalanced experimental conditions: an attention control and a 40-min bout of AE at 70% heart rate (HR) reserve. The attention control and AE treatments were followed by (a) 30 min of quiet rest, (b) exposure to mental and interpersonal threat, and (c) 5 min of recovery. Blood pressure (BP) and HR were monitored at baseline, during the stressors, and throughout recovery. Self-reported distress was assessed before each stressor and upon completion of the recovery period. The results provided clear evidence that exercise dampens BP reactivity to psychosocial stress. Additionally, compared with the attention placebo control, AE reduced both the frequency and intensity of anxiety-related thoughts that occur in anticipation of interpersonal threat and challenge.

Adaptation, Psychological↗
PubMed1992

Rapid inactivation of infectious pathogens by chlorhexidine-coated gloves.

OBJECTIVE: Gloves containing chlorhexidine gluconate in an instant-release matrix on their inner surface (CHG gloves) were tested to determine their ability to rapidly inactivate infectious pathogens that may permeate or leak through the latex surface. DESIGN: CHG gloves were exposed for 1 to 10 minutes to blood or media containing infectious pathogens (e.g., bacteria, fungi, parasites, and viruses) as well as to lymphocytes and macrophages that are known to be the primary carriers of human immunodeficiency virus (HIV). Inactivation of pathogens was determined either by in vitro assay or in vivo infectivity. Stressed control and CHG glove fingers were submerged in a viral pool (retrovirus or bacteriophage) and after a set time, the glove interiors were checked for presence of permeated virions. RESULTS: CHG gloves rapidly inactivate all the pathogens tested including retrovirus and hepatitis B virus (90% to 100%). In the stressed glove fingers, live virus was detected in 26% of the control group but not in any of the CHG group. CONCLUSIONS: The use of CHG gloves may reduce the risk of exposure to infectious fluid-borne pathogens should the integrity of the latex barrier be compromised by overt failure or by permeation of viruses. Rapid destruction of lymphocytes and macrophages may facilitate inactivation of HIV associated with these cells. Tests have shown that CHG coating does not alter physical properties of the glove, and, furthermore, CHG gloves do not show potential for dermal irritation or sensitization.

Animals↗
PubMed1985

Preliminary studies on the measurement of conjunctival oxygen tension in the foal.

The capability of a transconjunctival oxygen monitoring system to provide an accurate and reliable means of observing arterial oxygenation trends was evaluated in 12 horse and pony foals between 5 and 20 days of age. Ten of the foals were anesthetized with isoflurane in oxygen and nitrous oxide, and 2 foals were conscious. Inspired oxygen concentration was manipulated by differing proportions of oxygen and nitrous oxide in the fresh gas supplied to the breathing circuit. With arterial oxygen tension values ranging from less than 20 to greater than 400 mm of Hg, all foals had significant positive correlations between arterial and conjunctival oxygen tensions (P less than 0.001). Although the system seemed accurate and reliable, monitoring oxygenation in awake and mobile foals may require a ring conformer made to fit the foal's eye.

Animals↗
PubMed1976

Physiologic responses of men 49 to 65 years of age to endurance training.

A study was made of the effects of training for 30 minutes, three days a week for 20 weeks on certain physiologic measures of sedentary men between 49 and 65 years of age. Twenty-two subjects volunteered for the experimental group, and 8 others for the control group. Exercise sessions were conducted on a quarter-mile track and consisted of continuous bouts of walking and jogging. The average daily energy expenditures progressed from 228 to 365 kilocalories between weeks 4 and 20. For the same period, average exercise heart rates (HRs) progressed from 149 beats/minute (83 per cent maximum HR) to 155 beats/minute (91 per cent maximum HR). The experimental group showed significant increases in maximum oxygen intake (VO2 max) from 2.47 to 2.90 liters/minute (18 per cent) and in maximum pulmonary ventilation (VE max) from 105 to 121 liters/minute (BTPS), and decreases in resting HR, diastolic blood pressure, body weight, skinfold fat, and abdominal girth. Serum cholesterol and triglyceride levels and heart volume remained unchanged. The control subjects showed no significant changes. Regression analysis, with use of age as a covariate, showed a small but significant inverse relationship with changes in VO2 max. It was concluded that men of the 49-65 age group respond favorably to endurance exercise and show a magnitude of change similar to that found in previous investigations of similar design with younger subjects.

Age Factors↗
PubMed1975

Transient ischemic attacks due to atherosclerosis. A prospective study of 160 patients.

Patients with transient ischemic attacks (TIAs) due to atherosclerosis were studied by aortocranial arteriography. Onset of TIAs was before age 55 in 24% and between 55 and 64 in 47%. Men exceeded women by two to one. Of 160 patients, 77 were treated medically and 82 surgically. Five died in the immediate postoperative period. In the survivors, mortality has been the same in the medically and surgically managed groups. For patients with multiple lesions, surgical reconstruction of the carotid arteries was associated with very high surgical risk. In the medically treated group, anticoagulant therapy reduced the frequency of TIAs, but did not appear to protect patients from stroke. Mortality was 23% at four years, 57% of deaths being attributable to myocardial infarction and 38% to stroke.

Adult↗
PubMed1975

Frequency of training as a determinant for improvement in cardiovascular function and body composition of middle-aged men.

Frequency, duration and intensity of training have been shown to be important determinants for improving various physiological functions. This report represents a series of six training investigations conducted by the investigators over the past seven years. Within the six investigations ten separate groups were studied. These data were combined and tabulated to look at frequency of training as a determinant for improving cardiovascular function and body composition of middle-aged men. The subjects included 148 healthy, sedentary, volunteer men ranging from 28 to 64 years of age (x equal to 41). The experiments were carefully controlled and included running 30 to 45 minutes for two (four groups), three (three groups) or four (three groups) days each week for 20 weeks. The results show that all frequencies had a significant effect on cardiovascular function, but only three and four days/week regimens showed reduction in total body weight and fat. Changes in maximum oxygen consumption (VO2 max) were similar for two and three days/week programs, and significantly greater for four days. The data support the notion of frequency of training being an important criterion for improving cardiovascular function and body composition.

Adipose Tissue↗