Biomedical subjects

M M Barbour

Publications and source records attributed to M M Barbour.

28 records · Page 2Linked to original sources

PubMed1992

Effect of dipyridamole therapy on myocardial ischemia in patients with stable angina pectoris receiving concurrent anti-ischemic therapy.

The effects of oral dipyridamole on exercise performance and anginal symptoms were evaluated in 15 men with stable angina pectoris. In a double-blind, randomized, crossover design, patients received 75 mg of dipyridamole or placebo every 8 hours for 2 weeks in addition to their previously prescribed cardiac medications. Graded exercise tolerance testing was performed twice before randomization, at the end of each treatment period, and after single-blind placebo washout. When compared with baseline tests, the time to onset of 0.1 mV ST-segment depression was similar between dipyridamole and placebo treatments (316 +/- 89 vs 345 +/- 102 seconds, respectively, p = not significant). No significant differences existed between treatments in the peak systolic blood pressure-heart rate product or in the duration of exercise. Angina pectoris occurred during all 3 baseline exercise tests in 7 of the 15 subjects; the time to onset of angina was unchanged by either treatment. Analysis of symptom diaries conducted in 13 patients revealed no significant alteration in reported anginal symptoms during dipyridamole treatment compared with placebo treatment (0.6 +/- 0.9 vs 0.3 +/- 0.4 episodes per week). Ambulatory electrocardiographic monitoring in 12 patients revealed few episodes of ischemia during daily activities with no alteration in frequency of episodes during treatment periods. Plasma concentrations of dipyridamole did not correspond with the outcomes of exercise testing. It is concluded that chronic oral dipyridamole therapy given in its usual clinical dose does not adversely affect exercise performance, daily anginal episodes or ambulatory ischemia in patients receiving concurrent anti-ischemic medication.

Aged↗

PubMed1992

Influence of exercise intensity on the presence, distribution, and size of thallium-201 defects.

The effects of two levels of exercise intensity on the size and location of thallium-201 defects were compared in 22 patients with known ischemic coronary artery disease. A symptom-limited incremental exercise test was performed followed (greater than 48 hours) by submaximal steady-state exercise at 70% of the peak heart rate achieved during the incremental test. Planar thallium-201 myocardial scans obtained after each protocol were analyzed by means of both visual qualitative and computerized quantitative methods. After incremental exercise all patients exhibited reversible thallium-201 defects, and submaximal exercise still resulted in reversible defects in 20 (91%) patients. However, the size of the ischemic area and the degree of ischemia were significantly reduced by both qualitative and quantitative criteria after submaximal exercise. Therefore interpretation of thallium-201 scans with regard to severity of disease and prognosis should take into account exercise intensity.

Blood Pressure↗

PubMed1991

Comparison of chest pain, electrocardiographic changes and thallium-201 scintigraphy during varying exercise intensities in men with stable angina pectoris.

This study was performed to evaluate the presence of angina pectoris, electrocardiographic changes and reversible thallium-201 defects resulting from 2 different levels of exercise in 19 patients with known coronary artery disease and evidence of exercise-induced ischemia. The exercise protocols consisted of a symptom-limited incremental exercise test (Bruce protocol) followed within 3 to 14 days by a submaximal, steady-state exercise test performed at 70% of the maximal heart rate achieved during the Bruce protocol. The presence and time of onset of angina and electrocardiographic changes (greater than or equal to 0.1 mV ST-segment depression) as well as oxygen uptake, exercise duration and pressure-rate product were recorded. Thallium-201 (2.5 to 3.0 mCi) was injected during the last minute of exercise during both protocols, and the images were analyzed using both computer-assisted quantitation and visual interpretations. Incremental exercise resulted in anginal symptoms in 84% of patients, and electrocardiographic changes and reversible thallium-201 defects in all patients. In contrast, submaximal exercise produced anginal symptoms in only 26% (p less than 0.01) and electrocardiographic changes in only 47% (p less than 0.05), but resulted in thallium-201 defects in 89% of patients (p = not significant). The locations of the thallium-201 defects, when present, were not different between the 2 exercise protocols. These findings confirm the sequence of the ischemic cascade using 2 levels of exercise and demonstrate that the cascade theory is applicable during varying ischemic intensities in the same patient.

Angina Pectoris↗

PubMed1990

Altered theophylline metabolism in patients with psoriasis.

We observed two patients on theophylline therapy with concomitant severe psoriasis and a two- to threefold greater theophylline clearance than that reported in healthy, nonsmoking adults. There were no factors known to induce theophylline clearance. In both cases, the induction of theophylline metabolism was relatively selective for the 1-methyluric acid pathway. The altered metabolism in these patients appeared to correlate with the clinical severity of the disease. The data suggest the possibility that an observed lack of efficacy for theophylline in psoriasis may be related to pharmacokinetic effects. The concept that altered drug metabolism may occur in the presence of skin disease has important implications for pharmacotherapeutics in dermatology.

Aged↗

PubMedDate not supplied

Is a history of depressive symptoms associated with an increased risk of infertility in women?

Researchers have reported an association between self-reported antidepressant use and increased risk of ovulatory infertility but could not control for confounding by the drug indication. We evaluated the role of depressive symptoms in the development of infertility. We recontacted a population-based sample of Pawtucket Heart Health Program (PHHP) health survey respondents to perform this case-control study. Self-reported infertility was defined as an inability to conceive after 12 months of unprotected intercourse. Controls were women who reported at least one pregnancy. The index age for infertile women was the age at which they first experienced fertility problems, and for the fertile women it was the age of their first pregnancy. History of depressive symptoms was based on self-report before the index age. Women with a history of depressive symptoms were nearly twice as likely to report infertility relative to women without a history of depressive symptoms before the index age after controlling for potential confounders (90% confidence interval: 0.9-3.2). Our data suggest that depressive symptoms as well as the drugs used to treat these conditions may play an important role in the pathogenesis of infertility. The association between depressive symptoms and infertility should be explored further.

Adolescent↗

PubMedDate not supplied

Predictors of future antihypertensive use in patients with mildly elevated blood pressure.

We prospectively identified predictors of future antihypertensive use in untreated persons age 18-65 years who had elevated diastolic blood pressures of 90-104 mm Hg or systolic blood pressures of at least 140 mm Hg. Data were derived from two independent cohorts completing household surveys conducted in 1981-1984 and 8 years later, as part of the Pawtucket Heart Health Program. Demographics, self-reported health behaviors and beliefs, and physiologic measurements were obtained. Drug use was determined through structured interviews. Analysis of covariance and logistic regression were performed. In the 492 subjects, independent baseline predictors of future antihypertensive use (p < 0.05) included female gender, older age, diastolic blood pressure elevation, self-perceived high blood pressure, and self-reported salt limitation. Antihypertensive use for previously untreated mild hypertension is diverse. Older women with diastolic elevations who are health conscious are most likely to be treated.

Adolescent↗

PubMedDate not supplied

Is antidepressant use changing? Prevalence and clinical correlates in two New England communities.

We attempted to determine whether the prevalence of antidepressant use had increased in population-based samples between 1981 and 1993, and compared the characteristics of antidepressant users and nonusers. Data were derived from six biennial, random sample, cross-sectional household surveys conducted between 1981 and 1993 in two southeastern New England communities. For each survey, point prevalence estimates were determined for the major antidepressant categories. Antidepressant users were most likely to be women, slightly older, and less likely to be employed than nonusers (p < 0.0001). Comorbid conditions and concurrent drug therapy were present more frequently among users. The overall prevalence of antidepressant use per 1000 population increased from 7.8 (95% confidence interval 4.3, 11.3) in 1981-1982 to 31.4 (95% CI 23.9, 38.9) in 1992-1993, especially among women and respondents between ages 40 and 59 years.

Adolescent↗

PubMedDate not supplied

Changing trends in antihypertensive therapy in two New England communities during the 1980s.

The prevalence rates and correlates of antihypertensive drug use among individuals with hypertension were determined using data derived from five biennial population-based surveys conducted between 1981 and 1990 in two New England communities. Point prevalence estimates were determined for nine categories of antihypertensive agents at five time points, and were analyzed by age and sex using multiple logistic regression. In the first cross-sectional survey, the prevalence of use per 1000 individuals with hypertension was 235.4 for diuretics, 57.1 for beta-blockers, 65.5 for combination products, 29.2 for central alpha-agonists, 2.8 for peripheral alpha-antagonists, and 8.4 each for adrenergic blockers and direct vasodilators. The prevalence rates for calcium channel blockers and angiotensin-converting enzyme inhibitors increased sharply between the third and fourth survey cycles. Significant age- and sex-related differences in antihypertensive use were detected.

Adrenergic alpha-Agonists↗

PubMedDate not supplied

The drug data base of the Pawtucket Heart Health Program: development and description.

Pharmacoepidemiology has become an important tool for identifying patterns of drug use and adverse drug reactions in the general population. Drug data bases derived from population-based samples have been particularly useful in addressing questions such as adherence to national guidelines for the treatment of chronic diseases. As part of the Pawtucket Heart Health Program, a continuing community-based research and demonstration project, detailed information regarding the use of drugs among the general population of two southeastern New England cities was collected using cross-sectional and longitudinal methodologies.

Cardiovascular Diseases↗

PubMedDate not supplied

Correlates of oral contraceptive use in two New England communities: 1981-1993.

This study compared the sociodemographic and cardiovascular correlates of oral contraceptive users and nonusers between 1981 and 1993. We also sought to determine changes in the prevalence of oral contraceptive use among older premenopausal women. Using data from six biennial cross-sectional household surveys in a population-based sample of two New England communities, 5239 women between ages 18 and 45 years were identified. Women using oral contraceptives were 5 years younger and better educated than nonusers, and users more frequently reported a per capita income above the median for the survey population than nonusers. Users were more likely to report smoking and have a lower body mass index than nonusers. Little use of oral contraceptives was detected among women ages 40-45 years despite changes in FDA recommendations about their use and increasing evidence of their noncontraceptive benefits in healthy older nonsmoking women.

Adolescent↗