Biomedical subjects
Publications and source records attributed to M Limacher.
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BACKGROUND: Amid current changes in health care access across the United States, the importance of health insurance status and insurance type relative to demographic, actual, and perceived health variables as determinants of screening for breast, colorectal, and cervical cancer is uncertain. This analysis evaluates the hypothesis that health insurance independently predicts cancer screening in the Women's Health Initia tive Observational Study cohort. METHODS: Questionnaire data from 55,278 women en rolled in the Women's Health Initiative Observational Study between September 1994 and February 1997 were analyzed by multiple logistic regression to identify predictors of self-reported mammography within 2 years, Pap smear within 3 years, and stool guaiac or flexible sigmoidoscopy within 5 years. RESULTS: Positive determinants of reporting cancer screening were age, ethnic origin, household income, educational level, family history of cancer, having a usual care provider, time since last provider visit, and insurance status and type. Smoking, diabetes, and, among older women, prior cardiovascular events were negative determinants of cancer screening. Among women younger than 65, lacking health insurance or having fee-for-service insurance was strongly associated with failure to report cancer screening, independently of having or using a usual care provider and of demographics, self-perceived health, and health characteristics. Among women 65 and older, those with Medicare alone were less likely, whereas those with Medicare + prepaid insurance were more likely, to report cancer screening. CONCLUSIONS: In the Women's Health Initiative Obser vational Study, a large, diverse group of older women, health insurance type and status were among the most important determinants of cancer screening indepen dent of demographics, chronic health conditions, and self-perceived health characteristics.
Our objectives were to explore health insurance status and insurance type, adjusted for self-reported and perceived health variables, as determinants of having and using a usual care provider in the Women's Health Initiative (WHI) Observational Study (OS). This analysis describes insurance status in a large, diverse group of older women and tests the hypothesis that insurance was a key predictor of their access to healthcare in the mid-1990s. Multiple logistic regression analysis was used to evaluate determinants of having visited a usual healthcare provider within the proceeding 12 months, using cross-sectional information provided by a population-based cohort of 55,278 postmenopausal women. Five percent of women younger than 65 years and 0.2% of women 65 or older in the OS cohort lacked health insurance. Among the 31,684 women, aged 50-64 years, Hispanic women and those with fewer years of education and lower household income and who were current smokers were less likely, and those lacking insurance were the least likely, to have seen their healthcare provider within the preceding year. Among 23,594 women, aged 65-79 years, African American and Hispanic women and those with lower household income, and Medicare only and those who were current smokers, were less likely to have seen their healthcare provider within the preceding year. In both age groups, women with chronic medical conditions and poorer perceived health scores and those with prepaid insurance were more likely to have seen their healthcare provider. In the WHI OS, both health (self-reported and perceived) and type of health insurance remained independently associated with having visited a usual healthcare provider after multivariate adjustment for one another as well as for pertinent sociodemographic characteristics.
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BACKGROUND: A majority of all myocardial infarctions occur in patients who are 65 years of age or older and have average cholesterol levels, but little information is available on whether cholesterol lowering in such patients reduces the rate of recurrent cardiovascular disease. OBJECTIVE: To determine whether pravastatin reduces the rate of recurrent cardiovascular events in older patients. DESIGN: Subset analysis of a randomized, controlled trial. SETTING: 80 hospitals and affiliates in the United States and Canada. PATIENTS: 1283 patients aged 65 to 75 years who had had myocardial infarction and had a plasma total cholesterol level less than 6.2 mmol/L (240 mg/dL) and a low-density lipoprotein cholesterol level of 3.0 to 4.5 mmol/L (115 to 174 mg/dL). INTERVENTION: Pravastatin, 40 mg/d, or placebo. MEASUREMENTS: Five-year event rates of major coronary events (coronary death, nonfatal myocardial infarction, angioplasty, or bypass surgery) and stroke. RESULTS: Major coronary events occurred in 28.1% of placebo recipients and 19.7% of pravastatin recipients (difference, 9.0 percentage points [95% CI, 4 to 13 percentage points]; relative risk reduction, 32%; P < 0.001). Coronary death occurred in 10.3% of the placebo group and in 5.8% of the pravastatin group (difference, 4.6 percentage points [CI, 1.9 to 6.5 percentage points]; relative risk reduction, 45%; P = 0.004). Stroke incidence was 7.3% in the placebo group and 4.5% in the pravastatin group (absolute reduction, 2.9 percentage points [CI, 0.3 to 4.5 percentage points]; relative reduction, 40%; P = 0.03). The numbers of older patients needed to treat for 5 years were 11 (CI, 8 to 24) to prevent a major coronary event and 22 (CI, 15 to 53) to prevent a coronary death. For every 1000 older patients treated, 225 cardiovascular hospitalizations would be prevented compared with 121 hospitalizations in 1000 younger patients. CONCLUSIONS: In older patients with myocardial infarction and cholesterol levels in the average range, pravastatin is associated with a clinically important reduction in risk for major coronary events and stroke. Given the high cardiovascular event rate in older patients, the potential for absolute benefit in this age group is substantial.
OBJECTIVES: We sought to determine the effect of pravastatin on recurrent cardiovascular events in women with average cholesterol levels after myocardial infarction (MI). BACKGROUND: Little information is available on the effectiveness of lipid lowering in secondary prevention of coronary heart disease (CHD) in women; in particular, those with CHD and average cholesterol levels. METHODS: In the Cholesterol and Recurrent Events (CARE) trial, 576 postmenopausal women, between 3 and 20 months after MI, with a total cholesterol level <240 mg/dl and a low density lipoprotein cholesterol level 115 to 174 mg/dl, were randomized to receive pravastatin 40 mg/day or matching placebo for a median follow-up period of 5 years. The main outcome measures were combined coronary events (coronary death, nonfatal MI, percutaneous transluminal coronary angioplasty [PTCA] or coronary artery bypass graft surgery [CABG]), the primary trial end point (coronary death or nonfatal MI) and stroke. RESULTS: Women treated with pravastatin had a risk reduction of 43% for the primary end point (p = 0.035), 46% for combined coronary events (p = 0.001), 48% for PTCA (p = 0.025), 40% for CABG (p = 0.14) and 56% for stroke (p = 0.07). The 3,583 men in the CARE trial also showed a reduction in risk, but the magnitude tended to be less. Pravastatin improved plasma lipids similarly in men and women. There were no differences in risk of coronary events in the placebo group between men and women. Minor differences between men and women were present in baseline characteristics and treatment for MI, in general, conferring a higher risk status and a lower incidence of CABG in the women. CONCLUSIONS: Pravastatin led to significant early reduction of a wide range of cardiovascular events in post-MI women with average cholesterol levels.
BACKGROUND: Studies of Left Ventricular Dysfunction (SOLVD) demonstrated that enalapril therapy significantly improved the clinical course of patients with left ventricular (LV) dysfunction. The goals of this substudy were to evaluate changes in LV structure and function in SOLVD patients and to test the hypothesis that enalapril inhibits remodeling in patients with LV dysfunction. METHODS AND RESULTS: Patients entering both the prevention and treatment arms of SOLVD from 5 of the 23 clinical centers were recruited for this substudy. The 301 patients who participated underwent Doppler-echocardiographic evaluation according to standard protocol before randomization to either enalapril or placebo and again after 4 and 12 months of therapy. Recorded data were analyzed in a blinded fashion at a central core laboratory. Analysis of baseline clinical characteristics showed that patients enrolled in the substudy were generally representative of the SOLVD population, although prevention arm patients were slightly overrepresented in the substudy group (69.8% compared with 61.9% of remaining SOLVD patients). The enalapril group demonstrated significant reductions in the mitral annular E-wave-to-A-wave velocity ratio (due predominantly to a reduction in E-wave velocity), and this response was different from that seen in the placebo group (P = .030). Changes in the E-to-A ratio in the enalapril group correlated significantly with changes in plasma atrial natriuretic peptide (r = .56; P < or = .01). LV end-diastolic and end-systolic volumes increased in placebo but not enalapril-treated patients, and the differences in response between the treatment groups were significant (P = .025 and .019, respectively). LV mass tended to increase in placebo patients and to be reduced in enalapril-treated patients, and the difference in response between the groups was highly significant (P < or = .001). CONCLUSIONS: These data demonstrate that enalapril attenuates progressive increases in LV dilatation and hypertrophy in patients with LV dysfunction. The results support the possibility that the favorable effects of enalapril reported in the SOLVD trials were related to inhibition of LV remodeling.
The Studies of Left Ventricular Dysfunction (SOLVD) trials were designed to evaluate the effects of enalapril on long-term mortality in patients with severe left ventricular (LV) dysfunction. Patients with LV ejection fractions less than or equal to 0.35 and symptoms of congestive heart failure (CHF) were enrolled in the treatment trial, whereas those with no history of overt CHF and taking no treatment directed for LV dysfunction were enrolled in the prevention trial. The baseline clinical characteristics of SOLVD patients were compared to characterize differences between patients in these 2 separate but concurrent trials. From over 70,000 patients screened with LV dysfunction, 4,228 patients were enrolled in the prevention trial and 2,569 patients in the treatment trial. Ischemic heart disease was the primary cause of LV dysfunction in both prevention (83%) and treatment (71%) trial patients. Prior myocardial infarction was present in 80% of the prevention and 66% of the treatment trial patients (p less than 0.001). In the prevention trial, infarction was recent (less than or equal to 6 months) in 27% patients and remote (greater than 6 months) in 57% patients. Treatment trial patients had proportionately more women (20 vs 13%; p less than 0.001) and non-Caucasians (20 vs 14%; p less than 0.001), as well as the coexisting risk factors of hypertension (42 vs 37%; p less than 0.001) and diabetes (26 vs 15%; p less than 0.001) than did prevention trial patients. Clinical characteristics of patients in both trials were influenced by the gender and race of enrolled patients. Similarly, coronary artery bypass surgery was performed less often in women and non-Caucasians.(ABSTRACT TRUNCATED AT 250 WORDS)
Healthy volunteers received intravenous and/or oral doses of sodium dichloroacetate (DCA) in various single and multiple dose regimens. A crossover bioavailability study proved abortive because second and subsequent doses showed significantly longer terminal elimination half-lives (means 3.64 h and 9.9 h, respectively) than was the case for initial doses (1.58 h). A parallel bioavailability comparison failed to show that oral doses were significantly different from 100 per cent bioavailability (AUCoral, 604 micrograms h-1 ml-1; AUCi.v., 489 micrograms h-1 ml-1). The time required to elapse between individual doses, in order to prevent second doses having relatively long half-life values, varied in different individuals from 1 week to greater than 3 months. No cardiac or central nervous system effects were recorded by echocardiography and digit symbol substitution tests, respectively. The mean renal clearance of DCA was 42.9 ml h-1. No differences were observed in DCA kinetics between male and female subjects.
To evaluate the effects of 26 wk of aerobic and resistance training on the incidence of injury and program adherence in 70- to 79-yr-old men and women, 57 healthy volunteers (25 males, 32 females) were randomly assigned to a walk/jog (W/J, N = 21), strength (STREN, N = 23), or control (CONT, N = 13) group. Walk/jog training was for 30-45 min, 3 d.wk-1 with intensity equal to 40-70% heart rate max reserve (HRmax reserve) during the first 13 wk, and 75-85% HRmax reserve for weeks 14-26. STREN training consisted of one set (10-12 repetitions) each of 10 variable resistance exercises performed to volitional fatigue. Forty-nine of the original participants completed the training program. Walk/jog training increased VO2max from 22.5 to 27.1 ml.kg-1.min-1 (P less than or equal to 0.05) while STREN and CONT showed no change. STREN improved significantly in chest press and leg extension strength (P less than or equal to 0.05) while W/J and CONT showed no change. Adherence to training was 20/23 (87%) and 17/21 (81%) in STREN and W/J, respectively. One repetition maximum (1-RM) strength testing resulted in 11 injuries in the 57 subjects (19.3%) while STREN training resulted in only two injuries in 23 subjects (8.7%). Walk training during weeks 1-13 resulted in one injury in 21 subjects (4.8%). Eight of 14 subjects (57%) who began jogging intervals at week 14 incurred an injury: two of eight (25%) of the men and all of the women (6 of 6). All W/J training injuries were to the lower extremity.(ABSTRACT TRUNCATED AT 250 WORDS)
A 36-year-old man presented with a prolonged history of chest pain, and was given two sublingual nitroglycerin tablets. Subsequently, the patient became hypotensive, bradycardiac, apneic, and lost consciousness. The bradycardia resolved spontaneously. No evidence for acute myocardial infarction or ischemic disease was found. Thirty-four cases reported to date are reviewed, demonstrating that this response appears to be an independent effect of nitroglycerin taken in any form, in patients with and without myocardial infarction and to be unpredictable, especially without evidence of inferior or right ventricular infarction. Careful monitoring is warranted when administering nitroglycerin.
Assessed the number of sources of supportive and problematic social interactions in the total social network as well as the number who were the sources of consistently supportive or problematic interactions in a sample of 2nd year medical students. Number of problematic interaction sources was hypothesized to be more predictive of psychological and physical well-being than number of supportive interaction sources. Results showed that total supportive and total problematic interaction sources were equally predictive of life satisfaction. The presence of at least one individual who is a consistent source of problematic interactions was most predictive of lower life satisfaction. Results indicate the importance of studying both supportive and problematic social interactions. They also suggest that interactions with individuals that are consistently problematic may negatively impact upon well-being.
This study determined the effects of endurance or resistance exercise training on maximal O2 consumption (VO2max) and the cardiovascular responses to exercise of 70- to 79-yr-old men and women. Healthy untrained subjects were randomly assigned to a control group (n = 12) or to an endurance (n = 16) or resistance training group (n = 19). Training consisted of three sessions per week for 26 wk. Resistance training consisted of one set of 8-12 repetitions on 10 Nautilus machines. Endurance training consisted of 40 min at 50-70% VO2max and at 75-85% VO2max for the first and last 13 wk of training, respectively. The endurance training group increased its VO2max by 16% during the first 13 wk of training and by a total of 22% after 26 wk of training; this group also increased its maximal O2 pulse, systolic blood pressure, and ventilation, and decreased its heart rate and perceived exertion during submaximal exercise. The resistance training group did not elicit significant changes in VO2max or in other maximal or submaximal cardiovascular responses despite eliciting 9 and 18% increases in lower and upper body strength, respectively. Thus healthy men and women in their 70s can respond to prolonged endurance exercise training with adaptations similar to those of younger individuals. Resistance training in older individuals has no effect on cardiovascular responses to submaximal or maximal treadmill exercise.
Nuclear magnetic resonance imaging (MRI) was clinically useful in a case of aortic annular pseudoaneurysm complicating bacterial endocarditis. The MRI findings were proven by angiography and surgery. Although surgical correction was attempted, the aneurysm recurred and has been followed by MRI and two-dimensional echocardiography. In addition to two-dimensional echocardiography, MRI represents a useful noninvasive imaging method for diagnosis and follow up of aortic annular pseudoaneurysm.