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T Hartwell

Publications and source records attributed to T Hartwell.

14 recordsLinked to original sources
PubMed1998

Diabetes mellitus and its complications in an African-American community: project DIRECT.

Project DIRECT (Diabetes Intervention Reaching and Educating Communities Together) is a multilevel community-based intervention project designed to address diabetes and its complications in an African-American community. This article presents results of the Project DIRECT pilot study and describes risk factors for diabetes, diabetes prevalence, complications, and care practices. During 1993, a pilot study was conducted among persons 20 to 74 years of age in Wake County, North Carolina. The study involved household interviews and examinations, and more extensive health center interviews and examinations based on the race of the head of the household, previous diagnosis of diabetes, and results of capillary glucose tests done in the household. Of the black population aged 20 to 74 years, 52 +/- 3% reported being inactive and 51 +/- 3% were overweight; the prevalence of diagnosed diabetes was 5.2 +/- 0.9%; the prevalence of undiagnosed diabetes was 5.7 +/- 2.7%; and the prevalence of impaired glucose tolerance was 11.4 +/- 7.5%. Blacks with diabetes were significantly more likely than nonblacks with diabetes to have uncontrolled hypertension and to smoke cigarettes. Blacks with diabetes were significantly less likely to report having health insurance or to have a private health-care provider. Diabetes mellitus is a major public health problem in the African-American community of Wake County. Modifiable risk factors for diabetes and undiagnosed diabetes are common. Project DIRECT is attempting to improve the health-related quality of life of this population by reducing the burden of diabetes and its complications through a multilevel, community-based intervention.

Adult↗
PubMed1998

A project to reduce the burden of diabetes in the African-American Community: Project DIRECT.

Project DIRECT (Diabetes Interventions Reaching and Educating Communities Together) is the first comprehensive community diabetes demonstration project in the United States in an African-American community. This article describes its intervention components and evaluation design. The development and implementation of Project DIRECT has included the community since the project's beginning. Interventions are targeted in three areas: health promotion (improving diet and physical activity levels), outreach (improving diabetes awareness, detection of undiagnosed diabetes, and ensuring that persons with diabetes who are not receiving continuing diabetes care are integrated into the health-care system), and diabetes care (improving self-care, increasing access, and improving the quality of diabetes preventive care received within the health-care system). Evaluation will be internal (conducted by Project DIRECT staff to assess process outcomes in persons directly exposed to each specific intervention) and external (review of outcomes to assess the impact of the multi-intervention program at the level of the entire community). Because diabetes exacts a disproportionate toll among African Americans, the findings from this project should aid in developing strategies to lessen the burden of this disorder, particularly among minority populations.

Black or African American↗
PubMed1995

Smokers' baseline characteristics in the COMMIT trial.

BACKGROUND: Baseline telephone survey data from 10 COMMIT sites were submitted to statistical analyses to compare the smoking characteristics of non-Hispanic white (white), non-Hispanic black (black), Mexican-origin (Mexican), and Puerto Rican-origin (Puerto Rican) smokers. RESULTS: White men and women were more likely to be classified as "heavy smokers" than members of other racial/ethnic groups, although black and Puerto Rican smokers were more likely than whites to increase their smoking rates on weekends. Whites were less likely to report stopping smoking in the past. White and Mexican smokers were most likely to smoke light or ultralight brands and least likely to smoke menthol cigarettes. Blacks were most likely to report smoking their first cigarette of the day within 10 min of waking. CONCLUSION: The differences and similarities among different groups of smokers may have important implications for understanding patterns of tobacco-related disease in smokers from different racial/ethnic and sex groups.

Adult↗
PubMed1994

Effect of lovastatin on early carotid atherosclerosis and cardiovascular events. Asymptomatic Carotid Artery Progression Study (ACAPS) Research Group.

BACKGROUND: HMG CoA reductase inhibitors (or statins), a new class of lipid-lowering compounds, have raised expectations for more widespread use than that of the older lipid-lowering drugs. Not only are they more effective in lowering LDL cholesterol, but they are better tolerated as well. No data exist concerning the effect of statins on early carotid atherosclerosis and clinical events in men and women who have moderately elevated LDL cholesterol levels but are free of symptomatic cardiovascular disease. METHODS AND RESULTS: Lovastatin (20 to 40 mg/d) or its placebo was evaluated in a double-blind, randomized clinical trial with factorial design along with warfarin (1 mg/d) or its placebo. This report is limited to the lovastatin component of the trial. Daily aspirin (81 mg/d) was recommended for everyone. Enrollment included 919 asymptomatic men and women, 40 to 79 years old, with early carotid atherosclerosis as defined by B-mode ultrasonography and LDL cholesterol between the 60th and 90th percentiles. The 3-year change in mean maximum intimal-medial thickness (IMT) in 12 walls of the carotid arteries was the primary outcome; change in single maximum IMT and incidence of major cardiovascular events were secondary outcomes. LDL cholesterol fell 28%, from 156.6 mg/dL at baseline to 113.1 mg/dL at 6 months (P < .0001), in the lovastatin groups and was largely unchanged in the lovastatin-placebo groups. Among participants not on warfarin, regression of the mean maximum IMT was seen after 12 months in the lovastatin group compared with the placebo group; the 3-year difference was statistically significant (P = .001). A larger favorable effect of lovastatin was observed for the change in single maximum IMT but was not statistically significant (P = .12). Five lovastatin-treated participants suffered major cardiovascular events--coronary heart disease mortality, nonfatal myocardial infarction, or stroke--versus 14 in the lovastatin-placebo groups (P = .04). One lovastatin-treated participant died, compared with eight on lovastatin-placebo (P = .02). CONCLUSIONS: In men and women with moderately elevated LDL cholesterol, lovastatin reverses progression of IMT in the carotid arteries and appears to reduce the risk of major cardiovascular events and mortality. Results from ongoing large-scale clinical trials may further establish the clinical benefit of statins.

Adult↗
PubMed1992

Analysis strategies for serial multivariate ultrasonographic data that are incomplete.

Ultrasonographic measurement of intima-media thickness in the carotid artery has emerged as an important non-invasive means of assessing atherosclerosis, and has served to define primary outcome measures related to progression of arterial lesions in several large clinical trials and epidemiologic studies. It is characteristic that measurements often cannot be obtained from all sites during repeated examinations. This leads to incomplete multivariate serial data, for which the set and number of visualized sites may vary across time. We have contrasted several conditional and unconditional maximum likelihood analytical approaches, and have evaluated these with a simulation experiment based on characteristics of ultrasound measurements collected during the course of the Asymptomatic Carotid Artery Plaque Study. We examined analyses based on unweighted and generalized least squares regression in which we estimated cross-sectional summary statistics using raw means, unconditional maximum likelihood estimates and full maximum likelihood estimates. Since the genesis of missing data is not fully clear, and since the approaches we examined are based, to some degree, on the assumption that data are missing at random, we also examined the relative impact of deviations from such an assumption on each of the approaches considered. We found that maximum likelihood based approaches increased the expected efficiency of the analysis of serial ultrasound data over ignoring missing data by up to 21 per cent.

Arteriosclerosis↗
PubMed1992

Reproducibility of noninvasive ultrasonic measurement of carotid atherosclerosis. The Asymptomatic Carotid Artery Plaque Study.

BACKGROUND AND PURPOSE: To determine the effect of a lipid-lowering agent and/or a low-dose antithrombotic agent on the progression of early-stage carotid atherosclerosis, noninvasive B-mode ultrasound was used to measure intimal-medial thickness in asymptomatic individuals with moderately elevated lipids as part of the ongoing multicenter Asymptomatic Carotid Artery Plaque Study. METHODS: Uniform ultrasonic scanning and reading protocols were implemented to obtain maximum intimal-medial thickness measurements in 12 standard segments in patients having a small to moderate wall thickness (1.5-3.5 mm) in at least one of the carotid arteries. Paired B-mode image recordings on 858 patients, performed 1 month apart and read at a core laboratory (each pair by the same reader), determined both within-sonographer (W, n = 405) and between-sonographer (B, n = 453) reproducibility. RESULTS: The primary end point (mean +/- SD), defined in each individual as the mean value of the 12 maximum intimal-medial thickness measurements, was 1.31 +/- 0.21 mm (W) and 1.32 +/- 0.22 (B) at the time of the second examination. The mean difference in the primary end point (exam 2-exam 1) was -0.01 +/- 0.13 mm (W) and 0.00 +/- 0.15 mm (B). The Pearson correlation coefficients were 0.79 (W) and 0.75 (B). In 90% of the patients, the absolute difference in the primary end point was less than 0.22 mm (W) and less than 0.24 mm (B). Variability of the secondary end point, defined as the single largest intimal-medial thickness measurement in a patient, was between three and four times larger than the variability for the primary end point. Differences in sonographer performance between clinical centers were very small. CONCLUSIONS: The results demonstrate that standardized noninvasive ultrasonic techniques yield highly reproducible measures of carotid intimal-medial thickness, which can serve as a measure of carotid atherosclerosis in clinical trials that monitor small rates of lesion progression.

Adult↗
PubMed1991

The Los Angeles TEAM Study: personal exposures, indoor-outdoor air concentrations, and breath concentrations of 25 volatile organic compounds.

The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that indoor air concentrations exceeded outdoor concentrations by a factor of about three.

Adolescent↗
PubMed1989

The effect of diabetes mellitus on prognosis and serial left ventricular function after acute myocardial infarction: contribution of both coronary disease and diastolic left ventricular dysfunction to the adverse prognosis. The MILIS Study Group.

Patients with diabetes mellitus experience a more adverse outcome after acute myocardial infarction compared with nondiabetic patients, although the mechanisms responsible for these findings are not clear. From the Multicenter Investigation of the Limitation of Infarct Size (MILIS) study, the course of acute infarction in 85 diabetic patients was compared with that in 415 nondiabetic patients, all of whom had serial assessments of left ventricular function. The diabetic patients experienced a more complicated in-hospital and postdischarge course than did the nondiabetic patients, including a higher incidence of postinfarction angina, infarct extension, heart failure and death, despite the development of a smaller infarct size and similar levels of left ventricular ejection fraction. Although diabetic patients had a worse profile of cardiovascular risk factors at the time of the index infarction, the increased incidence of adverse outcomes among them persisted despite adjustment for these baseline imbalances. Diabetic women had a poor baseline risk profile compared with the other groups categorized by gender and diabetic status, and experienced an almost twofold increase in cardiac mortality despite development of the smallest infarct size during the index event. The duration of diabetes and the use of insulin at the time of the index infarction were associated with a better in-hospital mortality rate, but the duration of diabetes did not exert a major influence on the outcome of the diabetic patients. The factors responsible for the increased incidence of adverse outcomes among diabetic patients may be related to an acceleration of the atherosclerotic process, diastolic left ventricular dysfunction associated with diabetic cardiomyopathy or other unidentified unfavorable processes.

Cardiovascular Diseases↗
PubMed1988

Electrocardiographic diagnosis of myocardial infarction in the presence of complete left bundle branch block.

Whether myocardial infarction (MI) can be diagnosed electrocardiographically in the presence of left bundle branch block (LBBB) is controversial. Our study sought to test the reliability of ECG criteria for diagnosing MI in patients with LBBB. Among 985 patients presenting within 18 hours of the onset of ischemic chest pain, 35 had complete LBBB. Acute MI was identified by serial MB-creatine kinase (CK) elevations and prior MI was determined by previously documented ECG and/or enzyme changes. Among those with LBBB, 24 patients had acute and/or prior MI, while 11 had neither. Eleven ECG criteria previously proposed for detecting MI in the presence of LBBB were evaluated. In patients presenting with ischemic chest pain and complete LBBB, presence of any one of the following ECG criteria was highly specific (90% to 100%) and predictive (85% to 100%) for acute or prior MI: Q waves in at least two of leads I, aVL, V5, or V6; R wave regression from V1 to V4; notching of the upstroke of the S wave in at least two of leads V3, V4, or V5, and primary ST-T wave changes in two or more adjacent leads.

Bundle-Branch Block↗
PubMed1986

Prognostic significance of the treadmill exercise test performance 6 months after myocardial infarction.

A submaximal treadmill exercise test performed before hospital discharge after an uncomplicated myocardial infarction is often utilized to estimate prognosis and guide management, but there is little experience with a maximal exercise test performed 6 months after infarction to identify prognosis later in the convalescent period. The performance characteristics during an exercise test 6 months after myocardial infarction were related to the development of death, recurrent nonfatal myocardial infarction and coronary artery bypass surgery in the subsequent 12 months (that is, 6 to 18 months after infarction) in 473 patients. Mortality was significantly greater in patients who exhibited any of the following: inability to perform the exercise test because of cardiac limitations, the development of ST segment elevation of 1 mm or greater during the exercise test, an inadequate blood pressure response during exercise, the development of any ventricular premature depolarizations during exercise or the recovery period and inability to exercise beyond stage I of the modified Bruce protocol. By utilizing a combination of four high risk prognostic features from the exercise test, it was possible to stratify patients in terms of risk of mortality, from 1% if none of these features were present to 17% if three or four were present. Recurrent nonfatal myocardial infarction was predicted by an inability to perform the exercise test because of cardiac limitations, but not by any characteristics of exercise test performance. Coronary artery bypass surgery was associated with the development of ST segment depression of 1 mm or greater during the exercise test. Although clinical evidence of angina and heart failure 6 months after infarction was predictive of subsequent mortality among all survivors, among the low risk group without severely limiting cardiac disease, the exercise test provided unique prognostic information not available from clinical assessment alone. Therefore, a maximal exercise test performed 6 months after myocardial infarction is a valuable, noninvasive tool to evaluate prognosis. It provides information that is independent of and additive to clinical evaluation performed at the same time.

Adrenergic beta-Antagonists↗
PubMed1986

Concentrations of 20 volatile organic compounds in the air and drinking water of 350 residents of New Jersey compared with concentrations in their exhaled breath.

Twenty volatile organic compounds were measured in the personal air and drinking water of 350 New Jersey residents in the fall of 1981. Two consecutive 12-hour integrated personal air samples and two tap water samples were collected from each participant. At the end of the 24-hour monitoring period, each participant supplied a sample of exhaled breath. Simultaneous outdoor samples were collected in 100 residential locations in two cities. Eleven compounds were present much of the time in air, but only four (the trihalomethanes) in water; wide ranges of exposures (three to four orders of magnitude) were noted for most compounds. Ten of 11 compounds displayed significant correlations between air exposures and breath concentrations; the 11th (chloroform) was correlated with drinking water exposures. It was concluded that breath measurements are a feasible, cost-effective, and highly sensitive way to determine environmental and occupational exposures to volatile organic compounds.

Air Pollutants↗
PubMed1984

Personal exposure to volatile organic compounds. I. Direct measurements in breathing-zone air, drinking water, food, and exhaled breath.

A pilot study to test methods of estimating personal exposures to toxic substances and corresponding body burdens was carried out between July and December 1980. Individual exposures to about a dozen volatile organic compounds in air and drinking water were measured for nine volunteers in Bayonne and Elizabeth, New Jersey, and for three volunteers in Research Triangle Park, North Carolina during three 3-day visits over the 6-month period. Breath samples were also collected from all subjects on each visit. Composite food samples were collected in each locality. Sampling and analytical methods for air, water, food, and breath were evaluated and found generally capable of detecting concentrations as low as 1 microgram/m3 in air and breath, and 1 ng/g in water and food. About 230 personal air samples, 170 drinking water samples, 66 breath samples, and 4 food samples (16 composites) were analyzed for the target chemicals. Ten compounds were present in air and eight were transmitted mainly through that medium. The two target trihalomethanes (chloroform and bromodichloromethane) were predominantly transmitted through water and beverages. Food appeared to be a minor route of exposure, except possibly for trichloroethylene in margarine. Seven compounds were present in more than half of the breath samples. Diurnal and seasonal variations were noted in air and water concentrations of some compounds, with summer levels generally higher. For some chemicals, weekday air exposures were significantly higher than weekend exposures. Some, but not all, of the potentially occupationally exposed individuals had significantly higher workplace exposures to several chemicals. Distributions of air exposures were closer to log normal than normal for most chemicals. Several chemicals were highly correlated with each other in personal air samples, indicating possible common sources of exposure.

Air Pollutants↗