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W T Friedewald

Publications and source records attributed to W T Friedewald.

At least 19 recordsLinked to original sources

A north-south comparison of blood pressure and factors related to blood pressure in the People's Republic of China: a report from the PRC-USA Collaborative Study of Cardiovascular Epidemiology.

OBJECTIVES: To compare blood pressures in northern (Beijing) and southern (Guangzhou) Chinese population samples aged 35-54 years, males and females, urban and rural, and to assess the role of blood pressure-related traits in explaining north-south differences. DESIGN: Cross-sectional surveys were conducted in 1983-1984 of northern and southern populations employed in industry (urban) or farming (rural). METHODS: In the north samples were selected from the Capital Iron and Steel Complex (urban) and Shijingshan district (rural); in the south samples from the Guangzhou Shipyard (urban) and Panyu County (rural) were used. RESULTS: The number of subjects surveyed in north and south were 4706 and 4179, respectively: 1500 and 1052 urban males, and 717 and 914 rural males; and 1300 and 1061 urban females, and 1189 and 1152 rural females, respectively. Average systolic (SBP) and diastolic (DBP) blood pressures, were consistently higher in the north than in the south. SBP and DBP were significantly and independently related to age, body mass index, heart rate, use of antihypertensive drugs, serum triglycerides level, alcohol use (males only) and inversely to cigarette smoking. Northerners were older, taller, heavier and had higher body mass index and triglycerides level than southerners. With adjustment of SBP and DBP for blood pressure-related traits, north-south blood pressure differences decreased, but remained significant for urban males, rural males and rural females, with sizeable differences for rural samples in particular. CONCLUSIONS: North-south differences in blood pressure in these samples are accounted for only partly by north-south differences in the cited blood pressure-related traits. The role of other traits requires assessment.

Adult

Overview of recent clinical and methodological advances from clinical trials of cardiovascular disease.

Concurrently controlled, randomized clinical trials play an important role in the validation of treatment and control measures of cardiovascular disease. As such trials have been carried to conclusion, a great deal has been learned not only about the treatment of the disease but also about the methodology of clinical trials. Seven recently completed clinical trials, the Coronary Drug Project, the Aspirin Myocardial Infarction Study, the Anturane Reinfarction Trial, the Hypertension Detection and Follow-Up Program and three drug trials of betablockers, are reviewed from the perspective of both their clinical and methodological significance.

Adrenergic beta-Antagonists

Clinical trials.

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Bibliographies as Topic

Treatment of hypertension with biofeedback and relaxation techniques.

The present study describes a 16-week trial of the use of a combination of biofeedback and relaxation techniques for the treatment of hypertension. Twenty-two hypertensive patients were randomly allocated to one of three groups: (1) diastolic blood pressure feedback, electromyographic feedback, and verbal relaxation; (2) sham blood pressure feedback; and (3) no treatment. For the 14 patients completing active treatment during an initial or crossover period, the average changes in blood pressure as measured outside the laboratory were minimal (0/-1 and +1/0 mm Hg, supine and standing, respectively). Average blood pressure reduction in the laboratory was no greater with active than with sham blood pressure feedback (-3/-2 vs. -5/-2 mm Hg). One subject, however, after showing no change in blood pressure during sham feedback, achieved pronounced and prolonged improvement following active treatment. Overall results do not support the usefulness of these techniques as primary therapy in most hypertensives.

Adult

Randomized clinical trials. Perspectives on some recent ideas.

In spite of the controversy over the role of randomized clinical trials in medical research, the rationale underlying such trials remains persuasive as compared to recent suggestions for alternative non-randomized studies such as those relying on the use of historical controls and adjustment technics. Others have suggested that recent statistical innovations for improving clinical trials, including adaptive allocation of treatment to patients and sequential stopping procedures, are underutilized. These innovations, though theoretically interesting, are not easily adapted to large-scale, complex medical trials in which there may be multiple end points and delayed response times. Ethical considerations suggest that randomized trials are more suitable than uncontrolled experimentation in protecting the interests of patients. Randomized clinical trials remain the most reliable method for evaluating the efficacy of therapies.

Biometry

Clinical trials of hepatitis B immune globulin. Development of policies and materials for the 1972-1975 studies sponsored by the National Heart and Lung Institute.

Plasma from persons with high titers of hepatitis B antibody (anti-HBs) was used to manufacture one lot of hepatitis B "immune" globulin sufficient for four interlocking clinical trials of prevention or modification of hepatitis B infections. The trials were carried out in renal dialysis units, in medical personnel with accidental exposures to hepatitis B, in transfused patients, and in patients with fulminant hepatitis. A single policy board developed protocols that allowed comparisons among the four studies while respecting the unique requirements of each.

Antibodies

Effect of elevated triglycerides on the diffusing capacity of man.

In view of the decreased diffusing capacity recently reported in man during lipid infusion, studies have now been made on the effects of hyperlipidemia on the diffusing capacity for carbon monoxide (DLco). In normal volunteers and patients with hyperlipidemias, DLco and plasma triglyceride concentrations were determined during fat tolerance tests and while the patients were on diets that increased or decreased triglyceride concentrations. During the fat tolerance tests, the largest triglyceride and DLco changes were from 346 mg per 100 ml with a DLco of 18.8 ml per min per mm Hg to 1,545 mg per 100 ml with a DLco of 23.4 ml per min per mm Hg. While patients were on speical diets, the largest triglyceride and DLco changes were from 5,102 mg per 100 ml and 29.0 ml per min per mm Hg to 492 mg per 100 ml and 26.4 ml per min per mm Hg, respectively. Sta tistical tests showed no significant change of DLco with change in triglyceride concentration. The data suggest that there is normally no association between change in triglyceride concentration and change in DLco, and that triglycerides normally transported in plasma, even when present in extreme amounts as chylomicrons or very-low-density lipoprotein, do not affect the DLco.

Adult