The New England journal of medicine
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We studied the relation of oxygen delivery, mixed venous oxygenation, and pulmonary hemodynamics to prognosis in 50 randomly selected patients with chronic obstructive pulmonary disease. Cardiac catheterization was performed when the patients were clinically stable. Four years later, 27 patients (54 per cent) had died of respiratory failure. ⋯ After inhalation of 100 per cent oxygen for one hour, the mixed venous oxygen tension of nonsurvivors rose to a level equivalent to that of survivors, and their mean pulmonary arterial pressure fell significantly. These results indicate that, with respect to oxygen supply to the tissues, mixed venous oxygenation is one of the important prognostic factors in chronic obstructive pulmonary disease. Pulmonary and right ventricular hemodynamics measured during periods of clinical stability do not differentiate nonsurvivors from survivors.
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We studied 374 women taking oral contraceptives, 284 women taking estrogen preparations after menopause, and 1086 women taking no hormones, to determine the relation of plasma lipids and lipoprotein cholesterol concentrations to various types of estrogen/progestin formulations. Premenopausal women, using oral contraceptives containing a relatively low dose of estrogen combined with a medium or high dose of progestin (Norlestrin, Ovral, or Demulen) had a 24 per cent higher median concentration of low-density-lipoprotein cholesterol than did those not using hormones (P less than 0.05). ⋯ In postmenopausal women the use of estrogen was associated with concentrations of low-density-lipoprotein cholesterol that were 11 to 19 per cent below the levels in postmenopausal women who did not use hormones. The effects of estrogen-progestin balance on low-density and high-density lipoproteins may underlie the increased incidence of stroke and myocardial infarction in women of childbearing age who take oral contraceptives.