Low-dose oral contraceptive use and the risk of myocardial infarction.
Autor: | Rosenberg L; Slone Epidemiology Unit, Boston University School of Medicine, 1371 Beacon St, Brookline, MA 02446, USA. lrosenberg@slone.bu.edu, Palmer JR, Rao RS, Shapiro S |
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Jazyk: | angličtina |
Zdroj: | Archives of internal medicine [Arch Intern Med] 2001 Apr 23; Vol. 161 (8), pp. 1065-70. |
DOI: | 10.1001/archinte.161.8.1065 |
Abstrakt: | Background: Studies of oral contraceptives (OCs) containing 50 microg or more of estrogen suggest an increased risk of myocardial infarction (MI) among current users, particularly if they smoke heavily. Objective: To assess whether use of the newer lower-dose OCs increases the risk of MI. Methods: A case-control study was conducted from January 1985 through March 1999 in 75 hospitals in the greater-Boston and greater-Philadelphia areas. Data on OC use and MI risk factors were obtained by interview from 627 women with a nonfatal first MI (cases) and 2947 female hospital controls younger than 45 years. Results: The overall odds ratio (OR) for current OC use relative to never used was 1.3 (95% confidence interval [CI], 0.8-2. 2). The OR was elevated, 2.5 (95% CI, 0.9-7.5), among heavy smokers (>/=25 cigarettes per day) but close to 1.0 among lighter smokers (OR = 0.8) and nonsmokers (OR = 1.3). For current OC use together with heavy smoking relative to nonuse and nonsmoking, the OR was 32 (95 % CI, 12-81), considerably greater than that for heavy smoking alone, 12 (95% CI, 8.6-16). The ORs did not vary according to the type of formulation or the dose of estrogen; there were too few users to assess the new 20-microg preparations. Past OC use was unrelated to risk. Conclusion: Current use of low-dose OCs in the United States is unrelated to an increased risk of MI among nonsmokers and light smokers, but users who smoke heavily may be at greatly increased risk. |
Databáze: | MEDLINE |
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