Hormone replacement therapy and incidence of acute myocardial infarction. A population-based nested case-control study.

BACKGROUND: Epidemiological studies suggest a decreased risk of coronary heart disease (CHD) in healthy women taking hormonal replacement therapy (HRT). Whether this effect is shared by oral and transdermal preparations is unknown. METHODS AND RESULTS: We conducted a population-based case-control study nested in a cohort of women 50 to 74 years of age without cardiovascular disease history in the United Kingdom. Among 164 769 women from the General Practice Research Database (January 1, 1991, to December 31, 1995), we identified 1242 first acute myocardial infarctions (AMI) and confirmed 1013 after medical record review. We randomly selected 5000 age-frequency-matched control subjects. AMI incidence was 1.6 per 1000 person-years; 13% and 17% of cases and control subjects used HRT within 6 months before the index date. Risk factor and comorbidity-adjusted OR of AMI for current-recent HRT users compared with nonusers was 0.72 (95% CI 0.59 to 0.89). The OR was similar within 30 days before the index date. The beneficial effect was present after 1 year of use (OR 0. 68; 95% CI 0.53 to 0.86), with no increase in risk within the first year. ORs for unopposed and opposed therapy were 0.52 (95% CI 0.35 to 0.78) and 0.79 (95% CI 0. 59 to 1.08); 79% and 21% used oral and transdermal therapy. The protective effect was present at medium-high doses of estrogens with ORs for oral and transdermal therapy of 0.63 (95% CI 0.46 to 0.86) and 0.62 (95% CI 0.37 to 1.06) and ceased after 2 to 3 years since stopping HRT. CONCLUSIONS: Results are consistent with those previously reported in women without CHD who were taking oral HRT and, although based on few users, suggest that transdermal therapy might have similar cardioprotective effects.

Low-dose diclofenac, naproxen, and ibuprofen cohort study.

The risk of a newly diagnosed episode of upper gastrointestinal bleeding, acute liver and renal failure, agranulocytosis, aplastic anemia, severe skin disorders, and anaphylaxis was examined within 30 days after the first prescription for a low dose of diclofenac, naproxen, or ibuprofen in a cohort in the United Kingdom. We identified 22,146 persons using diclofenac (< or = 75 mg), 46,919 using naproxen (< or = 750 mg), and 54,830 using ibuprofen (< or = 1200 mg). Age, gender, and comorbidity were similar in the three cohorts. Overall 64 potential cases were identified, and 20 were confirmed by medical record review. Incidence rates (95% CI) of upper gastrointestinal bleeding/10,000 people using diclofenac, naproxen, and ibuprofen were 1.8 (0.5-4.6), 2.3 (1.2-4.2), and 0.4 (0.04-1.3), respectively. There were three cases of hepatic injury, one with naproxen and two with ibuprofen. Although low, the incidence of gastrointestinal toxicity remains the main serious adverse event for all study drugs.

Hormone replacement therapy and risk of venous thromboembolism: population based case-control study.

OBJECTIVE: To evaluate the association between use of hormone replacement therapy and the risk of idiopathic venous thromboembolism. DESIGN: Population based case-control study. SETTING: Population enrolled in the General Practice Research Database, United Kingdom. SUBJECTS: A cohort of 347,253 women aged 50 to 79 without major risk factors for venous thromboembolism was identified. Cases were 292 women admitted to hospital for a first episode of pulmonary embolism or deep venous thrombosis; 10,000 controls were randomly selected from the source cohort. MAIN OUTCOME MEASURES: Adjusted relative risks estimated from unconditional logistic regression. RESULTS: The adjusted odds ratio of venous thromboembolism for current use of hormone replacement therapy compared with non-users was 2.1 (95% confidence interval 1.4 to 3.2). This increased risk was restricted to first year users, with odds ratios of 4.6 (2.5 to 8.4) during the first six months and 3.0 (1.4 to 6.5) 6-12 months after starting treatment. No major risk differences were observed between users of low and high doses of oestrogens, unopposed and opposed treatment, and oral and transdermal preparations. The risk of idiopathic venous thromboembolism among non-users of replacement therapy was estimated to be 1.3 per 10,000 women per year. Among current users, idiopathic venous thromboembolism occurs at two to three times the rate in non-users, resulting in one to two additional cases per 10,000 women per year. CONCLUSIONS: Current use of hormone replacement therapy was associated with a higher risk of venous thromboembolism, although the risk seemed to be restricted to the first year of use.

Nonsteroidal anti-inflammatory drugs and the risk of hospitalization for acute renal failure.

BACKGROUND: Few studies have evaluated the association between use of nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of idiopathic acute renal failure (ARF) in the general population. METHODS: Population-based case-control study among persons in the Canadian province of Saskatchewan who received at least 1 NSAID prescription between January 1, 1982, and December 31, 1986. Health department databases were used for case detection, as the sampling frame for selecting controls (n = 1997), and as the primary source of information on drug use and comorbidity. A total of 306 hospital records were reviewed. Twenty-eight patients who were hospitalized fulfilled the diagnostic criteria for ARF. RESULTS: The incidence rate of hospitalization for ARF among the general population not exposed to NSAIDs was 2 per 100000 person-years. Current exposure to NSAIDs, acetylsalicylic acid and other nephrotoxic drugs, male gender, increasing age, cardiovascular comorbidity, and recent hospitalization for disorders other than renal were found to be independent risk factors for ARF. Current NSAID users had an adjusted odds ratio for ARF of 4.1 (95% confidence interval, 1.5-10.8). The risk of ARF was especially high during the first month of use (odds ratio, 8.5). For prescribed dose, we found that users of high daily doses of NSAIDs experienced an odds ratio of 9.8 for ARF. CONCLUSIONS: In the general population, hospitalizations for ARF were found to be a rare condition. The 4-fold increase in risk associated with NSAID use was dose-dependent and occurred especially during the first month of therapy. Concurrent comedication with other potentially nephrotoxic agents should be prescribed with care, especially in the elderly.