Charlene Belanger

Early menopause and the risk of myocardial infarction.

We evaluated the relation between age at menopause and the risk of nonfatal myocardial infarction (MI) among 121,964 nurses who responded to a mail questionnaire. Of 279 women who reported having been hospitalized for MI, 123 (44%) were postmenopausal (i.e., no longer menstruating) at the time of hospitalization, compared with 1,859 (33%) of 5,580 age-matched control subjects. Among women who became menopausal because of bilateral oophorectomy, the estimated relative risk of MI increased with decreasing age at menopause, and women who underwent bilateral oophorectomy before age 35 were estimated to have a risk of hospitalization for MI approximately 7.2 times (95% confidence interval, 4.5 to 11.4) that of premenopausal women. Hysterectomy without the removal of both ovaries was only weakly associated with an increased risk. The data support the hypothesis that premature cessation of ovarian function increases the risk of nonfatal MI.

Use of postmenopausal hormones and risk of myocardial infarction.

Information was collected by mail survey about myocardial infarction (MI), use of female hormones after menopause, and coronary risk factors from 121,964 registered nurses ages 30-55 years. One hundred twenty-three women with a known type of prior menopause reported hospitalization for MI. Overall, use of female hormones by these women was very similar to that of control women matched for age and type of menopause. Compared with nonusers, the relative risk (RR) for women who had ever taken female hormones was 0,9 (95% confidence limits 0.6-1.2), and for current users the RR was 0.7 (0.5-1.1). For women with bilateral oophorectomy, the RR for current users was 0.4 (0.20.8). These data imply that, at present, a decision to prescribe postmenopausal hormones should be based primarily on weighing possible benefits from the relief of menopausal symptoms against known or suspected risks of other diseases, particularly uterine cancer in women with an intact uterus.

Characteristics of respondents and non-respondents to a mailed questionnaire.

In establishing a cohort of U.S. nurses, an assessment of response bias was made comparing respondents and non-respondents with regard to age, education, state of residence, employment status, field of employment, and major specialty. Overall, the 122,328 respondents (69.7 per cent) and 43,222 non-respondents were quite similar. Together with the reasonable response rate in a homogeneous population, this suggests that estimation of exposure-disease associations is unlikely to be affected by major bias due to non-response.

Use of permanent hair dyes and cancer among registered nurses.

Abstract A survey of 120 557 married, female, registered U.S. nurses, aged 30 to 55 years, carried out in 1976, showed that 38 459 (31·9%) had at some time used hair dyes, and 3548 (2·9%) had had cancer. For all cancers combined, the risk ratio (R.R.) for the development of cancer among women who had used hair dyes at any time, compared with those who had never used them, was 1·10 (P=0·02). When cancers were subdivided by anatomical site into 16 main groups, only those of the cervix uteri (R.R.=1·44, P

A case-control study of risk indicators among women with premenopausal and early postmenopausal breast cancer.

Among 714 premenopausal and 130 postmenopausal breast cancer cases matched with 8440 controls for age in years and menopausal status, risk indicators for breast cancer were similar, although most associations were stronger in the premenopausal women. Compared with nulliparous women, the relative risk (RR) for those with first birth before age 25 years was 0.7 (95% confidence limits [CL] from 0.5 to 0.9) among premenopausal women, and 0.7 (0.4–1.4) for postmenopausal women. In the premenopausal cases, a history of breast cancer in a sister gave a RR of 3.0 (2.1–4.1) and in a mother 1.9 (1.4–2.5), whereas for the postmenopausal women the RRs were 1.4 (0.6–3.1) and 13 (0.6–2.6), respectively. Fibrocystic breast disease was also a significant predictor of subsequent breast cancer in the premenopausal and postmenopausal women. In relation to women having a single birth, premenopausal women with six or more births had a risk of breast cancer of 0.6 (0.4–1.0), which was present even after adjustment for age at first birth.

The Nursesʼ Health Study

RESULTS — During 2.22 million person-years of follow-up, 1,398 women had a hip fracture. Compared with women without diabetes, the age-adjusted relative risk (RRs) of hip fracture was 7.1 (95% CI 4.4–11.4) for women with type 1 diabetes and 1.7 (1.4–2.0) for those with type 2 diabetes. After further adjustment for BMI, smoking, physical activity, menopausal status, daily intake of calcium, vitamin D, protein, and postmenopausal hormone use, the multivariate RR of incident hip fracture in individuals with type 1 diabetes compared with individuals without diabetes was 6.4 (3.9–10.3) and with type 2 diabetes was 2.2 (1.8–2.7). The RRs increased with longer duration of type 2 diabetes (3.1 [2.3–4.0] for 12 years compared with no diabetes, P for trend 0.001) and ever use of insulin.