All women diagnosed with breast cancer before age 36 in eleven geographical areas in Britain were included in a case-control study designed to investigate the relation between oral contraceptive (OC) use and breast cancer risk. 755 cases each with a matched control were interviewed in their homes by trained interviewers. General practitioner notes and family planning clinic records were abstracted and combined with the interview data. There was a highly significant trend in risk of breast cancer with total duration of OC use with relative risks of 1.43 (95% confidence interval 0.97-2.12) for 49-96 months use, and 1.74 (95% confidence interval 1.15-2.62) for 97 or more months use. The relative risks were similar for use before and after first full-term pregnancy. There is some evidence that OCs containing less than 50 micrograms oestrogen have a lower risk associated with their use than higher oestrogen dose OCs and that there may be some protective effect of use of progestagen-only pills. These apparent differences between OC types are only marginally significant statistically and need further investigation. Extensive investigations of possible bias using data abstracted from general practitioner notes for both interviewed and non-interviewed cases and controls demonstrate that biases cannot explain these results although some relative risks may be slightly exaggerated. There is, however, no support for these findings in national breast cancer registration rates which are not increasing.

Some studies have suggested that lean hypertensive men may be at greater risk of major ischaemic heart disease (IHD) events than obese hypertensive men. The issue was examined on data from the British Regional Heart Study for 7735 middle-aged men followed up for an average of 7.5 years; during this time 443 men experienced a major IHD event. Hypertension was defined as systolic blood pressure of 160 mm Hg or above, diastolic blood pressure of 95 mm Hg or above, or receiving treatment for hypertension. For both hypertensive and normotensive men the rate of major IHD events, standardised for age and cigarette smoking, rose with increasing body mass index (BMI). The relative odds associated with a 5 kg/m2 difference in BMI (ie, a 15 kg difference in weight in men of average height [1.73 m]) were 1.30 (p = 0.02) and 1.43 (p = 0.0004) for hypertensive and normotensive men, respectively. A review of eleven prospective studies, including the British Regional Heart Study, presented in standard form for comparative purposes, suggests that lean hypertensive men are not at higher risk of major IHD events than overweight/obese hypertensive men. There seems to be no justification for the suggestion that a policy of weight reduction to lower blood pressure might be inappropriate.