Cortisol, estrogens and risk of ischaemic heart disease, cancer and all-cause mortality in postmenopausal women: a prospective cohort study.

BACKGROUND

Chronic stress may affect morbidity and mortality through neuroendocrine changes, and the ratio of cortisol to sex steroid hormones has been suggested as a biomarker of stress. We aim to address a relation between the ratio of cortisol to estrogens (C/E) and risk of ischaemic heart disease (IHD), hormone-dependent cancers and all-cause mortality among postmenopausal women.

METHODS

Estradiol and cortisol were measured in a subset of 838 women randomly drawn from the second wave of the Copenhagen City Heart Study (n = 5297 examined in 1981-83) as well as among all women who developed hormone-dependent cancers after baseline. The participants were followed in nationwide registers until 2007, with < 0.1% loss to follow-up.

RESULTS

The C/E ratio was not associated with self-reported stress, and there were no clear associations with IHD (highest vs lowest quartile: HR = 1.23; 95% confidence interval 0.83-1.81), hormone-dependent cancers (0.69; 0.45-1.08) or all-cause mortality (1.10; 0.86-1.41).

CONCLUSIONS

The C/E ratio was not associated with morbidity and mortality in women, and we cannot replicate the robust findings of a relation between the cortisol to testosterone ratio and IHD previously reported in men. Whether the C/E ratio is a reasonable biomarker of stress is debatable.