Elevated salivary cortisol in the evening in healthy elderly men and women: Correlation with bone mineral density

Background Aging is associated with a loss of bone mineral density (BMD) in men and women. Loss of BMD can also be caused by hypercortisolemia in men or women at any age, This study measured salivary cortisol at 2300 h and 07 00 h as indices of cortisol secretory activity in 228 elderly, community-dw elling subjects. Salivary cortisol results were correlated with BMD. We hyp othesized that salivary cortisol is elevated at 2300 h in elderly people, a nd that salivary cortisol will correlate negatively with BMD. Methods. Saliva was sampled at 2300 h (nadir in circadian rhythm) and 0700 h (peak in circadian rhythm) in 130 men (70.7 +/- 0.4 years old) and 98 wom en (70.0 +/- 0.4 years old); approximately half of the women were receiving hormone replacement therapy (I IRT). BMD was measured by dual energy x-ray absorptiometry. Results. Salivary cortisol at 2300 h was significantly elevated in men (2.3 +/- 0.1 nmol/L) and women (2.1 +/- 0.1 nmol/L) as compared to 73 younger c ontrols (1.2 +/- 0.1 nmol/L; 37 +/- 1 year old). Salivary cortisol at 0700 h was not different between older subjects and younger controls. There was a significant negative correlation of lumbar (L2 - 4) BMD and 2300 h saliva ry cortisol in older women (r = - 0.20, p = .05; n = 98); this correlation was significant only in women not on HRT. There was a highly significant ne gative correlation of lumbar (L2 - 4) BMD and 0700 h salivary cortisol in o lder men (r = - 031,p = .0003). Conclusions. Salivary cortisol is a simple, nonstressful method for assessi ng activity of the hypothalamic-pituitary-adrenal (HPA) axis in the elderly population. A major finding was an elevation in the late night nadir in co rtisol secretion. We also suggest that elevated cortisol secretion in elder ly people may contribute to the age-related loss in bone mineral density an d that this effect is prevented by HRT.