Association of salivary cortisol levels and later depressive state in elderly people living in a rural community: a 3-year follow-up study

Abstract

Background: Late-life depressive disorder is becoming an important issue in health economics in the world, as it has been reported to be one of major risk factors for incidence of dementia. Identification of predictive markers associated with depression in later life is therefore of high priority in public health. The aim of the study was to examine the association of salivary cortisol levels with a later depressive state in elderly healthy people living in a rural Japan community.

Methods: Salivary cortisol levels were measured in 68 elderly healthy people (24 men; 44 women) followed by completion of the BDI, MMSE, and FAB from 2004 to 2006. The same cohort underwent BDI again from 2007 to 2009.

Results: In healthy elderly women subject, a significant positive correlation was found between salivary cortisol levels at baseline and BDI scores at follow-up, but not at baseline. Salivary cortisol levels at baseline were not correlated with the score of either MMSE or FAB. When the cut-off point of BDI scores were set at 20/21, logistic regression analyses revealed that salivary cortisol levels at baseline had a significant positive relationship with a later depressive state. Age and gender were also significantly related with a later depressive state.

Limitations: The present study involves small number of participants.

Conclusions: Higher salivary cortisol levels were associated with a later depressive state in elderly healthy women living in rural community. Salivary cortisol might be a predictive marker for a later depressive state in elderly women.

Keywords: Cognitive decline; Depressive state; Elderly healthy people; Salivary cortisol.