Análise do potencial da razão cortisol/dheas capilar como indicador de nível de estresse e declínio cognitivo em idosos

Abstract

Chronic stress is related to an early and exacerbated decline in cognitive function in the elderly, which appears to be mediated by cortisol. However, studies seeking to establish associations between cortisol levels and cognitive performance in the elderly are controversial, in part because of the type of biological sample they use (serum, urine saliva), which is not able to monitor long-term changes in the secretion of cortisol, and possibly for analyzing only cortisol, ignoring neuroprotective steroids, such as DHEA-S. The present study aimed to verify whether the cortisol/DHEA-S ratio of hair samples is a more sensitive biomarker of cognitive dysfunction in the elderly than hair cortisol alone. Elderly (70.60 ± 7.74 years, n = 59) were classified according to the Lipp Stress Symptoms Inventory for Adults into two groups, stressed and not stressed (control), and subjected to a battery of neuropsychological tests that evaluated components of executive function (Trail A and B, Direct and Reverse Span, Stroop, Verbal and Phonemic Fluency) and declarative memory (Logical Memory I and II). Hair samples were collected to measure cortisol and DHEA-S levels by Tandem Mass Spectrometry (LC-MS/MS). Elderly of the stress group presented a slight cognitive impairment in comparison to the control group and higher levels of cortisol and cortisol/DHEA-S ratios. Cortisol showed a more robust association with stress than the cortisol/DHEA ratio. However, no significant associations were found between cortisol or the cortisol/DHEA ratio and cognitive performance in the elderly. In conclusion, capillary cortisol was a more sensitive marker of stress than the cortisol/DHEA-S ratio. Still, none of the measures was able to predict the cognitive performance of the elderly.