Higher cumulative physiologic stress reflected in salivary cortisol was associated with faster cognitive decline, a prospective study showed.
Older adults with high cumulative cortisol exposure had worse composite global cognition scores over time, reported Ted K. S. Ng, PhD, of Rush University Medical Center in Chicago, at the Alzheimer's Association International Conference. The findings were published in JAMA Network Open.
A moderate level of intra-day cortisol variability was associated with slower cognitive decline, Ng said. Black and white participants had different cortisol profiles at baseline, but associations between cortisol and cognitive decline were similar across racial groups.
"Our study suggests that how cortisol fluctuates across the day may provide important insights into cognitive aging," Ng noted.
"We examined five complementary indices capturing three key physiological dimensions of diurnal cortisol regulation -- intra-day variability, cumulative daily exposure, and diurnal change -- rather than relying on a single cortisol measure," he told MedPage Today. "We found that these different dimensions showed distinct relationships with cognitive aging, suggesting that different aspects of stress physiology may provide complementary insights."
