Cross‐Sectional Links between Baseline Serum Cortisol Levels and Cognitive Performance, Sleep, and Brain MRI Findings in a Rural Aging South‐Indian Cohort

The findings suggest that lower serum cortisol levels, rather than higher levels as previously suggested, are associated with poorer cognitive performance in the attention domain and increased reliance on sleep medication. These results highlight the potential role of adrenal insufficiency, whether endogenous or exogenous, in cognitive function and sleep quality in aging populations. Further research is needed to explore this association by using diagnostic criteria to characterize adrenal insufficiency and investigating its impact on cognition and brain MRI volumes.