What This Means
This research suggests that the cortisol awakening response (CAR) — a measure of how cortisol, the body's stress hormone, rises in the first hour after waking — is quite stable and predictable over time in people who have aphasia following a stroke. Two participants with aphasia independently collected saliva samples at home upon waking and at 30 and 60 minutes after waking, across 12 days spread over a month, while also reporting on their sleep, stress levels, and emotions. The CAR remained consistent from day to day and week to week for both individuals, suggesting that this biological stress marker does not fluctuate dramatically in this population over short-to-medium timeframes.
The study also examined whether everyday factors like sleep quality, how long someone slept, perceived stress, and emotional state were related to the CAR. While some weak-to-moderate relationships were observed, none reached statistical significance — possibly because these self-reported variables also remained fairly stable throughout the study period, leaving little variation to analyze. Importantly, both participants with aphasia were able to complete the home-based saliva collection independently, demonstrating that this type of research is feasible even for people with communication and language difficulties resulting from stroke.
This research matters because people with aphasia are an understudied population in stress and health research, partly due to challenges with communication and participation in complex study protocols. This pilot work suggests that larger studies tracking stress biology in people with aphasia are achievable, and that the CAR could be a useful, reliable measure for understanding how stress and recovery interact in this group. The findings lay groundwork for future studies that could ultimately help identify modifiable factors — like sleep and stress management — that might support recovery after stroke.