The cortisol awakening response in amyotrophic lateral sclerosis is blunted and correlates with clinical status and depressive mood

Abstract

Considerable evidence indicates that amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease of the motor system, has an enormous impact on the patient's emotional and physical well-being. As previous findings indicated that particularly the rise in cortisol levels immediately after awakening, i.e., the cortisol awakening response (CAR), is associated with indices of physical and emotional well-being, we compared the CAR of 29 admitted ALS patients with that of 12 age-matched caregiver controls. Saliva samples for cortisol measurement were collected immediately, 15, 30 and 45 min after awakening. The severity of ALS progression was quantified using the ALS functional rating scale (ALSFRS) and manual muscle test (MMT). Depressive mood status in ALS patients was determined with the Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS). Salivary cortisol levels of ALS patients did not differ from those of caregiver controls at awakening, 15 min or 45 min after awakening, but were significantly lower at 30 min after awakening. Area under the curve analysis confirmed that the CAR was significantly smaller in ALS patients than in caregiver controls. A smaller CAR in ALS patients was significantly correlated to poorer clinical status, as assessed with both the ALSFRS and MMT rating instruments. Further, a smaller CAR significantly correlated with a more severe depressive mood status. No correlations were observed between total cortisol output during the first 45 min post-awakening and clinical or depressive status. In conclusion, our findings indicate that ALS patients show a blunted CAR, correlated with disease and depression severity.