Plasma cortisol level in amyotrophic lateral sclerosis
Amyotrophic Lateral sclerosis (ALS) is associated with a significant distress, being linked to changes in hypothalamic-pituitary-adrenal axis activity. A loss of cortisol circadian rhythmicity in ALS patients was suggested,while more recently an increased plasma cortisol level in the disease has been reported. To assay the circadian plasma cortisol level in ALS and to study its relationship with the clinical phenotype and the rate of disease progression. 135 ALS patients (Bulbar, 33; Spinal, 102;M/F=1.73) and 110 controls (not affected by neurological or psychiatric disorders, free of drugs; M/F=1.75) were recruited. Disease progression was scored with ΔFS.Morning and evening plasma cortisol levels (μg/dl)were assayed from fasting ALS patients and controls using Elecsys® Cortisol Immunoassay System. We found that the morning level of cortisol in ALS patients was higher than controls (morning: ALS, 15.2[11.5-18.9] vs Controls, 11.4 [8.8 -14.3], p b 0.001; evening: ALS, 7.5[4.7–11.8] vs Controls, 7.9[5.4–10.0], p=0.6).Furthermore, the hormone's level was higher in the spinal-onset group (Spinal, 15.9[11.9–19.0] vs Bulbar,13.5[10.1–18.6] vs controls, 11.4[8.8–14.3], p b 0.001) and in patients with intermediate/rapid disease course. Morning plasma cortisol level is increased in ALS, mainly in spinal-onset patients and in those with intermediate/rapidly progressing disease. The plasmatic changes of the steroid hormone appear however too small to make it a sensitive biochemical marker in this severe neurodegenerative disease.