Regarding disturbed sleep patterns, a group of researchers investigated the circadian sleep/wake-related neuroendocrine and immune functions among CFS patients. Eleven CFS patients, and two control groups containing healthy participants or healthy participants with symptoms of fatigue, were included in the overnight study. Blood samples were drawn from each test group, and analyzed.
The amounts and activity of T-cells and natural killer cells were analyzed by immuno-fluorescence technique with flow cytometry. The plasma was assessed for cortisol, human growth hormone, and prolactin. Analysis were performed for sleep stages as well. In comparison to the two control groups, altered patterns of cortisol, prolactin, and natural killer cells which accompany the alpha EEG sleep disorder, sleepiness, pain, and daytime fatigue were found in CFS patients.