Objective The aim of this study was to determine the effects of obesity on the waking diurnal testosterone and dehydroepiandrosterone (DHEA) cycles in obese middle-aged male subjects. Methods Saliva samples were collected at awakening and every 3 hours from 9:00 to 21:00 hours on 2 consecutive days in eight obese non-diabetic and eight healthy non-obese control men. Results Saliva parameters showed day-to-day consistency, with an overall diurnal decline, except for testosterone in the obese group. Saliva testosterone concentrations were significantly lower (P < 0.05) at awakening, 9:00 and 12:00 hours in obese versus control subjects. No significant differences were observed in saliva DHEA concentrations between the obese and control subjects at any time of day. Conclusion The results of this investigation indicate that obesity alone does not affect the concentrations or the diurnal pattern of DHEA in middle-aged men, whereas the diurnal pattern of testosterone appears altered in this population, with significantly lower values during the first part of the day.
