Abstract
Background: Rotating night shift disrupts the circadian rhythms and has been associated with physiological stress, general fatigue, sleep disturbances and cardiovascular diseases. Alterations in the sleep pattern leads to increased cortisol and decreased melatonin which might be associated physiological stress and cardiovascular diseases.
Objectives: The objective of the present study was to investigate circadian secretion of salivary cortisol in rotating night shift nursing professionals.
Methods: 62 healthy nursing professionals of both genders performing day and night shifts duties were recruited. Each study subject had a monthly scheduled of regular 9 night shifts (12 hours night shift, from 20:00 to 08:00) followed by remaining 17-18 day shifts (6 hours day shift, from 08:00 to 14:00) with a total of 4 days off in between. Saliva samples were collected at around 8 hours interval while they were performing night duties and repeated when they were assigned day duties. Salivary cortisol level was estimated by the ELISA (Competitive) method.
Results: Significant difference was found in night cortisol among night (4.34 ± 3.37) vs day shift (2.70 ± 2.32), (p

Key words: Rotating night shift; circadian rhythm; salivary cortisol.