How early shift work affects daily stress hormone patterns, mood, and sleep in male airline pilots

Early shifts were associated with higher levels of circulating cortisol during waking hours compared to late shifts or rest days.

• Participants included 30 healthy male non-smoking pilots with a mean age of 39.4.
• A higher cortisol increase in response to awakening was observed during early shifts compared to late shifts and rest days.
• Total cortisol output throughout the day was greater on early shift days, indicating a stronger hormonal response.
• The rate of cortisol decline was slower on early shift days than on late shifts or rest days.
• Early shifts correlated with shorter sleep duration, though this did not change the observed effects on cortisol rhythm.
• Both early and late shifts were linked to increased stress, tiredness, and lower happiness compared to rest days.

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