Which statement correctly describes the hormonal changes associated with short sleep duration?

• A. Reduced growth hormone and prolactin
• B. Increased cortisol in the evening hours
• C. Increased growth hormone
• D. Increased insulin sensitivity

Answer: (A)

Short sleep duration disrupts hormones that are tightly linked to sleep stages, especially deep sleep. Growth hormone is released in pulses predominantly during slow-wave sleep, so when sleep is shortened and less deep sleep occurs, overall growth hormone secretion falls. Prolactin also rises during the night as part of the sleep-related hormonal pattern; with less sleep, nocturnal prolactin secretion decreases. This combination—lower growth hormone and lower prolactin—fits what typically happens when sleep is restricted.

Meanwhile, sleep loss tends to raise cortisol levels and reduce insulin sensitivity, rather than increase them, and growth hormone would not be expected to rise with short sleep. So the statement describing reduced growth hormone and prolactin best captures the hormonal changes associated with short sleep duration.