Lack of Sleep Hurts Women's Hearts Most

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"We found that for women, poor sleep is strongly associated with high levels of psychological distress, and greater feelings of hostility, depression and anger. In contrast, these feelings were not associated with the same degree of sleep disruption in men," Suarez said.

Women who were poor sleepers also had higher levels of C-reactive protein and interleukin-6 -- inflammation biomarkers associated with increased risk of heart disease and higher levels of insulin.

"Interestingly, it appears that it's not so much the overall poor sleep quality that was associated with greater risk, but rather the length of time it takes a person to fall asleep that takes the highest toll. Women who reported taking a half hour or more to fall asleep showed the worst risk profile," Suarez said.

He suggested the sleep/health risk differences between men and women may be partly due to variations in the activity of the number of naturally occurring substances in the body, such as the amino acid tryptophan, the neurotransmitter serotonin, and the neurohormone melatonin.

"All of these substances are known to affect mood, sleep, onset of sleep, inflammation and insulin resistance," said Suarez, who plans further research into the link between poor sleep and health risk in women and men.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about sleep.