Background Chronic sleep debt is becoming increasingly common and affects m
illions of people in more-developed countries. Sleep debt is currently beli
eved to have no adverse effect on health. We investigated the effect of sle
ep debt on metabolic and endocrine functions.
Methods We assessed carbohydrate metabolism, thyrotropic function, activity
of the hypothalamo-pituitary-adrenal axis, and sympathovagal balance in 11
young men after time in bed had been restricted to 4 h per night for 6 nig
hts. We compared the sleep-debt condition with measurements taken at the en
d of a sleep-recovery period when participants were allowed 12 h in bed per
night for 6 nights.
Findings Glucose tolerance was lower in the sleep-debt condition than in th
e fully rested condition (p<0.02), as were thyrotropin concentrations (p<0.
01). Evening cortisol concentrations were raised (p=0.0001) and activity of
the sympathetic nervous system was increased in the sleep-debt condition (
p<0.02).
Interpretation Sleep debt has a harmful impact on carbohydrate metabolism a
nd endocrine function. The effects are similar to those seen in normal agei
ng and, therefore, sleep debt may increase the severity of age-related chro
nic disorders.