When young men slept less, their bodies released more of the stress-related chemical norepinephrine, especially at night and in the morning, which may be a sign their stress system was overactive.
Scientific Claim
Three nights of shortened sleep (3.5 hours per night) in healthy young men caused a significant increase in urinary norepinephrine levels during nighttime and early morning hours (p=0.006), suggesting heightened sympathetic nervous system activity linked to sleep deprivation.
Original Statement
“There was a significant main effect of sleep conditions on norepinephrine (p = 0.006). After Bonferroni’s correction for multiple comparisons, norepinephrine levels were significantly higher in the 3.5-h sleep condition during the hours between 00:00–07:00 on day 3/4 and between 07:00–14:00 on day 5 than in the 7-h sleep condition.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The RCT design with timed urine collection and Bonferroni correction for multiple comparisons supports definitive causal language. The effect is statistically robust and biologically plausible.
Evidence from Studies
Supporting (0)
Contradicting (1)
Effect of shortened sleep on energy expenditure, core body temperature, and appetite: a human randomised crossover trial
This study looked at how less sleep affects hunger and body temperature, but it didn’t measure the stress hormone (norepinephrine) mentioned in the claim, so it can’t tell us whether that part is true or not.