Healthy sleepers show stronger sympathetic nervous system activity during sleep deprivation compared to those with chronic insomnia. This finding is from the abstract summary - full study details were not available

People with chronic insomnia show reduced low-frequency heart rate variability during sleep deprivation compared to those without insomnia. This finding is from the abstract summary - full study details were not available

Both people with chronic insomnia and healthy sleepers experience increased parasympathetic activity at night during sleep deprivation. This finding is from the abstract summary - full study details were not available

Sleep deprivation increases sympathetic nervous system activity, elevating heart rate and vascular resistance, while restorative sleep enhances parasympathetic activity, reducing cardiac output and vascular resistance.

During sleep deprivation, people with chronic insomnia don't show as much increase in parasympathetic activity at night compared to healthy people. This finding is from the abstract summary - full study details were not available