Sleep onset and cardiovascular activity in primary insomnia

Massimiliano De Zambotti, Naima Covassin, Giuliano De Min Tona, Michela Sarlo, Luciano Stegagno

Research output: Contribution to journalArticlepeer-review

77 Scopus citations


The transition from wakefulness to sleep is characterized typically by a shift from sympathetic to parasympathetic regulation. Physiological functions, depending on the neurovegetative system, decrease overall. Previous studies have shown cardiovascular and electroencephalographic hyperactivity during wakefulness and sleep in insomniacs compared with normal sleepers, but there is very little evidence of this in the process of sleep onset. The purpose of this study was to compare cardiovascular and autonomic responses before and after falling asleep in eight insomniacs (who met DSM-IV criteria for primary insomnia) and eight normal sleepers. Non-invasive measures of heart rate (HR), stroke volume (SV), cardiac output (CO) and pre-ejection period (PEP) were collected by impedance cardiography during a night of polysomnographic recording. Frequency domain measures [low-frequency (LF), high-frequency (HF)] of heart rate variability (HRV) were also estimated. Decrements in HR and CO and increases in SV and HF normalized units (n.u.) were found in both groups after sleep onset compared with wakefulness. Conversely, PEP (related inversely to sympathetic β-adrenergic activity) showed increases after sleep onset in controls, but remained unchanged in insomniacs. PEP was also significantly lower in insomniacs than in normal sleepers in both conditions. These data suggest that, whereas normal sleepers follow the expected progressive autonomic drop, constant sympathetic hyperactivation is detected in insomniacs. These results support the aetiological hypothesis of physiological hyperarousal underlying primary insomnia.

Original languageEnglish (US)
Pages (from-to)318-325
Number of pages8
JournalJournal of Sleep Research
Issue number2
StatePublished - Jun 2011


  • Cardiovascular system
  • Hyperarousal
  • Impedance cardiography
  • Primary insomnia
  • Sleep onset

ASJC Scopus subject areas

  • Cognitive Neuroscience
  • Behavioral Neuroscience


Dive into the research topics of 'Sleep onset and cardiovascular activity in primary insomnia'. Together they form a unique fingerprint.

Cite this