Diurnal rhythm of plasma delta-sleep-inducing peptide in humans: evidence for positive correlation with body temperature and negative correlation with rapid eye movement and slow wave sleep.
Level 4 - case-series / case-control
Prospective observational physiological case series in healthy volunteers
PubMed 8175965 · doi:10.1210/jcem.78.5.8175965
What was done
Plasma delta-sleep-inducing peptide-like immunoreactivity (DSIP-LI) was measured every 30 minutes for 24 hours in 12 healthy volunteers with simultaneous polygraphic sleep recording and body temperature monitoring to assess diurnal rhythms and relations to sleep stages.
What was found
Plasma DSIP-LI exhibited a diurnal rhythm with a maximum at 1500 h and a minimum at 0100 h. DSIP-LI concentrations were significantly lower during rapid eye movement (REM) sleep (P < 0.005) and slow wave sleep (SWS) (P < 0.05) relative to awake values. DSIP-LI did not rise before, during, or after SWS episodes, but correlated closely with body temperature (r2 = 0.66; P < 0.0001).
Why it matters
Contrary to hypotheses that DSIP promotes slow wave sleep, circulating DSIP in humans peaks during the day, tracks body temperature, and drops during sleep.
Limits
Small sample size (n = 12). Observational design without experimental manipulation. Peripheral plasma levels may not reflect central nervous system concentrations. Participant demographic characteristics are not detailed in the abstract.
Cited by
- context Delta sleep-inducing peptide (DSIP) has been shown to help regulate circadian rhythms.