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Peripheral vasoconstriction during REM sleep detected by a new plethysmographic method

DOI: 10.1038/76135
Authors:
Peretz Lavie at Technion - Israel Institute of Technology, Haifa, Israel
Peretz Lavie
  • Technion - Israel Institute of Technology, Haifa, Israel
Robert P. Schnall at Itamar Medical Ltd
Robert P. Schnall
Jacob Sheffy
Jacob Sheffy
Jacob Sheffy
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Arie Shlitner
Arie Shlitner
Arie Shlitner
  • This person is not on ResearchGate, or hasn't claimed this research yet.
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Abstract

Rapid-eye-movement (REM) sleep is associated with more sympathetic activation than is NONREM sleep1, 2. So far, there are no data regarding vascular tone during REM and NONREM sleep in humans. Using a new plethysmographic technique to measure peripheral arterial tone (PAT), we report here that REM sleep in humans is associated with considerable peripheral vasoconstriction. The apparatus is essentially a plethysmograph that, unlike models now available, is able to envelop the finger up to and beyond its tip with a uniform pressure field. The applied pressure field is sufficient to substantially unload arterial wall tension, thereby improving the dynamic range of the system, while preventing the potential occurrence of venous engorgement that promotes vasoconstriction. Pressure within the probe originates from a pressurized balloon located over its outside wall. Pulsatile volume signals were recorded as optical density changes from the finger's palmar surface within the applied pressure field. The device was tolerated well for extended periods.
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606 NATURE MEDICINE • VOLUME 6 • NUMBER 6 • JUNE 2000
LETTERS TO THE EDITOR
To the editor—Rapid-eye-movement (REM)
sleep is associated with more sympathetic
activation than is NONREM sleep1,2. So
far, there are no data regarding vascular
tone during REM and NONREM sleep in
humans. Using a new plethysmographic
technique to measure peripheral arterial
tone (PAT), we report here that REM sleep
in humans is associated with consider-
able peripheral vasoconstriction. The ap-
paratus is essentially a plethysmograph
that, unlike models now available, is able
to envelop the finger up to and beyond
its tip with a uniform pressure field. The
applied pressure field is sufficient to sub-
stantially unload arterial wall tension,
thereby improving the dynamic range of
the system, while preventing the poten-
tial occurrence of venous engorgement
that promotes vasoconstriction. Pressure
within the probe originates from a pres-
surized balloon located over its outside
wall. Pulsatile volume signals were
recorded as optical density changes from
the finger’s palmar surface within the ap-
plied pressure field. The device was toler-
ated well for extended periods.
We measured pulsatile finger blood
flow throughout the night in 9 normal
young adults (25–40 years of age) and 17
patients with light-to-moderate sleep
apnea syndrome (35–60 years of age;
mean respiratory disturbance index, less
than 30). The PAT signals were analyzed
by a dedicated computer program in
terms of mean relative peak to peak am-
plitude in 1-minute ‘bins’ for the first
and second REM periods, and for 20 min-
utes of NONREM periods before and after
each REM period. PAT amplitudes were
expressed as percentages of the mean am-
plitude during the initial 5 minutes of
the NONREM period preceding each
REM period. Minutes with body move-
ments were omitted before analysis. In
both groups, REM sleep was associated
with considerable attenuation of the PAT
signal (Fig. 1). The decrease in amplitude
began during NONREM sleep and
reached a nadir during REM sleep. As
there were neither differences between
groups nor differences between the first
and second REM periods, we pooled data
and analyzed these by repeated measures
ANOVA . The percent change during
REM sleep (–16.3 ± 19.7%) was signifi-
cantly higher than that during NONREM
sleep before (–3.39 ± 14%) or after (–2.39
± 27.2%) REM sleep (P < 0.009). The
curves describing the change in ampli-
tudes during the transition from NON-
REM to REM and back to NONREM sleep
could be fitted with a quadratic trend (P <
0.02) with a minimum occurring 8.5
minutes after the start of REM sleep.
The intense sympathetic activation
during REM sleep and the preponderance
of REM in the early morning hours have
led to the suggestion that REM sleep may
be responsible for increased cardiac
events seen at this time3. Although we
have no data to show that REM-related
vasoconstriction also occurs in larger
blood vessels or is specific to the periph-
ery, the report that in a canine model, ex-
perimental occlusion of the coronary
arteries during REM sleep results in a
greater than expected decrease in coro-
nary blood flow4indicates that REM-re-
lated vasoconstriction may predispose
patients with compromised coronary ar-
teries to ischemic events during sleep5.
PERETZ LAVIE1, ROBERT P. SCHNALL2,
JACOB SHEFFY2& ARIE SHLITNER1
1Sleep Laboratory,
B. Rappaport Faculty of Medicine,
Technion-Israel Institute of Technology,
Haifa, Israel
2Itamar Medical Ltd.,
Caesarea, Israel
Email: plavie@tx.technion.ac.il
1. Berlad, I., Shlitner, A., Ben-Haim, S. & Lavie, P. Power
spectrum analysis and heart rate variability in stage 4
and REM sleep: Evidence for state-specific changes in
autonomic dominance. J. Sleep. Res. 2, 88–90 (1993).
2. Somers, V.K., Dyken, M.E., Mark, A.L. & Abboud,
F.M. Sympathetic nerve activity during sleep in nor-
mal subjects. N. Engl. J. Med. 328, 303–307 (1993).
3. Muller, J.E., Toffler, G.H., Willich, S.N. & Stone, P.H.
Circadian variation of cardiovascular disease and sym-
pathetic activity. Circulation 75, 131–138 (1987).
4. Kirby, D.A. & Verrier, R.L. Differential effects of sleep
stage on coronary hemodynamic function. Physiol.
Behav. 45, 1017–1020 (1989).
5. Schafer, H., Koehler, U., Ploch, T. & Peter, J.H. Sleep-
related myocardial ischemia and sleep structure in pa-
tients with obstructive sleep apnea and coronary
heart disease. Chest 111, 387–393 (1997).
Peripheral vasoconstriction during REM sleep detected by a
new plethysmographic method
Fig. 1 Peripheral vasoconstruction during REM sleep. a, Compressed
records of the PAT signal and electro-oculogram (EOG) during the transition
from NONREM to REM and back to NONREM sleep, in two subjects. The
EOG records help identify the times of the traditionally scored REM periods.
The gradual decrease in PAT amplitude starts at least 30 min before the be-
ginning of the traditionally scored REM sleep. *, Body movements artifact.
b, Mean percent change (± s.e.m.) in PAT amplitude, referenced to the
mean amplitude in the initial 5 minutes of the preceding NONREM period,
averaged across all 54 REM periods. The curve describing the
NONREM–REM transition is synchronized to the first minute of REM sleep
(vertical line). The curve for succeeding NONREM periods is synchronized
to the first NONREM minute (vertical line). As REM periods varied in length,
the percent change during REM sleep were calculated only when there were
at least five data points. Red line, quadratic trend fitted to the data.
b
a
© 2000 Nature America Inc. • http://medicine.nature.com
© 2000 Nature America Inc. • http://medicine.nature.com
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