23
AASM Membership Sections Newsletter
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Issue #7
American Academy of
Sleep Medicine
completed an unattended multichannel sleep study that
included a pulse transit time measurement as a marker of
autonomic activation. Not unexpectedly, those with SBD were
more likely to be overweight, have lower oxygen saturations
during the night, higher ODI, greater respiratory-related
autonomic arousals and total autonomic arousals. At a mean
follow up of 7.8 ± 0.9 years, severe OSA (oxygen desaturation
index [ODI] > 30) led to 3-fold increase in the likelihood of
attentional decline (OR 2.97; 95% CI, 1.45 – 6.10; P = 0.003).
Interestingly, while ODI did not correlate with decline in
executive and memory functions, minimal oxygen saturation
(for executive function) and respiratory autonomic arousal
index (for memory function) did.
This large, prospective, long-term follow up study in subjects
≥ 65 years of age, factors associated with SBD resulted in
statistically significant decline in cognitive function after
approximately 8 years. While the results are consistent with
several other studies, the clinical impact of the magnitude of
decline in cognitive function (0.4 standard units) is unclear.
Furthermore, we lack sufficient studies to know the potential
impact of CPAP use in affecting this outcome.
Karimi C, et al. Sleep apnea related risk of motor vehicle
accidents is reduced by continuous positive airway pressure:
Swedish traffic accident registry data. Sleep 2015;38(3):341-
349.
While it is known that sleep apnea is associated with increased
risk of motor vehicle accidents (MVA), effect of CPAP in
reducing this risk was unknown. So using the Swedish Traffic
Accident Registry (STAR - database of accidents as reported
by Swedish police and the major emergency hospitals), these
investigators compared MVA incidence between CPAP
compliant (≥ 4 hours/night) and noncompliant (< 4 hours/
night or those who returned CPAP) individuals. Baseline AHI
and ESS were higher in the CPAP compliant group while
their total sleep times did not differ. CPAP compliant group
had a 70% reduction in MVA whereas MVA increased by
54% among CPAP noncompliant group. This was in spite of a
general reduction in MVA over the study period (according to
the STAR) and higher driving distance by the CPAP compliant
group.
This large, retrospective cohort study with an objective
accident reporting database confirmed increased risk of MVA
in OSA patients (2.5 fold increase risk) but that the risk of
MVA in OSA patients can be significantly reduced with CPAP
adherence (≥ 4 hours/night).
