SLEEP 2011 Abstract Supplement

B. Clinical Sleep Science XIII. Sleep and Gender
0929
THE EFFECTS OF SUBTLE BREATHING ABNORMALITIES
DURING SLEEP IN PREGNANCY
DeYoung P 1 , Oxford C 1,2 , Foster A 1 , Campana LM 1 , Malhotra A 1,2
1
Sleep Medicine, Brigham and Womens Hospital, Boston, MA, USA,
2
Medicine, Harvard Medical School, Boston, MA, USA
Introduction: Sleep disordered breathing is known to cause an increase
in both nocturnal and daytime systemic blood pressure. Prior studies
have shown snoring and flow limitation during pregnancy may be associated
with blood pressure elevations. However, relatively little is
known about the effects of sleep disordered breathing and more subtle
breathing abnormalities during pregnancy. Inspiratory flow limitation is
commonly observed in pregnancy. In addition, saturation values above
95% are typically recommended although the data underlying this recommendation
are somewhat unclear. We hypothesized that pregnant
women with subtle breathing abnormalities would have higher nocturnal
blood pressure.
Methods: Twenty-five women admitted into our hospital in their third
trimester of pregnancy participated in a sleep study using an unattended
portable monitoring device. Following informed consent, participants
were given subjective sleep questionnaires. Blood Pressure was acquired
upon admission and during the night as part of usual care by
nursing staff. Subjects’ sleep was recorded for roughly 10 hours. We
then scored the sleep recordings using modified Chicago criteria(2 and
3 percent desaturation); an automated flow limitation marker was also
used and verified visually(Embla Software).
Results: To date, we have enrolled 25 women with ages ranging from
18-48 years, with pre-pregnancy BMI 17-45 kg/m2 and 8 having preeclampsia
and 17 pregnant controls. We observed minimal sleep apnea
using either a 2 or 3 percent desaturation criterion(RDI ranging from
0-6/h). Using a Spearman Correlation test, we found that flow limited
breathing was a predictor of raised blood pressure as measured during
the middle of the night. Among women without pre-eclampsia, we observed
that an increase in the flow limitation index(from 1- 27%) predicted
an increase in blood pressure with a mean nocturnal blood pressure of
104±13/63±10. We further observed that borderline hypoxemia during
the middle of the night(saturations below 95%) were predictive of blood
pressure as measured during the night(p value .04).
Conclusion: Pregnant women had relatively subtle breathing abnormalities
as manifest by flow limitation and saturations below 95%. Based on
nocturnal blood pressure measurements, we observed some predictive
value of flow limitation as well as sub-clinical hypoxemia. These data
suggest that subtle breathing abnormalities may be important in pregnant
women. Further research is clearly required.
Support (If Any): K24 HL03218
0930
SDB RISK, GESTATIONAL HYPERTENSION AND RACIAL
BACKGROUND IN PREGNANT WOMEN
Owusu JT 1 , Bullough AS 2 , Chames M 3 , Chervin RD 1 , O’Brien LM 1,4
1
Neurology, University of Michigan, Ann Arbor, MI, USA,
2
Anesthesiology, University of Michigan, Ann Arbor, MI, USA,
3
Obstetrics & Gynecology, University of Michigan, Ann Arbor, MI,
USA, 4 Oral & Maxillofacial Surgery, University of Michigan, Ann
Arbor, MI, USA
Introduction: Sleep-disordered breathing (SDB) may be associated
with gestational hypertension (GHTN), a leading cause of maternal morbidity.
Both GHTN and SDB are more common in African-American
women than Caucasians. Therefore, we hypothesized that an excess
frequency of SDB in African-Americans may explain the higher prevalence
of GHTN in this population.
Methods: Third-trimester pregnant women were recruited from obstetric
clinics and invited to complete several sleep questionnaires. Women
who were normotensive at study entry were enrolled and high risk for
SDB was defined as habitual snoring ≥3 nights/week. Diagnoses of
GHTN/pre-eclampsia were obtained from medical records.
Results: Among 1171 participants (mean age 29.6±5.6 years, mean
BMI 26.1±8.6kg/m2), 194 (17%) were African-American, 241 (21%)
had GHTN, and 403 (34%) had high SDB risk. The prevalence of
GHTN was similar in African-Americans and Caucasians (23% vs.
20%, p=0.42), as was SDB risk (37.5% vs. 35.5%, p=0.14). SDB was
more common in women with GHTN than in those without (48% vs.
34%, p