SAN ANTONIO — Women who snore frequently during pregnancy are at elevated risk for gestational diabetes mellitus, according to a case-control study.
Although the risk is particularly high in obese snorers, snoring remained an independent risk factor for developing gestational diabetes mellitus (GDM) even after controlling for body mass index, reported Louise M. O'Brien, Ph.D.
“These findings have important implications for the prevention of an event—gestational diabetes mellitus—and all its associated morbidities. I have to believe there is a role for patient education and screening: asking pregnant women about their sleep and especially about their snoring in order to improve pregnancy outcomes,” said Dr. O'Brien of the department of neurology at the University of Michigan, Ann Arbor.
She reported on 1,221 women in their third trimester who completed questionnaires about habitual snoring, which was defined as snoring three or more nights per week. Nearly 31% of the women were habitual snorers in their last trimester. Their mean response to a screening 1-hour oral glucose tolerance test was a blood glucose level of 124 mg/dL, significantly higher than the 117 mg/dL in nonsnorers. Thirty-seven percent of frequent snorers had a response of 130 mg/dL or more, compared with 30% of nonsnorers.
A formal diagnosis of GDM was made in 24% of the habitual snorers and 17% of nonsnorers, a significant difference. Altogether, 37% of study participants were obese in their third trimester. That struck some audience members as a high figure, but Dr. O'Brien said that it reflects the advanced state of the obesity epidemic in Michigan.
Habitual snorers were more likely to be obese. GDM was diagnosed in 34.5% of obese habitual snorers and 13% of nonobese nonsnorers.
In a multivariate regression analysis adjusted for age, race, gestational age, and parity, obese snorers were at 3.6-fold increased risk of developing GDM, compared with nonobese nonsnorers. Upon controlling further for body mass index, habitual snoring in pregnancy remained independently associated with a significant 1.5-fold increased rate of GDM.
Dr. O'Brien noted that this finding of an increased risk of GDM associated with snoring was independently confirmed in two other recent studies.
Physicians at Northwestern University in Chicago reported in a prospective sleep survey study of 189 healthy nulliparas that 18.5% of them snored at least 3 nights per week. Their mean 1-hour oral glucose tolerance test values were significantly higher than nonsnorers' by a margin of 118 to 108 mg/dL. Their 14.3% incidence of GDM was significantly higher than the 3.3% rate in nonsnorers, as well.
The 48% of women who averaged less than 7 hours of sleep per night had a 10.2% incidence of GDM, compared with 1.1% in those who slept at least 7 hours (Am. J. Obstet. Gynecol. May 25, 2010; PMID:20510182).
In the other study, investigators at Seattle's Swedish Medical Center interviewed 1,290 women early in pregnancy regarding sleep duration and snoring. The incidence of GDM among study participants was 5.3%.
Women who reported sleeping an average of 4 hours or less per night had a 5.6-fold greater rate of GDMs than those who slept 9 hours. Overweight short sleepers had a 9.8-fold increased risk. Overweight women who snored at least 3 nights per week had a 6.9-fold increased GDM incidence compared with normal-weight nonsnorers (BMC Womens Health May 14, 2010; PMID:20470416).
Disclosures: Dr. O'Brien reported having no financial conflicts.
This increased risk of GDM associated with snoring was independently confirmed in two other recent studies.
Source DR. O'BRIEN