By Molly Walker

Women but not men got less sleep when there were children in the house, a researcher said, and there is a dose effect.

For women 45 years of age or younger, having children in the household was the only significant factor in insufficient sleep (OR 1.46, 95% CI 1.14-1.87), reported Kelly Sullivan, PhD, of Georgia Southern University in Statesboro, Ga.

Moreover, each additional child increased the odds of insufficient sleep by 50% for these women, according to Sullivan, who will present the research in April.

Perhaps not surprisingly, gender differences were observed among households with children. Sullivan found that having children in the household was associated with "frequency of feeling unrested" among younger women (β=1.76, SD 0.54, P=0.001), but this was not significant among younger men (β=1.06, SD 0.64, P=0.10).

In an email, Sullivan said that previous research has shown that women are twice as likely to report insomnia and that women need more sleep to feel rested.

"Sleep needs and challenges differ, and the approach to address sleep challenges needs to be individualized," she said. "Women who are concerned about their sleep should also consider seeking the guidance of professionals such as therapists or physicians."

Sullivan performed a cross-sectional examination of the 2012 Behavioral Risk Factor Surveillance System, a nation-wide telephone-administered survey. She looked at data from 2,897 men and 2,908 women.

Sleep time was measured as a continuous variable (total sleep hours/day), which was categorized as either optimum (7-9 hours/day) or insufficient (<6 hours per day). An additional outcome was the number of days a participant felt unrested in the past month. Sullivan also examined basic demographic variables (BMI, age, race, education, income, marital status, and number of children in the household) as well as sleep-related variables, such as snoring.

Overall, longer sleep duration was significantly higher among both men and women with a higher education. Notably, men ages 45 years and younger with a high school education had a tenfold increased risk of insufficient sleep compared to college graduates -- albeit with extremely wide confidence intervals (OR 10.00, 95% CI 1.87-53.42).

Men who reported snoring were significantly less likely than non-snorers to report insufficient sleep (OR 0.31, 95% CI 0.11-0.87).

"The survey ... does not provide data that directly inform us about reasons for insufficient sleep. Therefore, reasons behind the observed gender disparity in the association of children and sleep are beyond the scope of this study," said Sullivan, adding that this will require insight from multiple disciplines and further research.