Last Updated: 2009-10-23 15:46:28 -0400 (Reuters Health)

Short sleep and hyperactive behavior show highly correlated trajectories in young children, according to a new study in the November issue of Pediatrics.

Dr. Jacques Y. Montplaisir of the Sacre-Coeur Hospital Sleep Disorders Centre in Montreal and his colleagues also found that the risk of short sleep in highly hyperactive children was greater than the risk of hyperactivity in short sleepers. "The results suggest that hyperactivity problems may interfere with nighttime sleep duration more than sleep problems lead to high hyperactivity scores," they write.

Dr. Montplaisir and his team looked at developmental trajectories of sleep duration and hyperactivity, as well as risk factors for short sleep and high hyperactivity, in 2057 children, following them from 1.5 to 5 years of age. Previous studies, they note, have looked at risk factors for hyperactivity and short sleep separately, but in this investigation they looked at both concomitantly.

The majority of the children persistently slept for 10 or 11 hours, while 5.1% were "short sleepers," getting less than nine hours of sleep a night, and 4.9% were "short increasing sleepers," that is, short sleepers at 2.5 years but became long sleepers thereafter.

Hyperactivity scores were consistent across the study period, with 30.3% of children having low hyperactivity scores throughout the study; 54.7% having medium scores; and 14.9% having high scores.

Highly hyperactive children were 5.1 times more likely to be short sleepers, while the persistently short sleepers were 4.2 times more likely to be highly hyperactive, the researchers found.

Several factors were linked with short sleep in combination with high hyperactivity: male sex; mother’s immigrant status; mother’s low education; insufficient family income; parental presence at sleep onset; and maternal over-protectiveness.

Compared to long sleepers with low to moderate hyperactivity scores, short sleepers with high hyperactivity scores had odds ratios of 2.7 for insufficient family income, 2.3 for male sex, 2.1 for having a mother with low education level, and 2.0 for being comforted outside the bed after nocturnal awakening at 1.5 years of age.

Also associated with short nighttime sleep in combination with high hyperactivity scores were mother’s immigrant status, parental presence at sleep onset, and maternal over-protectiveness.

It’s possible, the authors note, that "the influence of poverty on short-persistent nighttime sleep duration could be explained by other factors not measured in the present study, such as a noisy environment during the night."

The findings suggest that preventive interventions targeting less advantaged boys could help address both short sleep and hyperactivity, the researchers conclude.

Pediatrics 2009;124:e985-e993.