Adolescents who don’t sleep well at night do worse at school, a new study confirms.

However, socioeconomics also come into play in the poor sleep-low grade link, Dr. J. F. Pagel of the University of Colorado School of Medicine in Pueblo and colleagues report in the Journal of Clinical Sleep Medicine.

Several studies have shown that children with sleep problems perform worse at school than those who sleep well, Pagel and colleagues note, but low household income has been tied to both poor sleep and poor school performance.

To investigate the interplay of household income, sleep and school performance, the researchers looked at demographics, grade point average, and sleep quality in 238 middle and high school students.

Sixty percent of the study participants reported difficulty falling asleep at least once a week, while nearly three-quarters had difficulty waking up in the morning at least once weekly, the researchers found. Waking tired and unrefreshed at least once weekly was reported by 82.3%, while 45.7% had daytime sleepiness at least this often and 54.6% reported difficulty concentrating at least once a week.

Sleep factors linked to school performance included daytime sleepiness, snoring, and restless/aching legs at bedtime, reported by about one-third of students.

Among a number of different socioeconomic variables the researchers looked at, only household income had a significant link to kids’ GPA.

When the researchers adjusted for the effects of household income, only restless/aching legs at bedtime and difficulty concentrating at school remained associated with poor school performance.

“The correlation between the complaint of restless/aching legs in adolescence and poor school performance deserves further study in the adolescent population,” they note. The researchers conclude that household income should be addressed in future studies of sleep problems and school performance.

SOURCE: Journal of Clinical Sleep Medicine, February 1, 2007.