Study author Marcella Marinelli of the Center for Research in Environmental Epidemiology in Barcelona, Spain, and colleagues said prior research suggested television viewing could cause irregular sleep habits.
The American Academy of Pediatrics recommended in 2009 children age 2 and younger avoid exposure to any media and that for older children television time be limited to 1 to 2 hours per day.
The study authors examined the association between hours of television viewing and sleep in 1,713 children in Spain via parent-reported sleep duration reports.
The study, published in JAMA Pediatrics, found children who watched TV for 1.5 hours or more a day had shorter sleep duration at baseline. Children who reported increased TV viewing over time from less than 1.5 hours per day to 1.5 or more hours per day reported a reduction in sleep at follow-up visits.
"Further prospective studies are required to confirm these findings and to investigate the mechanisms that may underline the possible association," Marinelli said in a statement.