Study objective: To determine the impact of lower amounts of childhood sleep assessed by polysomnogram on development of obesity, being anxious or depressed, or having learning problems 5 years later.
Design: Prospective cohort.
Participants: Subjects were 304 community participants from the Tucson Children's Assessment of Sleep Apnea study, aged 6-12 years old at baseline.
Measurements and results: Children were classified according to baseline sleep as those who slept ≥ 9 h/night, those who slept > 7.5 to < 9 h/night, and those who slept ≤ 7.5 h/night. Odds of overweight/obese (≥ 85(th) BMI percentile), obese (≥ 95(th) BMI percentile), anxious or depressed, and learning problems at follow-up were assessed according to baseline sleep categories. Children who slept ≤ 7.5 h/night had higher odds of being obese (OR = 3.3, P < 0.05) at follow-up than children who slept ≥ 9 h/night. Borderline significance for overweight/obese (OR = 2.2, P < 0.1), anxious or depressed (OR = 3.3, P < 0.1), and having learning problems (OR = 11.1, P < 0.1) were seen for children who slept ≤ 7.5 h/night as compared to those who slept ≥ 9 h/night. A mean increase in BMI of 1.7 kg/m(2) (P = 0.01) over the 5 years of follow-up was seen for children who slept ≤ 7.5 h/night compared to those who slept ≥ 9 h/night. These relationships did not differ between Hispanic and Caucasian children.
Conclusions: Children with reduced amounts of sleep (≤ 7.5 h/night) had an increased risk for higher body weight in early adolescence. Similarly, children who slept ≤ 7.5 h/night had higher risk of being anxious or depressed or having learning problems in early adolescence.
Keywords: Sleep time; body mass index; childhood; obesity.