Effect of Methylphenidate on Sleep Parameters in Children with ADHD

OBJECTIVE: The primary aim of this study was to investigate the acute impact of methylphenidate (MPH) on sleep parameters in attention-deficit/hyperactivity disorder (ADHD) children. The second aim was to investigate the different effects of intermediate- and longacting MPH on sleep parameters. The third aim was to test the different effects of dose and age on sleep parameters. METHODS: Ninety-three ADHD children were enrolled and randomized to two different MPH preparations. Baseline and daily sleep diaries were evaluated for four weeks after taking medication. Weekday and weekend bedtimes, wake-up times, sleep latencies and total sleep times were compared by weeks. RESULTS: After taking MPH, there was a significant delay in bedtimes and a significant reduction of total sleep time (TST) both on weekdays and at weekends. There was also a significant delay in wake-up time on weekdays. However, the difference was applied to younger age group children only. There was no difference in changes of TST between metadate-CD and OROS-MPH. There also was no difference in changes of TST with different doses of MPH. CONCLUSION: MPH had negative impacts on sleep among young ADHD children, but different preparations and doses did not affect the result.

Sleep Duration and Body Mass Index in Korean Children

OBJECTIVES: We conducted this study to investigate the relationship between sleep duration and body mass index (BMI), in Korean children. METHODS: We performed a cross-sectional analysis of data collected on 3,639 boys and girls (aged 7-12) in Daegu, Korea. The data included each child's age, sex, weight, height, extracurricular activities, bedtime, wake-up time, sleep latency, total sleep duration, parents' occupations, and parents' educational levels. The relationship between sleep duration and each variable was examined via analysis of variance (ANOVA). RESULTS: The analysis showed an association between short sleep duration and high BMI. Boys showed a graded inverse relationship between sleep duration and BMI. However, there was no significant corresponding result for girls. In the total sample, hours of computer use, time when the computer was turned off, time when the television was turned off, mother's bedtime, and hours of extracurricular activity were associated with longer sleep duration. No association was found between sleep duration and hours of watching television, child's wake-up time, or educational level of the parents. CONCLUSION: The results of this study show an inverse relationship between a child's sleep duration and BMI;thus, children with shorter sleep duration tend to have higher BMIs.