|Martinez, Suzanna - University Of California|
|Greenspan, Louise - Kaiser Permanente|
|Butte, Nancy - Children'S Nutrition Research Center (CNRC)|
|Gregorich, Steven - University Of California|
|De Groat, Cynthia - University Of California|
|Deardorff, Julianna - University Of California|
|Penilla, Carlos - University Of California|
|Pasch, Lauri - University Of California|
|Flores, Elena - University Of San Francisco|
|Tschann, Jeanne - University Of California|
Submitted to: Sleep
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/28/2013
Publication Date: 12/16/2013
Citation: Martinez, S.M., Greenspan, L.C., Butte, N.F., Gregorich, S.E., De Groat, C.L., Deardorff, J., Penilla, C., Pasch, L.A., Flores, E., Tschann, J.M. 2013. Mother-reported sleep, accelerometer-estimated sleep and weight status in Mexican American children: sleep duration is associated with increased adiposity and risk for overweight/obese status. Sleep. 23:328-336.
Interpretive Summary: Most epidemiological and clinical studies rely on parents' report of sleep duration in their children. In this study, we compared children's sleep time reported by the parents with sleep time measured with an activity monitor (accelerometer). We also evaluated if either measures of sleep duration are related to obesity in children, estimated by body mass index (BMI). We measured how long a child slept by mother's report, by an activity monitor, and measured child's body measurements. We saw how closely the parent report matched the activity monitor readout Mothers reported an average of 9.8 hours of sleep compared with 9.6 hours measured by the activity monitor. The sleep duration measured by the accelerometer was more precise and correlated better with BMI. Use of the activity monitors seemed to be a more reliable way to measure sleep time than using mother's report, although the mother's report on average agreed with the activity monitor. Such findings will aid researchers in measuring accurately sleep time.
Technical Abstract: We know of no studies comparing parent-reported sleep with accelerometer-estimated sleep in their relation to paediatric adiposity. We examined: (i) the reliability of mother-reported sleep compared with accelerometer-estimated sleep; and (ii) the relationship between both sleep measures and child adiposity. The current cross-sectional study included 303 Mexican American mother-child pairs recruited from Kaiser Permanente Northern California. We measured sleep duration using maternal report and accelerometry and child anthropometrics. Concordance between sleep measures was evaluated using the Bland-Altman method. We conducted zero-ordered correlations between mother-reported sleep, accelerometer-estimated sleep and child BMI z-scores (BMIz). Using linear regression, we examined three models to assess child BMIz with mother-reported sleep (model 1), accelerometer-estimated sleep (model 2) and both sleep measures (model 3). Children had an average age of 8.86 years (SD = 0.82). Mothers reported that their child slept 9.81 +/- 0.74 h [95% confidence interval (CI): 9.72, 9.89], compared to 9.58 +/- 0.71 h (95% CI: 9.50, 9.66) based on accelerometry. Mother-reported sleep and accelerometer-estimated sleep were correlated (r = 0.33, P < 0.001). BMIz outcomes were associated negatively with mother-reported sleep duration (model 1: Beta = -0.13; P = 0.02) and accelerometer-estimated sleep duration (model 2: Beta = -0.17; P < 0.01). Accounting for both sleep measures, only accelerometer-measured sleep was related to BMIz (model 3: Beta = -0.14, P = 0.02). Each sleep measure was related significantly to adiposity, independent of covariates. Accelerometry appeared to be a more reliable measure of children's sleep than maternal report, yet maternal report may be sufficient to examine the sleep-adiposity relationship when resources are limited.