engleski

Objectively assessed sleep duration and efficiency in overweight and normal-weight 11-year old children

BACKGROUND AND AIMS: The growing epidemic of obesity is becoming more and more pronounced, even among children. Inverse associations between sleep duration and the risk to develop childhood obesity were consistently reported (Cappuccio et al., 2008). However, studies that evaluated sleep with objective measures are scarce. Therefore, the aim of the current study was to objectively evaluate sleep duration and efficiency in overweight and normal-weight 11-year old children in Croatia. SUBJECTS: Fifty seven 5th grade students (35 girls and 22 boys, mean age 11, 3 [0, 2] years) from five different elementary schools in Zagreb (Croatia) were selected to participate in the study. METHODS: Height and weight were measured and body mass index (BMI) was calculated. Ten girls and nine boys were considered overweight or obese according to IOTF BMI cut off points for age and gender (Cole et al., 2000). Sleep patterns were assessed using a multi-sensor body monitor (SenseWear Pro2 Armband, BodyMedia, Pittsburgh, USA). SenseWear armband has recently been validated as a sleep detection device (Germain et al., 2006). The device was worn for four consecutive nights including 2 weekdays and 2 weekend days. Sleep duration and time spent lying down were estimated and times of going to and out of bed were detected. Sleep efficiency index (SEFI) was calculated as sleep duration divided by time spent lying down. Group differences were tested using Student’s t-test for independent samples. All values are presented as mean [SD]. RESULTS: No significant differences between overweight and normal-weight children were found regarding either sleep duration (434 [36] min/day vs. 425 [40] min/day, respectively p=0, 40) or time spent lying down (548 [45] min/day vs. 531 [39] min/day, respectively p=0, 15). The average time children went to bed did not differ between overweight (22:33 [00:49]) and normal-weight children (22:47 [00:42]), (p=0, 30). The same was found for the time children got out of the bed (07:50 [00:55] and 07:44 [00:45], in overweight and normal-weight children, respectively, p=0, 65). No significant difference between groups was found for SEFI (0, 80 [0, 07] vs. 0, 80 [0, 07], p=0, 73). CONCLUSION: Results from this study do not support the hypothesis that overweight children have shorter sleep duration or lower sleep efficiency than their normal-weight peers.

obesity; sensewear armband; weight management

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