(P18-015-23) Association Between Sleep and Hydration in Children From the MetA-Bone Trial

Objectives: Poor sleep has been linked to obesity, cardiovascular disease, diabetes, and decreased cognitive function. About 34% of US children have poor sleep. Poor sleep may affect vasopressin, which is related to both the circadian rhythm and body water homeostasis. Studies in adults showed that poor sleep may disrupt the homeostatic systems intertwined with hydration but there is limited evidence on the association between sleep and hydration in children. Therefore, a secondary analysis of data collected in the baseline visit of the MetA-Bone Trial examined the associations between sleep and hydration in 9–14-year-old healthy children.

Methods: Sleep duration was self-reported as total sleep (hours) at night. Overall sleep quality was assessed using the Pediatric Daytime Sleepiness Scale (PDSS); higher scores indicated poor sleep quality. Hydration was objectively measured in 24-h urine samples using Urine Specific Gravity (USG); USG score < 1.020 μG indicated euhydration and ≥ 1.020 μG dehydration. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). Statistical analysis including descriptive statistics and linear regressions were performed with SPSS 26.0. Models were adjusted for age, sex, and total physical activity.

Results: A total of 88 children, mean age 11.7 ± 1.33 (55.7% males; 68.2% Hispanic) had complete data. Mean duration of sleep was 9.18 ± 7.34 hours (28.4% met the CDC recommendation of 9-10 hours of sleep), mean PDSS score was 12.5 ± 5.95 (84% had good overall sleep quality), and mean overall USG was 1.019 ± 0.01 μG indicating euhydration (55.6% were dehydrated). Linear regression showed that duration of sleep was not associated with USG in the unadjusted (β=-0.083; p=0.443) or adjusted (β=-0.109; p=0.347) models. Similarly, no associations were found between PDSS and USG (unadjusted β=0.019; p=0.864; adjusted β=-0.017; p=0.886).

Conclusions: Most children had adequate sleep quality, though failed to meet CDC sleep recommendations. However, these preliminary results did not show an association between sleep and hydration. Larger samples may be needed to identify these associations.

Funding Sources: Funding for this project was supported by the NIH (Eunice Kennedy Shriver National Institute of Child Health and Human Development, NICHD).