biostudies-literatureRae DESouth African National Research FoundationDST-NRF Centre of Excellence in Human DevelopmentNational Health and Medical Research CouncilUniversity of Cape Town Research CommitteeWellcome Trust571https://www.ebi.ac.uk/biostudies/studies/S-EPMC7986550biostudies-literatureUnknown21(1)<h4>Background</h4>The extent to which income setting or rural and urban environments modify the association between sleep and obesity in young children is unclear. The aims of this cross-sectional observational study were to (i) describe and compare sleep in South African preschool children from rural low-income (RL), urban low-income (UL) and urban high-income (UH) settings; and (ii) test for associations between sleep parameters and body mass index (BMI).<h4>Methods</h4>Participants were preschoolers (5.2 ± 0.7y, 49.5% boys) from RL (n = 111), UL (n = 65) and UH (n = 22) settings. Height and weight were measured. Sleep, sedentary behaviour and physical activity were assessed using accelerometery.<h4>Results</h4>UL children had higher BMI z-scores (median: 0.39; interquartile range: - 0.BMC public healthSleep and BMI in South African urban and rural, high and low-income preschool children.PMC7986550NA058893/Z/99/AAPP1070571085477/Z/08/ZCPRR13090934186069683/Z/02/Z085477/B/08/ZKahn KNorris SATomaz SAHinkley TTwine RRae DEDraper CEJones RAfalseSleep and BMI in South African urban and rural, high and low-income preschool children.<h4>Background</h4>The extent to which income setting or rural and urban environments modify the association between sleep and obesity in young children is unclear. The aims of this cross-sectional observational study were to (i) describe and compare sleep in South African preschool children from rural low-income (RL), urban low-income (UL) and urban high-income (UH) settings; and (ii) test for associations between sleep parameters and body mass index (BMI).<h4>Methods</h4>Participants were preschoolers (5.2 ± 0.7y, 49.5% boys) from RL (n = 111), UL (n = 65) and UH (n = 22) settings. Height and weight were measured. Sleep, sedentary behaviour and physical activity were assessed using accelerometery.<h4>Results</h4>UL children had higher BMI z-scores (median: 0.39; interquartile range: - 0.2021-01-01T00:00:00Z2021 Mar2025-04-04T20:35:18.261Z2025-04-04T20:35:18.261ZS-EPMC79865503375747910.1186/s12889-021-10591-5