title: Relationship between BMI, waist circumference, physical activity and probable developmental coordination disorder over time.
abstract: BACKGROUND
  Cross-sectional studies have shown that children with developmental coordination disorder (DCD) are less likely to be physically active and have excess weight gain. However, longitudinal studies examining the relationship between DCD and measures of body composition (BMI and waist circumference) over time are lacking. It is not known if sex and physical activity affect the relationship between DCD and measures of body composition over time.
  
  
  OBJECTIVE
  (1) To examine if BMI and waist circumference in children with and without probable DCD (pDCD) remain constant over time or change as children age, and whether this relationship varies by sex. (2) To examine if differences in physical activity between children with and without pDCD account for differences in BMI and waist circumference over time.
  
  
  METHODS
  Physical Health Activity Study Team (PHAST) data were used for this longitudinal analysis. At baseline, a total of 2,278 (pDCD=103) children aged 9-10 years were included in the analysis. The total follow-up period was five years. Mixed-effects modeling was used to estimate change in body composition measures in children over time.
  
  
  RESULTS
  Children with pDCD have higher BMI and waist circumference compared to typically developing children, and this difference increased over the study period. The relationship between pDCD and BMI over time also varied by sex. A similar trend was observed for waist circumference. Boys with pDCD were found to have a more rapid increase in BMI and waist circumference compared to girls with pDCD. Physical activity had neither a mediating nor a moderating effect on the relationship between pDCD and measures of body composition. However, physical activity was independently and negatively associated with measures of body composition.
  
  
  CONCLUSIONS
  pDCD is associated with higher body mass and waist circumference, both important risk factors for cardiovascular disease, type 2 diabetes, and psychological problems and other health conditions.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: Divya
authors.initials: D
authors.lastname: Joshi
authors.affiliation: CanChild Centre for Childhood Disability Research, Canada; School of Rehabilitation Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Missiuna
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Hanna
authors.affiliation: Department of Health Sciences, Brock University, St. Catharines, ON, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Hay
authors.affiliation: Department of Health Sciences, Brock University, St. Catharines, ON, Canada.
authors.forename: Brent E
authors.initials: BE
authors.lastname: Faught
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; CanChild Centre for Childhood Disability Research, Canada; Department of Family Medicine, McMaster University, Hamilton, ON, Canada; Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, ON, Canada; Department of Kinesiology, McMaster University, Hamilton, ON, Canada; Offord Centre for Child Studies, McMaster University, Hamilton, ON, Canada. Electronic address: cairnej@mcmaster.ca.
authors.forename: John
authors.initials: J
authors.lastname: Cairney
mesh_terms: D000293:Adolescent; D001823:Body Composition; D015992:Body Mass Index; D002318:Cardiovascular Diseases; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D019957:Motor Skills Disorders / Q000503:physiopathology*; D011336:Probability; D012307:Risk Factors; D013997:Time Factors; D055105:Waist Circumference
keywords: BMI; Children; Developmental coordination disorder; Physical activity; Waist circumference