title: Associations of vitamin D status, bone health and anthropometry, with gross motor development and performance of school-aged Indian children who were born at term with low birth weight.
abstract: OBJECTIVE
  There is little information regarding motor development of children born at term with low birth weight (LBW), a group that constitutes a large proportion of children in South Asia. We used data from infancy and at school age from a LBW cohort to investigate children's motor performance using causal inference.
  
  
  METHODS
  Cross-sectional follow-up study.
  
  
  METHODS
  Delhi, India.
  
  
  METHODS
  We recruited 912 children aged 5 years who had participated in a trial of vitamin D for term LBW infants in the first 6 months of life.
  
  
  METHODS
  We focused on gross motor development, using the Ages and Stages Questionnaire (ASQ) gross motor scale and several measures of motor performance. We examined the effects on these of current anthropometry, vitamin D status and bone health, controlling for age, sex, season of interview, socioeconomic variables, early growth, recent morbidity, sun exposure and animal food intake.
  
  
  RESULTS
  In adjusted analyses, stunted children (height-for-age Z (HAZ) <-2) took longer to run 20 m (0.52 s, 95% CI 0.35 to 0.70; p<0.001) and had greater odds of a failing score on the ASQ (OR 3.00, 95% CI 1.41 to 6.38, p=0.004). Greater arm muscle area was associated with faster run time, and the ability to perform more stands and squats in 15 s. Poorer vitamin D status was associated with the ability to perform more stands and squats. Lower tibia ultrasound Z score was associated with greater hand grip strength. Early growth and current body mass index had no associations with motor outcomes.
  
  
  CONCLUSIONS
  Current HAZ and arm muscle area showed the strongest associations with gross motor outcomes, likely due to a combination of simple physics and factors associated with stunting. The counterintuitive inverse associations of tibia health and vitamin D status with outcomes may require further research.
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Filteau
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Rehman
authors.affiliation: Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan.
authors.forename: Aisha
authors.initials: A
authors.lastname: Yousafzai
authors.affiliation: Institute of Home Economics, University of Delhi, Delhi, India.
authors.forename: Reema
authors.initials: R
authors.lastname: Chugh
authors.affiliation: Institute of Home Economics, University of Delhi, Delhi, India.
authors.forename: Manpreet
authors.initials: M
authors.lastname: Kaur
authors.affiliation: Sitaram Bhartia Institute of Science and Research, Delhi, India.
authors.forename: H P S
authors.initials: HP
authors.lastname: Sachdev
authors.affiliation: Institute of Home Economics, University of Delhi, Delhi, India.
authors.forename: Geeta
authors.initials: G
authors.lastname: Trilok-Kumar
mesh_terms: D000886:Anthropometry; D001132:Arm; D001208:Asia; D001827:Body Height; D001835:Body Weight; D015519:Bone Density; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007230:Infant, Low Birth Weight; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D012885:Skinfold Thickness; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D