Text Box: LONGITUDINAL GROWTH DURING INFANCY AND CHILDHOOD IN CHILDREN FROM SHANGHAI (N=1623) - PREDICTORS AND CONSEQUENCES OF THE AGE AT ONSET OF THE CHILDHOOD PHASE OF GROWTH Xu X1, Wang WP1, Guo ZP1, Karlberg J2 1Department of Child Health Care, Children’s Hospital, Fudan University, Shanghai, China 2Department of Pediatrics, University of Hong Kong, Queen Mary Hospital, Hong Kong, China Objective: To identify predictors for the ages when childhood onset occurs, and to examine the consequences that – this timing would have upon the subsequent heights of Shanghai children. Methods: A total of 1720 children with longitudinal length/height data from birth to six years of age were analyzed. The individual age at onset of the childhood phase was visually determined by means of a computerized growth chart. Results: The mean age of the infants at childhood onset was 11.2 months in boys and 10.7 months in girls. Compared to their Swedish counterparts, these means occurred 1.3 months later in boys and 1.4 months later in girls. Both age at childhood onset and length at six months of age significantly (p<0.05) contributed to the attained height from 12 months of age onward; one month delay in the onset of childhood reduced height, at 5 years of age, by 0.4 cm in boys and 0.5 cm in girls. The age at childhood onset was negatively associated (p<0.001) with mid-parental height, though positively related (p<0.001) to height at six months of age. Conclusions: The age at childhood onset is equally important when studying children from Shanghai, as it is with their Swedish counterparts. Mid-parental height was identified as an additional predictor of childhood onset, which implied a genetic influence upon the age at childhood onset. 1157