Abstract
BACKGROUND: Obesity can affect linear growth of children but there is uncertainty regarding the dynamics and potential causes. METHODS: In the population-based LIFE Child and the obesity-enriched Leipzig Obesity Childhood cohorts (8,629 children, 37,493 measurements), recruited from 1999 to 2018 in Germany, we compared height, growth, and endocrine parameters between normal-weight and children with obesity (0-20 years). Derived from the independent German CrescNet registry (12,703 children) we generated height reference values specific for children with obesity (data collected from 1999 to 2020). FINDINGS: Children with obesity were significantly taller than normal-weight peers, differing at maximum by 7·6 cm (1·4 height, standard deviation scores or SDS) at age 6-8 years. Already at birth, children with obesity were slightly taller and thereafter had increased growth velocities by up to 1·2 cm/year. This growth acceleration was unrelated to parental height, but was accompanied by increased levels of insulin-like growth factor-1 (IGF-1), insulin and leptin. During puberty, children with obesity showed a catch-down in height SDS. The reduction in pubertal growth velocity by up to 25% coincided with a decrease in levels of IGF-1 (by 17%) and testosterone (by 62%) in boys and estradiol (by 37%) in girls. We confirmed these alterations in growth in the independent CrescNet cohort and furthermore provide height reference values for children with obesity for open access. INTERPRETATION: Dynamics of linear growth are altered distinctively in different developmental phases in children with obesity. Early emergence before other profound comorbidities implies predisposition, environmental, and/or endocrine factors affecting growth in early life. Height reference values for children with obesity may enhance the precision of clinical health surveillance. FUNDING: German Research Foundation, German Diabetes Association, EU, ESF, ERDF, State of Saxony, ESPE, Hexal, Novo Nordisk, Pfizer Pharma.