Growth patterns in early juvenile idiopathic arthritis: Results from the Childhood Arthritis Prospective Study (CAPS)

摘要

ObjectivesTo investigate early vertical growth patterns and factors associated with poor growth in a modern inception cohort of UK children with juvenile idiopathic arthritis (JIA) using data from the Childhood Arthritis Prospective Study (CAPS). MethodsA study period of 3 years was chosen. Children included in this analysis had a physician diagnosis of JIA and had height measurements available at both baseline and at 3-years of follow-up. Height is presented asz-scores calculated using World Health Organisation growth standards for age and gender. Growth over the 3-year period was assessed using change inz-score and height velocity. Univariable and multivariable linear regressions were used to identify factors associated with heightz-score at baseline and change of heightz-score at 3 years. Results568 patients were included; 65% female, median baseline age 7.4 years [interquartile range (IQR) 3.6, 11.2], median symptom duration at presentation 5.5 months [IQR 3.1, 11.6]. Heightz-score decreased significantly from baseline to 3 years (p≤ 0.0001); baseline median heightz-score was ?0.02 (IQR ?0.71, 0.61), decreasing to ?0.47 (IQR ?1.12, 0.24) at 3 years. Growth restriction, defined as change of heightz-score ≤?0.5, was observed in 39% of patients. At 3 years, higher baseline heightz-score was the strongest predictor for a negative change in heightz-score [?0.3 per unit of baseline heightz-score (95% CI: ?0.36, ?0.24),p< 0.0001]. ConclusionsAlthough overall height at 3 years after initial presentation to rheumatology is within the population norm, as a cohort, children with JIA experience a reduction of growth in height over the first 3 years of disease. Late presentation to paediatric rheumatology services is associated with lower height at presentation. However, patients with the lowest heightzscores at presentation were also the most likely to see an improvement at 3 years. The impact of JIA on growth patterns is important to children and families and this study provides useful new data to support informed clinical care.