Long-term growth and final adult height outcome in childhood-onset systemic lupus erythematosus

Background Growth impairment is the most common complication in patients with childhood-onset systemic lupus erythematosus (cSLE). There are limited data on risk factors affecting growth development in Asian patients with cSLE. This study aimed to determine the predictors of growth impairment in such patients. Methods All SLE patients aged < 15 years diagnosed in Ramathibodi Hospital between 2006 and 2016 were enrolled in a retrospective cohort study. Baseline characteristics, including height, weight, clinical manifestations, disease activity score, and medications, were reviewed from medical records from the time at diagnosis to achievement of final adult height (FAH). Age at menarche in girls, adult voice appearance in boys, and parental height were collected by interview. Parent-adjusted FAH (PaFAH) Z-score was calculated as the difference between FAH Z-score for chronological age of the patients and their mid parental height-Z score. The patients were classified into two groups: (1) normal growth (PaFAH Z-score >= - 1.5, 2) growth impairment (PaFAH Z-score < - 1.5). Descriptive statistics and logistic regression analysis were used to analyze the data. Results Of 106 cSLE patients, 19 (18%) were male and 87 (82%) were female. The mean age at study enrollment was 20.6 +/- 3.0 years, mean age at diagnosis 12.1 +/- 2.3 years, and mean age at achievement of FAH 17.5 +/- 1.9 years. Growth impairment was found in 23.6% of patients (52.6% in boys and 17.2% in girls). Predictors of growth impairment were male sex, duration of disease before menarche in girls and adult voice appearance in boys, and cumulative corticosteroid dose (prednisolone equivalent) >= 230 mg/kg received before the late phase of puberty, with odds ratios of 7.07 (95%CI 2.11-23.74), 1.26 (95% CI 1.02-1.56), and 6.99 (95%CI 1.63-30.02), respectively. Conclusions One-fourth of cSLE patients developed growth impairment, which mostly affected male patients. Longer duration of disease before the late phase of puberty and corticosteroid dose >= 230 mg/kg received before the late phase of puberty were factors predictive of growth impairment.