BMI increase during early childhood in boys with cystic fibrosis and early adrenarche

Abstract

BackgroundIncrease in body mass index (BMI) in early childhood (1−6 years) was found to be a contributing factor for impaired final height in boys with Cystic Fibrosis (CF). Early adrenarche (before age 9 years in boys) may contribute to an impaired final height by triggering an early acceleration of bone age resulting in a compromised growth spurt during puberty. We aimed to analyze the timing of adrenarche in boys with CF and to associate BMI increase in early childhood to timing of adrenarche.MethodsBoys with CF, aged 8−9 years, visiting the CF expertize center Utrecht were included. Since 2018, anthropomorphic, pubertal and endocrine data were collected. Early adrenarche in boys was defined as a dehydroepiandrosterone sulfate (DHEAS) ≥ 1 µmol/L before the age of 9 years.ResultsThirteen boys (mean age 8.55 ± 0.27 years) were enrolled. The median (IQR) DHEAS‐level was 1.3 µmol/L (0.71−2.40). Eight boys (61.5%) had an early rise in DHEAS‐levels ≥ 1 µmol/L. Mean increase in BMI Z‐score between 1 and 6 years of age (ΔBMI1−6) was −0.07 ± 0.86. A significant correlation was found between ΔBMI1−6 and DHEAS‐levels at the age of 8−9 years (r = 0.624, p = 0.040). In five boys with early rise in DHEAS, accelerated bone age was found (average 1.55 ± 0.96 years).ConclusionIn this small cohort, 61.5% of boys with CF between 8 and 9 years had an early rise of DHEAS, which was correlated to ΔBMI1−6 between 1 and 6 years. Early adrenarche may be caused by ΔBMI1−6.