Bone mineral density and bone metabolism of prepubertal children with asthma after long-term treatment with inhaled corticosteroids.

Abstract

Little is known about the effect of long-term treatment with inhaled corticosteroids (ICS) on bone mineral density (BMD) in asthmatic children. In the present cross-sectional study BMD, bone metabolism, height, body composition, and bone age were evaluated in 40 prepubertal children (21 boys) with asthma, treated with a moderate to high dose of ICS over a period of 3 to 8 years. Body composition and BMD of the lumbar spine and total body were measured by Dual Energy X-ray Absorptiometry. BMD results were compared with 148 prepubertal healthy children of the same population. Blood samples were taken for the determination of biochemical bone parameters. The asthmatic children had decreased height, lean tissue mass and fat mass, and a delay of bone maturation, indicating growth retardation. ICS-treated asthma was negatively correlated with total body BMD in a multiple regression model with adjustment for age, gender, height and weight (P = 0.01). Duration of ICS therapy correlated negatively with total body BMD when it was added to the model (P = 0.01). Lumbar spine BMD was not affected by ICS in children with ICS-treated asthma. If age of the asthmatic children was replaced by their bone age in the model, no significant correlation was found between ICS-treated asthma and total body or lumbar spine BMD. The biochemical parameters of bone metabolism were within normal limits. In conclusion, children with asthma who have used ICS daily for 3 to 8 years had lower total body BMD than healthy controls. Long-term longitudinal studies are needed to investigate whether these children attain a normal peak bone mass.