Diurnal variation of body height in children with idiopathic scoliosis.

Background: Body height (BH) measurement is an important part of the clinical evaluation of children with idiopathic scoliosis (IS) as its progression is defined based on the observation of a growth spurt.

Objective: The aim of the study is to assess diurnal variation of BH in children with IS.

Methods: BH was measured in 98 children with IS (Cobb angle: 10∘-52∘, mean 21.2∘± 9.9∘) both in standing and sitting position. The measurements were performed 4 times a day - between: (1) 7:00 and 8:00; (2) 11:00 and 12:00; (3) 15:00 and 16:00 and (4) 19:00 and 20:00.

Results: A significant decrease in BH during the day was observed in both standing and sitting positions (p< 0.001). The highest decrease in height was observed between the measurements performed between 7:00 and 8:00 and measurements carried out in the evening (19:00-20:00). For standing, the mean loss of height was 0.7 cm (± 0.7), i.e. 0.43% of initial standing height, for sitting the mean decrease in height was 0.7 cm (± 0.7), i.e. 0.79% of initial sitting height.

Conclusions: BH decreases in children with IS during daytime. Due to diurnal BH variation, the time of the day should be recorded when measuring patients with IS.