The Effect of Clonidine Therapy on Height and Growth Velocity in Constitutional Growth and Puberty Delay

Background Constitutional delay of growth and puberty (CDGP) is the most common cause of short stature. This variant of normal growth can be associated with psychological stress in some affected individuals. Objectives We aimed to assess the effects of clonidine on short-term growth rate in children and adolescents with constitutional growth delay. Patients and Methods In this prospective, randomized clinical trial study, 48 prepubertal constitutionally short boys (6 -12 years old) with height standard deviation scores (HSDS) less than -2, bone age delay 2.1 ± 0.2 years, GH concentration > 10 μg/L after provocation and growth rates < 5 cm/year were included. Subjects were randomly assigned to group A (n = 24) who received clonidine 0.1 mg/m2 or group B (n = 24) who received placebo before sleep for 6 months. Height, weight and growth velocity were measured in 6th and 12th months. Results Mean age and height in two groups were similar at baseline. Mean growth velocity in group A was 2.9 ± 0.91 and 3.1 ± 0.98 cm/6 month at baseline and 6th months, respectively and in group B was 2.9 ± 0.94 and 2.4 ± 0.47 cm/6 month at baseline and 6th months, respectively (P = 0.01). Mean HSDS in group A was -2.79 ± 0.65 and 2.39 ± 0.39 at baseline and 6th months, respectively and in group B was 2.69±0.73 and 2.39 ± 0.48 at baseline and 6th months, respectively. Conclusions Although a slightly increase in HSDS was observed in treated group, but difference was not significant compared with control subjects. So, clonidine therapy could not improve height standard deviation score and growth velocity of children and adolescents with CDGP.