Catch-up growth following transfer from three times weekly im to daily sc administration of hGH in GH deficient patients, monitored by knemometry

A novel and non-invasive technique of growth measurement is introduced. By this method the length of the human lower leg is measured with an accuracy of 0.1 mm. Thus, growth velocities can be estimated within a few weeks. In the present study the immediate changes of growth velocity are demonstrated, following the transfer of growth hormone administration from three times weekly im to daily sc in 9 growth hormone deficient children, age 7.4 to 20.5 years. The first observation period (3 times weekly im administration) ranged from 32 to 72 days, the second observation period (daily sc administration) ranged from 160 to 267 days). During the study, the total weekly dosage of growth hormone remained unchanged (12 IU/m2/week). In all 9 patients growth velocity increased significantly after the transfer of application. Mean growth velocity of the lower leg rose from 0.04 mm/day up to 0.065 mm/day. Mean growth velocity of total body height rose form 4.8 cm/year up to 6.9 cm/year. In addition, differential lower leg growth rates of 3 to 4 week periods were established in all 9 patients, revealing a significant catch-up growth spurt immediately following the transfer of application. During this spurt mean lower leg growth velocity rose form 0.04 mm/day up to 0.091 mm/day. This marked increase of lower leg growth rates lasted for only a few weeks and was followed by a period of decreased growth velocity. On the long run, growth velocity shifted upward in a wave-like pattern, stabilizing on a significantly higher level than before the transfer of application.