3P-RT-4
GROWTH HORMONE TREATMENT OF CHILDREN BORN SMALL FOR GESTATIONAL AGE
Francis De Zegher, University of Leuven, Belgium
About 10% of
infants born Small-for-Gestational-Age (SGA) fail to present sufficient
catch-up growth to normalize their stature by early childhood.
When Growth
Hormone (GH) was considered as a treatment option, these short SGA children
used to be differentiated according to the presence or absence of GH deficiency
(GHD).
SGA children with GHD could receive an established GH treatment, and their growth responses were found to be comparable to those of non-SGA children with GHD, provided a slightly higher replacement dose was given to overcome the apparently associated distal block in the somatotropic axis. A series of randomized, multicenter studies have now evidenced that SGA children without GHD also respond to GH treatment given in either a continuous or discontinuous regimen.
Continuous GH with~33-67mcg/Kg/d
over 6yr was found to be safe and to induce mean height gains of ~2.0to 2.7 SD
without inducing excessive bone maturation, precocious puberty or glucose
intolerance.
The fist results
with continuous GH treatment for 8 yr indicate that final height will also be
increased.
Discontinuous
treatment with ~67-100 mcg/Kg/ in On/Off-treatment phases of 2-3 yr was found
to be safe and to swiftly normalize childhood stature in the majority of short
non-GHD children born SGA.
The
hyperinsulinemia characterzing such effective GH treatment is rapidly reversed
upon GH discontinuation.
In conclusion,
short SGA children respond well to continuous treatment with GH in a dose range
of 33-67 mcg/Kg/d, regardless of whether they are GHD or not.
Discontinuous
high-dose range of GH treatment deserves further exploration as an alternative
regimen, in particular for young non-GHD children.
Small body size
secondary to prenatal growth restriction may become one of the best indications
for GH treatment in childhood.