Growth Hormone Improves Body Composition, Fat ... - GGH Journal

were no noted side effects from GH therapy. Specifically, frequent
complete blood cell counts were performed to monitor for the risk
of acute lymphoblastic leukemia, which is known to occur more
frequently in children with Down syndrome. Prior to treatment,
the study group had a height SDS of -1.8 and the control group
had a height SDS of -1.7. After 36 months of treatment, the
study group SDS rose to -0.8, whereas the control group SDS
decreased to -2.2 (Figure). The study and control groups both
had better growth than the average child with Down syndrome.
The mean IGF-1 SDS in the study group was -1.6 before treatment,
0.28 after 3 years of treatment, and -1.11 one year after the
end of treatment. There was a significant difference in head circumference
between the 2 groups at the start of therapy, but there
was no significant change in head circumference SDS in either
group throughouthe treatment period. At the end of GH treatment,
the mean height of the treated group was significantly
above that of the control group, but during the years after treatment
these children grew less than the control group. However,
there was a slight difference in heights at the age of 6.5 years
(3 years after the end of treatment; P

(BMD) were determined by dual energy X-ray absorptiometry
(DXA). Resting energy expenditures (REE) and respiratory quotients
(RQ) were determined by indirect calorimetry. Physical
strength and agility were determined by using a modified Bruininks-
Oseretsky test.
After 12 months, GH-treated children had a mean growth rate of
10.1 cm/y, compared with 5 cm/y among controls. Mean IGF-1,
IGFBP-3, osteocalcin, and type 1 procollagen levels significantly
increased in GH-treated children. Baseline body composition
analysis revealed increased BF (45.2%:I: 8.3% vs 18% :I: 3.6%)
and lower LBM (50% vs 80%) compared with healthy children
without PWS. GH-treated patients experienced an 8% decrease in
BF. Their LBM increased compared with controls (Table). Ninetyfive
percent of PWS children had normal baseline BMD. Femoral
BMD increased by 0.09 :I: 0.02 g/cm2, while lumbar spine and total
body BMD remained unchangeduring GH treatment. Although
baseline REE was low in PWS, it did not increase after GH treatment;
however, RQ values decreaseduring GH treatment. GH
treatment increased strength, agility, and respiratory muscle
force. GH therapy improved the lipid profile as cholesterol and
HDL cholesterol levels fell. Lastly, GH therapy did not significantly
affect fasting and 2-hour postprandial insulin levels.
which could be aggravated by GH treatment. Finally, the chromosomal
abnormalities characteristic of PWS may add a risk factor
for potential GH-associated malignancies. Therefore, the estimated
potential benefit of this kind of treatment should be evaluated
on a long-term basis.
Fima Lifshitz, MD
2nd Editor's comment: This topic is of much current interest. To
supplement your knowledge about the recent literature, you can
refer to 2 articles abstracted in GGH previously (1999;15[1 J).
1. Thacker MJ, et al. Growth failure in Prader-Willi syndrome is
secondary to GH deficiency. Harm Res 1998;49:216-220.
2. Lindgren AC, et al. Growth hormone treatment of children
with Prader-Willi syndrome affects linear growth and body
composition favorably. Acta Paediatr 1998;87:28-31.
The data and conclusions in these articles are consistent.
Robert M. Blizzard, MD
The authors concluded that GH treatment promoted growth and
positively affected body composition, physical strength, and agility
in children with PWS.
Carrell A, et al. J Pediatr 1999;134:215-221
Editors comment: Obesity, short stature, and hypotonia are
some of the most striking physical signs of children with PWS.
This interesting, well-designed, prospective study describes the
effects of GH treatment-promoting growth while improving
body composition and physical capacity-in children with PWS.
The data are in agreement with previous studies and clearly
showed that GH therapy could represent one of the most important
therapeutic approaches to this disorder.
The response of PWS patients to GH treatment resembles the
positive effects of GH in hypopituitary patients. In addition, the
possibility that PWS patients are GH deficient because of hypothalamic
abnormalities needs to be considered, although the GH
axis has been difficult to assess because of the obesity of PWS
patients. The deleterious effects of GH treatment should be considered
as PWS children have an increased incidence of scoliosis,
Growth Hormone Treatment Increases CO2 Response, Ventilation and Central Inspiratory
Drive in Children With Prader- Willi Syndrome
Hypoventilation commonly occurs in subjects with Prader-Willi syn- rhGH (0.23 mg/kg/wk). This therapeutic program did not alter
drome (PWS). This has been attributed in large part to obesity and body mass index in this interval, although changes in body comthe
imposition of a large mechanical load, thereby impairing move- position were not reported. They found that in response to rhGH,
ment of the thoracic cage. However, there also is a problem with minute ventilation (mUkg/min) increased 126%; the ventilatory
ventilatory control in PWS patients, as evidenced by abnormal response (ie, sensitivity) to 4% CO2 increased 8-fold; and the cenresponses
to hyperoxia, hypoxia, and hypercarbia, as well as tral inspiratory drive, a measurement of airway occlusion pressure
decreased peripheral chemoreceptor activity (Menendez AA. fur J that is little affected by pulmonary mechanics (determined by the
Pediatr 1999;158:941-942). change in airway pressure during the first 0.1 second after beginning
an inspiration), increased 170%. In contrast, the response to
Lindgren et al studied resting ventilatory regulation in 9 prepubertal
children with PWS prior to and after 6 to 9 months of therapy with
hyperoxia, measured as an increase of the inspired O2 concentration
from room air to 100%, did not change during rhGH administration.
GGHVol. 16. No.1-March 2000
16