Page 24 - GALENIKA MEDICAL JOURNAL

Table 3. Goals of growth hormone replacement therapy in adults Contrary to that, patients with adult-onset growth hor-
To normalize the concentration of IGF-I mone deficiency (AOGHD) experience significant impro-
To correct abnormalities caused by growth hormone deficiency vement in Quality of Life (QoL) compared to childhood-on-
set growth hormone deficiency (COGHD). Women, older
- To improve body composition
(reduce abdominal fat, increase muscle mass) individuals, and those with higher body weight show a wea-
22
- To improve metabolic parameters ker response to growth hormone therapy .
(lipid profile, insulin sensitivity)
- To improve muscle function
(including cardiac) and increase physical endurance
Dosage of growth hormone in adults
- To increase bone mass
When determining the dose of GH for adult individuals,
- To improve heart function
(increase ejection fraction and left ventricular mass, improve diastolic function) factors such as gender and age of the patient are taken into
- To improve quality of life (QoL) account, as well as estrogen therapy in women. Treatment
typically starts with a lower dose, which is then individually
increases muscle mass and decreases fat mass primarily in titrated based on the clinical response, adverse effects, and
the abdominal region . GH therapy has a beneficial impact serum IGF-I levels. Due to the suppressive effect of estrogen
17
on the skeletal system, but its effects are biphasic because on hepatic production of IGF-I, women require higher doses
GH stimulates both bone formation and bone resorption. of GH than men to normalize IGF-I levels. Women with GHD
Therefore, in the first 12 months of treatment, there may who are on oral estrogen therapy require higher doses of
be a decrease in bone mass, but after 18-24 months, there GH compared to those on transdermal estrogen therapy .
23
is an increase in BMD primarily in the spine. Hence, bone
density measurement (Dual X-ray Absorptiometry, DXA) is For patients aged 30 to 60 years, the initial dose is typi-
conducted at least 12 months after starting GH therapy. The cally 0.2-0.3 mg daily, which is then adjusted based on the
favorable effects of GH therapy on body composition and IGF-I levels by increasing or decreasing by 0.1-0.2 mg every
bones are sustained for more than a decade of treatment 1-2 months until a normal IGF-I level is achieved for the pa-
with this hormone. A study by Elbornsson et al. showed a tient's age. For individuals younger than 30 years and those
tendency for an increase in muscle mass over 15 years and in the transitional period, the initial dose is higher, ranging
a reduction in fat mass in the first 7 years of therapy. After from 0.4-0.5 mg daily, and similarly titrated individually
the seventh year, there is a gradual increase in fat mass, based on IGF-I levels. For individuals older than 60 years,
which may be associated with aging . It is assumed that treatment usually starts with smaller daily doses of 0.1-0.2
18
the increase in body mass index and waist circumference is mg. The dosing regimen is the same for those who acqu-
caused by the physiological aging of the individual, regar- ired GH deficiency in childhood and those who developed
dless of GH levels. On the other hand, a study by a Dutch it in adulthood. To better mimic physiological nocturnal GH
group has shown that the long-term effects of GH therapy secretion, the GH dose is administered subcutaneously in
24
on body composition are not consistent. There are discre- the evening . Until now, daily injections of growth hormone
pancies among studies depending on their design regar- have been the only method of administration, but recently,
ding the effects on body composition . The effects of GH long-acting weekly formulations have also been introduced.
19
25
replacement therapy also manifest in the cardiovascular This will significantly improve adherence to this therapy .
system. It increases ejection fraction, thickness of the left
ventricular wall, and diastolic function of the left ventricle.
Improvement in lipoprotein metabolism is likely due to the Monitoring the effects of
induction of hepatic LDL receptors, leading to a decrease in growth hormone therapy
serum LDL cholesterol levels . Changes in the lipoprotein Adjustment of growth hormone (GH) dosage should be
20
status become evident after one year of GH therapy. Impro- done every 1-2 months during the initial months of its ad-
vement in Quality of Life (QoL) on growth hormone therapy ministration. Once the maintenance dose of GH is achieved,
is apparent as early as three months, with maximal effect monitoring is conducted every 6 months. After the main-
after 12 months of therapy and a tendency to maintain for tenance dose of GH is established, monitoring of the effe-
up to 15 years of treatment . ctiveness and safety of the therapy should continue thro-
12
The effects of GH therapy depend on the gender and ughout the treatment period. The best way to monitor the
age of the patient, as well as when the deficiency of this hor- biochemical effects of GH is through IGF-I levels.
mone occurrs. Improvement in bone mineral density (BMD) IGF-I is an essential marker for monitoring the safety
is more pronounced in men compared to women, as well of GH therapy. Changes in IGF-I concentration can be me-
as in patients with childhood-onset growth hormone defi- asured rapidly after adjusting the GH dose, enabling early
ciency (COGHD) compared to those with adult-onset growth detection of dose excess . Besides biochemical monitoring,
24
hormone deficiency . clinical signs are also crucial in assessing the effectiveness
21
of growth hormone treatment. Body composition (waist/

22 DOI: 10.5937/Galmed2409023D