scholarly journals Enhancement of the peripheral sensitivity to growth hormone in adults with GH deficiency

2001 ◽  
pp. 267-272 ◽  
Author(s):  
G Aimaretti ◽  
G Fanciulli ◽  
S Bellone ◽  
M Maccario ◽  
E Arvat ◽  
...  

OBJECTIVE: Adults with severe GH deficiency (GHD) need recombinant human growth hormone (rhGH) replacement to restore body composition, structure functions and metabolic abnormalities. The optimal rhGH dose for replacement has been progressively reduced to avoid side effects. The aim of the present study was to define the minimal rhGH dose able to increase both IGF-I and IGF binding protein (BP)-3 levels in GHD and to verify the possible change in GH sensitivity. DESIGN AND PATIENTS: To this goal, we studied the effect of 4-day treatment with 3 rhGH doses (1.25, 2.5 and 5.0 microg/kg/day) on IGF-I and IGFBP-3 levels in 25 panhypopituitary adults with severe GHD (12 males and 13 females, age: 44.5+/-3.0 years, body mass index (BMI): 27.0+/-0.9 kg/m(2)) and 21 normal young adult volunteers (NV, 12 males and 9 females, age: 30.5+/-2.0 years, BMI: 20.8+/-0.5 kg/m(2)). RESULTS: Basal IGF-I and IGFBP-3 levels in GHD were lower (P<0.001) than in NV. In NV the 1.25 microg/kg dose of rhGH did not modify IGF-I levels. The dose of 2.5 microg/kg rhGH significantly increased IGF-I levels in men (P<0.001) but not in women, while the 5.0 microg/kg dose increased IGF-I levels in both sexes (P<0.001). IGFBP-3 levels were not modified by any of the administered rhGH doses. In GHD patients, all rhGH doses increased IGF-I levels 12 h after both the first (P<0.01) and the fourth rhGH dose (P<0.001). At the end of treatment percentage increases in IGF-I were higher (P<0.001) in GHD patients than in NV. In contrast with NV, in GHD patients the IGF-I response to short-term stimulation with rhGH was independent of gender. Moreover, GHD patients showed increases in IGFBP-3 after the fourth administration of both 2.5 and 5.0 microg/kg rhGH. CONCLUSION: The results of the present study demonstrate that the minimal rhGH dose able to increase IGF-I and IGFBP-3 levels in GHD patients is lower than in normal subjects, at least after a very short treatment. This evidence suggests an enhanced peripheral GH sensitivity in GH deprivation.

Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 2075-2081 ◽  
Author(s):  
E Vihervuori ◽  
M Virtanen ◽  
H Koistinen ◽  
R Koistinen ◽  
M Seppala ◽  
...  

Erythropoiesis was investigated in 32 children wih short stature and in eight children with skeletal dysplasia by studying blood hemoglobin in relation to growth and to serum concentrations of insulin-like growth factor I (IGF-I), IGF binding protein-3 (IGFBP-3), and erythropoietin (EPO) before, during, and after 12 months of recombinant human growth hormone (GH) treatment. Blood hemoglobin concentration was positively correlated with relative body height and with serum IGF-I and IGFBP-3 levels (P = .001 to .02), but not with the concentrations of EPO. The normal age-dependency of hemoglobin was lacking. Hemoglobin levels and their responses to GH treatment were similar in the patients with GH deficiency and those with normal GH secretion. Treatment with GH accelerated growth and elevated the concentrations of hemoglobin, IGF- I, and IGFBP-3. In the eight patients with skeletal dysplasia, body mass increased similarly, but gain in height was less than in the other patients, and the increase in hemoglobin was markedly pronounced. In this group, the correlations between hemoglobin, IGF-I, and IGFBP-3 were extremely close (r = 0.80 to 0.85, P = .031 to .008). These findings are in accord with earlier observations from in vitro and animal studies, and suggest that the GH-IGF axis is involved in the physiologic elevation of hemoglobin levels during childhood.


Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 2075-2081 ◽  
Author(s):  
E Vihervuori ◽  
M Virtanen ◽  
H Koistinen ◽  
R Koistinen ◽  
M Seppala ◽  
...  

Abstract Erythropoiesis was investigated in 32 children wih short stature and in eight children with skeletal dysplasia by studying blood hemoglobin in relation to growth and to serum concentrations of insulin-like growth factor I (IGF-I), IGF binding protein-3 (IGFBP-3), and erythropoietin (EPO) before, during, and after 12 months of recombinant human growth hormone (GH) treatment. Blood hemoglobin concentration was positively correlated with relative body height and with serum IGF-I and IGFBP-3 levels (P = .001 to .02), but not with the concentrations of EPO. The normal age-dependency of hemoglobin was lacking. Hemoglobin levels and their responses to GH treatment were similar in the patients with GH deficiency and those with normal GH secretion. Treatment with GH accelerated growth and elevated the concentrations of hemoglobin, IGF- I, and IGFBP-3. In the eight patients with skeletal dysplasia, body mass increased similarly, but gain in height was less than in the other patients, and the increase in hemoglobin was markedly pronounced. In this group, the correlations between hemoglobin, IGF-I, and IGFBP-3 were extremely close (r = 0.80 to 0.85, P = .031 to .008). These findings are in accord with earlier observations from in vitro and animal studies, and suggest that the GH-IGF axis is involved in the physiologic elevation of hemoglobin levels during childhood.


1995 ◽  
Vol 132 (4) ◽  
pp. 433-437 ◽  
Author(s):  
Burkhard Tönshoff ◽  
Werner F Blum ◽  
Mark Vickers ◽  
Sabine Kurilenko ◽  
Otto Mehls ◽  
...  

Tönshoff B, Blum WF, Vickers M, Kurilenko S, Mehls 0, Ritz E. Quantification of urinary insulin-like growth factors (IGFs) and IGF binding protein 3 in healthy volunteers before and after stimulation with recombinant human growth hormone. Eur J Endocrinol 1995;132:433–7. ISSN 0804–4643 We examined excretion of urinary insulin-like growth factors I and II (IGF-I and IGF-II) and their major binding protein IGFBP-3 in comparison to their respective serum concentration in nine healthy female volunteers (median age 25 years, range 22–27) under baseline conditions and after stimulation with recombinant human growth hormone (rhGH), 4.5 IU twice daily subcutaneously for a period of 3 days. The IGFs were measured in unconcentrated urine by use of recently developed, highly sensitive radioimmunoassays. The IGFBP-3 was measured by a specific radioimmunoassay. The mean (±sd) urinary concentrations of IGF-I (0.08 ± 0.07 μg/l), IGF-II (1.02 ± 0.47 μg/l) and IGFBP-3 (19.1 ± 6.9 μg/l) were two to three orders of magnitude lower than in serum. The ratio of IGF-II over IGF-I concentration in urine (13:1) was five times higher than in serum (2.5:1), and the ratio of IGFBP-3 over the sum of IGF-I and IGF-II in urine (17:1) was four times higher than in serum (4:1). Urinary excretion was 63.3 ± 46.6 ng·m−2 · 24 h−1 for IGF-I, 1002 ± 598 ng·m−2 · 24 h−1 for IGFII and 18039 ± 4983 ng·m−2·24 h−1 for IGFBP-3. Using fast protein liquid exclusion chromatography, only immunoreactive IGFBP-3 components of less than 60 kD were detected in urine, with a major peak at 20kD. Urinary IGFBP-3 excretion correlated with serum IGFBP-3 (r = 0.61, p < 0.01) and the glomerular filtration rate (r = 0.56, p < 0.05) measured by steady-state inulin infusion clearances. Administration of rhGH stimulated significantly (p < 0.005) the serum IGF-I concentration by 50%, but not the urinary IGF-I excretion. In conclusion: the considerably higher ratio of IGF-II to IGF-I in urine compared to serum indicates that urinary IGF excretion does not represent only filtered IGFs, urinary IGF-I is a less sensitive indicator of GH activity than serum IGF-I, and as urinary IGFBP-3 excretion is in proportion to the glomerular filtration rate and serum IGFBP-3, it presumably reflects renal filtration of small immunoreactive IGFBP-3 fragments from the circulation. Burkhard Tönshoff, University Children's Hospital, Im Neuenheimer Feld 150, 69120 Heidelberg, Germany


1996 ◽  
Vol 134 (3) ◽  
pp. 352-356 ◽  
Author(s):  
Ezio Ghigo ◽  
Gianluca Aimaretti ◽  
Laura Gianotti ◽  
Jaele Bellone ◽  
Emanuela Arvat ◽  
...  

Ghigo E, Aimaretti G, Gianotti L, Bellone J, Arvat E, Camanni F. New approach to the diagnosis of growth hormone deficiency in adults. Eur J Endocrinol 1996;134:352–6. ISSN 0804–4643 Pyridostigmine (PD), a muscarinic cholinergic agonist, and arginine (ARG) clearly increase the growth hormone (GH) response to growth hormone-releasing hormone (GHRH) in man. The current study was undertaken to investigate the value and safety of PD + GHRH and ARG + GHRH tests as well as the measurement of serum insulin-like growth factor I (IGF-I) in diagnosing GH deficiency in adults. Fifty-four patients considered GH deficient from extensive organic or idiopathic pituitary disease and 326 healthy adults were studied. The IGF-I concentrations were lower than the 3rd percentile of normal values in only 31 of the 54 (57.4%) patients with hypopituitarism. However, the IGF-I levels in hypopituitary patients and in normal subjects overlapped more frequently between 41 and 60 years (50%) and between 61 and 80 years (92.3%) as opposed to between 20 and 40 years (8.6%). In contrast to the IGF-I measurement, the ranges of peak GH responses to PD + GHRH and ARG + GHRH tests were clearly differentiated between the hypopituitary (0.2–6.8 and 0.1–9.5 μg/l, respectively) and normal subjects 17.7–114 and 16.1–119 μg/l, respectively). However, the PD + GHRH test was reliable only in subjects of 20–40 years of age. In conclusion, IGF-I measurement had no value in the diagnosis of GH deficiency in adults aged over 40 years, but is reliable enough when young adults of 20–40 years of age are considered. Both PD + GHRH and ARG + GHRH testing should be considered more reliable biochemical measurements of GH deficiency. In contrast to the PD + GHRH test, the ARG + GHRH test is reliable throughout the adult lifespan and appears to be the most appropriate for patient compliance and safety. F Camanni, Divisione di Endocrinologia, Ospedale Molinette, C.so Dogliotti 14, 10126 Torino, Italy


1992 ◽  
Vol 127 (6) ◽  
pp. 555-564 ◽  
Author(s):  
Subburaman Mohan ◽  
Donna D Strong ◽  
Uta G Lempert ◽  
Florence Tremollieres ◽  
Jon E Wergedal ◽  
...  

Previous studies have shown that the actions of IGF-II in bone are determined not only by its concentration, but also by the concentration of IGFBP-4 as well as other IGFBPs. In this study, we sought to determine by Western ligand blotting the effects of growth hormone, IGF-I and IGF-II on the production of IGFBP-3 and IGFBP-4 in TE89 human osteosarcoma cells and in untransformed normal human bone cells derived from rib. Human growth hormone at 10 μg/l decreased the amount of IGFBP-4 but had no effect on the IGFBP-3 level in the conditioned medium of low density cultures of TE89 cells and human bone cells derived from rib. Human growth hormone had no effect on IGFBP-3 or IGFBP-4 levels in the conditioned medium of high density human bone cell cultures. IGF-I and IGF-II, which increased human bone cell proliferation, decreased the level of IGFBP-4 (30% of control at 100 μg/l IGF-I and IGF-II) but increased the level of IGFBP-3 (3–10 fold at 100 μg/l IGF-I and IGF-II) after 48 h of treatment in the conditioned medium of both low and high density TE89 cell cultures. Similar changes in IGFBP-3 and IGFBP-4 levels were also seen in the conditioned medium of human bone cells derived from rib after treatment with IGF-I and IGF-II. Studies to determine the underlying molecular mechanisms by which IGF-II decreased the amount of IGFBP-4 in the conditioned medium revealed that IGF-II decreased the IGFBP-4 mRNA abundance and increased the IGFBP-3 mRNA abundance in human bone cells. Based on the above findings, we conclude that the production of both IGFBP-3 and IGFBP-4 is regulated in bone cells and that local and systemic agents may modulate the responsiveness of bone cells to IGFs by regulated secretion of IGFBP-3 and IGFBP-4.


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