Concomitant impairment of growth hormone secretion and peripheral sensitivity in obese patients with obstructive sleep apnea syndrome.
To clarify the impairment of the GH/IGF-I axis in obstructive sleep apnea syndrome (OSAS), in 13 adult male patients with OSAS (OSA) as well as 15 weight-matched patients with simple obesity (OB) and 10 normal lean male subjects (NS), we studied: 1) the GH response to GHRH (1 micro g/kg iv) plus arginine (30 g iv); and 2) the IGF-I and IGF binding protein-3 responses to a very low dose recombinant human (rh)GH treatment (5.0 microg/kg sc per day for 4 d). The GH response to arginine plus GHRH in OSA was lower than in OB (P < 0.05), which in turn was lower than in NS (P < 0.001). Basal IGF-I levels in OSA were lower than in OB (P < 0.05), which in turn were lower than in NS (P < 0.03). As opposed to OB and NS, in OSA a very low rhGH dose did not affect IGF-I. Adjusting for age and basal values, rhGH-induced IGF-I rise in OSA was lower than in OB (P < 0.01). IGF binding protein-3, glucose, and insulin levels in the three groups were not modified by rhGH. OSA show a more marked impairment of the maximal secretory capacity of somatotroph cells together with reduced IGF-I sensitivity to rhGH stimulation. These findings suggest that OSAS is connoted by a concomitant impairment of GH secretion and sensitivity.
Gianotti
L
L
Division of Endocrinology, Department of Internal Medicine, University of Turin, C. so Dogliotti 14, 10126 Turin, Italy.
Pivetti
S
S
Lanfranco
F
F
Tassone
F
F
Navone
F
F
Vittori
E
E
Rossetto
R
R
Gauna
C
C
Destefanis
S
S
Grottoli
S
S
De Giorgi
R
R
Gai
V
V
Ghigo
E
E
Maccario
M
M
D000328:Adult; D001120:Arginine; D001786:Blood Glucose / Q000378:metabolism; D015331:Cohort Studies; D013007:Growth Hormone-Releasing Hormone; D019382:Human Growth Hormone / Q000378:metabolism* / Q000494:pharmacology*; D006801:Humans; D006973:Hypertension / Q000150:complications; D007328:Insulin / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology
D001786:Blood Glucose; D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D013007:Growth Hormone-Releasing Hormone; D001120:Arginine