Measurement of salivary insulin-like growth factor-I in acromegaly: comparison with serum insulin-like growth factor-I and growth hormone concentrations.
The aim of this study was to establish the concentration of insulin-like growth factor-I (IGF-I) in saliva of acromegalic patients, and to compare it with the basal levels of serum IGF-I and growth hormone. IGF-I was determined in extracted serum or neat saliva by a disequilibrium RIA using antibodies and iodinated ligand from Amersham and WHO 87/518 as standard. The detection limit of the assay was 0.5 microgram/l, and the intra- and interassay coefficients of variations were 7.9% and 15% respectively. Our study included 13 healthy adult individuals and 17 acromegalics. Compared with healthy adult subjects, acromegalics had significantly higher salivary IGF-I concentrations (mean +/- SEM 5.4 +/- 2.64 vs. 10.5 + -5.69 micrograms/l; p < 0.01), as well as serum IGF-I (176 +/- 42.9 vs. 520 +/- 98.8 micrograms/l; p < 0.0001) and somatotropin levels (1.2 +/- 1.02 vs. 15.4 +/- 9.89 micrograms/l; p < 0.0001). However, 47.1% patients (8 out of 17) with active acromegaly had salivary IGF-I concentrations within the normal range. Serum IGF-I and somatotropin concentrations were found to follow more closely the disease activity after adenomectomy, compared with the concentrations of salivary IGF-I. These results suggest that the IGF-I levels in serum and saliva are somatotropin-dependent. According to our results, measurement of IGF-I in saliva cannot be considered as an additional measure for evaluation of the disease activity in acromegaly, being less reliable than the determination of IGF-I and somatotropin in serum.
Halimi
S
S
Department of Endocrinology of Metabolism, Clinical Hospital Center, Zagreb, Croatia.
Tepavcević
D
D
Suchanek
D
D
Giljević
Z
Z
Palvsić
V
V
Korsić
M
M
D000172:Acromegaly / Q000097:blood / Q000175:diagnosis / Q000378:metabolism*; D000328:Adult; D001798:Blood Proteins / Q000378:metabolism; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*; D012984:Software
D001798:Blood Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone