The measurement of insulin-like growth factor-I (IGF-I) concentration in random urine samples.
The aim of the present study was to assess a suitable expression of the urinary concentration of a protein/ peptide hormone such as insulin-like growth factor-I (IGF-I), measured in the urine of healthy individuals when the specimen collection is executed randomly. One hundred and twenty male subjects were divided by age into four groups, namely healthy sedentary young (SYA) and older (SOA) adults, older (OC) and young (YC) children. In a single urine specimen, randomly collected during the morning from each individual, total urinary IGF-I was measured by immunoradiometric method, and urinary creatinine (uCr) and total proteins (utPr) were measured by capillary electrophoresis and spectrophotometric methods, respectively. The urinary IGF-I concentrations were not significantly different in all groups investigated and they were (mean +/- SD): 82.7 +/- 82.8 ng/l, 103.5 +/- 83.3 ng/l, 80.4 +/- 64.4 ng/l in OC, SYA and SOA, respectively; only in the YC group there was a tendency to higher values (125.2 +/- 93.2 ng/l) compared with the other groups. utPr ranged from 26 to 40 mg/l and did not demonstrate significant differences between groups. The urinary IGF-I correlated with uCr and utPr, and statistical significance was observed in all measurements. The measurement of urinary IGF-I in random urine and its ratio to utPr is an innovative, useful way of investigation of urinary protein/peptide hormones.
De Palo
Elio F
EF
Department of Medical Diagnostic Sciences and Special Therapies, University of Padova, Italy. eliof.depalo@unipd.it
Gatti
Rosalba
R
Lancerin
Federica
F
Cappellin
Enrico
E
Sartorio
Alessandro
A
Spinella
Paolo
P
D000293:Adolescent; D000328:Adult; D000375:Aging / Q000652:urine*; D001827:Body Height; D001835:Body Weight; D002096:C-Peptide / Q000652:urine; D002648:Child; D003404:Creatinine / Q000652:urine; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011392:Proline / Q000652:urine; D011863:Radioimmunoassay / Q000379:methods; D011897:Random Allocation; D012016:Reference Values; D012044:Regression Analysis; D012494:Sampling Studies; D013053:Spectrophotometry
D002096:C-Peptide; D007334:Insulin-Like Growth Factor I; D011392:Proline; D003404:Creatinine