Normal values of serum IGF-1 in adults: results from a Brazilian population.
OBJECTIVE
To determine the normal values of serum IGF-1 (Immulite 2000) in a Brazilian adult (21-70 years) population.


METHODS
Healthy volunteers were divided into 10 groups according to age (5-year intervals), with 100 subjects (50 men and 50 women) per group. One-hundred participants were selected for repetition of the test after 12 weeks.


RESULTS
No difference in IGF-1 values was observed between men and women, but a progressive reduction of serum IGF-1 with age was seen. The reference values provided by the manufacturer of the assay, although discretely higher, were very close to the values found in this study. A second measurement of IGF-1 after 12 weeks revealed a variation < 20% in 99% of subjects.


CONCLUSIONS
This study established the reference range for IGF-1 determined with the Immulite 2000 assay for a large number of healthy Brazilian adults stratified according to age, and suggests that variations > 20% in IGF-1 levels within an interval of 12 weeks cannot be attributed to interassay variability.
Rosario
Pedro Weslley
PW
Santa Casa de Belo Horizonte, Departamento de Neuroendocrinologia, Santa Casa de Belo Horizonte, MG, Brazil. pedrorosario@globo.com
D000328:Adult; D000368:Aged; D001938:Brazil; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D055815:Young Adult
D007334:Insulin-Like Growth Factor I