Insulin-like growth factor-1, insulin-like growth factor binding protein-3, and body mass index: clinical correlates of prostate volume among Black men.
OBJECTIVE
To examine the relationship between insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and body mass index and prostate volume, as a surrogate marker for benign prostatic hyperplasia, in a community-based sample of black men. Epidemiologic studies examining the role of IGF-1 and IGFBP-3 suggest that increased levels of serum IGF-1 and decreased levels of serum IGFBP-3 are associated with an increased risk of prostate cancer. Few studies have examined these factors with respect to benign prostatic hyperplasia, and these have been limited to white men.


METHODS
The study population consisted of a sample of 364 black men, 40 to 79 years of age, residing in Genesee County, Michigan. Men with prostate cancer or prior prostate surgery were excluded. All subjects completed a clinical examination, which included a complete urologic examination with transrectal ultrasonography, anthropometric measurements, and serum assays for IGF-1 and IGFBP-3.


RESULTS
Multivariable regression models demonstrated that prostate volume increased with increasing age (P <0.0001) and body mass index (P = 0.03). IGFBP-3 rather than IGF-1 was positively associated with increasing prostate volume (P = 0.003).


CONCLUSIONS
This is the largest study describing the relationships between IGF-1, IGFBP-3, and body mass index and prostate volume, and the only study in black men. Although earlier studies demonstrated an association between IGF-1 and prostate cancer risk, our findings indicate that IGFBP-3 is more relevant for prostate enlargement, suggesting that IGF-1 and IGFBP-3 may play different pathophysiologic roles in benign and malignant prostatic conditions.
Sarma
Aruna V
AV
Department of Urology, University of Michigan, Ann Arbor, Michigan 48109-0330, USA.
Jaffe
Craig A
CA
Schottenfeld
David
D
Dunn
Rodney
R
Montie
James E
JE
Cooney
Kathleen A
KA
Wei
John T
JT
D000368:Aged; D000375:Aging / Q000502:physiology; D015415:Biomarkers / Q000097:blood; D044383:Black People; D015992:Body Mass Index; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011467:Prostate / Q000000981:diagnostic imaging*; D011470:Prostatic Hyperplasia / Q000175:diagnosis / Q000208:ethnology* / Q000378:metabolism; D014463:Ultrasonography
D015415:Biomarkers; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I