2020
Experienced Member
- Reaction score
- 50
squeegee said:One of the known target genes of androgen receptor activation is insulin-like growth factor I (IGF-1).
Vertex balding, plasma insulin-like growth factor 1, and insulin-like growth factor binding protein 3.
Platz EA, Pollak MN, Willett WC, Giovannucci E.
Source
Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA.
Abstract
BACKGROUND:
A recent report suggested that men with vertex balding have higher levels of plasma insulin-like growth factor 1 (IGF-1). The association of its major carrier protein, insulin-like growth factor binding protein 3 (IGFBP-3), with male pattern hair loss has not been examined.
OBJECTIVE:
We evaluated the relations of plasma concentrations of IGF-1 and IGFBP-3 with vertex balding in middle-aged and elderly men.
METHODS:
Participants were 431 male members of the Health Professionals Follow-up Study who responded to a question in 1992 on their hair pattern at 45 years of age and who were 47 to 81 years old when they provided a blood specimen in 1993-1994. Odds ratios (ORs) of vertex balding associated with IGF-1 and IGFBP-3 were estimated from logistic regression models mutually adjusting for each other and controlling for age at blood draw.
RESULTS:
Of the 431 men, 128 had vertex balding at age 45. Compared with men who were not balding, for a 1 standard deviation increase in plasma IGF-1 level (72.4 ng/mL), the OR for vertex balding was 1. 31 (95% CI, 0.95-1.81). For a 1 standard deviation increase in plasma IGFBP-3 (957 ng/mL), the OR for vertex balding was 0.62 (95% CI, 0.44-0.88).
CONCLUSION:
Older men with vertex balding have lower circulating levels of IGFBP-3 and higher levels of IGF-1 when controlling for IGFBP-3 level.
Reduction of ventral prostate weight by finasteride is associated with suppression of insulin-like growth factor I (IGF-I) and IGF-I receptor genes and with an increase in IGF binding protein 3.
Huynh H, Seyam RM, Brock GB.
Source
Lady Davis Research Institute of the Jewish General Hospital and Department of Surgery, McGill University, Montreal, Quebec, Canada.
Abstract
Finasteride, a competitive and specific inhibitor of 5alpha-reductase, is widely used in the treatment of symptomatic benign prostatic hyperplasia. We demonstrate here that finasteride, when administered in an in vivo experimental system, caused ventral prostate regression. Intraprostatic dihydrotestosterone levels decreased, whereas testosterone levels increased in a dose-dependent manner following finasteride treatment. Finasteride also inhibited the expression of insulin-like growth factor (IGF)-I and IGF-I receptor genes in the ventral prostate. Finasteride significantly increased IGF binding protein-3 and slightly decreased IGF binding protein-2, -4, and -5 gene expression. Because IGFs are potent mitogens for prostate epithelial cells, this newly described activity of finasteride may contribute to its antiproliferative properties, particularly with regard to the inhibition of prostate growth seen clinically and in animal models.
... and how is this relevant to MSM?