(HealthDay News) – Insulin-like peptide 3 (INSL3) levels are decreased in cryptorchidism and correlate negatively with bisphenol A (BPA), according to a study presented at the annual meeting of The Endocrine Society, held from June 15–18 in San Francisco.
Noting that fetal testicular descent is controlled by INSL3 and testosterone, Patrick Fenichel, MD, PhD, from the University Hospital of Nice in France, and colleagues conducted a prospective study from 2002–2005 in which they measured cord blood INSL3 and testosterone in 180 boys. Participants included 52 cryptorchidic boys born after 34 weeks of gestation (26 transient and 26 persistent) and 128 term-, weight-, and time of birth-matched controls.
The researchers found that, in the cryptorchidic boys, INSL3 was significantly decreased, particularly in those with transient undescended testis. Testosterone levels were unchanged and luteinizing hormone (LH) was increased. There was a negative correlation for LH with INSL3 in the whole population. In the undescended testis group, none of the environmental endocrine disrupters were significantly increased. However, there was a significant negative correlation between BPA and INSL3 in the whole population.
“Alone, our study cannot be considered as definitive evidence for an environmental cause of undescended testis,” Fenichel said in a statement. “But it suggests, for the first time in humans, a link that could contribute to one co-factor of idiopathic undescended testis, the most frequent congenital malformation in male newborns.”