title: Digit-Length Ratios (2D:4D) as a Phenotypic Indicator ofin UteroAndrogen Exposure is Not Prognostic for Androgenic Alopecia: a Descriptive-Analytic Study of 1200 Iranian Men.
abstract: The etiology of androgenic alopecia (AGA) involves several factors, including genetics, androgens, age and nutrition. Digit-length ratio of the index and ring finger (2D:4D) is an indicator of prenatal exposure to sex hormones. There is a paucity of studies that systemically review the possible positive predictive value of 2D:4D in the development of AGA. We performed a single-site, descriptive-analytical study among a racially homogeneous population. Our results revealed that no significant association was determined between right 2D:4D and AGA severity within our entire population (P=0.384, r=0.025), however a positive correlation coefficient was identified in subjects above the age of 40. Based on the receiver operating characteristic curve analysis, 2D:4D does not predict the development of AGA. AGA is truly a multifactorial disease. Further, our findings suggest that increasedin uteroexposure to androgens as a fetus does not predispose men to develop AGA.
authors.affiliation: Department of Dermatology, Jahrom University of Medical Sciences , Jahrom, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Feily
authors.affiliation: Department of Dermatology, Jahrom University of Medical Sciences , Jahrom, Iran.
authors.forename: Masoomeh
authors.initials: M
authors.lastname: Hosseinpoor
authors.affiliation: Department of Dermatology, Jahrom University of Medical Sciences , Jahrom, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Bakhti
authors.affiliation: Department of Dermatology, Jahrom University of Medical Sciences , Jahrom, Iran.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Nekuyi
authors.affiliation: Hormozgan University of Medical Sciences , Bandarabas, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Sobhanian
authors.affiliation: Department of Community Health, Jahrom University of Medical Sciences , Jahrom, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Fathinezhad
authors.affiliation: Department of Anesthesiology, Jahrom University of Medical Sciences , Jahrom Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Sahraei
authors.affiliation: Department of Anesthesiology, Jahrom University of Medical Sciences , Jahrom Iran.
authors.forename: Marigdalia K
authors.initials: MK
authors.lastname: Ramirez-Fort
keywords: Androgenic alopecia; digit-length ratio; hair loss; predictive value