AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
2d 4d ratio9/18/2023 More convincing evidence regarding a link between prenatal testosterone and digit ratio comes from observations of digit ratios in girls with congenital adrenal hyperplasia 4 and in genetic males with complete androgen insensitivity. 15 As a result, a high level of foetal testosterone relative to foetal estradiol is associated with a low digit ratio. 1, 11, 14Ī previous study reported that the digit ratio of the right hand was negatively correlated with the foetal testosterone/foetal estradiol ratio. 13 These observations have led to the suggestion that patterns of digit formation may be related to gonad function. 13 observed that the mean testis volume was significantly negatively correlated with the right digit ratio in azoospermic men. 6, 7, 8, 9, 10 Across vertebrate species including humans, the Homeobox ( Hox) a and d genes regulate limb development, including fingers and toes, as well as development of the urogenital system, including testes, ovaries and penises. The ratio of second to fourth digit length (digit ratio, 2D:4D) is sexually dimorphic in humans (the mean digit ratio is lower in males than females) 1, 2, 3, 4, 5 and is thought to be fixed early in development. Based on this evidence, we suggest that the digit ratio can predict adult penile size and that the effects of prenatal testosterone may in part explain the differences in adult penile length. Univariate and multivariate analysis using linear regression models showed that only height was a significant predictive factor for flaccid penile length (univariate analysis: r=0.185, P=0.026 multivariate analysis: r=0.172, P=0.038) and that only digit ratio was a significant predictive factor for stretched penile length (univariate analysis: r=−0.216, P=0.009 multivariate analysis: r=−0.201, P=0.024 stretched penile length=−9.201×digit ratio + 20.577). Under anaesthesia, flaccid and stretched penile lengths were measured by another investigator who did not measure nor have any the information regarding the digit lengths. Right-hand second- and fourth-digit lengths were measured by a single investigator prior to measurement of penile length. Korean men who were hospitalized for urological surgery at a single tertiary academic centre were examined in this study, and 144 men aged 20 years or older who gave informed consent were prospectively enrolled. In this study, we investigated the relationship between digit ratio and penile length. Both prenatal testosterone and the AR play a central role in penile growth. In the females with AD, the 2D/4D ratios in the left hand was 0.021 and 0.017 in the right hand compared with the controls.Ĭonclusion: Our findings suggest that the development of AD in female may be related with higher testosterone and lower estrogen exposure during fetal period.The second to fourth digit ratio (2D:4D) has been proposed as a putative biomarker for prenatal testosterone and covaries with the sensitivity of the androgen receptor (AR). Results: We found that the females with AD had significantly lower 2D/4D ratios than the female controls. Analysis of covariance was used to investigate an association between fetal sex-hormone exposure and the development of AD after adjusting age, education level, Korean Mini-Mental Status Examination and head circumference. Subjects are measured the ratio of the length of the second to the fourth digit (2D/4D) to estimate fetal sex-hormone exposure. Methods: Twenty four AD patients and 25 normal controls were included from Memory Impairment Clinic of Pusan National University Hospital in Korea. Objective: The purpose of this study is to investigate an association between sex-hormone exposure during fetal period and the development of Alzheimer’s disease (AD).
0 Comments
Read More
Leave a Reply. |