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). Both prenatal testosterone and the AR ...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). Both prenatal testosterone and the AR play a central role in penile growth. In this study, we investigated the relationship between digit ratio and 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. Right-hand second- and fourth-digit lengths were measured by a single investigator prior to measurement of penile length. 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. 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 xdigit ratio + 20.577). 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.展开更多
Sex and sex hormones play a major role in lung physiology. It has been proposed that the ratio of the second to fourth digits (digit ratio) is correlated with fetal sex hormones. We therefore hypothesized that digit...Sex and sex hormones play a major role in lung physiology. It has been proposed that the ratio of the second to fourth digits (digit ratio) is correlated with fetal sex hormones. We therefore hypothesized that digit ratio might help predict lung function. We investigated the relationship between digit ratio and pulmonary function test (PFT) findings. A total of 245 South Korean patients (162 male, 83 female) aged from 34 to 90 years who were hospitalized for urological surgery were prospectively enrolled. Before administering the PFTs, the lengths of the second and fourth digits of the right hand were measured by a single investigator using a digital Vernier caliper. In males (n = 162), univariate and multivariate analysis using linear regression models showed that digit ratio was a significant predictive factor of forced vital capacity (FVC) and forced expiratory volume in I second (FEV1) (FVC: r = 0.156, P = 0.047; FEVI: r = 0.160, P = 0.042). In male ever-smokers (n = 69), lung functions (FVC and FEV1) were correlated with smoking exposure rather than digit ratio. In female never-smokers (n = 83), lung functions (FEV1 and FEVI/FVC ratio) were positively correlated with digit ratio on univariate analysis (FEVI: r = 0.242, P = 0.027; FEVI/FVC ratio: r = 0.245, P = 0.026). Patients with lower digit ratios tend to have decreased lung function. These results suggest that digit ratio is a predictor of airway function.展开更多
文摘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). Both prenatal testosterone and the AR play a central role in penile growth. In this study, we investigated the relationship between digit ratio and 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. Right-hand second- and fourth-digit lengths were measured by a single investigator prior to measurement of penile length. 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. 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 xdigit ratio + 20.577). 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.
文摘Sex and sex hormones play a major role in lung physiology. It has been proposed that the ratio of the second to fourth digits (digit ratio) is correlated with fetal sex hormones. We therefore hypothesized that digit ratio might help predict lung function. We investigated the relationship between digit ratio and pulmonary function test (PFT) findings. A total of 245 South Korean patients (162 male, 83 female) aged from 34 to 90 years who were hospitalized for urological surgery were prospectively enrolled. Before administering the PFTs, the lengths of the second and fourth digits of the right hand were measured by a single investigator using a digital Vernier caliper. In males (n = 162), univariate and multivariate analysis using linear regression models showed that digit ratio was a significant predictive factor of forced vital capacity (FVC) and forced expiratory volume in I second (FEV1) (FVC: r = 0.156, P = 0.047; FEVI: r = 0.160, P = 0.042). In male ever-smokers (n = 69), lung functions (FVC and FEV1) were correlated with smoking exposure rather than digit ratio. In female never-smokers (n = 83), lung functions (FEV1 and FEVI/FVC ratio) were positively correlated with digit ratio on univariate analysis (FEVI: r = 0.242, P = 0.027; FEVI/FVC ratio: r = 0.245, P = 0.026). Patients with lower digit ratios tend to have decreased lung function. These results suggest that digit ratio is a predictor of airway function.