AUTHOR=Yan Xueqi , Zhu Aiqing , Li Yexing , Yang Ziyi , Wang Yuteng , Liu Li , Liu Wei , Liu Dan , Li Fenghua , Du Juan , Cheng Fang , Gao Xueying , Zhao Junli 

TITLE=Systematical assessment of digit ratio in a female masculinization disease: polycystic ovary syndrome

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1146124

DOI=10.3389/fendo.2023.1146124

ISSN=1664-2392

ABSTRACT=Background: In recent years, the right ratio of 2nd and 4th digit length (2D:4D) is regarded as an anatomical marker of prenatal testosterone exposure. Polycystic ovary syndrome (PCOS) is a female masculinized disease and is determined by prenatal testosterone exposure. Whether the ratio in the right hand of PCOS women is reduced compared with the non-PCOS or not is under debate. To further investigate the relationship between PCOS and digit ratio, we systematically measured all the digit ratio.
Methods: we recruited 31 non-PCOS women, 116 PCOS women and 40 men and systematically measured all the ratio of digit length (2D:3D, 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D) of right hands and left hands.
Results: Significantly lower digit ratio (P=0.033 in left 2D:3D and P=0.033 in left 2D:4D) was observed in PCOS compared with non-PCOS women. In the subgroup analysis, the left ratio of digit length in 2D:3D and 2D:5D of hyperandrogenism subgroup was lower than non-hyperandrogenism subgroup without statistical significance. Logistic regression model of PCOS revealed that 2D:3D, 2D:4D, 2D:5D and 3D:4D of left hands were statistically related to diagnosis of PCOS among all the digit ratios. 
Conclusion: not only 2D:4D but also other digit ratios, such as 2D:3D and 2D:5D represented the marker of prenatal testosterone exposure and may be anatomical marker of PCOS. Digit ratio in left hand was more stable than in right hand due to long-time use resulting in distortion.