The Ratio of Second to Fourth Digit Length (2D:4D) and Coronary Artery Disease in a Han Chinese Population

Abstract

Background: The association between index finger to ring finger length ratio (2D:4D) and cardiac disorders has been reported, however it has not been discussed in terms of coronary artery disease (CAD). We investigated whether 2D:4D could be used as a marker for predisposition to CAD as assessed by coronary angiography in Chinese men and women.Methods: This study included 1764 persons divided into 4 groups, 441 cases with CAD and 441 persons without CAD as control in each sex of the same age. Finger lengths were measured twice for both hands using electronic calipers. Student t test was used to detect the difference of 2D:4D among groups. The receiver operator characteristic curves (ROCs) were used to detect the diagnostic effect of 2D:4D for CAD.Results: There were no significant differences in age among the four groups. A significant difference of 2D:4D ratios between right and left hand were observed only in men in both control and CAD groups. On the right hand in the control group and on both hands in the CAD group, the 2D:4D ratios were higher in women than in men (all, P < 0.001). In men with CAD, mean 2D:4D was higher than mean 2D:4D in control men (right hand 0.962±0.042:0.927±0.038; left hand 0.950±0.044:0.934±0.048; both hands, P < 0.001), but this was not observed in women. No relationship was found between 2D:4D and age (all, P >0.05). The area under the curve of right hand 2D:4D in male was 0.72 (95% CI 0.683-0.753, p<0.001), while it was 0.602 (95% CI 0.565-0.639, p<0.001) in left hand.Conclusions: The present study showed an association between high 2D:4D ratio and CAD in both hands in men. There were no significant differences in mean 2D:4D between women with CAD and controls.

The Ratio of Second to Fourth Digit Length (2D:4D) and Heart Disease

“…The mechanisms of the link between 2D:4D and coronary artery disease are not clear 1 . The reason for these differential observations among the gender is believed to be caused by the prenatal sex hormones which may also affect multiple organ system including cardiovascular system 3 .…”

“…Research report has emphasized the positive association between 2D:4D ratio in both hands of Chinese men and CAD 1 . This report also highlighted non-significant differences in mean 2D:4D ratio in the women with CAD and control of the same population 1 .…”

“…It is the most dexterous and sensitive finger of the hand. Ratio between the length of 2 nd digit and 4 th digit (popularly known as 2D:4D ratio) is known to show correlations with certain disorders like Coronary artery disease (CAD) 1 and with behavioral traits 2 . Research report has emphasized the positive association between 2D:4D ratio in both hands of Chinese men and CAD 1 .…”

“…Ratio between the length of 2 nd digit and 4 th digit (popularly known as 2D:4D ratio) is known to show correlations with certain disorders like Coronary artery disease (CAD) 1 and with behavioral traits 2 . Research report has emphasized the positive association between 2D:4D ratio in both hands of Chinese men and CAD 1 . This report also highlighted non-significant differences in mean 2D:4D ratio in the women with CAD and control of the same population 1 .…”

“…Young people who are at risk of heart disease early in their adult life can be identified simply by measuring their fingers length and their ratio 1 . The ring finger is the fourth digit of the human hand and the second most ulnar finger, while the index finger is the second digit of a human hand.…”