The relationship between 2D: 4D ratio and respiratory function in young, healthy adults

Abstract

Background: 2D: 4D digit ratio can be used as a marker for exposure to pre-natal testosterone and is a sexually dimorphic trait, with males having a longer ring finger relative to their index finger, known as a low 2D: 4D ratio and females having a high 2D: 4D ratio. Objectives: To measure 2D: 4D ratio using a digital caliper and measure lung function using a vitalograph to investigate if there is a correlation between 2D: 4D ratio and lung function. Methods: 43 volunteers participated in this project and allowed finger length, height and lung function to be measured. Each participant completed a short questionnaire. Volunteers were separated into groups of males (n=13), female (n=30), Caucasian (n=37) and Non-Caucasian (n=6). Results: Mean digit ratio was higher in males (0.974) than females (0.958). Male lung function test values were also higher VC Actual (4.12), FEV Actual (4.23), FEV1 (3.63) and FVC/FEV1 (87%) than female lung function test values VC Actual (3.61), FEV Actual (3.79), FEV1 (3.29) and FVC/FEV1 (88%). Mean digit ratio for Caucasian group was higher (0.963) than non-Caucasian group (0.959). Caucasian group showed greater lung function VC Actual (3.83), FEV Actual (3.98), FEV1 (3.43) and FVC/FEV1 (88%) than non-Caucasian group VC Actual (2.23), FEV Actual (2.63), FEV1 (2.45) and FVC/FEV1 (93%). Conclusion: No significant correlation between 2D: 4D digit ratio and lung function was found. Significant differences were found between height and lung function. Low digit ratio was related to a decreased lung function in participants. This suggests that 2D: 4D ratio may be a predictor of pulmonary function and therefore is reflective of prenatal androgen exposures among individuals.