Investigating the relationship between the 2D:4D digit ratio and respiratory function in young, healthy adults.
(2016) Investigating the relationship between the 2D:4D digit ratio and respiratory function in young, healthy adults., no. 28.
The prenatal exposure to the sex hormones, testosterone and oestrogen, that are responsible for the second and fourth digit ratio has been widely researched in its positive and negative exertion in different endocrine systems throughout the body. One in particular that has been observed to be influenced by these prenatal sex hormones is the respiratory system. Sex hormones play a major role in an individual's respiratory system and are recognised as influencers in lung function both as a fetus and postnatal. Due to both the 2D:4D digit ratio and lung function being affected by prenatal sex hormones, we hypothesised that, males would have a lower 2D:4D digit ratio than females and that those with a lower 2D:4D digit ratio would have a lower lung function. A total number of 45 Queen Margaret students (13 male, 32 female) aged between 18 and 39 years were recruited. Firstly, the second and fourth digit of their dominant hand was measured using a digital caliper. Secondly, the participant's lung function was measured using a Vitalograph. The results of this study were unsupportive of our original hypothesis, revealing males to have a statistically higher 2D:4D digit ratio in comparison to females (0.975 ± 0.995 vs 0.958 ± 0.026 P=0.03) in this study. The correlation between 2D:4D digit ratio and lung function also revealed no statistical significance in the results of this study with P>0.05. However, the results of this study did uncover that females had a statistically lower VC (4.54 ± 0.95 vs 3.21 ± 1.05, P= 0.0004), FVC (4.59 ± 0.96 vs 3.44 ± 0.91, P= 0.002) and FEV1 (3.83 ± 0.87 vs 3.06 ± 0.66, P= 0.01) than males. As mentioned above, we found females to have a statistically significantly lower 2D:4D digit ratio than men. Although we did not identify a significant correlation between 2D:4D digit ratio and lung function, these findings, that females in this study have a lower lung function and a lower 2D:4D digit ratio, do pose as a potential link between low lung function and low 2D:4D digit ratio as hypothesised. This research has identified the potential use of 2D:4D digit ratio, being used as a non-invasive biomarker for endocrine systems that may be affected by prenatal sex hormone exposure - in particular oestrogen and testosterone. Key words: 2D:4D digit ratio; lung function; prenatal sex hormones; testosterone; oestrogen; fetal lung development; fetal 2D:4D digit development