An Investigation of the Relationship Between 2D:4D Ratio and Respiratory Function Parameters.
(2017) An Investigation of the Relationship Between 2D:4D Ratio and Respiratory Function Parameters., no. 33.
Background: 2D:4D digit ratio is used as a biomarker for exposure to prenatal sex hormone exposure and is a sexually dimorphic trait, with males having a lower 2D:4D ratio than females. Sex hormones have been shown to play a significant role in physiological processes including lung development and maturation, proposing that there is a direct link between prenatal sex hormone exposure and lung physiology. The hypothesis is therefore that digit ratio may be related to lung function. Objectives: To investigate if a significant correlation exists between 2D:4D ratio and pulmonary function of QMU students and to determine if the relationship provides evidence for 2D:4D ratio to be a clinical indicator of lung function. Methods: Forty-two healthy individuals with no cardiovascular or respiratory conditions including current infections participated. Individuals second and fourth digits of the right hand were measured using digital calipers. Height was measured using a stadiometer. Lung function tests were carried out on a Vitalograph Alpha. Age, ethnicity and smoking status/number of cigarettes smoked per day were also taken from each participant. Student's paired and independent t-tests were used for analysis of results along with Pearson's Linear correlation using Excel 2016. Results: The average age of all 40 participants was 22 years. No significance in age existed between genders. Mean 2D:4D ratio was lower in males compared to females (0.99 + 0.04 vs. 1.00 + 0.03). Males were significantly taller than women (178.87 +6.6 vs. 164.84 +7.1, p < 0.001). The actual LFT values for the total population were significantly lower than predicted for all parameters. Males had significantly higher VC, FVC and FEV1 actual results compared to females. No significant correlations were observed between 2D:4D and LF for any cohort. Significant strong positive correlations were observed between the predicted and actual values for VC, FVC and FEV1 in all, male and female cohorts. Significant strong and very strong positive correlations were observed between height and actual LFT values of the total population (VC: r= 0.796; FVC: r= 0.823; FEV1: r= 0.809). Conclusion: Results from this study demonstrated no significant correlation between 2D:4D ratio and lung function however males had lower 2D:4D than females, consistent with pervious findings. There were significances between predicted and actual LFT values. Height also correlated significantly with lung function and this provides evidence that with further research, 2D:4D ratio could be used as a non-invasive biomarker of pulmonary function and a better understanding of the roles of prenatal sex hormone exposure in both lung function and digit formation could be established. Key Words: 2D:4D, digit ratio, sex hormones, pulmonary function, lung function test