Digit ratio and its implications on exercise capacity among non-athlete Indian male subjects

Abstract

Background: The index (2D)-to-ring (4D) finger length ratio (2D:4D) commonly known as digit ratio has been the subject of recent interest and is thought to be related to sports ability, endurance running, disease susceptibility, and myocardial infarction at early age. Sexually dimorphic digit ratio is widely accepted as a putative marker for prenatal androgen exposure with men tends to have smaller ratio. Aim and Objective: The present study was conducted to evaluate any relation between digit ratio and exercise capacity in non-athlete Indian males. Materials and Methods: The study was conducted in the Department of Physiology of Mayo Institute of Medical Sciences, Barabanki, with 50 clinically normal healthy male volunteers. Finger lengths were measured directly using digital Vernier calipers. Exercise tolerance testing was done as per Bruce protocol with Allengers Gemini A-DX treadmill. Results: Two groups of higher (n = 26) and lower (n = 24) finger length ratio (right hand) were formed using median split. Significant difference observed (P = 0.0012, P < 0.05) for exercise capacity or percentage of predicated metabolic equivalents (METs) achieved having higher percentage by the low finger length ratio group. No significant difference observed for METs achieved for the groups. Correlation study shows a significant moderate negative correlation between digit ratio (right) and exercise capacity. Similar correlation was not significant for the left hand. Conclusion: These results suggest that a low digit ratio (right hand) is related to better aerobic capacity and exercise capacity in the males although the exact role of prenatal androgen exposure is unclear.