Measurement Of 2D:4D ratio and neck circumference in adolescents: Sexual dimorphism and its implications in obesity – A cross sectional study

Abstract

Introduction: A bidirectional relationship between testosterone and obesity is explained by the hypogonadal obesity cycle and evidence from reports stating that weight loss leads to increased testosterone levels. There is an alarming rise in the prevalence of obesity among children and adolescents. The objectives of the present study were to measure the 2D:4D ratio of adolescent students and study its association with neck circumference (NC). Materials and Methods: After obtaining ethical clearance, the study was conducted on 168 adolescents pursuing their undergraduate education in a South Indian university. 2D:4D ratio and NC were measured using Digital Vernier Calipers and plastic inch tape, respectively. All the participants were divided into three groups (normal, overweight, and obese) on the basis of their BMI. Mean 2D:4D ratio and NC were compared between the three groups using one-way ANOVA. Results: Mean right and left hand ratios of the study population were 0.973 ± 0.030 and 0.975 ± 0.069, respectively. Comparison of 2D:4D ratios between the sexes revealed statistical significance (males = 0.966, females = 0.977, and P value = 0.019). There was no significant correlation between 2D:4D ratios and BMI. There was a significant negative correlation between NC and 2D:4D ratios of the individuals with normal BMI. However, no statistically significant correlation between NC and 2D:4D ratios was observed in overweight and obese individuals. Conclusion: 2D:4D ratio and NC could be used as simple measures for screening of people at higher risk for heart disease and metabolic syndrome. However, studies on a larger sample might help us reveal the association between NC and 2D:4D ratios.

Keywords

• 2D:4D ratio
• digit ratio
• neck circumference
• obesity
• prenatal testosterone