Comparison of inhibin B, AMH, DHEA-S serum levels and finger ratio (2D/4D) with healthy controls in boys diagnosed with autism spectrum disorder

Background and Aim: Autism Spectrum Disorder (ASD) is more common in male than female. It is thought that one of the factors leading to male bias may be the androgen effect. Although testosterone in the prenatal period and Inhibin B and Anti-Müllerian Hormone (AMH) in the prepubertal period are suspected for this androgenic effect, the relationship between Inhibin B and Anti-Müllerian Hormone (AMH) and male bias has not been sufficiently investigated yet. In this study, it is aimed to compare Inhibin B, AMH, DHEA-S (Dihydroepiandrosterone sulfate) levels and 2D/4D finger ratio with the normal population in boys with ASD. Method: This study consists of two groups which are the case group and the control group. Forty-two male participants diagnosed with ASD according to DSM-5 diagnostic criteria were included in the case group, and the same number of male subjects consisting of healthy volunteer were included in the control group. Sociodemographic data form was used to evaluate the clinical and sociodemographic characteristics of the study sample, and KSAD-S was used to evaluate psychiatric diagnoses. In addition, the Strengths and Difficulties Questionnaire, Childhood Autism Rating Scale, Social Communication Questionnaire, and Aberrant Behavior Checklist were used to evaluate the clinical characteristics of the case group. Approximately 5-8 ml of venous blood was collected from both groups. Serum samples were evaluated by ELISA method and Inhibin B, AMH and DHEA-S levels were measured. In addition, 2D/4D finger ratio was calculated for hand anthropometric measurements. Results: Serum Inhibin B levels of the case group were found to be significantly higher than the control group (p= 0.003). Serum DHEA-S levels were found to be significantly lower in the case group compared to the control group (p=0.007). Serum AMH levels of both groups were similar (p>0.05). A positive strong correlation was found between ASD severity and AMH levels (R=0.281, p = 0.05). Right hand 2D/4D finger ratios were found to be significantly lower in the case group compared to the control group (p<0.001), while 2D/4D finger ratios for the left hand were similar between the groups (p>0.05). A strong correlation was found between left 2D/4D finger ratio and autism severity, right 2D/4D finger ratio and autism symptoms severity of B group (p<0.05). Conclusion: The results of this study suggest that the difference in Inhibin B and DHEA-S levels may contribute to male bias in ASD. Our results regarding AMH and 2D:4D finger ratio show that AMH and 2D:4D finger ratio may be related to ASD severity. Conducting more studies with larger samples would be beneficial for understanding the etiology of male bias in ASD.