Potential role of maintaining physiological testosterone levels in improving glucose metabolism among normal-weight Japanese women: a pilot exploratory study.

Background: Traditionally, elevated androgen levels in women have been associated with obesity and deteriorated glucose metabolism. However, most existing data are derived from patients with polycystic ovary syndrome (PCOS) or obesity. Consequently, the physiological role of maintaining testosterone levels in normal-weight women remains poorly understood. Objective: To eliminate metabolic biases associated with obesity, this exploratory study investigated the relationship between serum total testosterone levels and parameters of body fat and glucose metabolism (HbA1c, fasting plasma glucose, and HOMA-IR) specifically in normal-weight Japanese women (BMI 18.5-25 kg/m²). Methods: Out of 100 Japanese women who underwent health checkups, 69 normal-weight individuals were included in the analysis. Correlations between total testosterone levels and glucose metabolism indices were examined. Results: Total testosterone levels showed significant inverse correlations with HbA1c ( Conclusion: This study demonstrates that even in normal-weight women, low total testosterone levels are associated with impaired glucose metabolism. These results suggest that, in the absence of obesity-induced androgen excess, the maintenance of physiological androgen levels may contribute to metabolic maintenance in women. These findings suggest a novel perspective on female metabolic health, highlighting the potential importance of physiological androgen homeostasis in the regulation of glucose metabolism.