Sex-Specific Associations of Prolactin and Progesterone With Glycemic Control in Adults With Type 1 Diabetes.

Background: Type 1 diabetes (T1D) is an autoimmune disease characterized by insulin deficiency and impaired glucose regulation. While sex hormones are known to influence insulin sensitivity, their specific roles in T1D remain underexplored. Prolactin and progesterone have been associated with glucose metabolism, yet their influence in individuals with T1D, particularly men, has not been well studied. This study investigated the relationship between key sex hormones and glycemic control in men and women with T1D. Methods: Seventy-eight adults with T1D (25 men, 53 women) were recruited for a cross-sectional study examining associations between circulating sex hormone concentrations and hemoglobin A1c (HbA1c). Participants underwent anthropometric and body composition assessments and provided fasting blood samples for measurement of estradiol, progesterone, prolactin, total testosterone, free testosterone, and HbA1c. Pearson's correlations were used to evaluate associations between hormone levels and HbA1c. Results: In men, higher concentrations of prolactin (r = -.571, P = .003) and progesterone (r = -.434, P = .030) were significantly associated with lower HbA1c. No such associations were observed in women for prolactin, progesterone, estradiol, or testosterone. Similarly, in men, estradiol, total testosterone, and free testosterone were not significantly correlated with HbA1c. Conclusions: This study provides novel evidence that prolactin and progesterone may be linked to improved glycemic control in men with T1D. These associations were not observed in women. The findings underscore the importance of sex-specific approaches in endocrine and metabolic research. Further longitudinal and mechanistic studies are needed to confirm these relationships and explore the potential of prolactin and progesterone as therapeutic targets in T1D management.