Associations Between Iron Metabolism and Obstructive Sleep Apnea Severity in Female and Male Individuals With Self‐Reported Androgenetic Alopecia: A Propensity‐Score Matching Analysis From the <scp>EPISONO</scp> Database

Androgenetic alopecia (AGA) is a common hair loss condition. Iron deficiency contributes to hair loss; and sleep disorders, particularly obstructive sleep apnea (OSA), have systemic effects, especially hypoxia OSA-induced that links hair loss with iron metabolism. The study aimed to investigate how iron markers relate to OSA severity in AGA. Data from the 4th edition of the São Paulo Epidemiological Sleep Study (EPISONO) were analysed. Participants self-reported AGA, underwent polysomnography, and provided blood samples. Propensity score matching (PSM) was used to control for age, sex, and metabolic syndrome. From 769 participants, 747 self-reported AGA status; 81 were enrolled in the AGA group (17 women and 64 men) and 666 in the Non-AGA group (423 women and 243 men). After PSM, 160 individuals (80 matched pairs) were retained, including 34 women (n = 17 per group) and 126 men (n = 63 per group). In the AGA group, serum iron was significantly correlated with the apnea-hypopnea index (AHI) in both sexes, particularly in women. Ferritin levels were positively associated with AHI and desaturation index in women. Serum iron was negatively correlated with the desaturation index in men. In Non-AGA men, transferrin was positively correlated with AHI and negatively correlated with sleep efficiency. These associations remained significant even after PSM. In conclusion, serum components of iron metabolism, particularly iron and ferritin, can have an association with OSA severity in AGA. This highlights the importance of considering iron profiles in the management of OSA, including AGA. Further examinations are warranted to explore the mechanisms underlying these metabolic associations.