Obstructive sleep apnea, low transferrin saturation levels, and male‐pattern baldness

Background There are limited data on the association between obstructive sleep apnea ( OSA ), which is characterized by intermittent hypoxia, and male‐pattern baldness ( MPB ). Low blood iron levels are reportedly associated with hypoxia and hair loss. This study explored a possible link among OSA , iron status, and MPB . Methods Polysomnography ( PSG ) and hair assessments were conducted in a cross‐sectional study including 932 men aged 46–76 years. OSA was defined as an apnea‐hypopnea index ≥5 by PSG evaluation and MPB as scales from IV to VII according to the Norwood‐Hamilton scale classification. Serum transferrin saturation ( TSA ) levels were assessed. Results A total of 224 men (24%) were identified as MPB cases and 495 men (53%) as having OSA . After considering potential risk factors, OSA and other sleep‐related variables were not associated with MPB . In joint analysis of OSA and family history of hair loss, men with these two factors showed a sevenfold higher multivariate odds ratio (95% confidence interval: 3.70, 12.56) for MPB than those without both of them ( P  < 0.05 for the interaction between OSA and family history of hair loss). TSA levels were significantly associated with MPB and OSA . OSA cases without MPB as well as MPB cases showed lower TSA levels than those with neither OSA nor MPB ( P  < 0.05). Conclusions These findings suggest that OSA may be a risk factor for MPB in men who have a family history of hair loss and that low serum TSA levels associated with hypoxia may be involved in a pathway linking OSA and MPB .