Contribution of Hair Density and Hair Diameter to the Appearance and Progression of Androgenetic Alopecia in Japanese Men

This study investigated the contribution of hair density and hair diameter to the appearance and progression of androgenetic alopecia (AGA) in Japanese men. The study found that hair thickness is more important than hair density in the appearance and progression of baldness in male subjects with AGA. Hair density in male subjects with AGA is not significantly different from that in male subjects without AGA. Hair density decreases in male subjects of ≥ 25 years of age, regardless of the presence or absence of AGA. The study concluded that hair loss in male AGA subjects mainly results from the miniaturisation of hair follicles rather than the loss of hair (shedding), at least for individuals who are ≥ 25 years of age and present with AGA.