Prognostic factors in the treatment of androgenetic alopecia with minoxidil

Introduction . Androgenetic alopecia (AGA) is the most common type of alopecia, characterized by diffuse progressive thinning of the hair in the fronto-parietal area in patients with a genetic predisposition. Topical minoxidil remains the primary pharmacological treatment for AGA both in men and women. The efficacy in hair regrowth is reported to be between 40 and 50%. Aim. To evaluate prognostic factors of minoxidil response in AGA patients. Matherials and methods. The prospective open study was carried out. Thirty participants with AGA were enrolled and completed the study (twenty one women I–II Ludwig stage and nine men I–III Hamilton – Norwood stage). Primary outcomes consisted of measuring of hair density, telogen hair rate, the percentage of vellus hairs and hair diameter at baseline and repeated at 4 months. The SULT1A1 enzyme activity and the concentration of ATP in plucked hairs were measured at baseline. Patients were treated with 5% topical minoxidil applying daily for 4 months. In order to investigate prognostic factors in groups of responders and non-responders to minoxidil treatment these measured morphometric and biochemical characteristics were assessed. Results . After 4 months of treatment 77% of patients demonstrated hair regrowth and improvement of hair density, hair diameter and decrease of vellus hairs level. The SULT1A1 enzyme activity (p = 0.0008), the concentration of ATP (p = 0.004) in plucked hairs and baseline total hair density (p = 0.01) was significantly lower in group of non-responders compared to group of responders. The study demonstrated strong positive correlation between SULT1A1 enzyme activity and increase of total hair density (r = 0.7, р = 0.00002); moderate positive correlation was founded between concentration of ATP and increase of total hair density (r = 0.6, р = 0.0004). Conclusion . The negative prognostic factors for minoxidil treatment of AGA include SULT1A1 enzyme activity, concentration of ATP in plucked hairs and low total hair density at baseline.