Abstract
BACKGROUND: Although the genetic basis of androgenic alopecia has been clearly established, little is known about its non-genetic causes, such as environmental and lifestyle factors. OBJECTIVE: This study investigated blood and urine heavy metals concentrations, environmental exposure factors, personal behaviors, dietary intakes and the genotypes of related susceptibility genes in patients with androgenic alopecia (AGA). DESIGN: Age, AGA level, residence area, work hours, sleep patterns, cigarette usage, alcohol consumption, betel nut usage, hair treatments, eating habits, body heavy metals concentrations and rs1998076, rs913063, rs1160312 and rs201571 SNP genotype data were collected from 354 men. Logistic regression analysis was performed to examine whether any of the factors displayed odds ratios (ORs) indicating association with moderate to severe AGA (≥ IV). Subsequently, Hosmer-Lemeshow, Nagelkerke R(2) and accuracy tests were conducted to help establish an optimal model. RESULTS: Moderate to severe AGA was associated with the AA genotype of rs1160312 (22.50, 95% CI 3.99-126.83), blood vanadium concentration (0.02, 95% CI 0.01-0.04), and regular consumption of soy bean drinks (0.23, 95% CI 0.06-0.85), after adjustment for age. The results were corroborated by the Hosmer-Lemeshow test (P = 0.73), Nagelkerke R(2) (0.59), accuracy test (0.816) and area under the curve (AUC; 0.90, 0.847-0.951) analysis. CONCLUSIONS: Blood vanadium and frequent soy bean drink consumption may provide protect effects against AGA. Accordingly, blood vanadium concentrations, the AA genotype of rs1160312 and frequent consumption of soy bean drinks are associated with AGA.