Androgenic Alopecia Is Associated with Less Dietary Soy, Higher Blood Vanadium and rs1160312 1 Polymorphism in Taiwanese Communities

Higher Blood Vanadium and rs1160312 1 Polymorphism in Taiwanese Communities. PLoS ONE 8(12): e79789. doi:10.1371/journal.pone.0079789 Androgenic Alopecia Is Associated with Less Dietary Soy, Higher Blood Vanadium and rs1160312 1 Polymorphism in Taiwanese Communities Ching-Huang Lai 0 Nain-Feng Chu 0 Chi-Wen Chang 0 Shu-Li Wang 0 Hsin-Chou Yang 0 Chi-Ming Chu 0 Chu-Ting Chang 0 Ming-Huang Lin 0 Wu-Chien Chien 0 Sui-Lung Su 0 Yu-Ching Chou 0 Kang-Hua Chen 0 Wei-Ming Wang 0 Saou-Hsing Liou 0 Qinghua Sun, The Ohio State University, United States of America 0 1 Department of Epidemiology, School of Public Health, National Defense Medical Center , Taipei, Taiwan , 2 Taitung Hospital, Department of Health, Executive Yuan, Taiwan, 3 School of Nursing, College of Medicine, Chang-Gung University , Taoyuan, Taiwan , 4 Division of Environmental Health and Occupational Medicine, National Health Research Institutes, MiaoLi, Taiwan, 5 Institute of Statistical Science Academia Sinica , Taipei, Taiwan , 6 Department of Dermatology, Tri-Service General Hospital , Taipei , Taiwan Background: Although the genetic basis of androgenic alopecia has been clearly established, little is known about its nongenetic 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, HosmerLemeshow, Nagelkerke R2 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 R2 (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. - Funding: This research was supported by Taichung County Government in Taiwan (5168-038). The interpretation and conclusions contained herein do not represent those of Bureau of Health, Taichung County or National Health Research Institutes. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. The incidence of androgenic alopecia (AGA) is increasing, while the age of onset of AGA continues to decrease. Studies have associated AGA with a variety of diseases, such as coronary heart disease [1,2,3], hypertension [4], prostate cancer [5,6], and ischemic heart disease [7], and it is likely that AGA is a precursor symptom of these diseases. In 2007, Merck & Co. reported US$405 million in global sales of medical products related to AGA treatment, highlighting the tremendous social and economic impact of AGA [8],[9]. Moreover, AGA has important effects on mental health due to the changes in physical appearance that are caused by hair loss. Many studies have been devoted to the genetic and androgenrelated aspects of AGA [8,10,11],[12]. Based on a screening of 1025 blood samples from men aged 35 to 75, Richards et al. identified a baldness susceptibility gene that increases the risk of AGA six-fold; the variance explained by this allele was reported to be 13.7% [8]. Nyholt et al. [13] reasoned that the major contributing factor to AGA is heredity, which accounts for 80% of the variance. However, the genetic aspect lacks specificity because an individual carrying a risk-associated allele will not suffer from AGA until he or she reaches a certain age. This indication that AGA risk alleles are modulated by age is consistent with the world-wide increase in the prevalence of AGA with age. Consequently, earlier onset AGA is associated with more severe characteristics [14]. To date, three AGA susceptibility genes have been identified: the AR gene on the X chromosome and two autosomal loci, 3q26 [15] and 20p11 [8,10]. Richards et al. observed that variants in the 20p11 locus and the AR gene are common among Europeans and that men with at least one risk allele (20p11.22 or AR) at either locus have a seven-fold greater probability of developing AGA than those without either risk allele [8]; carriers of at least one risk allele accounted for one-seventh of all men in the study. Hillmer et al. also showed that the 20p11 locus is associated with early-onset AGA [10,11]. In addition, Hillmer et al. discovered that DNA short tandem repeats on chromosome 3 (namely D3S3053, D3S1556 and D3S2425) are related to AGA [15]. Chen et al [16] reported that the expression level of SRY increases with the severity of baldness. Therefore, we attempted to investigate two single nucleotide polymorphisms (SNPs) within the SRY gene. Although a strong genetic basis for AGA has been established, little is known about its non-genetic causes, such as environmental and dietary factors. This study investigated the bodily heavy metals concentrations, dietary habits and genotypes of related susceptibility genes in patients with AGA. It has been suggested that air pollution may lead to the overaccumulation of certain heavy metals in the scalp, resulting in hair loss [17],[18]. A study conducted in Lithuania reported that bald individuals had higher concentrations of lead, copper and cadmium and lower concentrations of zinc in their hair follicles than did individuals with normal hair [18]. It has been proposed that lead may replace zinc in heme, while cadmium substitutes for zinc in metallothionein, and the combination of these losses of zinc likely cause alopecia [19]. Smoking also affects the development of AGA because the genotoxic compounds in cigarettes may damage the DNA in hair follicles and subsequently cause microvascular poisoning in hair papillae [20]. Studies have established that a family history of AGA, the age of AGA onset (age #40 years old) and smoking are all correlated with AGA [9]. Despite the discovery of genes associated with this disorder, many factors contributing to the variable levels of AGA have yet to be elucidated. To date, no (...truncated)