The Contribution of Endogenous and Exogenous Factors to Male Alopecia: A Study of Identical Twins
and Dallas, Texas From the Department of Plastic Surgery, University Hospitals Case Medical Center, Case Western Reserve University School of Medicine, and the Department of Plastic Surgery, University of Texas Southwestern Medical Center. Plastic and Reconstructive Surgery
(Impact Factor: 2.99).
05/2013; 131(5):794e-801e. DOI: 10.1097/PRS.0b013e3182865ca9
: The purpose of this study was to investigate the potential contribution of environmental factors and testosterone on male alopecia.
: Ninety-two identical male twins were recruited from 2009 to 2011. A comprehensive questionnaire was completed followed by the acquisition of sputum samples for testosterone analysis and standardized digital photography. Frontal, temporal, and vertex hair loss was assessed from these photographs. Hair loss was then correlated with survey responses and testosterone levels between twin pairs. Two independent, blinded observers also rated the photographs for hair thinning.
: Increased smoking duration (p < 0.001) and the presence of dandruff (p = 0.028) were significantly associated with increased frontal hair loss. Increased exercise duration (p = 0.002), consumption of more than four alcoholic drinks per week (p = 0.042), and increased money spent on hair loss products (p = 0.050) were all associated with increased temporal hair loss. Daily hat use (p = 0.050), higher body mass index (p = 0.012), and higher testosterone levels (p = 0.040) were associated with decreased temporal hair loss. Factors that were significantly associated with increased vertex hair loss included abstinence from alcohol consumption (p = 0.030), consumption of more than four alcoholic drinks per week (p = 0.004), increased smoking duration (p = 0.047), increased exercise duration (p = 0.050), and increased stress duration (p = 0.010). Lower body mass index, more children, increased caffeine consumption, history of skin disease, and abstinence from alcohol were significantly associated with increased hair thinning scores (p < 0.05).
: This study offers substantial evidence that exogenous factors may have a clinically significant impact on hair loss.
: Risk, III.
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ABSTRACT: Current literature provides little information about the impact of environmental exposures on the severity of acquired blepharoptosis.
The authors assessed environmental factors that may contribute to eyelid ptosis in a population of identical twins.
Photographs of 286 sets of twins from a prospectively collected database from 2008 to 2010 were reviewed. The authors identified 96 sets of identical twins (192 individual persons) who had differing severity of ptosis. Digital photographs were analyzed, and the degree of ptosis was measured in each eye of every subject. The external factors that could potentially contribute to blepharoptosis were taken into consideration. The authors then assessed the correlations of 9 different environmental risk factors with ptosis. Generalized linear mixed model were constructed to determine the associations of ptosis measurements with environmental risk factors obtained from the subject survey database.
The mean level of upper eyelid ptosis in the study population was 1.1 mm. The mean difference in ptosis between twins was 0.5 mm. Wearing contact lenses, either hard or soft, was significantly associated with ptosis. The mean ptosis measurement among twins who did not wear contact lenses was 1.0 mm; for those who wore soft contact lenses, the mean was 1.41 mm, and for those who wore hard contact lenses, the mean was 1.84 mm.
Acquired ptosis is not linked to body mass index, smoking behavior, sun exposure, alcohol use, work stress, or sleep. Wearing either hard or soft lenses was associated with an increased risk of ptosis. These influences are independent of genetic predisposition.
© 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: firstname.lastname@example.org.
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ABSTRACT: Male baldness is the most common diagnosis in men that present with hair loss. It is a genetically determined condition that is clearly an androgen-dependent trait, mainly driven by dihydrotestosterone action on the hair follicles, leading to miniaturization. Although in general this condition is socially accepted as a natural process in a man's life, for some individuals it might significantly impact quality of life, reducing self-esteem and increasing stress. This chapter encompasses the most important aspects of the practical evaluation (clinical features, trichoscopy, trichogram, histopathology, relevant blood tests) and management of male baldness, diffuse baldness and senescent alopecia.
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Male pattern baldness is positively associated with androgens as well as insulin-like growth factor 1 (IGF-1) and insulin, all of which are implicated in pathogenesis of colorectal neoplasia.
From 1992 through 2010, we prospectively followed participants in the Health Professionals Follow-Up Study. Hair pattern at age 45 years was assessed at baseline with five image categories (no baldness, frontal-only baldness, frontal-plus-mild-vertex baldness, frontal-plus-moderate-vertex baldness, and frontal-plus-severe-vertex baldness). Cancer analysis included 32 782 men and used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted to men who underwent at least one endoscopy over the study period, adenoma analysis included 29 770 men and used logistic regressions for clustered data to estimate odds ratios (ORs) and 95% CIs.
Over the mean follow-up of 15.6 years, 710 cases of colorectal cancer (478 for colon, 152 for rectum, and 80 unknown site) developed. Significantly increased risks associated with frontal-only baldness and frontal-plus-mild-vertex baldness relative to no baldness were observed for colon cancer with respective HR being 1.29 (95% CI, 1.03-1.62) and 1.31 (95% CI, 1.01-1.70). Over the 19-year study period, 3526 cases of colorectal adenoma were detected. Evidence for an increased risk of colorectal adenoma relative to no baldness was significant with frontal-only baldness (OR, 1.16; 95% CI, 1.06-1.26) and borderline insignificant with frontal-plus-severe-vertex baldness (OR, 1.14; 95% CI, 0.98-1.33).
Subtypes of male pattern baldness at age 45 years were positively associated with colorectal neoplasia. Future studies are warranted to confirm our results and to determine the predictive value of male pattern baldness to identify those at high risk for colorectal neoplasia.
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