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Another one to the pile. Some curious findings in this one. Pretty new as well, published on May 24.
http://dermatology.jwatch.org/cgi/content/full/2013/524/1
[h=1]Bald Twins[/h] Wear a hat, de-stress, and don't smoke if you want to be the more lushly haired brother.
Genetics may contribute to male (androgenic) alopecia (AA), but even within families, the expression and penetrance is variable. To address more directly the influence of other factors on AA, investigators studied 92 identical male twins (mean age, 51; range, 23–84), comparing completed questionnaires, four-view standardized photographs, and sputum samples analyzed for testosterone levels. Degree of hair thinning was assessed from photographs by two independent, blinded observers using the Likert scale. Linear regression modeling identified independent predicators of hair loss measures.
Independent factors that contributed to hair loss included genetics, older age, smoking, dandruff, having more children, higher caffeine ingestion, lower BMI, and history of skin disease. Not all of these factors affected hair loss at all anatomic sites (frontal, temporal, vertex). Increased testosterone levels were significantly associated with increased vertex hair loss and decreased temporal hair loss, but a difference between twins was not a predictor.
In intertwin analysis, twins who reported longer duration of stress had significantly greater hair loss than their identical counterpart. Twins with relatively increased durations of exercise had more vertex hair loss (P=0.05). A twin who drank more than four alcoholic drinks per week had more vertex hair loss than his more abstinent twin brother (P=0.004), but vertex hair loss was also found more commonly in twins who didn't drink at all (P=0.03)
Comment: Intertwin analysis found daily hat use associated with decreased temporal hair loss — information that could further motivate men to wear them. The testosterone story is complicated. Saliva testosterone serves as an indirect measure of free testosterone, as sex hormone–binding globulin is not secreted in saliva, but levels do not reflect the critically important ability of follicles to convert free testosterone to dihydrotestosterone. Dandruff was associated with greater temporal and frontal hair loss, suggesting that looking for and treating dandruff might benefit balding men over the long term.
— Mark V. Dahl, MD
Published in Journal Watch Dermatology May 24, 2013
[h=2]Citation(s):[/h] Gatherwright J et al. The contribution of endogenous and exogenous factors to a male alopecia: A study of identical twins. Plast Reconstr Surg 2013 May; 131:794e. (http://dx.doi.org/10.1097/PRS.0b013e3182865ca9)
http://dermatology.jwatch.org/cgi/content/full/2013/524/1
[h=1]Bald Twins[/h] Wear a hat, de-stress, and don't smoke if you want to be the more lushly haired brother.
Genetics may contribute to male (androgenic) alopecia (AA), but even within families, the expression and penetrance is variable. To address more directly the influence of other factors on AA, investigators studied 92 identical male twins (mean age, 51; range, 23–84), comparing completed questionnaires, four-view standardized photographs, and sputum samples analyzed for testosterone levels. Degree of hair thinning was assessed from photographs by two independent, blinded observers using the Likert scale. Linear regression modeling identified independent predicators of hair loss measures.
Independent factors that contributed to hair loss included genetics, older age, smoking, dandruff, having more children, higher caffeine ingestion, lower BMI, and history of skin disease. Not all of these factors affected hair loss at all anatomic sites (frontal, temporal, vertex). Increased testosterone levels were significantly associated with increased vertex hair loss and decreased temporal hair loss, but a difference between twins was not a predictor.
In intertwin analysis, twins who reported longer duration of stress had significantly greater hair loss than their identical counterpart. Twins with relatively increased durations of exercise had more vertex hair loss (P=0.05). A twin who drank more than four alcoholic drinks per week had more vertex hair loss than his more abstinent twin brother (P=0.004), but vertex hair loss was also found more commonly in twins who didn't drink at all (P=0.03)
Comment: Intertwin analysis found daily hat use associated with decreased temporal hair loss — information that could further motivate men to wear them. The testosterone story is complicated. Saliva testosterone serves as an indirect measure of free testosterone, as sex hormone–binding globulin is not secreted in saliva, but levels do not reflect the critically important ability of follicles to convert free testosterone to dihydrotestosterone. Dandruff was associated with greater temporal and frontal hair loss, suggesting that looking for and treating dandruff might benefit balding men over the long term.
— Mark V. Dahl, MD
Published in Journal Watch Dermatology May 24, 2013
[h=2]Citation(s):[/h] Gatherwright J et al. The contribution of endogenous and exogenous factors to a male alopecia: A study of identical twins. Plast Reconstr Surg 2013 May; 131:794e. (http://dx.doi.org/10.1097/PRS.0b013e3182865ca9)
- Medline abstract (Free)
