Prevalence and types of androgenetic alopecia in Shanghai, China: a community-based study

There are ethnic differences in the prevalence and types of androgenetic alopecia (AGA). Although there have been several reports on the prevalence and types of AGA in caucasian and Asian populations, there are very few data on a Chinese population that have been derived from a sufficient number of samples. To estimate the prevalence and types of AGA in a Chinese population, and to compare the results with those in caucasians and Koreans reported previously in the literature. A population-based cross-sectional study was carried out in 7056 subjects (3519 men and 3537 women) from May 2006 to December 2006 in a community of Shanghai. Questionnaires were completed during face-to-face interviews at the subjects' homes. The degree of AGA was classified according to the Norwood and Ludwig classifications. The prevalence of AGA in Chinese men was 19.9%, and the prevalence of female pattern AGA in men was 0.1%. The most common type in men was type III vertex (3.5%). The prevalence of AGA in women was 3.1%, while male pattern AGA was found in those aged over 50 years (0.4%), and the most common type was type I (Ludwig classification) (1.4%). A family history of AGA was present in 55.8% of men and 32.4% of women with AGA. The prevalence of AGA in Chinese men was lower than in caucasian men but was similar to that in Korean men; however, over the age of 60 years it was approaching that in caucasian men but was higher than that in Korean men. The most common type in Chinese men with AGA was type III vertex. Interestingly, the prevalence of AGA in Chinese women was lower than that in Korean women and caucasian women, and type I was the most common type (Ludwig classification).