Vol.23 No.4

Original Article

Age at onset and gender distribution of systemic lupus erythematosus, polymyositis/dermatomyositis, and systemic sclerosis in Japan

Authors

Akiko Ohta1 , Masaki Nagai1 , Motoko Nishina1 , Hiroyuki Tomimitsu2 , Hitoshi Kohsaka3

  • Department of Public Health, Saitama Medical University Faculty of Medicine, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama 350-0495, Japan
  • Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
  • Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
Received:

17 May 2012

Accepted:

27 July 2012

Published online:

19 August 2012

Full Text

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Abstract

Objectives The aim of this study was to describe age, gender distribution, and age at onset of systemic lupus erythematosus (SLE), polymyositis/dermatomyositis (PM/DM), and systemic sclerosis (SSc) in Japan.
Methods We used epidemiological information on 21,405, 6,327, and 10,058 patients with SLE, PM/DM, and SSc, respectively, in a Japanese nationwide registration database of patients with intractable diseases.
Results All three diseases occur predominantly in women, with the female-to-male ratio being 8.2:1, 2.6:1, and 7.7:1 for SLE, PM/DM, and SSc, respectively. The most susceptible age for SLE is 15?44 and 20?39 years for males and females, respectively. For PM/DM it is 45?64 and 40?64 years and for SSc, 50?69 and 40?59 for men and women, respectively.
Conclusions The basic descriptive epidemiological characteristics of SLE,PM/DM, and SSc in Japan, such as gender distribution, present age, and age at onset, were surveyed nationwide for fiscal 2007. It was found that these characteristics were similar to those in Western populations. Our finding provides new information on the natural history of disease development.

Key words

Age at onset, Epidemiology, Polymyositis/dermatomyositis (PM/DM), Systemic lupus erythematosus (SLE), Systemic sclerosis (SSc)