Shichikawa K, Inoue K, Hirota S, Maeda A, Ota H, Kimura M, Ushiyama T, Tsujimoto M
Yukioka Hospital, 2-2-3, Ukita Kita-ku,Osaka 530-0021, Japan.
Ann Rheum Dis. 1999 Dec;58(12):751-6. doi: 10.1136/ard.58.12.751.
To evaluate secular trends in the incidence and prevalence of rheumatoid arthritis (RA) in Japan.
The incidence and prevalence of RA were determined in a longitudinal population based study in the Kamitonda district, Wakayama, Japan, from 1965 to 1996.
In the study area consisting of about 3000 inhabitants, 16 incident cases, satisfying definite RA by the Rome criteria were detected during the study period. The age and sex adjusted incidence in both men and women combined and the age adjusted incidence in women significantly decreased (p<0.025 and p<0. 01, respectively). The age and sex adjusted prevalence in all inhabitants tended to decrease (p<0.1), and the age adjusted prevalence in women significantly declined (p<0.025). In men, however, neither incidence nor prevalence showed significant change.
The decline of incidence and prevalence of female RA may be reducible to some environmental changes preferentially occurring more obviously in Japanese women than in men. Because the use of oral contraceptives has been extremely low in Japan, the decline should be explained by other factors.
评估日本类风湿关节炎(RA)发病率和患病率的长期趋势。
在日本和歌山县上富田地区开展的一项基于人群的纵向研究中,确定了1965年至1996年期间RA的发病率和患病率。
在约有3000名居民的研究区域内,研究期间共检测到16例符合罗马标准的确诊RA病例。男性和女性合并的年龄和性别调整发病率以及女性的年龄调整发病率均显著下降(分别为p<0.025和p<0.01)。所有居民的年龄和性别调整患病率呈下降趋势(p<0.1),女性的年龄调整患病率显著下降(p<0.025)。然而,男性的发病率和患病率均未显示出显著变化。
女性RA发病率和患病率的下降可能归因于一些环境变化,这些变化在日本女性中比在男性中更为明显。由于日本口服避孕药的使用率极低,这种下降应由其他因素来解释。