Costenbader Karen H, Chang Shun-Chiao, Laden Francine, Puett Robin, Karlson Elizabeth W
Section of Clinical Sciences, Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115, USA.
Arch Intern Med. 2008 Aug 11;168(15):1664-70. doi: 10.1001/archinte.168.15.1664.
The geographic variation in rheumatoid arthritis (RA) incidence in the United States is unknown.
We studied residential region from January 1, 1921, to May 31, 1976, and RA risk in a prospective cohort of women, the Nurses' Health Study. Information on state of residence was collected at baseline in 1976 (when participants were aged 30-55 years) and on state of residence at birth, at age 15 years, and at age 30 years in 1992. Among 83,546 participants reporting residence for all 4 time points, 706 incident RA cases from June 1, 1976, to May 31, 2004, were confirmed by screening questionnaire and record review for American College of Rheumatology criteria. Residential region was classified as West, Midwest, mid-Atlantic, New England, and Southeast. Multivariate Cox proportional hazards regression models were used to assess relationships between region and RA risk, adjusting for age, smoking, body mass index, parity, breastfeeding, postmenopausal status, postmenopausal hormone use, father's occupation, race, and physical activity. Analyses were performed in participants who lived in the same regions, or moved, over time.
Compared with those in the West, women in New England had a 37% to 45% elevated risk of RA in multivariate models at each time point (eg, state of residence in 1976: rate ratio [RR], 1.42; 95% confidence interval [CI], 1.10-1.82). In analyses of women who lived in the same region at birth, age 15 years, and age 30 years, living in the Midwest was associated with greater risk (RR, 1.47; 95% CI, 1.05-2.05), as was living in New England (RR, 1.40; 95% CI, 0.98-2.00). Compared with living in the West at birth, age 15 years, and age 30 years, RA risk was higher in the East.
In this large cohort of US women, significant geographic variation in incident RA existed after controlling for confounders. Potential explanations include regional variation in behavioral factors, climate, environmental exposures, RA diagnosis, and genetic factors.
美国类风湿关节炎（RA）发病率的地理差异尚不清楚。
我们在一项前瞻性队列研究——护士健康研究中，研究了1921年1月1日至1976年5月31日期间的居住地区以及女性患RA的风险。1976年（参与者年龄为30 - 55岁）在基线时收集了居住州的信息，以及1992年出生时、15岁时和30岁时的居住州信息。在报告了所有4个时间点居住情况的83546名参与者中，通过筛选问卷和根据美国风湿病学会标准进行记录审查，确认了1976年6月1日至2004年5月31日期间的706例RA新发病例。居住地区分为西部、中西部、大西洋中部、新英格兰和东南部。使用多变量Cox比例风险回归模型评估地区与RA风险之间的关系，并对年龄、吸烟、体重指数、生育状况、母乳喂养、绝经后状态、绝经后激素使用、父亲职业、种族和身体活动进行了调整。分析在长期居住在同一地区或搬过家的参与者中进行。
在多变量模型中，与西部女性相比，新英格兰地区的女性在每个时间点患RA的风险升高了37%至45%（例如，1976年居住州：率比[RR]，1.42；95%置信区间[CI]，1.10 - 1.82）。在对出生时、15岁时和30岁时居住在同一地区的女性进行的分析中，居住在中西部地区与更高的风险相关（RR，1.47；95% CI，1.05 - 2.05），居住在新英格兰地区也是如此（RR，1.40；95% CI，0.98 - 2.00）。与出生时、15岁时和30岁时都居住在西部相比，东部的RA风险更高。
在这个大型美国女性队列中，在控制混杂因素后，RA新发病例存在显著的地理差异。潜在的解释包括行为因素、气候、环境暴露、RA诊断和遗传因素的地区差异。
