Moradi T, Nyrén O, Bergström R, Gridley G, Linet M, Wolk A, Dosemeci M, Adami H O
Department of Medical Epidemiology, Karolinska Institutet, Stockholm, Sweden.
Int J Cancer. 1998 May 29;76(5):665-70. doi: 10.1002/(sici)1097-0215(19980529)76:5<665::aid-ijc9>3.0.co;2-o.
Notwithstanding its biologic plausibility, the association between physical activity and endometrial cancer has been analyzed in only a few epidemiological studies. Retrospective assessment of exposure and small sample size often hampers interpretation of published data. We studied risk for endometrial cancer in relation to physical activity at work in a large cohort of Swedish women identified in the nationwide censuses in 1960 and 1970, with jobs that could be consistently classified into one of 4 levels of physical demands. Follow-up from 1971 through 1989 was accomplished through record linkages. Multivariate Poisson regression models were used to estimate relative risk. The risk for endometrial cancer increased regularly with decreasing level of occupational physical activity (p for trend < 0.001), and was associated more strongly with activity in 1970 than in 1960. In multivariate analyses, adjusted for age at follow-up, place of residence, calendar year of follow-up, and social class, the relative risk among women with the same physical activity level in 1960 and in 1970 was 30% higher for sedentary as compared with high/very high activity level; (p for trend=0.04). The protective effect of physical activity appeared to be confined to women aged 50 to 69, among whom sedentary work was associated with a 60% higher risk than that observed among women estimated to be physically most active. The excess seemed to disappear within 10 years after a change in physical activity level. Although confounding cannot be ruled out in our data, occupational physical activity appears to reduce the risk for endometrial cancer.
尽管从生物学角度看有其合理性，但仅有少数流行病学研究分析了体力活动与子宫内膜癌之间的关联。对暴露情况的回顾性评估以及样本量较小常常妨碍对已发表数据的解读。我们在一大群瑞典女性中研究了工作中的体力活动与子宫内膜癌风险的关系，这些女性是通过1960年和1970年的全国人口普查确定的，其工作可始终如一地归类为4种体力需求水平之一。1971年至1989年的随访通过记录链接完成。使用多变量泊松回归模型来估计相对风险。子宫内膜癌的风险随着职业体力活动水平的降低而有规律地增加（趋势p<0.001），并且与1970年的活动关联比1960年更强。在多变量分析中，对随访时的年龄、居住地点、随访的日历年和社会阶层进行调整后，1960年和1970年体力活动水平相同的女性中，久坐不动者与高/非常高活动水平者相比，相对风险高30%；（趋势p=0.04）。体力活动的保护作用似乎仅限于50至69岁的女性，其中久坐工作者的风险比估计体力最活跃的女性高60%。体力活动水平改变后，这种风险增加似乎在10年内消失。尽管我们的数据中不能排除混杂因素，但职业体力活动似乎可降低子宫内膜癌的风险。
