Objectives. The normal aortic diameter (AD) varies with gender, age and body surface area (BSA). The aortic size index (ASI) is defined as the AD divided by BSA. The primary aim of this study was to investigate if ASI is a predictor of development AAA, and to compare the predictive impact of ASI to that of the absolute AD. Design. Population-based prospective study including 4161 individuals (53.2% women) from the Tromsø study with two valid ultrasound measurements of the AD and no AAA at baseline (Tromsø 4, 1994). The primary outcome was AAA (AD ≥30 mm) in Tromsø 5 (2001). A secondary outcome was aortic growth of >5 mm over 7 years. Estimates of relative risk were calculated in logistic regression models. The main exposure variable was ASI. Adjustments were made for age, gender, smoking, body mass index, total and high-density lipoprotein (HDL) cholesterol, and hypertension. Results. In total, 124 incident AAAs (20% among women) were detected. In adjusted analyses, both ASI and AD were strong predictors of AAA, with similar results for men and women. Both ASI and AD were also significant predictors of aortic growth >5 mm. In comparison, AD was superior to ASI as a predictor of both endpoints. Conclusions. ASI was a significant predictor of both AAA development and aortic growth of >5 mm for both men and women, but not a better predictor of either outcomes compared to the AD. The role of ASI compared to the AD as a predictor of AAA development seems to be limited.

中文翻译：

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主动脉大小指数与腹主动脉瘤的预测指标相关吗？基于人群的前瞻性研究：Tromsø研究。

目标。正常主动脉直径（AD）随性别，年龄和体表面积（BSA）而变化。主动脉大小指数（ASI）定义为AD除以BSA。这项研究的主要目的是调查ASI是否是AAA发展的预测因子，并将ASI的预测影响与绝对AD的影响进行比较。设计。基于人群的前瞻性研究包括Tromsø研究的4161名个体（女性占53.2％），对AD进行了两次有效的超声测量，基线时无AAA（Tromsø4，1994）。Tromsø5（2001）的主要结果是AAA（AD≥30 mm）。次要结果是7年内主动脉生长> 5 mm。在逻辑回归模型中计算相对风险的估计值。主要的暴露变量是ASI。对年龄，性别，吸烟，体重指数，总胆固醇和高密度脂蛋白（HDL）胆固醇以及高血压。结果。总共检测到124个AAA事件（女性中占20％）。在调整后的分析中，ASI和AD都是AAA的有力预测指标，男女结果相似。ASI和AD也是主动脉生长> 5 mm的重要预测指标。相比之下，AD作为两个终点的预测指标均优于ASI。结论。无论是男性还是女性，ASI都是AAA发育和主动脉生长> 5 mm的重要预测指标，但与AD相比，这两个指标均不能更好地预测。与AD相比，ASI在AAA发展方面的作用似乎是有限的。男女结果相似。ASI和AD也是主动脉生长> 5 mm的重要预测指标。相比之下，AD作为两个终点的预测指标均优于ASI。结论。无论是男性还是女性，ASI都是AAA发育和主动脉生长> 5 mm的重要预测指标，但与AD相比，这两个指标均不能更好地预测。与AD相比，ASI在AAA发展方面的作用似乎是有限的。男女结果相似。ASI和AD也是主动脉生长> 5 mm的重要预测指标。相比之下，AD作为两个终点的预测指标均优于ASI。结论。无论是男性还是女性，ASI都是AAA发育和主动脉生长> 5 mm的重要预测指标，但与AD相比，这两个指标均不能更好地预测。与AD相比，ASI在AAA发展方面的作用似乎是有限的。