Inoue K, Yoshii K, Ito H
Towa Clinic, Department of Community and Family Medicine, Jichi Medical School, Tochigi, Japan.
Gerontology. 1999 Jan-Feb;45(1):53-8. doi: 10.1159/000022056.
The effect of aging on the components of the cardiothoracic ratio (CTR) in the chest roentgenogram in women remains obscure. There have been only a few reported studies that have investigated longitudinal changes of the CTR in women.
To determine whether there is an effect of aging on the CTR in women.
The study population consisted of 110 women who attended an annual health screening and underwent chest roentgenography both in 1981 and 1990 in a mountain village in Japan. We used the data obtained from an annual health screening in order to determine thoracic diameter (TD), cardiac diameter (CD), and lung height (LH) and then calculated the CTR. We analyzed CTR, TD, CD, and LH on the basis of the age of the participants.
In the cross-sectional analysis of the groups stratified by age in 1981, mean CD and CTR increased, and TD decreased in the advanced-age group. The percentage of radiographic cardiomegaly (CTR >50%) strikingly increased in the advanced-age group. In the longitudinal analysis between 1981 and 1990, the mean CD increased, and the mean TD decreased significantly. The mean CTR increased by 2.0% (95% CI 1. 2-2.8%). The changes of the CTR in 9 years were positively correlated with those of CD and negatively correlated with those of TD and LH. The longitudinal data generally accorded with the cross-sectional data, except LH.
The CTR in women increases with aging as a result of the increase in CD, except in the case of advanced old age, and the decrease in TD. LH could be another major factor that has an influence on CTR. Caution should be exercised to avoid overestimating CTR when LH changes. The classical upper limit of 50% for CTR in our adopted method should not be applied to elderly women because of the possibility that changes with normal aging are misclassified as abnormal findings.
衰老对女性胸部X线胸片中心胸比率（CTR）各组成部分的影响仍不明确。仅有少数报道研究调查了女性CTR的纵向变化。
确定衰老是否对女性CTR有影响。
研究人群包括110名女性，她们于1981年和1990年在日本一个山村参加年度健康筛查并接受胸部X线检查。我们利用年度健康筛查获得的数据来确定胸径（TD）、心径（CD）和肺高（LH），然后计算CTR。我们根据参与者的年龄分析CTR、TD、CD和LH。
在1981年按年龄分层的组的横断面分析中，高龄组的平均CD和CTR增加，TD降低。高龄组中X线显示心脏增大（CTR>50%）的百分比显著增加。在1981年至1990年的纵向分析中，平均CD增加，平均TD显著降低。平均CTR增加了2.0%（95%CI 1.2 - 2.8%）。9年中CTR的变化与CD的变化呈正相关，与TD和LH的变化呈负相关。除LH外，纵向数据总体上与横断面数据一致。
除高龄情况外，女性的CTR因CD增加和TD降低而随衰老增加。LH可能是另一个影响CTR的主要因素。当LH发生变化时，应谨慎避免高估CTR。由于正常衰老变化可能被误分类为异常发现，我们采用的方法中CTR的经典上限50%不适用于老年女性。
