Clínica Universidad de Navarra, Pamplona, Spain.
COPD. 2011 Aug;8(4):300-5. doi: 10.3109/15412555.2011.589870. Epub 2011 Jul 18.
The 6-minute walk distance (6MWD) has been useful in the evaluation of men with COPD. Little is known about 6MWD in women with the disease.
Using healthy women as a reference, to evaluate the factors that help determine 6MWD in women with COPD. To explore if the 350 meters threshold differentiates survival in women as it does in men.
Healthy women (n = 164) and with COPD (n = 223) were included in the study. Age, pack-years history, smoking status, comorbidities (Charlson Index), BMI, MRC dyspnea, spirometry and 6MWD were recorded in all participants and PaO(2) and IC/TLC in COPD women. The patients were prospectively followed and deaths registered. Factors predicting 6MWD were determined by multiple regression analysis. ROC analysis was used to calculate the best threshold value for the 6MWD with mortality as gold standard. Kaplan-Meier curves compared survival of patients that walked more or less than 350 m by age categories.
The 6MWD is decreased in women with COPD. Values decrease with age and GOLD stages. Age, BMI, smoking status, comorbidities, MRC and FEV(1%) are statistical significant predictors of 6MWD. A 350 m cut-off value has a good sensitivity and specificity to predict (73% and 80% respectively) and differentiate survival (p < 0.001 for log rank comparisons) in these patients.
In women with COPD, the 6MWD decreases with age and GOLD stages. A 350 m distance is a valid threshold to differentiate survival. Further studies in different settings should confirm our findings.
6 分钟步行距离（6MWD）已被用于评估男性 COPD 患者。但对于患有该疾病的女性，人们对 6MWD 知之甚少。
以健康女性为参照，评估有助于确定 COPD 女性 6MWD 的因素。探索 350 米的阈值是否像在男性中那样可以区分女性的生存率。
研究纳入了健康女性（n=164）和 COPD 女性（n=223）。所有参与者记录了年龄、吸烟年数、吸烟状态、合并症（Charlson 指数）、BMI、MRC 呼吸困难、肺量计检查和 6MWD，以及 COPD 女性的 PaO2 和 IC/TLC。对患者进行前瞻性随访并记录死亡情况。通过多元回归分析确定预测 6MWD 的因素。使用 ROC 分析计算以死亡率为金标准的 6MWD 最佳阈值值。Kaplan-Meier 曲线按年龄类别比较了步行距离超过或少于 350 米的患者的生存情况。
COPD 女性的 6MWD 降低。随着年龄和 GOLD 阶段的增加，值降低。年龄、BMI、吸烟状态、合并症、MRC 和 FEV1%是 6MWD 的统计学显著预测因素。350 米的截断值具有良好的敏感性和特异性来预测（分别为 73%和 80%）并区分这些患者的生存率（对数秩检验比较 p<0.001）。
在 COPD 女性中，6MWD 随年龄和 GOLD 阶段而降低。350 米的距离是区分生存率的有效阈值。应在不同环境中进行进一步研究以证实我们的发现。
