Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Canada.
PLoS One. 2011;6(11):e27993. doi: 10.1371/journal.pone.0027993. Epub 2011 Nov 16.
In pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patient's daily life physical activities (DL(PA)). Whether DL(PA) are decreased in PAH and whether the 6MWT is representative of patient's DL(PA) remain unknown.
15 patients with idiopathic PAH (IPAH) and 10 patients with PAH associated with limited systemic sclerosis (PAH-SSc) were matched with 15 healthy control subjects and 10 patients with limited systemic sclerosis without PAH. Each subject completed a 6MWT. The mean number of daily steps and the mean energy expenditure and duration of physical activities >3 METs were assessed with a physical activity monitor for seven consecutive days and used as markers of DL(PA).
The mean number of daily steps and the mean daily energy expenditure and duration of physical activities >3 METs were all reduced in PAH patients compared to their controls (all p<0.05). The mean number of daily steps correlated with the 6MWT distance for both IPAH and PAH-SSc patients (r = 0.76, p<0.01 and r = 0.85, p<0.01), respectively.
DL(PA) are decreased in PAH and correlate with the 6MWT distance. Functional exercise capacity may thus be a useful surrogate of DL(PA) in PAH.
在肺动脉高压（PAH）中，六分钟步行试验（6MWT）被认为是患者日常生活体力活动（DL（PA））的代表。PAH 患者的 DL（PA）是否减少，以及 6MWT 是否代表患者的 DL（PA）仍不清楚。
将 15 例特发性 PAH（IPAH）患者和 10 例与局限性系统性硬化症相关的 PAH（PAH-SSc）患者与 15 名健康对照者和 10 名无 PAH 的局限性系统性硬化症患者相匹配。每位患者均完成 6MWT。使用活动监测器连续 7 天评估每日平均步数以及平均能量消耗和 3METs 以上体力活动的持续时间，作为 DL（PA）的标志物。
与对照组相比，PAH 患者的每日平均步数以及平均每日能量消耗和 3METs 以上体力活动的持续时间均减少（均 p<0.05）。对于 IPAH 和 PAH-SSc 患者，每日平均步数与 6MWT 距离均呈正相关（r=0.76，p<0.01 和 r=0.85，p<0.01）。
PAH 患者的 DL（PA）减少，并与 6MWT 距离相关。因此，功能运动能力可能是 PAH 患者 DL（PA）的有用替代指标。
