Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway
Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway.
Eur Respir J. 2016 Jul;48(1):82-91. doi: 10.1183/13993003.00975-2015. Epub 2016 Apr 13.
The 6-min walk test (6MWT) is an exercise test that measures functional status in chronic obstructive pulmonary disease (COPD) patients and provides information on oxygen desaturation. We investigated oxygen desaturation during 6MWT as a risk factor for important COPD outcomes: mortality, frequency of exacerbations, decline in lung function and decline in lean body mass.433 COPD patients were included in the Bergen COPD Cohort Study 2006-2009, and followed-up for 3 years. Patients were characterised using spirometry, bioelectrical impedance measurements, Charlson comorbidity score, exacerbation history, smoking and arterial blood gases. 370 patients completed the 6MWT at the baseline of the study. Information on all-cause mortality was collected in 2011.Patients who experienced oxygen desaturation during the 6MWT had an approximately twofold increased risk of death (hazard ratio 2.4, 95% CI 1.2-5.1), a 50% increased risk for experiencing later COPD exacerbations (incidence rate ratio 1.6, 95% CI 1.1-2.2), double the yearly rate of decline in both forced vital capacity and forced expiratory volume in 1 s (3.2% and 1.7% versus 1.7% and 0.9%, respectively) and manifold increased yearly rate of loss of lean body mass (0.18 kg·m(-2) versus 0.03 kg·m(-2) among those who did not desaturate).Desaturating COPD patients had a significantly worse prognosis than non-desaturating COPD patients, for multiple important disease outcomes.
6 分钟步行试验（6MWT）是一项衡量慢性阻塞性肺疾病（COPD）患者功能状态的运动试验，并提供关于氧饱和度降低的信息。我们研究了 6MWT 期间的氧饱和度降低作为 COPD 重要结局的危险因素：死亡率、加重频率、肺功能下降和去脂体重下降。2006-2009 年，433 例 COPD 患者纳入卑尔根 COPD 队列研究，随访 3 年。患者通过肺量测定、生物电阻抗测量、Charlson 合并症评分、加重史、吸烟和动脉血气进行特征描述。370 例患者在研究基线时完成了 6MWT。2011 年收集了所有原因死亡率的信息。在 6MWT 期间经历氧饱和度降低的患者死亡风险增加约两倍（风险比 2.4，95%CI 1.2-5.1），经历后期 COPD 加重的风险增加 50%（发病率比 1.6，95%CI 1.1-2.2），用力肺活量和 1 秒用力呼气量的年下降率均增加一倍（分别为 3.2%和 1.7%，而未发生低氧血症的患者分别为 1.7%和 0.9%），去脂体重的年下降率呈倍数增加（0.18kg·m(-2)比 0.03kg·m(-2)）。与非低氧血症 COPD 患者相比，低氧血症 COPD 患者的预后在多个重要疾病结局方面明显更差。
