Factors associated with changes in the 12-m stair-climbing time after lung lobectomy

Postoperative loss-of-exercise capacity is one of the main concerns for patients undergoing lung cancer surgery. This study was designed to identify the factors associated with loss-of-exercise capacity after lobectomy, using an easy surrogate measure: the 12-m stair-climbing time (SCt).

Ninety-eight patients undergoing lobectomy for suspected stage I lung cancer were prospectively enrolled. SCt and pulmonary function test were evaluated preoperatively as baseline and at 6 months postoperatively. At 6 months postoperatively, 20 patients dropped out. Loss-of-exercise capacity was defined as at least a 3.3% decline (lower quartile) in the estimated maximal oxygen uptake (VO₂t: 43.06 - 0.4 × SCt). Factors associated with loss-of-exercise capacity were analyzed.

Median (interquartile range) baseline SCt was 31.5 (28.2-36.7) s. Baseline SCt was not significantly associated with complications. At 6 months postoperatively, SCt increased by + 4.4 (+ 3.2, + 6.8) s in patients with loss-of-exercise capacity. Sex, smoking status, lobe, procedure, and forced expiratory volume in 1 s showed no significant association with loss-of-exercise capacity. In the multivariable logistic regression, older age (≥ 73 years) (odds ratio: 5.25, 95% confidence interval: 1.50-18.43, p = 0.010) and lower baseline diffusing capacity of the lung for carbon monoxide (< 75%) (odds ratio: 9.23, 95% confidence interval: 1.94-43.93, p = 0.005) were significantly associated with loss-of-exercise capacity.

Age and the baseline diffusing capacity of the lung for carbon monoxide were identified as significant variables associated with variation of exercise capacity after lung cancer surgery, using pre- and postoperative SCt.