The association between dynamic lung volume and peak oxygen uptake in a healthy general population: the HUNT study

Abstract

Background

Although dynamic lung volume is not considered a limiting factor of peak oxygen uptake (VO _2peak) in healthy subjects, an association between forced expiratory lung volume in one second (FEV ₁) and VO _2peak has been reported in a healthy population aged 69 – 77 years. We hypothesized that a corresponding association could be found in a healthy general population including young and middle-aged subjects.

Methods

In a population-based study in Norway, we investigated the association between FEV ₁ above the lower limit of normal (LLN) and VO _2peak using linear regression and assessed the ventilatory reserve (VR) in healthy subjects aged 20 – 79 years ( n = 741).

Results

On average, one standard deviation (SD) increase in FEV ₁ was associated with 1.2 ml/kg/min (95% CI 0.7 – 1.6) higher VO _2peak. The association did not differ statistically by sex ( p-value for interaction = 0.16) and was similar (0.9 ml/kg/min, 95% CI 0.2 – 1.5) in a sensitivity analysis including only never-smokers ( n = 376). In subjects below and above 45 years of age, corresponding estimates were 1.2 ml/kg/min (95% CI 0.5 – 1.8) and 1.2 ml/kg/min (95% CI 0.5 – 1.9), respectively. Preserved VR (≥ 20%) was observed in 66.6% of men and 86.4% of women.

Conclusions

Normal dynamic lung volume, defined as FEV ₁ above LLN, was positively associated with VO _2peak in both men and women, in never-smokers and in subjects below and above 45 years of age. The majority of subjects had preserved VR, and the results suggest that FEV ₁ within normal limits may influence VO _2peak in healthy subjects even when no ventilatory limitation to exercise is evident.