Sources of variability between subjects
The variability in FVC between subjects has been estimated (ref. 1) to be attributable to the following factors:
Factors that contribute to variability between subjects:
- Level of physical activity: a high level of physical leading to strongly developed muscles of the shoulder girdle (e.g. rowing, swimming, diving) is said to be associated with a larger than average lung volume.
- Altitude: being born and raised at an altitude of more
than 3000 m is associated with greater than average lung
Ref. 1 - Variability in spirometric indices
- Becklake MR. Concepts of normality applied to the measurement of lung function. Am J Med 1986; 80: 1158-1164.
- Becklake MR, Permutt S. Evaluation of tests of lung function for ‘screening’ for early detection of chronic obstructive lung disease. In: PT Macklem & S Permutt (eds), The lung in the transition between health and disease. New York, Dekker, 1979, 345-387.
- Cotes JE. Lung Function. Assessment and application in medicine. Ed. 5, Blackwell Scientific Publications, Oxford, 1993.