The effect of aging and cardiorespiratory fitness on the lung diffusing capacity response to exercise in healthy humans.
Aging is associated with deterioration in the structure and function of the pulmonary circulation. We characterized the lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), and pulmonary-capillary blood volume (Vc) response to discontinuous incremental exercise at 25, 50, 75, and 90% of peak work (Wpeak) in four groups:1) Young [27 ± 3 yr, maximal oxygen consumption (V̇o2max): 110 ± 18% age predicted]; 2) Young Highly Fit (27 ± 3 yr, V̇o2max: 147 ± 8% age predicted);3) Old (69 ± 5 yr, V̇o2max: 116 ± 13% age predicted); and4) Old Highly Fit (65 ± 5 yr, V̇o2max: 162 ± 18% age predicted). At rest and at 90% Wpeak, DLCO, DmCO, and Vc were decreased with age. At 90% Wpeak, DLCO, DmCO, and Vc were greater in Old Highly Fit vs. Old adults. The slope of the DLCO-cardiac output (Q̇) relationship from rest to end exercise at 90% Wpeakwas not different between Young, Young Highly Fit, Old, and Old Highly Fit (1.35 vs. 1.44 vs. 1.10 vs. 1.35 mlCO·mmHg-1·liter blood-1,P= 0.388), with no evidence of a plateau in this relationship during exercise; this was also true for DmCO-Q̇ and Vc-Q̇. V̇o2maxwas positively correlated with1) DLCO, DmCO, and Vc at rest; and2) the rest to end exercise change in DLCO, DmCO, and Vc. In conclusion, these data suggest that despite the age-associated deterioration in the structure and function of the pulmonary circulation, expansion of the pulmonary capillary network does not become limited during exercise in healthy individuals regardless of age or cardiorespiratory fitness level.NEW & NOTEWORTHYHealthy aging is a crucial area of research. This article details how differences in age and cardiorespiratory fitness level affect lung diffusing capacity, particularly during high-intensity exercise. We conclude that highly fit older adults do not experience a limit in lung diffusing capacity during high-intensity exercise. Interestingly, however, we found that highly fit older individuals demonstrate greater values of lung diffusing capacity during high-intensity exercise than their less fit age-matched counterparts.
Mayo Graduate School, Mayo Clinic, Rochester, Minnesota.
Kirsten E
KE
Coffman
Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota; and.
Alex R
AR
Carlson
Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota; and.
Andrew D
AD
Miller
Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota; and.
Bruce D
BD
Johnson
Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota; and b.j.taylor@leeds.ac.uk.|School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
Bryan J
BJ
Taylor
D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism / Q000502:physiology*; D001810:Blood Volume / Q000502:physiology; D002196:Capillaries / Q000378:metabolism / Q000502:physiology; D002248:Carbon Monoxide / Q000378:metabolism; D002302:Cardiac Output / Q000502:physiology; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism / Q000502:physiology*; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D011650:Pulmonary Alveoli / Q000098:blood supply / Q000378:metabolism / Q000502:physiology; D011652:Pulmonary Circulation / Q000502:physiology; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D012146:Rest / Q000502:physiology
D002248:Carbon Monoxide; D010100:Oxygen
alveolar-capillary membrane conductance; lung diffusing capacity; maximal aerobic capacity; pulmonary circulation; pulmonary-capillary blood volume