0
Clinical Investigations: PULMONARY FUNCTION TESTS |

Clinical Significance of Elevated Diffusing Capacity*

Ghulam Saydain; Kenneth C. Beck; Paul A. Decker; Clayton T. Cowl; Paul D. Scanlon
Author and Funding Information

*From the Pulmonary and Critical Care Division (Dr. Saydain), Nassau University Medical Center, East Meadow, NY; Department of Radiology (Dr. Beck), University of Iowa, Iowa City, IA; Mayo Clinic and Mayo Medical School (Mr. Decker, and Drs. Cowl and Scanlon), Rochester, MN.

Correspondence to: Ghulam Saydain MD, FCCP, Pulmonary and Critical Care Division, 10th floor, Nassau University Medical Center, 2201 Hempstead Tpk, East Meadow, NY, 11554; e-mail: gsaydain@numc.edu



Chest. 2004;125(2):446-452. doi:10.1378/chest.125.2.446
Text Size: A A A
Published online

Study objective: Single-breath diffusing capacity of the lung for carbon monoxide (Dlco) is used as a pulmonary function test (PFT) to assess gas transfer in the lungs. The implications of a low Dlco are well-recognized, but the clinical significance of a high Dlco is not clear. The aim of this study was to identify the clinical correlates of a high Dlco.

Patients and methods: We identified 245 patients with a high Dlco (ie, > 140% predicted) and a matched group of 245 patients with normal Dlco (ie, 85 to 115% predicted), who were selected from a laboratory database of 45,000 patients tested between January 1997 and December 1999. We compared the demographic features, clinical diagnoses, and PFT data between the two groups.

Settings: Large multispecialty group practice.

Results: The patients in the high Dlco group were heavier (mean [± SD] weight, 96.0 ± 22.9 vs 85.0 ± 21.3 kg, respectively; p < 0.001), had a higher mean body mass index (32.9 ± 7.4 vs 29.4 ± 6.4 kg/m2, respectively; p < 0.001), larger body surface area (p < 0.001), and larger mean total lung capacity (p = 0.007) and alveolar volume (p < 0.001). The clinical diagnoses of obesity (p < 0.001) and asthma (p < 0.001) were more common among patients with high Dlco values. The majority of patients (62%) with a high Dlco had a diagnosis of obesity, asthma, or both. Polycythemia, hemoptysis, and left-to-right shunt were uncommon.

Conclusion: A high Dlco on a PFT is most frequently associated with large lung volumes, obesity, and asthma. Other conditions are much less common. A clinical condition, which typically reduces Dlco, may deceptively normalize Dlco in such patients.


Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Figures

Tables

References

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Find Similar Articles
CHEST Journal Articles
PubMed Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543