0
Abstract: Poster Presentations |

IMPAIRED LUNG MEMBRANE DIFFUSION REDUCES OXYGEN SATURATION IN EXERCISE-TRAINED PATIENTS WITH TYPE 1 DIABETES FREE TO VIEW

Nicholas A. Cassuto, BS*; Courtney M. Wheatley, BS; William T. Foxx-Lupo, BS; James C. Baldi, PhD; Eric M. Snyder, PhD
Author and Funding Information

University of Arizona, Tucson, AZ


Chest


Chest. 2009;136(4_MeetingAbstracts):123S-c-124S. doi:10.1378/chest.136.4_MeetingAbstracts.123S-c
Text Size: A A A
Published online

Abstract

PURPOSE:  Lung diffusing capacity (DLCO) can be a limiting factor for oxygen transport and is influenced by pulmonary capillary blood volume (Vc) and alveolar-capillary membrane conductance (DM), both of which can be impaired in patients with type-I diabetes due to changes in the pulmonary vasculature associated with this disease. We sought to determine the influence of type-I diabetes on DLCO, Vc and DM, along with the relationship between these variables and SaO2 at rest and at peak exercise.

METHODS:  To determine this we recruited 10 type-I diabetic patients who were training for an Ironman triathlon (female = 20%, age = 37 ± 7yrs., ht. = 181 ± 9cm., wt = 75 ± 9kg., BMI = 23 ± 2kg/m2, VO2peak = 130 ± 20% predicted, HbA1c = 7 ± 0.7%, glucose = 200 ± 52mg/dL mean ± SD) along with 10 healthy control subjects (female = 20%, age = 28 ± 6yrs., ht. = 180 ± 10cm., wt = 72 ± 2kg., BMI = 22 ± 4kg/m2, VO2peak = 115 ± 30%predicted, HbA1c = 4 ± 0.2%, glucose = 90 ± 4mg/dL) and measured DLCO, DM, and Vc along with SaO2 and cardiac output (Q) at rest and at peak exercise.

RESULTS:  There were no differences in Q, DLCO, DM, Vc, or SaO2 at rest, however DLCO/Q and DM/Q were lower (p < 0.05) in patients with type-I diabetes (Q = 5.8 ± 1.2 vs 5.3 ± 0.8l/min, DLCO = 24 ± 6 vs 26 ± 6ml/min/mmHg, DM = 32 ± 8 vs 34 ± 11ml/min/mmHg, Vc = 69 ± 30 vs 85 ± 30ml, SaO2 = 97 ± 3 vs 97 ± 3%, DLCO/Q = 6.0 ± 1.4 vs 7.5 ± 1.4, DM/Q = 8.2 ± 1.8 vs 10.1 ± 2.8, for diabetic patients and healthy subjects, respectively). At peak exercise, the diabetic patients had lower DLCO/Q and DM/Q (p < 0.05) which led to a reduction in SaO2 (p < 0.05)(Q = 20.7 ± 3.5 vs 18.3 ± 3.5l/min, DLCO = 35 ± 8 vs 38 ± 7ml/min/mmHg, DM = 43 ± 10 vs 49 ± 12ml/min/mmHg Vc = 135 ± 37 vs 184 ± 90ml, SaO2 = 94 ± 3 vs 97 ± 2%, DLCO/Q = 2.5 ± 0.5 vs 3.2 ± 0.5, DM/Q = 3.2 ± 0.6 vs 4 ± 0.7). There was a relationship between DM/Q and SaO2 at peak exercise but not at rest (rest, r2 = 0.06, p = 0.77; peak exercise r2 = 0.54, p = 0.01), providing evidence that the membrane diffusion limitation resulted in the drop in SaO2.

CONCLUSION:  These results demonstrate a reduction in lung membrane diffusion in type-I diabetics at rest and during exercise and a greater reduction in SaO2 at peak exercise, suggesting the diffusion limitation becomes functionally important as the transit time of red blood cells through the lung is reduced.

CLINICAL IMPLICATIONS:  Type-I diabetics may be more prone to pulmonary edema with environmental and physiological challenges.

DISCLOSURE:  Nicholas Cassuto, No Financial Disclosure Information; No Product/Research Disclosure Information

Wednesday, November 4, 2009

12:45 PM - 2:00 PM


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.

Related Content

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

CHEST Journal Articles
PubMed Articles
Guidelines
Guideline for management of postmeal glucose.
International Diabetes Federation | 5/29/2009
Wisconsin essential diabetes mellitus care guidelines.
Wisconsin Diabetes Prevention and Control Program | 4/24/2009
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543