Lung diffusing capacity in sub-Saharan Africans versus European Caucasians

Single breath measurements of lung diffusing capacity (DL) for carbon monoxide (CO) and nitric oxide (NO) were performed in age-, sex-, weight- and height-matched 32 sub-Saharan Africans (13 women) and 32 Caucasian Europeans, and repeated in 14 of each group at 80% of maximum exercise capacity. In Africans versus Caucasians respectively, DLNO was 153 31 vs 176 +/- 38 ml/mmHg/min at rest (P < 0.001) and 210 +/- 48 vs 241 +/- 52 ml/mmHg/min at exercise (P < 0.01) while hemoglobin-adjusted DLCO was 29 +/- 6 vs 34 +/- 6 mlimmHg/min at rest (P < 0.001), and 46 +/- 11 vs 51 +/- 13 ml/mmHg/min at exercise (P < 0.01). However there were no differences in DLCO/alveolar volume(V-A) (K-CO) and DLNO/V-A(K-NO). The sitting-to standing height ratio was lower in the Africans. Differences in lung volume with respect to body height explain lower DLNO and DLCO in sub-Saharan Africans as compared to Caucasian Europeans. (C) 2017 Published by Elsevier B.V.