Cardiopulmonary Exercise Testing in Childhood in Late Preterms: Comparison to Early Preterms and Term-Born Controls

Background: Late preterm (34(0)-36(6) weeks gestational age [GA]) infants may have abnormal pulmonary development and possible exercise physiology parameters. We aim to assess the effect of late prematurity on exercise capacity in childhood and to compare it to early preterm (EP) (born < 30(0) GA), and to term healthy control (TC) (>37(0) week GA). Methods: Late preterm and early preterm (7-10 years) completed a cardiopulmonary exercise test (CPET) and spirometry and were compared to EP and to TC. Results: Eighty-four children (age 9.6 +/- 1.0 years, 48% girls) participated. Twenty-one former LP were compared to 38 EP (15 with Bronchopulmonary dysplasia (BPD) [EP+], 23 without BPD [EP-]) and to 25 TC children. Peak oxygen uptake (peakV?O-2) was statistically lower than in the TC, but within the normal range, and without difference from the EP (LP 90.2 +/- 15.1%, TC 112.4 +/- 16.9%, p < 0.001; EP+ 97.3 +/- 25.5%, EP- 85.4 +/- 20.8%, p = 0.016 and p < 0.001, respectively, when compared with TC). Lung function (FEV1) was lower than normal only in the EP+ (75.6 +/- 14.9% predicted, compared with 12.5 +/- 87.8 in EP-, 87.5 +/- 16.9 in LP and 91.0 +/- 11.7 in TC). Respiratory and cardiac limitations were similar between all four study groups. Conclusions: This study demonstrated lower exercise capacity (peakV?O-2) in former LP children compared with healthy term children. Exercise capacity in LP was comparable to that of EP, with and without BPD. However, the exercise test parameters, specifically peakV?O-2, were within the normal range, and no significant physiological exercise limitations were found.