Table 5.

Comparison of cardiopulmonary exercise measures in the group of adults born EP with- or without LVCP, EP-born controls and term-born controls.

	PDA-surgery							EP-born controls			Term-born controls
	Total N = 25 (12 females)		LVCP n = 13 (5 females)		No LVCP n = 12 (7 females)			n = 30 (17 females)			n = 36 (13 females)
CPET variables	Mean	95%CI	Mean	95%CI	Mean	95%CI	p a	Mean	95%CI	p b	Mean	95%CI	p c	p d
Peak heart rate, beat/min	191	185, 197	191	181, 201	191	183, 199	0.98	193	190, 196	0.54	195	191, 198	0.27	0.43
RER at peak exercise, units	1.24	1.21, 1.28	1.22	1.16, 1.27	1.27	1.22, 1.31	0.16	1.27	1.23, 1.30	0.24	1.26	1.24, 1.28	0.36	0.65
Ti/Ttot, %	51.0	49.9, 52.1	52.4	51.2, 53.6	49.4	47.8, 51.0	0.004	49.7	48.7, 50.7	0.09	49.5	48.6, 50.3	0.03	0.75
Breathing reserve, %	17	11, 23	20	13, 28	13	3, 23	0.19	16	11, 22	0.93	11	6, 16	0.12	0.11
Peak respiratory rate, breaths/min	46	42, 50	43	38, 48	49	42, 55	0.13	48	44, 51	0.47	54	50, 58	0.003	0.01
Females	47	41, 53	44	35, 53	50	40, 60	0.27	46	42, 51	0.76	51	45, 57	0.36	0.19
Males	44	39, 50	43	35, 50	47	34, 61	0.42	49	44, 54	0.18	56	50, 61	0.004	0.06
Peak minute ventilation, L/min	89	74, 99	90	74, 105	89	75, 103	0.94	101	92, 110	0.07	134	123, 144	<0.001	<0.001
Females	77	67, 86	72	51, 93	80	66, 94	0.43	90	80, 99	0.07	102	93, 110	<0.001	0.03
Males	101	86, 115	101	80, 121	101	68, 135	0.95	118	106, 129	0.06	152	141, 162	<0.001	<0.001
Distance, meter	892	805, 978	935	783, 1,086	835	779, 890	0.19	858	763, 953	0.59	1,117	1,017, 1,216	0.001	<0.001
Females	856	627, 1,084	932	305, 1,558	780	682, 878	0.50	777	667, 887	0.49	917	810, 1,024	0.59	0.06
Males	914	840, 988	936	809, 1,063	879	820, 937	0.35	964	801, 1,127	0.55	1,230	1,104, 1,355	<0.001	0.01
Peak VO2, ml/kg/min	37.5	34.9, 40.2	38.5	33.6, 43.4	36.5	33.9, 39.0	0.43	38.1	35.1, 41.1	0.76	43.6	41.0, 46.5	0.002	0.007
Females	35.8	31.0, 40.5	38.1	23.9, 52.3	34.1	31.8, 36.4	0.48	36.4	32.6, 40.2	0.82	38.5	35.0, 42.0	0.32	0.40
Males	39.2	36.1, 42.3	38.8	33.7, 43.9	39.8	35.6, 44.0	0.70	40.4	35.2, 45.5	0.67	46.6	43.3, 49.9	0.001	0.04
Peak VO2, % of predicted	79.6	73.5, 85.8	80.3	68.1, 92.4	79.0	74.9, 79.3	0.83	83.1	76.5, 89.6	0.44	90.2	85.5, 94.9	0.007	0.08
Females	85.0	73.6, 96.4	90.6	56.3, 124.9	81.0	75.5, 86.6	0.49	87.4	78.1, 96.6	0.73	92.2	83.9, 100.4	0.28	0.41
Males	74.7	68.8, 80.5	73.8	64.1, 83.5	76.1	68.3, 83.9	0.65	77.4	67.8, 87.1	0.60	89.1	82.9, 95.3	0.001	0.04

CPET, cardiopulmonary exercise test; EP, Extremely preterm (gestational age <28 weeks and/or birthweight <1,000 g); LVCP, left vocal cord paralysis; PDA, patent ductus arteriosus; RER, respiratory exchange ratio; Ti/Ttot, Inspiratory time/Total inspiratory and expiratory time ratio; VO₂, oxygen consumption; 95% CI, 95% confidence interval. Breathing reserve is the difference between maximal voluntary ventilation (FEV₁ x 35) and peak minute ventilation reported as the percentage of maximal voluntary ventilation. (p) Independent sample t-test (equal variance not assumed);

^a LVCP vs. no LVCP;

^b PDA-surgery group vs. EP-born controls;

^c PDA-surgery group vs. term-born controls;

^dEP-born controls vs. term-born controls.