Effects of training flights of combat jet pilots on parameters of airway function, diffusing capacity and systemic oxidative stress, and their association with flight parameters

Table 4 Dependence of indices of diffusing capacity indices from combinations of binary exposure variables obtained by mixed model ANOVA (see text)

Combination of exposure parameters	Outcome parameters	FeNO	DL_NO	K_NO	DL_CO	K_CO	V_A
Duration and altitude low: n = 40 high: n = 96	Estimate [%]	3.26 ± 4.65	− 2.48 ± 1.02	− 1.44 ± 0.74	− 2.38 ± 1.04	− 1.33 ± 0.75	− 1.00 ± 0.60
	95% CI [%]	− 6.00; 12.51	− 4.49; − 0.47	− 2.91; 0.03	− 4.45; − 0.31	− 2.81; 0.15	− 2.20; 0.19
	p value	0.486	0.016	0.054	0.025	0.077	0.099
Duration and G-Force low: n = 28 high: n = 108	Estimate [%]	2.94 ± 4.88	− 1.65 ± 1.16	− 0.82 ± 0.84	− 1.50 ± 1.19	− 0.69 ± 0.85	− 0.77 ± 0.68
	95% CI [%]	− 6.77; 12.65	− 3.95; 0.65	− 2.49; 0.85	− 3.86; 0.86	− 2.37; 0.99	− 2.12; 0.58
	p value	0.548	0.159	0.332	0.211	0.417	0.259
G-Force and Altitude low: n = 28 high: n = 108	Estimate [%]	− 5.18 ± 4.71	− 1.46 ± 1.15	− 0.58 ± 0.83	− 1.37 ± 1.18	− 0.33 ± 0.84	− 1.09 ± 0.67
	95% CI [%]	− 14.55; 4.19	− 3.74; 0.81	− 2.22; 1.07	− 3.70; 0.96	− 1.99; 1.32	− 2.41; 0.24
	p value	0.274	0.205	0.489	0.246	0.691	0.106
G-Force and Altitude and Duration low: n = 13 high: n = 123	Estimate [%]	3.67 ± 6.75	− 2.90 ± 1.55	− 0.91 ± 1.14	− 3.20 ± 1.59	− 1.19 ± 1.14	− 1.98 ± 0.90
	95% CI [%]	− 9.76; 17.10	− 5.98; 0.18	− 3.16; 1.35	− 6.35; − 0.06	− 3.45; 1.07	− 3.77; − 0.19
	p value	0.588	0.065	0.426	0.046	0.299	0.030

Exposure variables were defined from the three basic exposure parameters: flight duration (≤ 86 min vs > 86 min), maximum altitude (≤ 30,000 ft vs > 30,000 ft), and ≤ 11 vs > 11 occurrences of at least 4 G_z-events during the flight. The combined exposures were also binary and defined via the requirement that at least one of the two or three, respectively, exposure parameters was in the higher category, i.e., the reference of each combined exposure reflected low exposure in all single parameters of the combination. Results are given as mean and SEM of the difference of percent changes post- versus pre-flight, whereby the low value of the combined exposure parameter served as reference. DL_NO diffusing capacity for NO, DL_CO diffusing capacity for CO, K_NO diffusing capacity for NO per volume V_A, K_CO diffusing capacity for CO per volume V_A, V_A alveolar volume. Significant (p < 0.05) effects are marked in boldface

ISSN: 2047-783X