Imaging-based measurements across the groups
| CF IS (n=26) | CR (n=16) | HC (n=12) | CF HS (n=26) | p-value | p-value (CF vs HC) | p-value (CF vs CR) | p-value (CR vs HC) | p-value (CF HS vs CF IS) | |
| MCC | |||||||||
| Whole lung | 38 (26–49) | 36 (30–43) | 36 (26–47) | 55 (35–70) | 0.97 | 0.49 | 1.00 | 0.83 | 0.0001 |
| Peripheral lung | 36 (16–43) | 35 (31–39) | 35 (28–43) | 54 (35–62) | 0.81 | 0.84 | 0.63 | 0.44 | <0.0001 |
| ABS | |||||||||
| Whole lung | 21 (8–26) | 13 (7–24) | 6 (0–13) | 18 (6–25) | 0.03 | 0.01 | 0.14 | 0.14 | 0.21 |
| Peripheral lung | 20 (11–32) | 17 (5–22) | 7 (0–18) | 14 (8–25) | 0.05 | 0.03 | 0.15 | 0.16 | 0.03 |
| Cen% | 51 (47–57) | 52 (48–57) | 49 (46–51) | 52 (48–56) | 0.22 | 0.14 | 0.43 | 0.16 | 0.83 |
Data are presented as median (interquartile range), unless otherwise stated. CF: cystic fibrosis; IS: isotonic saline; CR: single CF transmembrane conductance regulator mutation carrier; HC: healthy control; HS: hypertonic saline; MCC: mucociliary clearance rate; ABS: technetium-99m-DTPA absorption rate; Cen%: percentage of radioactive counts deposited in the central lung zone (see supplementary material). All groups inhaled IS during the MCC/ABS scan. CF subjects performed an additional study day where they inhaled 7% HS during the scan. Data are presented graphically in supplementary figures S4 and S5 (CF HS versus CF IS). p-values comparing all groups by Kruskal–Wallis (nonparametric). Group comparisons by Dunn's test with Holm adjustment (nonparametric, multiple comparisons). HS versus IS comparison for CF group by Wilcoxon matched-pairs signed-ranks test (nonparametric, paired).