Table 7.
Association between sweat test markers and CFTR mutation screening.
| Variable | Category | N | Mean | Standard Variation | Median | Minimum | Maximum |
|---|---|---|---|---|---|---|---|
| CFTR mutation | |||||||
| Sweat weight (mg)a | IM/IM | 169 | 163 | 4.4 | 161 | 79 | 326 |
| IM/NIM | 87 | 174 | 4.6 | 174 | 78 | 276 | |
| NIM/NIM | 152 | 160 | 3.9 | 152 | 96 | 268 | |
| Sweat sodium (mEq/L)a | IM/IM | 169 | 84.16 | 21.86 | 83.7 | 10.1 | 145.08 |
| IM/NIM | 87 | 85.51 | 18.16 | 85.2 | 44.4 | 128.76 | |
| NIM/NIM | 152 | 68.62 | 20.76 | 67.2 | 14.23 | 113.8 | |
| Sweat chloride (mEq/L)b | IM/IM | 169 | 107.29 | 27.08 | 109.42 | 13.1 | 159.2 |
| IM/NIM | 87 | 107.03 | 23.41 | 113.6 | 46.8 | 152.5 | |
| NIM/NIM | 152 | 71.03 | 25.68 | 66 | 12.4 | 140.16 | |
| Sodium–chlorideb | IM/IM | 169 | −23.13 | 18.21 | −21.1 | −82.7 | 22 |
| IM/NIM | 87 | −21.52 | 17.5 | −19.2 | −71.97 | 13.27 | |
| NIM/NIM | 152 | −2.41 | 11.71 | −0.46 | −46.01 | 32.7 | |
| Chloride/sodiumb | IM/IM | 169 | 1.292 | 0.261 | 1.25 | 0.57 | 2.11 |
| IM/NIM | 87 | 1.269 | 0.255 | 1.226 | 0.8 | 2.12 | |
| NIM/NIM | 152 | 1.029 | 0.174 | 1.007 | 0.49 | 1.73 | |
| F508del mutation screening | |||||||
| Sweat sodium (mEq/L)c | +/+ | 88 | 84.4 | 20.8 | 84.95 | 10.1 | 124.6 |
| +/− | 136 | 84.02 | 21.71 | 83.05 | 30.2 | 145.08 | |
| −/− | 184 | 71.95 | 21.15 | 70.35 | 14.23 | 118.81 | |
| Sweat chloride (mEq/L)c | +/+ | 88 | 107.69 | 25.86 | 106.8 | 13.1 | 159.2 |
| +/− | 136 | 105.52 | 26.89 | 111.36 | 21.6 | 158.6 | |
| −/− | 184 | 78.33 | 29.51 | 72.61 | 12.4 | 152.5 | |
| Sodium–chloridec | +/+ | 88 | −23.27 | 16.78 | −23.2 | −64.3 | 11.5 |
| +/− | 136 | −21.5 | 18.39 | −18.65 | −82.7 | 22 | |
| −/− | 184 | −6.39 | 15.88 | −1.85 | −73.42 | 32.7 | |
| Chloride/sodiumc | +/+ | 88 | 1.294 | 0.23 | 1.263 | 0.87 | 1.98 |
| +/− | 136 | 1.273 | 0.275 | 1.21 | 0.57 | 2.12 | |
| −/− | 184 | 1.077 | 0.22 | 1.03 | 0.49 | 2.04 | |
NIM––unknown mutation in the CFTR gene, or with one or two mutations in the CFTR gene belonging to classes IV, V, or VI; IM––known mutations in the CFTR gene belonging to class I, II, and/or III; (+) shows that the F508del allele is present; (−) shows that the F508del allele is not present.
aIM/NIM genotype showed difference regarding the other groups.
bNIM/NIM genotype showed difference regarding the other groups.
c−/− genotype showed difference regarding the other groups.
Statistical analysis was made by Kruskal–Wallis test. For all analyses, P-value was <0.001. α = 0.05.
CFTR, cystic fibrosis transmembrane regulator; IM, identified mutation; mEq/L, milliequivalents per liter; mg, milligram; N, number of subjects; NIM, non-identified mutation.