Longitudinal comparison of clinical measures in CF and control groups divided into two age groups: children (5–10 years) and adolescents (11–18 years)
| Group | Time | Time × CF | ||||
|---|---|---|---|---|---|---|
| β estimate (95% CI) | p value | β estimate (95% CI) | p value | β estimate (95% CI) | p value | |
| FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; 25OHD, 25-hydroxyvitamin D; 1,25(OH)2D, 1,25 hydroxyvitamin D. | ||||||
| *Variables adjusted for age, sex, and age × sex interactions. | ||||||
| †Data required log transformation to obtain a normal distribution (untransformed results reported). | ||||||
| ‡25 hydroxyvitamin D adjusted for significant seasonal variation | ||||||
| §Activity questionnaire score adjusted for age due to significant interaction. | ||||||
| Group represents the difference (CF − control) at study commencement, time represents the change in aBMD over time for the whole group, and “time × CF” represents the difference between the CF and control groups in the changes in aBMD over time. There are no group comparisons available for lung function parameters or serum measures of vitamin D. | ||||||
| Children | ||||||
| Weight (kg)*† | −1.01 (−3.82 to 1.81) | 0.48 | 0.35 (0.29 to 0.40) | <0.001 | −0.09 (−0.17 to −0.01) | 0.03 |
| Height (cm)* | −1.13 (−4.06 to 1.79) | 0.45 | 0.51 (0.46 to 0.56) | <0.001 | −0.05 (−0.12 to 0.02) | 0.14 |
| Lean tissue mass (kg)* | 0.19 (−0.92 to 1.30) | 0.73 | 0.20 (0.17 to 0.24) | <0.001 | −0.04 (−0.09 to 0.01) | 0.13 |
| Calcium intake (g/day) | 591.8 (232.0 to 951.6) | 0.001 | 7.61 (2.8 to 12.5) | 0.002 | −2.3 (−24.8 to 19.6) | 0.82 |
| Recommended caloric intake (%) | 22.06 (−0.94 to 45.07) | 0.06 | 0.32 (−0.25 to 0.88) | 0.27 | −1.01 (−2.37 to 0.36) | 0.15 |
| Activity questionnaire | 0.45 (0.12 to 0.79) | 0.008 | 0.01 (−0.00 to 0.02) | 0.11 | −0.02 (−0.03 to 0.00) | 0.06 |
| FEV1 (% predicted) | −0.20 (−0.12 to 0.01) | 0.07 | ||||
| FVC (% predicted) | −0.16 (−0.36 to 0.03) | 0.10 | ||||
| 25OHD (nmol/l)‡ | −0.36 (−0.52 to−0.20) | <0.001 | ||||
| 1,25(OH)2D (pmol/l) | −0.32 (−0.93 to 0.29) | 0.30 | ||||
| Adolescents | ||||||
| Weight (kg)* | −8.33 (−11.6 to −5.11) | <0.001 | 0.35 (0.28 to 0.42) | <0.001 | −0.06 (−0.16 to 0.03) | 0.17 |
| Height (cm)* | −9.58 (−12.10 to −7.06) | <0.001 | 0.32 (0.25 to 0.39) | <0.001 | 0.07 (−0.04 to 0.17) | 0.20 |
| Lean tissue mass (kg)* | −6.01 (−8.09 to −3.93) | <0.001 | 0.22 (0.17 to 0.27) | <0.001 | 0.00 (−0.07 to 0.08) | 0.91 |
| Calcium intake (g/day) | 362.0 (150.0 to 574.1) | <0.001 | 4.0 (−0.5 to 8.5) | 0.08 | −2.2 (−11.7 to 7.4) | 0.66 |
| Recommended caloric intake (%) | 15.68 (0.91 to 30.45) | 0.04 | −0.44 (−0.78 to −0.10) | 0.01 | −0.77 (−1.47 to −0.07) | 0.03 |
| Activity questionnaire§ | 0.19 (−0.09 to 0.47) | 0.18 | −0.01 (−0.02 to −0.01) | <0.001 | −0.01 (−0.02 to 0.01) | 0.41 |
| FEV1 (% predicted) | −0.36 (−0.58 to −0.14) | 0.002 | ||||
| FVC (% predicted) | −0.25 (−0.45 to −0.05) | 0.01 | ||||
| 25OHD (nmol/l)‡ | −0.36 (−0.64 to 0.08) | 0.06 | ||||
| 1,25(OH)2D (pmol/l) | −0.13 (−0.67 to 0.42) | 0.65 | ||||