This work is licensed under a Table 1.
Differences in anthropometry, biochemical profile and dietary indices by group.
| Dependent | BD | LC+ | LC− | ANOVA |
|---|---|---|---|---|
| Variable | n=20 | n=20 | n=24 | P value |
| Anthropometry | ||||
| Age (years) | 11.9 (2.4) | 12.3 (2.5) | 12.3 (2.3) | 0.8 |
| Sex (F/M) | 7/13 | 12/8 | 7/17 | 0.1 |
| Height (cm) | 141.4 (14.9) | 142.7 (14.3) | 143.7 (12.7) | 0.8 |
| Sitting height (cm) | 70.8 (6.2) | 71.4 (5.4) | 72.2 (6.0) | 0.6 |
| Weight (kg) | 32.2 (9.7) | 31.5 (9.5) | 32.3 (9.2) | 0.4 |
| BMI (kg/m2) | 15.7 (2.0)b | 15.0 (1.9)a | 15.3 (2.1) | 0.1 |
| % Fat Tanita | 16.9 (4.5)b | 15.6 (3.1)a | 14.7 (3.7) | 0.01 |
| % Trunk fat mass | 12.4 (3.5)b,c | 9.9 (2.3)a | 9.7 (2.9)a | 0.004 |
| Plasma biochemistry | ||||
| iCa (7.4) (mmol/l) | 1.13 (0.02) | 1.14 (0.03) | 1.13 (0.03) | 0.7 |
| Ca (mmol/l) | 2.32 (0.04) | 2.34 (0.07) | 2.32 (0.05) | 0.2 |
| 25OHD (nmol/l) | 61.1 (16.8) | 62.1 (16.5) | 57.8 (13.8) | 0.6 |
| 25OHD-t1/2 (days) | 24.5 (6.1)c | 27.8 (6.4) | 31.5 (11.5)a | 0.09 |
| 1,25(OH)2D (pmol/l) | 339.9 (71.4) | 352.7 (84.0) | 301.5 (79.4) | 0.1 |
| PTH (pg/ml) | 41.0 (19.4) | 39.9 (18.8) | 35.9 (21.9) | 0.6 |
| PO43− (mmol/l) | 1.48 (0.17) | 1.47 (0.17) | 1.56 (0.15) | 0.3 |
| C-FGF23*(RU/ml) | 84.7 (53.7, 140.0)b | 229.8 (86.9, 607.4)a,c | 78.9 (37.3, 166.9)b | 0.0001 |
| I-FGF23*(pg/ml) | 25.7 (19.2, 34.5)b | 34.3 (22.8, 51.5)a | 28.2 (19.6, 40.7) | 0.05 |
| TALP (U/l) | 321.6 (73.2) | 348.9 (108.7) | 362.3 (107.2) | 0.4 |
| Cys C (mg/l) | 0.81 (0.15)c | 0.86 (0.15)c | 0.99 (0.17)a,b | 0.002 |
| Cr (μmol/l) | 47.2 (8.5) | 43.3 (7.0) | 46.5 (10.4) | 0.2 |
| Albumin (g/l) | 38.5 (2.3) | 38.6 (2.9) | 37.4 (2.4) | 0.2 |
| Hb*(g/dl) | 13.4 (12.4, 14.4) | 12.6 (10.4, 15.3) | 13.3 (12.3, 14.3) | 0.2 |
| ZnPP*(μmol/mol per haem) | 69.4 (51.2, 93.9)b | 99.8 (66.2, 150.7)a,c | 68.8 (50.2, 94.2)b | 0.008 |
| Ferr*(μg/l) | 31.6 (15.5, 40.7) | 20.2 (8.30, 48.9) | 29.7 (17.0, 51.9) | 0.2 |
| sTfR*(μg/ml) | 4.91 (3.96, 6.09)b | 7.45 (4.48, 6.09)a,c | 4.89 (3.90, 6.11)b | 0.0001 |
| AGP (μmol/l) | 17.0 (5.6) | 18.3 (5.7) | 18.2 (3.9) | 0.5 |
| CRP*(mg/dl) | 2.12 (0.74, 6.07) | 2.32 (0.99, 4.45) | 2.38 (0.99, 5.48) | 0.9 |
| Mg (mmol/l) | 0.85 (0.06) | 0.85 (0.07) | 0.84 (0.08) | 0.5 |
| eGFR and mineral excretion | ||||
| eGFR (ml/min) | 102.2 (22.6)c | 95.5 (22.8) | 78.8 (17.2)a | 0.002 |
| TmP:GFR (mmol/l) | 1.82 (0.29)c | 1.88 (0.20) | 1.98 (0.21)a | 0.08 |
| 2-h uPO43−:Cr*(mol/mol) | 1.29 (0.80, 2.08) | 0.93 (0.47, 1.83) | 1.20 (0.87, 1.64) | 0.1 |
| 2-h uCa:Cr*(mol/mol) | 0.35 (0.15, 0.81) | 0.29 (0.16, 0.51) | 0.87 (0.46, 1.65) | 0.4 |
| 24-h uPO43:Cr*(mol/mol) | 1.98 (1.44, 2.74) | 1.92 (1.44, 2.55) | 1.83 (1.18, 2.83) | 0.7 |
| 24-h uCa:Cr*(mol/mol) | 0.32 (0.16, 0.67) | 0.24 (0.14, 0.42) | 0.26 (0.13, 0.50) | 0.5 |
| Two-day weighed dietary intake | ||||
| Ca (mg) | 259 (129) | 273 (133) | 263 (108) | 0.9 |
| Phosphorus (mg) | 679 (267) | 722 (315) | 671 (260) | 0.5 |
| Ca/P (mol/mol) | 0.30 (0.11) | 0.30 (0.12) | 0.32 (0.10) | 0.8 |
BD, history of rickets and a previously measured elevated C-terminal FGF23 (C-FGF23) concentration; LC+, local controls with a previously measured high C-FGF23 concentration; and LC−, local controls with a previously measured normal C-FGF23 concentration. All measurements were conducted on the entire dataset (n=64), with the exception of 25OHD half-life (25OHD-t1/2), which was conducted on a subset (BD: n=12, LC+: n=12, and LC−: (n=13)). For normally distributed data, the results are mean (s.d.); for positively skewed data (denoted by *), the results are geometric mean (−1s.d., +s.d.). The ANOVA P value is age- and sex-adjusted with the exception of the sex variable, which is a χ2 P value. Significant differences between the groups as determined by two-sample Student's t-tests are denoted by a superscript, i.e. a= significantly different from BD, b=significantly different from LC+, and c=significantly different from LC−.