Table 2.

Twelve-month surveillance of 7 burosumab-treated XLH patients.

	Baseline	6 months	12 months	p a	p b
Age, years (range)	8.7 ± 3.2 (5.1–13.3)	9.3 ± 3.1 (5.7–13.8)	9.8 ± 3.1 (6.4–14.3)
Anthropometric measurements
Rickets severity score	2.29 ± 1.07	Not done	0.43 ± 0.73		0.005
Height, cm	121.3 ± 16.3	125.4 ± 16.3	128.3 ± 15.4	<0.001	<0.001
Height SDS	−1.59 ± 0.81	−1.41 ± 0.77	−1.37 ± 0.77	0.023	0.548
Weight, kg	28.5 ± 9.6	29.7 ± 9.6	31.6 ± 10.9	0.001	0.063
Weight SDS	−0.21 ± 0.78	−0.31 ± 0.79	−0.31 ± 0.75	0.060	0.990
BMI	19.1 ± 3.2	18.5 ± 2.9	18.7 ± 3.5	0.072	0.661
BMI SDS	0.92 ± 0.92	0.66 ± 0.96	0.56 ± 0.84	0.006	0.366
Body composition analysis
Fat mass, kg	7.0 ± 3.1	7.2 ± 2.9	7.9 ± 4.1	0.313	0.231
Fat mass, %	24.40 ± 3.13	24.06 ± 2.18	24.24 ± 3.96	0.645	0.822
Fat-free mass, kg	21.1 ± 6.7	22.5 ± 6.9	23.5 ± 7.2	0.001	0.046
Fat-free mass, %	74.26 ± 2.93	75.82 ± 2.57	75.20 ± 3.65	0.175	0.497
Fat-free mass percentile	11.00 ± 9.98	18.86 ± 15.96	21.71 ± 14.82	0.068	0.518
ASMM, kg	7.4 ± 3.0	8.0 ± 3.2	8.4 ± 3.3	0.012	0.034
ASMM, %	25.28 ± 3.09	26.18 ± 3.01	26.32 ± 2.22	0.130	0.722
ASMM percentile	8.14 ± 8.45	22.00 ± 16.43	25.57 ± 19.60	0.006	0.356
Muscle-to-fat ratio (range)	1.06 ± 0.20 (0.87–1.56)	1.10 ± 0.15 (0.88–1.54)	1.11 ± 0.18 (0.78–1.63)	0.420	0.824

Data are expressed as mean ± standard deviation (SD) or number (percent).

p^a represents a comparison between the variable at baseline and after 6 months of treatment.

p^b represents a comparison between the variable at 6 months and at 12 months of treatment.

Bold indicates significant.

ASMM, appendicular skeletal muscle mass; BMI, body mass index; SDS, standard deviation score; XLH, X-linked hypophosphatemia.