TABLE 1:

Clinical Characteristics and Body Composition Measures at Baseline and Changes over 12 Months in the Surgical and Non- Surgical Groups

Clinical Characteristics	Baseline Measure (Mean ± standard error of mean)		Within group change over 12-months [Mean (95% confidence interval)]		P-value comparing changes over 12 months in surgical vs. non-surgical groups
	Non-Surgical (n=24)	Surgical (n=24)	Non-Surgical (n=24)	Surgical (n=24)
Age (years)	17.1 ± 0.5	17.8 ± 0.4		-	-
Height (cm)	167.1 ± 1.6	168.6 ±1.8	-	-	-
Weight (kg)	120.7 ± 4.8	134.4 ± 3.7*	−1.0 (−5.0, 3.1)	−39.0 (−46.1, −32.0)	<0.0001
Body mass index (kg/m2)	43.0 ± 1.2	47.4 ± 1.3*	−0.8 (−2.3, 0.8)	−13.7 (−16.1, −11.2)	<0.0001
Body mass index z-score	2.5 ± 0.1	2.6 ± 0.1	−0.1 (−0.2, −0.0)	−0.8 (−1.0, −0.5)	<0.0001
25-hydroxy vitamin D (ng/ml)	23.4 ± 1.5	23.9 ± 2.0	−1.5 (−4.8, 1.8)	5.5 (−1.0, 12.0)	0.054
Calcium (mg/dl)	9.3 ± 0.1	9.3± 0.1	−0.1 (−0.2, 0.1)	0.0 (−0.1, 0.2)	0.963
Phosphorus (mg/dl)	3.5 ± 0.1	3.5 ± 0.2	0.1 (−0.3, 0.4)	0.2 (−0.1, 0.5)	0.329
Hemoglobin A1c** (%)	5.5 (5.2, 5.7)	5.6 (5.4, 5.8)	−0.7 (−1.8, 0.3)	−0.7 (−1.2, −0.2)	0.003
Moderate to vigorous physical activity (hours/week)	27.5 ± 4.9	29.6 ± 4.3	4.0 (−10.5, 18.4)	3.0 (−10.0, 16.1)	0.868
Dual Energy X-Ray Absorptiometry (DXA) Measures of Body Composition
Lean Mass (kg)	64.5 ± 2.3	68.8 ± 1.9	1.5 (0.5, 2.5)	−9.2 (−12.3, −6.1)	<0.0001
Lean Mass (%)	53.3 ± 0.9	51.5 ± 1.0	1.4 (−0.3, 3.1)	7.6 (3.9, 11.3)	0.0002
Fat Mass (kg)	57.1 ± 2.8	65.5 ± 2.6*	−1.5 (−5.1, 2.2)	−23.1 (−31.4, −14.7)	<0.0001
Fat Mass (%)	46.7 ± 0.9	48.5 ± 1.0	−1.4 (−3.1, 0.3)	−7.6 (−11.3, −3.9)	0.0002

^*p<0.05 for baseline differences between groups; significant changes from baseline, and significant differences between groups are bolded

^**Baseline measure indicated as median (interquartile range)