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 ± SEM)		Change over 12-months [Mean (95% CI)]		P-value comparing changes over 12 months in surgical vs. non-surgical groups
	Non-Surgical (n=22)	Surgical (n=22)	Non-Surgical (n=22)	Surgical (n=22)
Age (years)	17.0 ± 0.5	18.3 ± 0.5	-	-	-
Weight (kg)	119.5 ± 4.7	132.7 ± 4.4	−0.0 (−4.0, 3.9)	−35.9 (−41.6, −30.2)	<0.0001
BMI (kg/m²)	42.4 ± 1.3	47.0 ± 1.5^*	−0.5 (−1.9, 1.0)	−12.8 (−14.8, −10.9)	<0.0001
BMI z-score	2.5 ± 0.1	2.6 ± 0.1	−0.1 (−0.2, −0.0)	−0.7 (−0.9, −0.6)	<0.0001
25(OH) vitamin D (ng/ml)	22.2 ± 1.7	23.9 ± 1.9	−0.6 (−3.7, 2.5)	2.5 (−3.3, 8.3)	0.186
Calcium (mg/dl)	9.3 ± 0.1	9.3 ± 0.1	−0.1 (−0.2, 0.1)	−0.0 (−0.2, 0.1)	0.460
Phosphorus (mg/dl)	3.7 ± 0.1	3.5 ± 0.2	0.0 (−0.3, 0.3)	0.5 (−0.0, 0.9)	0.279
HBA1c (%)	6.1 ± 0.4	5.7 ± 0.2	−0.7 (−1.7, 0.3)	0.1 (−1.4, 1.6)	0.355
Moderate to vigorous physical activity (hours/week)	23.2 ± 4.7	31.0 ± 4.7	6.7 (−6.5, 19.9)	5.0 (−7.2, 17.3)	0.891

DXA Measures of Body Composition	Non-Surgical (n=22)	Surgical (n=22)	Non-Surgical (n=22)	Surgical (n=22)
Lean Mass (kg)	63.9 ± 2.3	67.5 ± 2.4	2.2 (0.7, 3.6)	−8.5 (−10.9, −6.0)	<0.0001
Lean Mass (%)	53.2 ± 1.0	51.1 ± 1.1	1.6 (−0.0, 3.1)	7.7 (4.8, 10.7)	0.001
Fat Mass (kg)	56.7 ± 2.8	64.9 ± 2.9^*	−1.4 (−4.8, 2.1)	−22.3 (−28.5, −16.2)	<0.0001
Fat Mass (%)	46.8 ± 1.0	48.8 ± 1.1	−1.6 (−3.1, 0.0)	−7.6 (−10.5, −4.7)	0.001

p<0.05 for baseline comparisons; BMI: body mass index; HbA1C: hemoglobin A1C. Significant changes from baseline and significant p values are bolded. Baseline measures and differences between groups were compared using the Student t-test; Within group changes over 12 months were assessed using the paired t-test.