Weight loss on stimulant medication: how does it affect body composition and bone metabolism? – A prospective longitudinal study

Table 2 Growth rates of the subjects over different time periods on medication

Time period (months: mean ± SD)	Pre-treatment	0-6 months	6-12 months	12-24 months	24-36 months
Time period (months: mean ± SD)	(16.6 ± 9.4)	(6.3 ± 1.5)	(7.3 ± 2.0)	(11.4 ± 2.1)	(10.9 ± 2.5)
	n=11	n=30	n=30	n=28	n=24
Height velocity (cm/year)	6.5 ± 1.1	4.3 ± 1.9	4.5 ± 1.3	4.7 ± 1.2	5.3 ± 1.2
Weight velocity (kg/year)	2.7 ± 1.8	−1.5 ± 2.8	3.2 ± 3.1	2.9 ± 2.3	4.1 ± 2.3
Change in BMI/year	0.08 ± 0.86	−2.09 ± 1.89	0.81 ± 1.74	0.45 ± 1.05	0.83 ± 0.95
Δ Height Z-score/year	−0.04 ± 0.17	−0.32 ± 0.38***	−0.22 ± 0.21***	−0.11 ± 0.19**	−0.02 ± 0.17
Δ Weight Z-score/year	−0.09 ± 0.36	−1.04 ± 0.74***	0.03 ± 0.63	−0.13 ± 0.27*	0.06 ± 0.29
Δ BMI Z-score/year	−0.08 ± 0.44	−1.29 ± 0.94***	0.26 ± 0.96	−0.10 ± 0.39	0.12 ± 0.43

*p<0.05; **p<0.01; ***p<0.001 for the change in Z-score over the time period using single sample t-tests against a test value of zero.
Statistical analysis was applied to the changes in Z-scores only and used single sample t-tests with a test value of zero.