TABLE 3

BMD Annual Growth (g/cm² per year) by Gender, Tanner Stage, and BMI-for-Age Percentiles

Parameter	BMI-for-Age Percentiles								Total		P^b
	Quartile 1		Quartile 2		Quartile 3		Quartile 4		Total
	Rate^a	No. of Visits	Rate^a	No. of Visits	Rate^a	No. of Visits	Rate^a	No. of Visits	Rate^a	No. of Visits
Boys
Tanner stage
1	0.020	252	0.020	221	0.025	188	0.030	214	0.023	875	<.0001
2	0.020	171	0.026	141	0.028	116	0.030	143	0.027	571	.0700
3	0.032	70	0.045	67	0.048	78	0.053	79	0.045	294	.0010
4	0.061	86	0.074	92	0.077	100	0.074	88	0.071	366	.1500
5	0.061	134	0.065	170	0.074	186	0.064	177	0.065	667	.0700
Total	0.030	713	0.038	691	0.045	668	0.046	701	0.040	2773	<.0001
Girls
Tanner stage
1	0.024	147	0.024	100	0.021	76	0.027	71	0.023	394	.0300
2	0.056	79	0.057	72	0.058	88	0.058	79	0.057	318	.9900
3	0.076	75	0.084	80	0.084	72	0.088	75	0.082	302	.2000
4	0.050	61	0.071	90	0.081	88	0.104	57	0.071	296	<.0001
5	0.017	51	0.029	98	0.034	135	0.038	148	0.032	432	.0700
Total	0.039	413	0.051	440	0.045	459	0.054	430	0.046	1742	<.0001

↵a Rate (median) = (BMD at current visit − BMD at previous visit)/years since last visit; Tanner stage (determined by genital stage for boys and breast stage for girls) and BMI-for-age percentile determined at current visit.
↵b Obtained from simple linear regression of the ranks of BMD rate on quartile of BMI-for-age percentile accounting for correlation of repeated measurements on same individual; P value for the test of the interaction of Tanner stage and quartile of BMI-for-age percentile on BMD annual growth was .07 for boys and .04 for girls.