Adjusted linear regression	N	Regression coefficient	P value	N	Regression coefficient	P value	N	Regression coefficient	P value
Trabecular bone mineral density, mg/cm³	1194	0.17	<0.001	1030	0.18	<0.001	164	0.12	0.016
Total cross-sectional area 4%, mm²	1123	0.24	<0.001	967	0.26	<0.001	156	0.16	0.002
Cortical bone mineral density, mg/cm³	1084	0.37	<0.001	933	0.42	<0.001	151	0.39	0.001
Total cross-sectional area 66%, mm²	1084	0.39	<0.001	933	0.44	<0.001	151	0.31	<0.001
Cortical thickness, mm²	1084	0.27	<0.001	933	0.29	<0.001	151	0.14	0.013
Endosteal circumference, mm²	1084	0.41	<0.001	933	0.43	<0.001	151	0.30	<0.001
Periosteal circumference, mm²	1084	0.43	<0.001	933	0.46	<0.001	151	0.37	<0.001
Polar stress-strain index, mm³	1084	0.25	<0.001	933	0.28	<0.001	151	0.20	<0.001

Linear regression adjusted for child and parental age, sex and height. Regression coefficients are unstandardised betas.
N, number of participants in cohort with this measure (denominator).