Table 5

Univariate analysis of independent variables with BMD of the L2 to L4 vertebrae

		Boys			Girls
		n	Mean		SE	p value	n	Mean	SE	p value
Genitalia
Stage 1, 2, 3	66	0.592	0.008	0.0015-150
Stage 4, 5	26	0.718	0.034
Testicular size
⩽ 12 ml	55	0.582	0.009	< 0.0015-150
> 12 ml	37	0.696	0.025
Pubic hair
Stage 1, 2, 3	82	0.605	0.009	0.0155-150	60	0.716	0.013	< 0.0015-150
Stage 4, 5	10	0.815	0.070		27	0.840	0.017
Breast
Stage 1, 2, 3					29	0.656	0.016	< 0.0015-150
Stage 4, 5					58	0.804	0.011
Menarche
No					38	0.679	0.015	< 0.0015-150
Yes					49	0.813	0.013
Group
Art	39	0.587	0.012	0.0035-150	46	0.721	0.015	0.0025-150
Physical education	53	0.658	0.019		41	0.792	0.018
Ball games
No	62	0.615	0.016	0.1475-150	69	0.742	0.013	0.0405-150
Yes	30	0.654	0.019		18	0.803	0.024
Track and field
No	74	0.608	0.009	0.0545-150	75	0.749	0.013	0.2775-150
Yes	18	0.711	0.049		12	0.787	0.034
Water sports
No	83	0.631	0.014	0.2515-150	80	0.752	0.013	0.4145-150
Yes	9	0.602	0.020		7	0.788	0.036
Other sports
No	88	0.629	0.013	0.7025-150	79	0.752	0.012	0.5295-150
Yes	4	0.605	0.048		8	0.778	0.054
Level of sports
PE group—National/school team	38	0.662	0.017	0.023^†	30	0.801	0.020	0.005^†
PE group—Recreational purpose	15	0.647	0.055		11	0.769	0.038
ARTS group—Recreational purpose	33	0.583	0.014		39	0.714	0.016