Table 2.

Comparison of bone health at study entry in early COC users and other COC users

Variables at study entry	Early COC use n = 8	COC use n = 26	P
Age (years)a	19.5 ± 0.7	19.2 ± 0.5	0.173
Body mass index (kg/m2)a	24.2 ± 3.8	23.2 ± 2.7	0.434
Years after menarche began COCa Bone sitesb (g/cm2)	2.9 ± 0.9	5.5 ± 1.0	< 0.001
Anterior–posterior spine	0.972 ± 0.029	1.020 ± 0.016	0.151
Lateral spine	0.745 ± 0.024	0.790 ± 0.013	0.105
Femoral neck	0.835 ± 0.038	0.925 ± 0.021	0.048
Total hip	0.934 ± 0.030	1.009 ± 0.017	0.035
Whole body	1.007 ± 0.020	1.053 ± 0.011	0.050

P value for MANCOVA controlling for lean body mass at study entry, with Bonferroni correction

COC combined oral contraceptives, Early COC User women who began using COC medication ≤ 4 years menarche, COC Use women who began using COCs > 4 years after menarche

^aMeans with standard deviations

^bAdjusted means with standard error