Table 3 Mean (SD) bone mineral density ratio (the BMD changes from baseline) for each group by gruen zone at different time points

 ZA group

1.20(0.74)

1.18(0.28)^a

1.13(0.62)

1.07(0.23)^a

1.13(0.41)

1.13(0.13)^a

1.15(0.21)^a

 Control

0.93(0.14)

1.04(0.12)

0.98(0.08)

0.97(0.04)

1.00(0.07)

1.00(0.15)

0.93(0.22)

 ZA group

1.05(0.19)^a

1.13(0.12)

1.05(0.21)

1.04(0.07)

1.04(0.18)

1.14(0.12)^a

1.09(0.20)^a

 Control

0.92(0.18)

1.07(0.19)

0.99(0.08)

0.97(0.06)

1.01(0.07)

1.02(0.18)

0.88(0.29)

 ZA group

1.05(0.19)^a

1.10(0.10)^a

1.00(0.09)

1.03(0.08)^a

1.07(0.12)^a

1.13(0.13)^a

1.07(0.22)^a

 Control

0.86(0.24)

0.98(0.25)

0.95(0.22)

0.93(0.20)

0.95(0.24)

0.97(0.28)

0.84(0.29)

 ZA group

1.08(0.21)^a

1.12(0.11)

1.00(0.11)

1.04(0.09)^a

1.08(0.15)

1.16(0.13)^a

1.06(0.22)^a

 Control

0.89(0.14)

1.10(0.46)

1.00(0.08)

0.96(0.07)

1.02(0.10)

1.00(0.19)

0.83(0.20)