Table 2 Mean (SD) of heel quantitative ultrasound parameters by age group

Men

(n = 30)

(n = 46)

(n = 140)

(n = 124)

(n = 18)

 Stiffness index

98.2 (14.6)

89.6 (14.5)

87.6 (15.6)

83.2 (16.7)

76.0 (12.2)

< 0.001

 SOS (m/sec)

1569.1 (27.4)

1551.5 (28.3)

1545.8 (29.9)

1541.5 (29.0)

1529.3 (18.7)

< 0.001

 BUA (dB/MHz)

118.4 (12.3)

113.0 (12.3)

112.3 (13.3)

107.5 (14.5)

101.8 (11.5)

< 0.001

Women

(n = 27)

(n = 87)

(n = 189)

(n = 178)

(n = 22)

 Stiffness index

88.3 (14.5)

78.1 (14.4)

71.6 (12.8)

64.0 (12.1)

56.4 (8.5)

< 0.001

 SOS (m/sec)

1550.1 (35.7)

1539.6 (24.9)

1527.8 (22.6)

1516.0 (23.0)

1504.6 (16.4)

< 0.001

 BUA (dB/MHz)

111.6 (13.0)

100.6 (13.4)

95.8 (12.3)

89.4 (11.1)

82.6 (7.7)

< 0.001