Table 2 Comparison of variables between the robust and physical pre-frailty groups

Age (years)

72.6 ± 3.9

72.1 ± 3.8

73.6 ± 4.1

 < 0.001, − 2.302– − 0.597^*

Sex (Male)

188 (49)

130 (51)

58 (46)

0.363, 0.795–1.870^†

Body mass index (kg/m²)

23.0 ± 3.3

22.9 ± 3.1

23.4 ± 3.1

0.161, − 1.250–0.208^*

Male

23.0 ± 2.8

24.0 ± 3.4

Female

22.7 ± 3.4

22.8 ± 3.6

Maximum grip strength (kg)

29.4 ± 7.9

30.7 ± 7.8

26.7 ± 7.6

 < 0.001, 2.457–5.733^*

Male

37.4 ± 4.6

33.0 ± 5.2

Female

23.8 ± 2.7

21.2 ± 4.4

5 m maximum gait speed (s)

2.7 ± 0.5

2.6 ± 0.4

2.8 ± 0.6

 < 0.001, − 0.371– − 0.134^*

Body fat mass (kg)

15.0 ± 6.1

14.9 ± 6.1

16.1 ± 6.5

0.101, − 2.509–0.225^*

Male

13.0 ± 5.3

15.4 ± 6.1

Female

17.0 ± 6.2

16.7 ± 6.9

Skeletal muscle mass (kg)

40.6 ± 7.8

41.1 ± 7.7

39.6 ± 8.0

0.090, − 0.231–3.147^*

Male

47.7 ± 4.9

47.0 ± 5.0

Female

34.2 ± 2.8

33.3 ± 2.9

Number of remaining teeth

22.6 ± 7.4

23.0 ± 6.9

21.7 ± 8.1

0.109, − 0.306–3.027^*

Masticatory performance

7.9 ± 1.2

8.0 ± 1.1

7.7 ± 1.3

0.015, 0.066–0.600^*

Tongue pressure (kPa)

36.7 ± 7.5

37.1 ± 7.3

35.8 ± 8.0

0.127, − 0.373–2.975^*

ODK /pa/

Normal

319 (84)

220 (86)

99 (79)

0.055, 0.335–1.016^†

Decreased

62 (16)

35 (14)

27 (21)

ODK /ta/

Normal

312 (82)

219 (86)

93 (74)

0.004, 0.272–0.788^†

Decreased

69 (18)

36 (14)

33 (26)

ODK /ka/

Normal

236 (62)

166 (65)

70 (56)

0.071, 0.434–1.036^†

Decreased

145 (38)

89 (35)

56 (44)

Social activity

Yes

306 (80)

215 (84)

91 (72)

0.005, 1.234–3.462^†

No

75 (20)

40 (16)

35 (28)

Exercise habit

Yes

214 (56)

148 (58)

66 (52)

0.295, 0.819–1.931^†

No

167 (44)

107 (42)

60 (48)