Table 2 The characteristics of the Psoas and posterior paraspinal muscle index and density in different gender, age, and BMI groups

PSMI (cm²/m²)^b

16.9 ± 2.3

19.1 ± 2.1

20.7 ± 2.8

PSMI (cm²/m²)^b

14.1 ± 1.7

15.9 ± 2.1

18.3 ± 3.2

PMI (cm²/m²)^b

7.1 ± 1.6

7.8 ± 1.4

8.7 ± 1.9

PMI (cm²/m²)^b

4.9 ± 1.0

5.6 ± 1.1

6.2 ± 1.1

PSMD (HU)^a

50.1 ± 5.8

47.9 ± 6.0

47.0 ± 5.8

PSMD (HU)^a

44.6 ± 6.2

43.2 ± 6.6

41.5 ± 6.7

PMD (HU)^b

51.6 ± 4.7

49.4 ± 5.0

48.3 ± 4.0

PMD (HU)^#

48.0 ± 5.8

47.6 ± 4.6

46.8 ± 4.8

41 ~ 60 years

normal

(N = 205)

overweight (N = 261)

obesity

(N = 111)

41 ~ 60 years

normal

(N = 512)

overweight (N = 406)

obesity

(N = 194)

PSMI (cm²/m²)^b

16.7 ± 2.7

18.2 ± 2.7

19.5 ± 2.7

PSMI (cm²/m²)^b

14.7 ± 2.2

15.8 ± 2.5

16.6 ± 2.8

PMI (cm²/m²)^b

6.9 ± 1.7

7.7 ± 1.7

8.4 ± 1.8

PMI (cm²/m²)^b

5.2 ± 1.3

5. 6 ± 1.4

6.0 ± 1.5

PSMD (HU)^b

47.1 ± 6.5

45.4 ± 5.9

43.1 ± 6.1

PSMD (HU)^b

41.3 ± 6.5

39.1 ± 6.6

38.4 ± 6.6

PMD (HU)^a

47.9 ± 5.0

47.0 ± 4.8

46.0 ± 4.9

PMD (HU)^a

44.7 ± 4.6

43.7 ± 4.8

44.2 ± 4.8

61 ~ 80 years

normal

(N = 318)

overweight (N = 310)

obesity

(N = 125)

61 ~ 80 years

normal

(N = 463)

overweight (N = 477)

obesity

(N = 225)

PSMI (cm²/m²)^b

15.7 ± 2.8

16.6 ± 2.9

17.8 ± 3.2

PSMI (cm²/m²)^b

13.9 ± 2.5

15.2 ± 2.4

15.4 ± 2.4

PMI (cm²/m²)^b

6.7 ± 1.5

7.2 ± 1.5

7.9 ± 1.6

PMI (cm²/m²)^b

5.0 ± 1.1

5.4 ± 1.9

5.5 ± 1.5

PSMD (HU)^a

42.0 ± 6.3

40.6 ± 7.4

39.9 ± 6.8

PSMD (HU)^a

36.3 ± 7.1

34.7 ± 6.9

32.9 ± 6.9

PMD (HU)^#

44.3 ± 4.5

44.1 ± 4.7

44.5 ± 5.1

PMD (HU)^#

40.8 ± 4.7

40.4 ± 4.8

40.4 ± 5.3