Table 2.

Multivariable linear regression results of CT parameters.

	Corrected r2	Constant	Adj. mean difference	95% CI	P-value
SUBCUTANEOUS FAT L3
SUBCUTANEOUS FAT T12	0.93	117.61	1.24	1.02 to 1.45	< 0.001
Sex			− 4.0	− 34.93 to 26.93	0.793
Age			− 1.43	− 2.80 to − 0.05	0.043
BMI			1.25	− 1.95 to 4.45	0.430
MRA L3
MRA T12	0.67	21.94	0.67	0.45 to 0.88	< 0.001
Sex			3.11	− 2.99 to 9.21	0.305
Age			− 0.22	− 0.56 to 0.11	0.182
BMI			− 0.09	− 0.58 to 0.40	0.714
SMA L3
SMA T12	0.76	25.64	2.59	1.92 to 3.26	< 0.001
Sex			24.79	10.22 to 39.35	0.002
Age			− 0.36	− 1.06 to 0.34	0.301
BMI			0.69	− 0.48 to 1.86	0.235
FMR	0.35	139.70	− 18.63	− 35.08 to − 2.18	0.028
Sex			43.65	20.13 to 67.18	0.001
Age			− 0.78	− 1.93 to 0.36	0.172
BMI			3.25	1.02 to 5.47	0.006
SMI
SMA T12	0.64	7.41	0.80	0.56 to 1.03	< 0.001
Sex			2.35	− 2.51 to 7.21	0.330
Age			− 0.03	− 0.27 to 0.20	0.785
BMI			0.26	− 0.14 to 0.65	0.199
FMR	0.11	41.58	− 5.14	− 10.50 to 0.22	0.059
Sex			7.25	− 0.36 to 14.85	0.061
Age			− 0.13	− 0.49 to 0.24	0.488
BMI			0.90	0.14 to 1.66	0.023

Results of the multivariable linear regression for CT parameters at T12 as independent variable and CT parameters at L3 as dependent variable (in bold letters) including the results of the adjusting variables sex, age, and body mass index (BMI) (not bold).

Adj. mean difference = adjusted mean difference, CI = confidence interval, L3 = at the level of the third lumbar vertebra, T12 = at the level of the twelfth thoracic vertebra, MRA = muscle radiodensity attenuation in Hounsfield units, SMA = skeletal muscle area [cm²], FMR = fat to muscle ratio calculated by waist circumference at the height of T12/((circumference of the right posterior paraspinal muscle + circumference of the left posterior paraspinal muscle)/2) according to Kottlors et al.¹⁷.