Skip to main content

View full-text article in PMC

. Author manuscript; available in PMC: 2019 Mar 1.

Published in final edited form as: Arthritis Care Res (Hoboken). 2018 Feb 6;70(3):333–342. doi: 10.1002/acr.23278

Table 3.

Adjusted Regression Models of Associations between Quadriceps Density, HU (Skeletal Muscle Fat) ^† and Physical Function and Physical Activity.

Dependent Variable	Step	Confounder variable	Independent variable	Beta- coefficient	R²	R²Δ	R² Adjusted	F- change	P- value

Quad Strength	1	Age		.104	.771		.758	62.727	<.001
		BMI		−.143
		Quad Area		.896^*
	2		Quad Density	.212^*	.794	.023	.779	6.118	.017

Stair Climb (Inverse)	1	Age		−.444^*	.627		.607	31.426	<.001
		BMI		−.541^*
		Strength		.410^*
	2		Quad Density	.006	.627	.000	.600	.002	.961

Gait Speed	1	BMI		−.276^*	.142		.127	9.438	.003
	2		Quad Density	.306^*	.226	.084	.198	6.051	.017

Single Leg Stance	1	Age		−.213	.172		.157	12.027	.001
	2		Quad Density	.416^*	.304	.132	.279	10.801	.002

Chair Rise Time (Inverse)	1	Age		−.298	.195		.166	6.660	.003
	2	BMI	Quad Density	−.383^*
			Quad Density	−.004	.195	.000	.150	.001	.979

HAQ	1	Age		−.200	.230		.188	5.471	.002
		BMI		.240
		Strength		−.211
	2		Quad Density	−.345^*	.286	.056	.233	4.237	.044

Physical Activity (Sqrt)	1	BMI		−.296	.167		.133	4.818	.012
		Strength		−.547^*
		Quad Area		.395
	2		Quad Density	.530^*	.415	.248	.377	19.881	<.001

^*

significant at alpha level 0.05

^†

Higher values of muscle density corresponds to lower amount of skeletal muscle fat

BMI: Body Mass Index, Quad: Quadriceps muscle, HAQ: Health Assessment Questionnaire, Sqrt: Square root transformed