Table 2.

PCA for sleep duration, VMCPM, sedentary time, light intensity PA, MVPA, and VPA (99.5% of variance explained for COPD and 99.6% of variance explained for controls, P<0.001)

Accelerometry variables	COPD				Controls
	Percent of variance	Component loading			Percent of variance	Component loading
		Component				Component
		1	2	3		1	2	3
VMCPM	54.8	0.897	0.428	0.010	18.2	0.679	0.714	0.135
Stationary		−0.849	−0.113	−0.513		−0.410	−0.839	−0.355
LPA		0.953	0.098	−0.282		0.108	0.982	−0.148
MVPA	27.2	0.242	0.961	−0.109	63.8	0.969	0.237	0.039
VPA		0.138	0.983	−0.076		0.979	0.184	0.039
Sleep	17.5	−0.039	−0.151	0.998	17.5	0.042	0.030	0.999

Notes: COPD: component 1, “low-intensity movement”; component 2, “high-intensity movement”; and component 3, “sleep.” Controls; component 1, “high-intensity movement”; component 2, “low-intensity movement”; and component 3, “sleep.” Bold values indicate the main contributing variables to each component.

Abbreviations: MVPA, moderate-to-vigorous PA; PA, physical activity; VMCPM, vector magnitude counts per minute (average movement intensity); VPA, vigorous PA; LPA, light PA.