Table 3. Multiple linear regression models of low-intensity daily walking activity and hippocampal volume stratified by sex.

	Model 2
	Women		Men
	Hippocampus (cm3)		Hippocampus (cm3)
Amount	β	SE	β	SE
Low-intensity steps/daya (per 1000 steps increase)	0.10**	0.04	-0.16	0.10
Moderate- to vigorous-intensity steps/dayb (per 1000 steps increase)	0.04	0.10	0.09	0.25
Age	-0.03	0.01	-0.01	0.04
CVD c	-0.22*	0.09	-0.50*	0.22
Exercise d	0.08**	0.07	0.12	0.06
Duration
Low-intensity min/daya (per 1000 steps increase)	0.02*	0.01	-0.04	0.03
Moderate-intensity min/dayb (per 1000 steps increase)	0.06	0.11	-0.12	0.20
Age	-0.03*	0.01	-0.01	0.04
CVD c	-0.21*	0.09	-0.50*	0.23
Exercise d	0.08**	0.03	0.13	0.07
Frequency
Low-intensity bouts/daya (per 1, 10-minute bout)	0.04*	0.02	-0.04	0.04
Moderate- to vigorous-intensity bouts/dayb (per 1, 10-minute bout)	0.06	0.21	-0.38	0.79
Age	-0.03*	0.01	-0.01	0.04
CVD c	-0.18*	0.09	-0.49	0.23
Exercise d	0.08**	0.03	0.12	0.06

SE = standard error; CVD = cardiovascular disease burden;

^*p<0.05

^**p<0.01

Note: all models included the following covariates; intercranial volume (ICV), age, years of education, body mass index (BMI), CVD, exercise, moderate- to vigorous-intensity walking activity, and the Mini Mental State Exam (MMSE)

^aLow-intensity defined as walking activity at < 100 steps/min

^bModerate- to vigorous-intensity is defined as walking activity at ≥ 100 steps/min

^cCVD calculated by summing participants self-report of vascular disease

^dExercise calculated as estimated caloric expenditure/week of self-reported exercise-related physical activities using the Community Health Activities Model Program for Seniors (CHAMPS) questionnaire