Table 2.

Summary of cross-sectional studies on physical activity and white matter hyperintensities published in English through March 18, 2014.

Citation	Sample	Physical activity	White matter hyperintensities (WMH)	Statistical analysis	Results
Ho et al. (2011)	Pittsburgh, PA, U.S., n = 226, 42% male, mean age 77.9 (SD = 3.6). Exclusion criteria: mild cognitive impairment or Alzheimer's disease.	Modified Minnesota Leisure-Time Activities Questionnaire covered two weeks prior to when MRI was obtained, estimated in kcal/week which was divided into quintiles.	Expert visual grading on a scale of 0 to 9, with no white matter findings classified as grade 0 and the most severe WMH classified as grades 8 and 9.	Kruskal–Wallis one-way ANOVA (WMH not normally distributed)	No association
Rosano et al. (2010)	Pittsburgh, PA, U.S., n = 27, 3% male, mean age 81 (SD = 3.4), 20 remained active and 10 remained sedentary 2 years after a pilot intervention; 18 of the active group had WMH measurements. Inclusion criteria: age of 70–89 years, sedentary lifestyle (< 20 min/week spent in structured physical activity during the past month), being able to walk 400 m within 15 min without sitting and without use of any assistive device, having a Short Physical Performance Battery score 9 (on a scale of 0–12), having completed behavioral tests related to logging health behavior, and not planning to move for at least 9 months.	The physically active group was asked if they completely stopped their regular physical activity after the pilot intervention ended, and were included if they responded “No.” The sedentary group was asked if they spent at least 20 min a week getting regular exercise after the pilot intervention ended and were included if they responded “No.”	WMH was measured with a fully deformable automatic algorithm.	t-Test	No association
Saczynski	Reykjavik, Iceland, population-based sample of older adults, n = 1787, 38.9% male, mean age = 75.9 (SD = 5.4).	Questionnaire, current moderate/vigorous physical activity was assessed as never (reference), rarely, 1 h/week, 1–3 h/week, 4–7 h/week, or > 7 h/week and dichotomized into the upper quartile (high leisure activity) compared with the bottom three quartiles (low leisure activity).	WMH measured with a rating scale. Individuals in the upper quartile of WMH load for either subcortical or periventricular WMH were compared with the reference group comprising those in the lower three quartiles (reference group).	Age-adjusted analysis of variance	Compared to the low WMH/high activity group, the high WMH/low activity (F = 53.9) and high WMH/high activity (F = 41.0) were more likely to be physically inactive (p < .0.05).
Sen et al. (2012)	Austria, community-based cohort, n = 715, 46% male, mean age 65, range 44–83. Exclusion criteria: dementia, previous strokes.	VO2 max on cycle ergometer.	Two experienced investigators marked and outlined each WMH, which was positively skewed and log-transformed.	Linear regression; adjusted for age, sex, hypertension, body mass index, cholesterol, smoking status, diabetes, treatment with β-blockers or calcium channel blockers.	Significant association in men (β = − 0.10, p = 0.02), not women.
Smith	Midwest U.S., community-based white adults, n = 777, 41% male, mean age 60 (SD = 10). Inclusion criteria: essential hypertension diagnosed before age 60 years.	Self-report average # of hours/day engaged in sedentary, moderate and heavy activity.	Global WMH was obtained with a fully automated algorithm. Brain scans with cortical infarctions were excluded due to distortions in the automated segmentation algorithm. The natural logarithm (cm3) of WMH was obtained after adjustment for age, sex, and total brain volume.	Least squares linear regression; tested for association between each of the predictor variables (1649 single nucleotide polymorphisms and quantitative covariates): hypertension, BMI, pulse pressure, smoking history, coronary heart disease, serum triglycerides, creatinine, total cholesterol, high-density lipoprotein, low-density lipoprotein, & five novel vascular risk factors including C-reactive protein, homocysteine, fibrinogen, Lp(a), and LDL particle size.	No association
Tseng et al. (2013)	U.S., n = 20, 75% male, mean age 73 ± 5 years, free of major medical problems based on a detailed medical history and physical exams including 12-lead electrocardiogram and echocardiogram. Exclusion criteria: smoking, used recreational drugs, had clinical evidence of cardiovascular (e.g., hypertension, diabetes mellitus, hyperlipidemia) or cerebrovascular diseases (e.g., history of stroke, transient ischemic attack or the presence of cortical infarction on MRI scans), dementia, major psychiatric and neurologic disorders.	10 master athletes: history of endurance training > 15 years, who were still engaged in endurance exercise at the time of this study. 10 sedentary older adults: not engaging in moderate or high intensity aerobic exercise for more than 30 min, 3 times/week over the past two years. Aerobic fitness was measured with maximal oxygen uptake (VO2 max) testing.	Total, periventricular, and deep WMH were obtained with a semiautomatic method.	Mann–Whitney Rank Sum Test was conducted to detect differences in WMH volume and cardiopulmonary fitness between groups.	No differences in total or periventricular WMH between groups. Masters athletes showed 83% reduction in deep WMH volume when compared with the sedentary elderly.
Zheng	Eastern Sydney, Australia, prospective community-dwelling cohort, n = 287, aged 70–90, 46.3% male, mean 77.8 ± 4.5 years. Exclusion criteria: Diagnosis of dementia and inability to walk 20 m without a walking aid due to a neurological, cardiovascular, or major musculoskeletal impairment.	Incidental and Planned Exercise Questionnaire (last week — 3 months preceding interview), hour/week.	A validated automatic procedure was carried out to calculate WMH volume. Regional WMH comprised deep (frontal, parietal, temporal and occipital) and periventricular regions (anterior cap, posterior cap and periventricular body).	t-Test examined differences in baseline physical activity between participants with high and low volumes of WMH (cut off at the median).	No association