Background and Purpose--Exaggerated blood pressure (BP) responses to mental stress, an index of autonomic dysregulation, have been related to enhanced risk for stroke. This study examined cross-sectional relations of stress-induced BP reactivity to silent cerebrovascular disease assessed by magnetic resonance imaging (MRI) in healthy older adults.

Methods--Sixty-seven nondemented, community-dwelling older adults (ages 55 to 81; 75% male) free of major medical, neurological, or psychiatric disease, engaged in: (1) clinical assessment of resting systolic and diastolic BP; (2) assessment of systolic and diastolic BP responses to 3 laboratory-based mental stressors; and (3) MRI. MRIs were rated for small silent infarcts (3 mm), infarct-like lesions (<3 mm), and periventricular and deep white matter hyperintensities (WMH).

Results--After adjustment for age, gender, resting clinic BP, and fasting glucose levels, higher systolic BP reactivity was associated with an increased number of small silent infarcts (r²=0.14; P=0.004) and greater severity ratings of periventricular (r²=0.08; P<0.04) and deep WMH (r²=0.06; P<0.05). Higher diastolic BP reactivity was similarly associated with an increased number of small silent infarcts (r²=0.08; P<0.04), and greater severity ratings of periventricular (r²=0.08; P<0.04) and deep WMH (r²=0.11; P=0.009).

Conclusions--These results indicate that greater stress-induced BP reactivity is associated with enhanced silent cerebrovascular disease on MRI in healthy asymptomatic older adults independent of resting BP levels. Exaggerated stress-induced BP reactivity warrants further examination as a potential biobehavioral risk factor for cerebrovascular disease.