Cerebral Pulsatility and Habitual Exercise

Abstract

Increased pulsatility of the cerebral arteries has been correlated with an increased risk of developing cerebral pathology. Previous research has suggested that a 16-week endurance training intervention does not alter middle cerebral artery (MCA) pulsatility in young athletes; however, the effects of long-term habitual exercise on cerebral pulsatility have not been evaluated. PURPOSE: To compare MCA pulsatility in sedentary adults and habitual exercisers. METHODS: We evaluated 49 subjects, including 28 habitual exercisers (EX; age= 38 ± 16 y, women= 11, VO2max= 44 ± 7 ml/kg/min, BMI= 24.2 ± 3.0 kg/m2) and 21 sedentary controls (SED; age= 46 ± 20 y, women= 12, VO2max= 27 ± 6 ml/kg/min, BMI= 24.9 ± 2.0 kg/m2). Mean arterial pressure (MAP) and middle cerebral artery velocity (MCAv) were continuously recorded during rest. Pulsatility index (PI) was calculated by subtracting diastolic MCAv from systolic MCAv and dividing the result by the mean MCAv. RESULTS: Habitual exercisers had a lower MCAv compared to sedentary controls (EX= 57.2 ± 3.5 cm/s vs. SED= 68.3 ± 4.0 cm/s; p< 0.05), and MAP was similar between the two groups (EX= 88 ± 2 mmHg vs. SED= 89 ± 2 mmHg; p= 0.69). Habitual exercisers tended to have a lower PI (EX= 0.75 ± 0.03 vs. SED= 0.83 ± 0.04; p= 0.09), and VO2max was inversely associated with PI (r= -0.341, p< 0.05) when evaluating all subjects. CONCLUSIONS: Habitual exercisers tended to have a lower PI, although the results did not reach statistical significance. The inverse association between VO2max and cerebral PI suggests that individuals with a higher fitness may have a lower risk of developing cerebrovascular-related pathology. Supported by NIH grant HL118154