Elevation in cerebral blood flow velocity with aerobic fitness throughout healthy human ageing

Abstract

It is known that cerebral blood flow declines with age in sedentary adults, although previous studies have involved small sample sizes, making the exact estimate of decline imprecise and the effects of possible moderator variables unknown. Animal studies indicate that aerobic exercise can elevate cerebral blood flow; however, this possibility has not been examined in humans. We examined how regular aerobic exercise affects the age-related decline in blood flow velocity in the middle cerebral artery (MCAv) in healthy humans. Maximal oxygen consumption, body mass index (BMI), blood pressure and MCAv were measured in healthy sedentary (n = 153) and endurance-trained (n = 154) men aged between 18 and 79 years. The relationships between age, training status, BMI and MCAv were examined using analysis of covariance methods. Mean ± s.e.m. estimates of regression coefficients and 95% confidence intervals (95% CI) were calculated. The age-related decline in MCAv was −0.76 ± 0.04 cm s −1 year −1 (95% CI = −0.69 to −0.83, r 2 = 0.66, P < 0.0005) and was independent of training status (P = 0.65). Nevertheless, MCAv was consistently elevated by 9.1 ± 3.3 cm s −1 (CI = 2.7-15.6, P = 0.006) in endurance-trained men throughout the age range. This ∼17% difference between trained and sedentary men amounted to an approximate 10 year reduction in MCAv 'age' and was robust to between-group differences in BMI and blood pressure. Regular aerobic-endurance exercise is associated with higher MCAv in men aged 18-79 years. The persistence of this finding in older endurance-trained men may therefore help explain why there is a lower risk of cerebrovascular disease in this population.

Aging blunts hyperventilation-induced hypocapnia and reduction in cerebral blood flow velocity during maximal exercise

“…Importantly, the current data are consistent with others that have reported agerelated differences in MCA V mean (Buijs et al 1998;Ainslie et al 2008), and the progressive decline in CBF from the age of 30 to 70 years has been confirmed repeatedly using a variety of imaging techniques (Kashimada et al 1994(Kashimada et al , 1995Buijs et al 1998;Scheel et al 2000;Beason-Held et al 2007;Stoquart-ElSankari et al 2007). …”

“…CBF during mild-to-moderate intensity exercise: influence of age Despite no disturbances to total cerebral oxygen consumption with healthy aging, there is a progressive decline in CBF (approximately 28-50%) from 30 to 70 years of age (Yam et al 2005;Ainslie et al 2008;Fisher et al 2008;Ogoh and Ainslie 2009) that is associated with global cerebral atrophy Buijs et al 1998). In contrast to healthy YA, as mentioned, only two studies (Fisher et al 2008;Heckmann et al 2003) have examined CBF in middle-aged OA during mild-to-moderate exercise.…”

“…In this context, if CBF was further blunted or abolished during exercise in OA, this may conceivably lead to a vicious cycle of reduced cerebral perfusion, cerebral atrophy and metabolic demand. Thus, despite the progression of cerebral atrophy with healthy aging (Buijs et al 1998;Ainslie et al 2008), the capability of CBF to meet the metabolic demands imposed during moderate-to-high intensity exercise is maintained with aging. How these responses may be hindered with pathologies such as cognitive impairment or mild Alzheimer disease would be a noteworthy future question.…”

“…With healthy aging, there is a progressive decline in CBF (approx: 28-50%) from 30 to 70 years of age (Yam et al 2005;Ainslie et al 2008;Fisher et al 2008;Ogoh and Ainslie 2009). Such declines are caused by global cerebral atrophy without any disturbance in cerebral oxygen consumption Buijs et al 1998).…”

Cerebral Vasomotor Reactivity during Hypo- and Hypercapnia in Sedentary Elderly and Masters Athletes

“…5,20 Consistent with previous findings, the current study demonstrated the reductions in systolic, diastolic, and mean CBFV in the sedentary elderly, although the lack of MCA diameter data does not provide us the actual volumetric flow measurement. 6,21 However, it should be highlighted that given the age range of 45 years between our young and old sedentary subjects and a reduction of mean CBFV byB25% in this study, the rate of reduction in CBFV would be B0.6% per year (assuming a constant rate of decline). These results are consistent with previous findings of age-related decline in brain perfusion measured with positron emission tomography or phase-contrast MRA.…”