Reduced large elastic artery stiffness with regular aerobic exercise in middle-aged and older adults: potential role of suppressed nuclear factor κ B signalling.

Abstract

Aortic pulse-wave velocity (aPWV) increases with age and is a strong independent predictor of incident cardiovascular diseases (CVDs) in healthy middle-aged and older adults. aPWV is lower in middle-aged and older adults who perform regular aerobic exercise than in their sedentary peers. As exercise is associated with reduced systemic inflammation, we hypothesized that suppression of the pro-inflammatory transcription factor nuclear factor κ B (NFκB) may mediate this process. aPWV was measured in young sedentary [n = 10, blood pressure (BP) 108 ± 3/59 ± 2 mmHg; mean ± SEM], middle-aged and older sedentary (n = 9, 124 ± 7/73 ± 5 mmHg) and middle-aged and older aerobic exercise-trained (n = 12, 110 ± 4/67 ± 2 mmHg) healthy, nonhypertensive men and women. Baseline aPWV increased with age [626 ± 14 (young sedentary) vs. 859 ± 49 (middle-aged and older sedentary) cm/s, P < 0.001] but was 20% lower in middle-aged and older trained (686 ± 30 cm/s) than in middle-aged and older sedentary (P < 0.005). Short-term (4 days x 2500-4500 mg) treatment with the NFκB inhibitor salsalate (randomized, placebo-controlled cross-over design) reduced aPWV (to 783 ± 44 cm/s, P < 0.05) without changing BP (P = 0.40) or heart rate (P = 0.90) in middle-aged and older sedentary, but had no effect in young sedentary (623 ± 19) or middle-aged and older trained (699 ± 30). Following salsalate treatment, aPWV no longer was significantly different in middle-aged and older sedentary vs. middle-aged and older trained (P = 0.29). The reduction in aPWV with salsalate administration was inversely related to baseline (placebo) aPWV (r = -0.60, P < 0.001). These results support the hypothesis that suppressed NFκB signalling may partially mediate the lower aortic stiffness in middle-aged and older adults who regularly perform aerobic exercise. Because aPWV predicts incident cardiovascular events in this population, this suggests that tonic suppression of NFκB signalling in middle-aged and older exercising adults may potentially lower cardiovascular risk.