Habitual exercise influences carotid artery strain and strain rate, but not cognitive function in healthy middle-aged females

Abstract

Purpose: Aging females are at risk of declining vascular and cognitive function. Exercise can augment both factors independently; however, the influence of exercise on their interdependence is less clearly understood. Ultrasound speckle tracking is a sensitive novel measure of arterial aging but has not previously been used in middle-aged females. We aimed to elucidate the potential interactions between vascular and cognitive variables in active aging females.

Methods: Twelve active (56 ± 5 years; [Formula: see text]: 34.5 ± 6.1 ml.kg.min^-1) and 13 inactive (57 ± 4 years; 22.8 ± 2.6 ml.kg.min^-1) healthy middle-aged females were included. Ultrasound speckle tracking assessed short-axis common carotid artery (CCA) compliance via peak circumferential strain (PCS) and strain rate (PSR) at rest, during, and after 3-min isometric handgrip exercise. Flow-mediated dilation (FMD) of the brachial artery was assessed using ultrasound. Cognitive function was measured using Verbal Fluency, Trail Making, Stroop, and Digit Span tests.

Results: PCS (P = 0.003) and PSR (P = 0.004), were higher in the active cohort. FMD was similar between groups (P > 0.05). Minimal differences in cognitive function existed between groups, although the inactive group performed better in one test of animal Verbal Fluency (P < 0.01). No associations were observed between PCS, PSR, or FMD with cognitive function (all P > 0.05).

Conclusion: This is the first study to assess PCS and PSR in middle-aged females and demonstrates that active middle-aged females exhibit a superior carotid artery profile compared to their inactive counterparts. However, PCS and PSR of the carotid artery may not be linked with cognitive function in middle-aged females.

Keywords: Aging; Carotid function; Cognitive function; Exercise; Flow-mediated dilation; Speckle tracking.

Fig. 1

Schematic of participant recruitment, group allocation and reasons for exclusion within the middle-aged cohort. HT hormone therapy, BP blood pressure

Fig. 2

Schematic of the order and timings of the vascular ultrasound protocol. CCA, common carotid artery; ICA, internal carotid artery; SAX, short axis; IHG, isometric handgrip

Fig. 3

Active and inactive group differences in peak circumferential strain (%; a), peak strain rate (1/s; b) at rest, during and immediately after the 3-min handgrip (IHG) exercise. Data are presented as individual data points, means ± standard deviations. †  A significant main group effect in favor of the active cohort at P < 0.01

Fig. 4

Correlation analysis between measured ${\dot{\mathrm{V}}\mathrm{O}}_{2\mathrm{peak}}$ values and PCS (a), PSR (b), β (c) and E_p (d) when measured during the 3-min IHG exercise. Significant correlation coefficients and their respective p values are displayed in bold