Objectives. Vascular mechanisms underlying brain atrophy and white matter lesions (WML) in patients with type 2 diabetes (T2DM) are unknown. Increased exercising blood pressure (BP) is associated with end-organ damage and could explain these brain abnormalities. This study examined associations between exercise central haemodynamics and brain structure.

Methods: Forty healthy participants (53±9 years; 50% male) and 40 T2DM (62±9 years; 50% male) were examined at rest and during light exercise. Resting and exercise central haemodynamics, including systolic BP (SBP), pulse pressure (PP) augmented pressure (AP), augmentation index (AIx), aortic stiffness and aortic reservoir function (including excess pressure integral [xsP]) were recorded by tonometry. Segmented grey (GM) and white matter (WM) and WML volumes were derived from magnetic resonance imaging.

Results: T2DM participants had lower WM (p=0.004) and GM (p=0.07) volumes, and significant elevation of all central hemodynamic variables during exercise (p<0.01 all). At rest, greater central (not brachial) haemodynamics (SBP, AP, AIx and PP) were independently associated with greater WML volume (β=0.54, p=0.031, β=0.55, p=0.01; β=0.46, p=0.046 and; β=0.48, p=0.01, respectively) in controls (not T2DM). During exercise, increased xsP was independently associated with reduced WM (β =−0.54, p=0.006) and GM (β=−0.63, p=0.013) volumes only in T2DM independent of age, sex, heart rate, and 24-hour ambulatory SBP.

Conclusions: In T2DM, aortic reservoir function and transmission of excess pressure during exercise is associated with brain atrophy. These findings suggest that vascular mechanisms underlying structural brain changes may differ between healthy individuals and those with T2DM.