Background. An abnormal brachial BP response to postural stress is associated with increased risk of developing hypertension and stroke. However, the hemodynamic responses contributing to changes in central BP with postural stress are not well characterised, and we aimed to determine these in healthy controls (HC) and patients with type 2 diabetes (T2DM); in whom we hypothesised would have an abnormal postural response.

Methods. 20 HC (53±8yrs,45% male) and 21 T2DM (61±9yrs,48% male) patients underwent measurement of central BP (by radial tonometry), with simultaneous bioimpedance cardiography to determine stroke volume (SV) and cardiac output (CO), in seated and standing postures. Systemic vascular resistance (SVR; mean arterial pressure/CO), and arterial elastance (E_A; end systolic pressure/SV) were calculated. Postural changes were defined as seated minus standing values.

Results. Central pulse pressure (PP) was higher in patients with T2DM and did not significantly change from the seated-to-standing positions (P=0.461), whereas there was a significant decrease upon standing in HC (P=0.022). The change in central SBP correlated with the change in SVR and E_A in HC (r=0.67, P=0.002 and 0.68, P=0.001 respectively), but not in patients with T2DM (r=−0.05, P=0.790 and r=0.03, P=0.910 respectively). SV was the only significant correlate of change in central systolic BP in patients with T2DM (r=0.62, P=0.004), and this was not observed in HC (r=−0.08 P=0.760).

Conclusions. Central hemodynamic responses to postural stress are altered in patients with T2DM and result in persistent elevation of central PP while standing. This may contribute to increased cardiovascular risk associated with T2DM.