An abnormal increase or decrease in blood pressure (BP) in response to postural stress is associated with increased risk of developing hypertension and stroke. However, the haemodynamic responses contributing to changes in central BP with postural stress are not well characterised. We aimed to determine this in controls compared to patients with type 2 diabetes mellitus (T2DM), whom we hypothesised would have an abnormal postural response. 41 participants (20 control, 21 T2DM) underwent measurement of brachial and central BP (by radial tonometry), with simultaneous bioimpedance cardiography (to determine stroke volume (SV) and cardiac output (CO)) and heart rate variability 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. Central pulse pressure (PP) was higher in patients with T2DM and did not change from seated-to-standing positions, whereas there was a significant decrease upon standing in controls (P < 0.05). The change in central systolic BP (SBP) correlated with change in SVR and E_A in controls (r = 0.67 and 0.68, P < 0.05, respectively), but not in patients with T2DM (r = -0.05 and r = 0.03, P > 0.05, respectively). SV was the only significant correlate of change in central SBP in T2DM patients (r = 0.62, P < 0.05) and this was not observed in controls (r = -0.08 P > 0.05). We conclude that central haemodynamic 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.

Item Type:	Refereed Article
Keywords:	haemodynamics, type 2 diabetes, pulse wave analysis, posture
Research Division:	Medical and Health Sciences
Research Group:	Cardiorespiratory Medicine and Haematology
Research Field:	Cardiology (incl. Cardiovascular Diseases)
Objective Division:	Health
Objective Group:	Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:	Cardiovascular System and Diseases
Author:	Schultz, MG (Dr Martin Schultz)
Author:	Climie, RED (Miss Rachel Climie)
Author:	Nikolic, SB (Mrs Sonja Nikolic)
Author:	Ahuja, KD (Dr Kiran Ahuja)
Author:	Sharman, JE (Professor James Sharman)
ID Code:	82483
Year Published:	2013 (online first 2012)
Deposited By:	Menzies Institute for Medical Research
Deposited On:	2013-02-05
Last Modified:	2017-11-02
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