OBJECTIVE To examine the effect of handgrip exercise induced ischaemia on non-invasive assessment of endothelial function in the brachial artery.

DESIGN AND SETTING High frequency ultrasound was used to measure brachial artery diameter at rest and after reactive hyperaemia induced by forearm cuff occlusion with and without handgrip exercise induced ischaemia.

SUBJECTS 10 healthy subjects, < 40 years, without known cardiovascular risk factors.

MAIN OUTCOME MEASURES Brachial artery dilatation and blood flow.

RESULTS Hyperaemia following forearm occlusion with handgrip exercise induced ischaemia increased brachial artery diameter significantly more than hyperaemia following occlusion alone, 6.9 (3.2)% and 4.5 (1.6)%, respectively (95% confidence interval 0.3% to 4.5%). There was no difference in peak blood flow with and without exercise induced ischaemia

CONCLUSIONS Handgrip exercise induced ischaemia with forearm occlusion caused more pronounced brachial artery dilatation than occlusion alone without change in peak blood flow. This suggests continued brachial artery responsiveness to the stimulus of ischaemia despite maximum blood flow and peripheral vasodilatation with occlusion alone.