Determinants of post-ischaemic reactive hyperaemia in patients with diabetes mellitus type II

Dysfunction of resistance arteries is thought to be an early reversible stage in the development of atherosclerosis. Dynamics of post-ischaemic reactive hyperaemia are believed to constitute a useful tool for monitoring resistance vessel function. Patient characteristics influencing reactive hyperaemia, however, need to be defined more precisely. Since reactive hyperaemia is a dynamic process, yielding submaximal peak values after 5 min of ischaemia, this period was chosen to investigate the determinants of reactive hyperaemia in 100 type II diabetic patients as well as in 61 control subjects. Reactive hyperaemia was measured by venous-occlusion plethysmography; clinical and laboratory data were acquired by routine methods. Statistical comparison was performed with SYSTAT 5.0 for Apple Macintosh. Overall, no significant differences between diabetic patients and controls were observed by group comparison. In control subjects, only gender showed an influence on peak reactive hyperaemia (females 40.5 +/- 15.3; males 51.8 +/- 17.7 ml min-1 100 ml-1, P < 0.01). In diabetic patients, in addition to gender, actual blood glucose (r = 0.377, P < 0.05) and meal intake (non-fasting 42.8 +/- 19.2; fasting 51.2 +/- 19.5 ml min-1 100 ml-1, P < 0.05) were found to influence reactive hyperaemia. Further investigation revealed a loss of the correlation between peak reactive hyperaemia and actual blood glucose observed in the fasting state (P < 0.001) in non-fasting diabetic patients, indicating an influence of meal intake on resistance vessel reactivity. Our results suggest that, in diabetic subjects, in addition to gender actual blood glucose and the postprandial situation impacts on peak reactive hyperaemia.