Platelet function and conjugated diene concentrations in diabetic and non-diabetic survivors of acute myocardial infarction.
OBJECTIVE
The aim was to compare platelet function in diabetic and non-diabetic survivors of acute myocardial infarction and to relate it to an index of free radical activity in these patients.


METHODS
In vivo and in vitro indices of platelet function and diene conjugate molar ratios were measured in diabetic and non-diabetic infarct survivors on admission to hospital and sequentially for 72 h.


METHODS
The patients were 17 diabetics (age 61.9 years, range 32-74) and 12 non-diabetics (60.8 years, range 39-75) admitted to hospital with acute myocardial infarction confirmed according to WHO criteria.


RESULTS
Agonist induced platelet aggregation, beta thromboglobulin levels, and linoleic acid 18:2(9,11)/18:2(9,12) molar ratios did not differ between diabetic and non-diabetic patients on admission. Concentrations of adrenaline producing 50% maximum platelet aggregation (EC50) in whole blood on admission were lower than non-infarct controls in both patient groups. The EC50 values in platelet rich plasma in both groups fell during the 72 h following admission (increases in platelet sensitivity). beta Thromboglobulin concentrations fell following admission in the diabetic group. Diene conjugate molar ratios were higher at 12 h and 24 h compared to admission in diabetic patients. Increases in diene conjugate ratios between admission and 24 h correlated with peak aspartate transaminase levels in both patient groups. No correlations were observed between platelet aggregation, beta thromboglobulin levels, or diene conjugate molar ratios.


CONCLUSIONS
During 72 h following myocardial infarction there is a reduction in platelet activation in vivo and an increase in platelet sensitivity to exogenous agonists in vitro. Free radical generated isomers of linoleic acid increase in relation to infarct size, but are unrelated to platelet function. There were no differences in platelet function between diabetic and non-diabetic subjects.
Hendra
T J
TJ
Whittington Hospital, London, United Kingdom.
Wickens
D G
DG
Dormandy
T L
TL
Yudkin
J S
JS
D000208:Acute Disease; D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000502:physiology*; D003920:Diabetes Mellitus / Q000097:blood*; D004837:Epinephrine; D005260:Female; D005609:Free Radicals; D006801:Humans; D008041:Linoleic Acids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology; D011379:Prognosis; D001620:beta-Thromboglobulin / Q000032:analysis
D005609:Free Radicals; D008041:Linoleic Acids; D001620:beta-Thromboglobulin; D004837:Epinephrine