Platelet reactivity in diabetic patients subjected to acute exercise stress test.
BACKGROUND
Previous studies have reported ambiguous results regarding the effect of acute exercise on platelet reactivity in healthy and cardiac patients.


OBJECTIVE
We aimed to assess platelet reactivity among diabetic patients before and immediately after an acute exercise stress test.


METHODS
Patients (controls: mean age 53.1 ± 12.1 years; four males; body mass index 27.0 ± 5.7 kg/m(2); HbA(1c) 6.0 ± 1.1%, n = 8) and diabetic patients (52.9 ± 11.3; six males; body mass index 30.7 ± 2.2 kg/m(2); HbA(1c) 7.8 ± 1.7%, n = 8) referred for diagnostic nuclear exercise stress test were recruited. Blood samples obtained at rest and immediately post-exercise were stimulated with adenosine diphosphate (ADP), collagen and arachidonic acid. Expression of CD41 (pan-platelet marker) and CD62p (platelet stimulation marker) were measured by flow cytometry. Aspirin responsiveness was measured using VerifyNow.


RESULTS
Although peak systolic blood pressure was significantly higher in the diabetics compared with nondiabetics (186.3 ± 25.4 vs. 157.1 ± 19.1, respectively, P = .028), peak exercise heart rate was similar (156.5 ± 8.3 vs. 155.5 ± 12.1 for diabetics and nondiabetics, respectively). No differences were observed between groups for aspirin resistance. Platelet stimulation with ADP exhibited significantly lower CD62p-positive cell population (%) in the diabetic patients both prior to and following the exercise stress test (P = .03). In addition, although not significant, platelet stimulation was higher post-exercise in the diabetic patients (6.3 ± 4.7% vs. 12.0 ± 5.6%, for pre- and post-exercise, respectively, P = .2) with no difference in controls (9.2 ± 5.5% vs. 8.9 ± 5.9%).


CONCLUSIONS
Platelet stimulation in diabetic patients is blunted and might be explained by the prolonged exposure of platelets to multiple diabetic risk factors.
Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
Mickey
M
Scheinowitz
Rajbabu
R
Pakala
Itsik
I
Ben-Dor
Gilles
G
Lemesle
Rebecca
R
Torguson
Augusto D
AD
Pichard
Joseph
J
Lindsay
Ron
R
Waksman
D000244:Adenosine Diphosphate; D000328:Adult; D000368:Aged; D016718:Arachidonic Acid; D001241:Aspirin / Q000494:pharmacology; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D016022:Case-Control Studies; D003094:Collagen; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D004219:District of Columbia; D004351:Drug Resistance; D005080:Exercise Test; D005260:Female; D005434:Flow Cytometry; D006339:Heart Rate; D006801:Humans; D039421:Integrin alpha2 / Q000097:blood; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D010979:Platelet Function Tests; D013997:Time Factors
D015415:Biomarkers; C056564:ITGA2B protein, human; D039421:Integrin alpha2; D019007:P-Selectin; D010975:Platelet Aggregation Inhibitors; C546937:SELP protein, human; D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D003094:Collagen; D001241:Aspirin