COX-1 sensitivity and thromboxane A2 production in type 1 and type 2 diabetic patients under chronic aspirin treatment.
OBJECTIVE
Although aspirin treatment is useful in reducing ischaemic events in diabetic patients, recent studies suggest that it is less effective when compared with non-diabetics (ND). We sought to evaluate COX-1 sensitivity and thromboxane A(2) (TxA(2)) production in type 1 (T1DM) and type 2 diabetic (T2DM) patients under chronic aspirin treatment, and also evaluate the association between thromboxane A(2) (TxA(2)) production and markers of inflammation and metabolic control, such as high-sensitivity C-reactive protein, fasting blood glucose, and haemoglobin A1c (HbA1c).


RESULTS
Agonist-induced platelet aggregation (PA) and TxB(2), a stable metabolite of TxA(2), production, serum TxB(2), and platelet COX-1 and COX-2 expression were studied in T2DM patients, T1DM patients, and high-risk ND subjects, all receiving a low dose of aspirin. TxB(2) formation was studied in platelets treated in vitro with aspirin alone or with a COX-2 inhibitor (NS-398). PA, collagen-induced TxB(2) production, and serum TxB(2) were higher in T1DM and T2DM patients than in ND subjects. TxB(2) production was reduced in diabetic patients by in vitro treatment with aspirin. COX-2 was expressed in all diabetic patients but only in 46% of ND patients. In diabetic patients significant correlations were observed between TxB(2) production and both fasting plasma glucose and HbA1c.


CONCLUSIONS
COX-1 sensitivity and TxB(2) production is similarly reduced in both T1DM and T2DM patients under chronic aspirin treatment. The association between TxB(2) production and either fasting plasma glucose and HbA1c levels suggests that in diabetic patients hyperglycaemia is a determinant of the reduced platelet sensitivity to aspirin.
Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy. fabio.pulcinelli@uniroma1.it
Fabio M
FM
Pulcinelli
Luigi M
LM
Biasucci
Silvia
S
Riondino
Simona
S
Giubilato
Andrea
A
Leo
Livia
L
Di Renzo
Elisabetta
E
Trifirò
Teresa
T
Mattiello
Dario
D
Pitocco
Giovanna
G
Liuzzo
Giovanni
G
Ghirlanda
Filippo
F
Crea
D000328:Adult; D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003925:Diabetic Angiopathies / Q000517:prevention & control*; D004351:Drug Resistance; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D018709:Statistics, Nonparametric; D013928:Thromboxane A2 / Q000096:biosynthesis*
D001241:Aspirin; D002097:C-Reactive Protein; D051545:Cyclooxygenase 1; D006442:Glycated Hemoglobin; D010975:Platelet Aggregation Inhibitors; D013928:Thromboxane A2