Diabetes, glucose control and mean platelet volume: a single-centre cohort study

Diabetes is a major determinant of cardiovascular risk, mainly due to higher prothrombotic status and enhanced platelet reactivity. Mean platelet volume (MPV) has been suggested as indicator of platelet reactivity and moreover, diabetics have been shown to have larger MPV. The aim of our study was to evaluate the impact of diabetes and glycemic control on MPV in a large cohort of patients. METHODS: Our population is represented by 3414 patients undergoing coronary angiography at Azienda Ospedaliera-Universitaria, "Maggiore della Carità", Novara, Italy. We obtained a fasting blood sample for glycemic assessment and for MPV evaluation. History of diabetes and pharmacological treatment, together with main cardiovascular risk factors were recorded. New diagnosis of diabetes was defined as nonfasting glucose >200mg/dL, fasting glucose ≥126mg/dL, or HbA1c >48mmol/L. RESULTS: Diabetes was observed in 1272 patients (37.2%). Diabetes was related to older age, waist circumference, arterial hypertension, smoking, hypercholesterolemia, renal failure, previous MI and PCI, therapy with ACE-inhibitors, ARBs, beta-blockers, diuretics, statins (respectively p<0.001) and ASA (p=0.004). Diabetics had lower haemoglobin (p<0.001), higher fibrinogen (p=0.001) and worst lipid profile (p<0.001). MPV was related with diabetes mellitus (p<0.001) and glycemic control (p=0.05; at linear regression r=0.07; p<0.001 for fasting glycaemia; r=0.09; p<0.001 for HbA1c, respectively). However, this relationship was not confirmed at multivariate analysis (OR[95%CI]=1.2[0.97-1.5], p=0.09 for diabetes, OR[95%CI]=1.05[0.96-1.15], p=0.25 for HbA1c). Independent predictors of MPV above median value (10.8fL) resulted to be age (OR[95%CI]=1.02[1.01-1.03], p=0.002), treatment with ARBs (OR[95%CI]=1.4[1.1-1.8], p=0.007) and haemoglobin levels (OR[95%CI]=1.2[1.15-1.23], p<0.001), while inverse relationship was found with total cholesterol (OR[95%CI]=0.99[0.99-1], p=0.002). CONCLUSION: Larger MPV is associated with ageing, treatment with ARBs, cholesterol and haemoglobin levels. Diabetes mellitus and glycemic control are not independently associated with larger platelet size.