Arterial stiffness associates with changes in subpopulations of microparticles during postprandial conditions in males with and without the metabolic syndrome

Objectives: The partly modifiable risk factors, that constitute the metabolic syndrome (MetS), do not fully account for the associated functional and structural vascular abnormalities and increased cardiovascular disease risk. Cell-derived microparticles, which reflect ongoing cellular stress but also associate with cardiovascular disease, are elevated in subjects with MetS in the fasting state. We studied the relation between arterial stiffness and circulating microparticles under postprandial conditions in males with and without MetS. Methods: In 15 males with MetS and 15 controls, blood was collected before and following 3 consecutive meals during 24h. Arterial stiffness was measured as distensibility coefficient by carotid ultrasound. Microparticles were measured by flowcytometry. Results: MetS versus control males (both mean age 56 years) had higher body mass index, waist, blood pressure, fasting triglycerides and lower HDL-cholesterol. Twenty-four hour area under the curve (24h-AUC) triglycerides and insulin were elevated in MetS males compared to controls (both P<0.01), whereas 24h-AUC glucose was similar. The 24h-AUC of erythrocyte-derived, activated granulocyte and platelet-derived microparticles differed significantly (both P<0.05), whereas 24h-AUC of total and platelet-derived microparticles did not differ. Distensibility coefficient was negatively associated with 24h-AUC of triglycerides, insulin, and erythrocyte-derived-Conclusions: Postprandial changes in subpopulations of microparticles in healthy males and males with MetS were associated with arterial stiffness. Our findings suggest protective and deleterious effects of microparticles on arterial stiffness that may be associated with the cellular origin of these microparticles.