Relationship between mean platelet volume and morning blood pressure surge in newly diagnosed hypertensive patients.

OBJECTIVE: Morning blood pressure surge (MBPS) is an independent predictor of atherothrombotic cardiovascular events in hypertensive patients. There is evidence from studies supporting the validity of mean platelet volume (MPV) as a marker of vascular risk and predictor of thrombotic complications. The aim of this study is to investigate the relationship between MPV and MBPS in hypertensive patients. METHODS: Measurements were obtained from 298 patients with newly diagnosed essential hypertension (Mean age: 51.9 ± 11.7 years). The patients were divided into two groups (MPV(low) group; <10.8 fL, MPV(high) group; ≥ 10.8 fL). The MBPS was calculated as mean systolic BP during the 2 hours after awaking minus the mean systolic BP during the 1 hour that included the lowest sleep BP. RESULTS: MPV was independently associated with MBPS (ß=0.554, p<0.001) and hs-CRP level (ß=0.286, p<0.001). CONCLUSION: Finally, higher MPV values related to enhanced MBPS which are associated with atherothrombotic cardiovascular events.

Effects of rosiglitazone on altered electrical left ventricular papillary muscle activities of diabetic rat.

The action potential configuration of the left ventricular papillary muscle as well as the rosiglitazone-dependent changes in ventricular papillary muscle action potential amplitude were studied, and the duration was studied and compared in both healthy and diabetic rats. In this study, we used four groups: (1) nondiabetic control animals (C), (2) rosiglitazone-treated nondiabetic control animals (C+RSG), (3) diabetic animals (D), and (4) rosiglitazone-treated diabetic animals (D+RSG). Diabetes was induced by a single intravenous (i.v.) injection of streptozotocin (STZ). Conventional microelectrode techniques were applied to record action potentials after the establishment of diabetes (8 weeks after STZ treatment). Resting membrane potential (RMP) was decreased significantly in both RSG-treated C and D rats (from -70.2 +/- 0.7 to -63.2 +/- 0.7 and from -69.2 +/- 0.4 to -61.2 +/- 0.4). C+RSG and D+RSG groups showed increase in action potential amplitude compared with C and D groups (from 67.1 +/- 0.8 to 68.2 +/- 0.5 and from 67.1 +/- 0.8 to 80.1 +/- 0.8 and from 68.2 +/- 0.5 to 79.3 +/- 0.3) Depolarization time was significantly prolonged in diabetic rats (12.1 +/- 0.4 to 27.5 +/- 0.9). However, this prolongation in D+RSG group was significantly lower according to D group (from 27.5 +/- 0.9 to 19.2 +/- 0.7). There was no difference between C and C+RSG rats (12.1 +/- 0.4 to 11.6 +/- 0.2). Half repolarization time was also prolonged in diabetic rats (17.5 +/- 0.6 to 59.9 +/- 1.0). Moreover, D+RSG rats showed a slight and statistically insignificant difference according D rats (59.9 +/- 1.0 to 55.9 +/- 1.7). C+RSG rats showed a slight significant increase in half repolarization time compared with C group (17.5 +/- 0.6 to 29.4 +/- 0.7). Treatment of rats with RSG markedly decreased insulin resistance and also increased insulin sensitivity of the heart. Our data suggest that the beneficial effects of RSG treatment on the electrical activities of the diabetic rat papillary appear to be due to the diminished K+ currents, partially related to the decrease of hyperglycemia.