The VO(2)-on kinetics in constant load exercise sub-anaerobic threshold reflects endothelial function and dysfunction in muscle microcirculation.

To propose a test to evaluate endothelial function, based on VO(2) on-transition kinetics in sub-anaerobic threshold (AT) constant load exercise, we tested healthy subjects and patients with ischemic-hypertensive cardiopathy by two cardiopulmonary tests on a cycle ergometer endowed with an electric motor to overcome initial inertia: a pre-test and, after at least 24 h, one 6 min constant load exercise at 90 % AT. We measured net phase 3 VO(2)-on kinetics and, by phase 2 time constant (tau), valued endothelial dysfunction. We found shorter tau in repeated tests, shorter time between first and second test, by persisting endothelium-dependent arteriolar vasodilatation and/or several other mechanisms. Reducing load to 80 % and 90 % AT did not produce significant changes in tau of healthy volunteers, while in heart patients an AT load of 70 %, compared to 80 % AT, shortened tau (delta=4.38+/-1.65 s, p=0.013). In heart patients, no correlation was found between NYHA class, ejection fraction (EF), and the two variables derived from incremental cycle cardio-pulmonary exercise, as well as between EF and tau; while NYHA class groups were well correlated with tau duration (r=0.92, p=0.0001). Doxazosin and tadalafil also significantly reduced tau. In conclusion, the O(2) consumption kinetics during the on-transition of constant load exercise below the anaerobic threshold are highly sensitive to endothelial function in muscular microcirculation, and constitute a marker for the evaluation of endothelial dysfunction.

Prospective evaluation of the effect of statins on blood pressure control in hypertensive patients in clinical practice.

BACKGROUND AND AIM: Some clinical evidence supports a statin antihypertensive effect. Our aim is to evaluate the statin effect on blood pressure control in hypertensive patients in the setting of clinical practice, and the role of some predetermined individual patient characteristics (age, gender, baseline BP levels, pre-treatment LDL-C levels) on the supposed statin BP lowering effect. METHODS AND RESULTS: Two hundred and fifty-four hypertensive patients with hypercholesterolemia were enrolled in the Ambulatory service of the Hypertension Research Unit of Bologna University Hospital. After 2-4 weeks of a run-in period patients were allocated to statin treatment and followed-up for 24 weeks. The blood pressure response to statins was compared in several subgroups of patients according to age, gender, baseline BP and pre-treatment cholesterolemia. In the overall study population, the use of statins was associated with a significant reduction in systolic (-7.6+/-4 mmHg, p<0.05) and diastolic blood pressures (-5.2+/-3 mmHg, p<0.05) in comparison to baseline. The blood pressure decrease was more pronounced in patients younger than 65 years (p<0.05), with higher baseline systolic blood pressure (p<0.005), and in those with higher cholesterolemia before statins (p<0.05). CONCLUSIONS: Our study suggests a BP-lowering effect of statins, consistent with some other literature. Some parameters like age, baseline systolic blood pressure and cholesterolemia influence the antihypertensive effect of statins. The lack of consideration for these confounding factors may be one of the reasons for the conflicting results about the BP lowering effects of statins.

[Metabolic syndrome and hypertension: prevention and treatment]. / Sindrome metabolica e ipertensione: prevenzione e trattamento.

Since the 1950s the definition of the aggregate of metabolic disorders possibly presenting with adult obesity has evolved without reaching a unifying agreement on what metabolic syndrome is. After years of consensus on and research into identifying the extent to which certain criteria of metabolic syndrome may be predisposing factors for cardiovascular events, a reverse shift can be noticed in recent studies raising numerous points of contention about various elements that may be diagnostic for the syndrome. Of these, one of the most tenuous is probably arterial hypertension. Uncertainties have emerged regarding the arbitrariness of cut-off values, which differ according to the classification system the study applied, the methods of measurement, and the dilemma of hyperinsulinemia/insulin resistance which is present in only 50-60% of individuals with hypertension. Currently available data fail to solve these conundrums; however, some studies have correlated hypertension and dislipidemia with an increased risk of cardiovascular events. International epidemiologic data indicate that the prevalence of the syndrome varies between populations and between the sexes within the same populations, suggesting that diagnostic criteria need to take better account of ethnic group origin. Prevention of metabolic syndrome is still based on lifestyle changes; the huge risk of an imminent pandemic has called the attention of the American Heart Association to the importance of prevention and early treatment of the pediatric population--a new segment at risk of early cardiovascular events. Pharmacological therapy is directed at controlling various risk factors, particularly hypertension and metabolic disturbances. ACE inhibitors, sartans and statins are currently the drugs of first choice in treating metabolic syndrome.