Combined aerobic and resistance training improves microcirculation in metabolic syndrome.

BACKGROUND: Exercise intervention improves macrovascular function in metabolic syndrome (MeS) patients, but few studies have evaluated the effect of exercise on microcirculatory dysfunction, which plays a key role in the development of MeS and its correlated organ damage. We carried out this intervention study to evaluate the influence of an aerobic and resistance training on skin microvascular reactivity in MeS patients. METHODS: Postocclusive reactive hyperemia (PORH) of the forearm skin was evaluated, by laser-Doppler flowmetry, before and after a 12-week program of aerobic and resistance training in 15 MeS patients referring to our Lipid Metabolism Outpatients Clinic, together with anthropometric, fitness and metabolic parameters; 15 matched MeS patients who did not exercise, served as a control group. The exercise training consisted of 2 sessions/week of aerobic and resistant exercise. RESULTS: Following exercise program, we observed a significant reduction in body weight, fat mass, fasting blood glucose, serum HbA1c and triglycerides, while HDL-cholesterol significantly increased. The exercise-treated group experienced a significant improvement in the area of hyperemia (AH) after PORH, and in all fitness parameters: VO2max, strength on the pulldown lat machine, chest press, leg press and leg extension. A significant correlation emerged between the increase in AH and the reduction in HbA1c and between increase in AH and strength at the chest press, and at the leg extension. CONCLUSIONS: Our study showed that a short-term combined aerobic-resistance training positively affects microvascular reactivity in MeS patients. This improvement is correlated with the reduction of HbA1c and fitness parameters, and particularly with increased muscle strength at the upper and lower limbs.

Prognostic value of low and high ankle-brachial index in hospitalized medical patients.

BACKGROUND: Peripheral arterial disease (PAD) is frequently underdiagnosed in the clinical practice, leading to a lack of opportunity to detect subjects at a high risk for cardiovascular (CV) death. The ankle-brachial pressure index (ABI) represents a noninvasive, objective tool to diagnose PAD and to predict adverse outcome. METHODS: ABI was determined by means of Doppler velocimetry, in 707 patients, aged 50 years or older, consecutively hospitalized in an internal medicine ward, who were followed-up for at least 12 months in order to assess all-cause and CV mortality. RESULTS: Symptomatic PAD affected 8% of the population while the prevalence of PAD, defined as ABI <0.90, was 29%; high ABI (>1.40) was found in 8% of the patients. After a mean follow-up period of 1.6 years, both low and high ABI were independently associated with CV mortality with a hazard ratio of 1.99 (p=0.016) for low and 2.13 (p=0.04) for high ABI, compared with normal ABI (0.90-1.40). High ABI also independently predicted all-cause mortality with a hazard ratio of 1.77 (p=0.04). DISCUSSION: ABI measurement reveals a large number of individuals with asymptomatic PAD among those hospitalized in an internal medicine department. An increased mortality was observed in patients with both low and high ABI. Hospital admission for any reason may serve as an opportunity to detect PAD and start appropriate preventive actions.

Prognostic impact of prolonged ventricular repolarization in hypertension.

BACKGROUND: QT interval prolongation on the surface electrocardiogram (ECG) predicts cardiovascular complications in high-risk subjects, but its prognostic role in uncomplicated hypertension has been understudied. METHODS: For up to 13 years (average, 5.3 years), we followed up 2110 white patients with initially untreated essential hypertension (mean +/- SD age, 49 +/- 12 years; 55% men) without prevalent cardiovascular or renal disease who underwent 12-lead ECG before therapy. We excluded patients with ECG abnormalities including ischemia, necrosis, complete bundle branch block, atrial fibrillation, arrhythmias, and ventricular preexcitation. RESULTS: Heart rate-corrected QT interval (QTc) showed a weak but significant direct association with systolic blood pressure (r = 0.07; P<.001), diastolic blood pressure (r = 0.11; P<.001), and Cornell voltage (r = 0.06; P = .006). During follow-up, 84 patients developed new-onset ischemic heart disease (0.75 event per 100 patient-years). After adjustment (Cox model) for the effects of age, sex, diabetes mellitus, serum cholesterol level, serum creatinine level, smoking, left ventricular hypertrophy, and 24-hour systolic blood pressure, patients with a prolonged QTc (>or=450 milliseconds in women and >or=440 milliseconds in men) had a nearly 2-fold increase in risks of coronary events (hazard ratio, 1.95; 95% confidence interval, 1.12-3.42; P = .02) and cardiovascular death (hazard ratio, 2.05; 95% confidence interval, 1.03-4.37; P = .04). Coronary heart disease risk was independently higher by 33% (95% confidence interval, +7% to +66%; P = .01) for each 32-millisecond increase in QTc. CONCLUSIONS: Prolonged ventricular repolarization is a risk factor for ischemic heart disease and cardiovascular mortality in subjects with uncomplicated hypertension. Its prognostic significance adds to that of several traditional cardiovascular risk factors, including left ventricular hypertrophy.

Capillary rarefaction and abnormal cardiovascular reactivity in hypertension.

OBJECTIVE: To determine the effects of capillary rarefaction on cardiovascular reactivity and microcirculatory functioning in essential hypertension. DESIGN: Hypertension is associated with abnormal cardiovascular reactivity and increased vasoconstriction. Capillary rarefaction amplifies these abnormalities, which modify microcirculatory hemodynamics. Hence this study of the hemorheological pattern and the veno-arteriolar reflex in hypertensive patients and normotensive control subjects. METHODS: Sixty-one men with never-treated essential hypertension and capillary rarefaction (< 80 capillaries per field) and 20 age-matched and sex-matched controls underwent a strenuous cycle ergometer test to monitor, during exercise and recovery, the blood pressure profile and the hemorheological pattern: blood viscosity at low shear, hematocrit and leukocyte counts, soluble P-selectin levels, and red and white blood cell filterability rates. The veno-arteriolar reflex was determined by laser-Doppler flowmetry before exercise and at recovery.RESULTS Hypertensive men with < or = 72 capillaries per field had an abnormal hemorheological profile before exercise. The physiological response to exercise was observed only in the controls and in hypertensives with > or = 73 capillaries per field. Abnormal responses to exercise worsened as capillaries were more rarefied. At recovery, hemorheological parameters in hypertensives with 65-72 capillaries per field returned to baseline, remaining significantly (P < 0.05) different to control values. Variations in the hemorheological pattern in hypertensives with < 64 capillary per field persisted at recovery. The veno-arteriolar reflex followed the same pattern. CONCLUSION: A reduced microvascular network may contribute to abnormal cardiovascular reactivity and to exercise-induced rheological abnormalities in hypertension.