Effects of different dietary protein intakes on body composition and vascular reactivity.

OBJECTIVE: To assess the effects of a diet rich in protein of animal origin in comparison to one with a protein intake of about 15% of the total daily calories on body composition and arterial function. DESIGN: Randomized prospective study with parallel groups. Body weight (BW), blood pressure (BP), main parameters of carbohydrate and lipid metabolism, body mass composition by bioelectrical impedance analysis, forearm blood flow at rest and in the postischaemic phase by strain gauge plethysmography and flow-mediated dilation of the brachial artery by echography were measured at baseline and after 6 months of the dietary intervention. SUBJECTS: In total, 15 clinically healthy male volunteers, regularly performing a mixed training three times weekly for 90 min. INTERVENTION: The participants were randomly prescribed a diet with high (1.9 g/kg BW) or normal (1.3 g/kg BW) protein content. STATISTICAL ANALYSIS: Differences between means were evaluated by the t-tests for paired or unpaired data and by one way analysis of variance. The strength of correlation between variables was investigated by bivariate Pearson correlation. RESULTS: Serum cholesterol significantly decreased with both diets in comparison to baseline values, whereas BW was slightly but significantly reduced only by the high-protein (HP) diet. No change was detected in BP and the other metabolic parameters. Body mass composition was not significantly modified by either diet. On the other hand, postischaemic flow-mediated dilation of the brachial artery was enhanced by the sole normal protein (NP) diet, whereas no change in the forearm blood flow, both at rest and in the postischaemic phase, was detected. CONCLUSIONS: These preliminary results indicate that HP diet was found to be not useful in increasing the muscle mass in comparison to a NP intake. In contrast to this, the latter diet seems to enhance the endothelial function of the arterial vessels with a more pronounced dilatation of the lumen in response to the increase in blood flow.

Clinic and ambulatory pulse pressure segregate a cluster of cardiovascular risk factors.

Office pulse pressure (PP) has been found to be independently associated with cardiovascular morbidity and mortality. While there is evidence that 24 h blood pressure (BP) is a better marker of the cardiovascular complications of hypertension than office BP, this information is still lacking in regard to PP. The aim of the present study was, therefore, to evaluate possible differences between office and 24 h PP in their relationship with cardiovascular risk profile. This cross-sectional study was performed in a group of 175 (104 M, 71 F) hypertensives (43 never treated before the study) free of clinical evidence of target organ disease. BP was measured at rest and during 24 h monitoring; cardiac structure and function was studied by ultrasounds; biochemical analyses were performed to evaluate some parameters of lipid and carbohydrate metabolism. Patients were divided into tertiles of office PP and of 24 h PP. Those in the highest tertile of PP had a significantly higher office and 24 h systolic BP along with a reduction in peripheral insulin sensitivity. Regarding cardiac structure and function, a significantly higher prevalence of concentric left ventricular hypertrophy (23 vs 55%; P=0.05) and an initial impairment of diastolic function with increase of the A wave was detected in hypertensives with higher PP. No difference between office and 24 h PP in detecting patients at higher cardiovascular risk was observed. In conclusion, office and 24 h pulse pressures were both able to segregate patients with a cluster of cardiovascular risk factors.