2.4 SODIUM CONSUMPTION, CENTRAL AND PERIPHERAL BLOOD PRESSURE, AND FOOD HABITS IN A POPULATION OF HEALTHY ADOLESCENTS. THE MACISTE STUDY

Abstract

Objective: The relationship between sodium consumption, central BP and the main dietary sources of daily sodium intake in adolescence has been poorly explored. We have evaluated sodium intake, central and peripheral BP in a population of Italian adolescents. Methods: 401 healthy adolescents aged 17±1 years (58% boys, average brachial/central BP: 124/67±11/7 mmHg, and 105/69±9/8 mmHg), attending a High School, Terni, Italy, were evaluated. Daily sodium intake was estimated from a single fasting urine by a validated formula. Sources of daily sodium intake were investigated by a self-administered food frequency questionnaire. Central BP was estimated by radial and brachial applanation tonometries, and calibrated to brachial MAP/DBP (SphygmoCor). Results: 24-h estimated urinary sodium (24-hUNa) was 13530 mmol/d (3.116 g/d). The 89% of the population showed excess sodium intake. 24-hUNa was directly correlated to brachial and central SBP (r=0.14 and r=0.15, both p<0.01), to brachial and central PP (r=0.19 and r=0.24, both p<0.01), and to central-to-peripheral PP amplification (r=−0.13, p<0.01), but not to central-to-peripheral SBP amplification (r=−0.01, p=0.85). In a fully-adjusted multivariate regression model, 24-hUNa (b=0.10, p=0.04) was independently related to central-to-peripheral PP amplification, but not to other measures of both peripheral and central BP. In a factorial analysis, the main daily dietary sources of sodium were bread, biscuits, and salt added to foods. Conclusions: Sodium intake has a direct relationship with both central and peripheral SBP and PP, and shows an independent association with central-to-peripheral PP amplification. The adverse effects of an excess of sodium intake are more pronounced in central than in peripheral PP.