THE EFFECT OF DIETARY-SODIUM IN INFANCY ON BLOOD-PRESSURE AND RELATED FACTORS - STUDIES OF INFANTS FED SALTED AND UNSALTED DIETS FOR 5 MONTHS AT 8 MONTHS AND 8 YEARS OF AGE

Abstract

The results of animal and epidemiological studies suggest commercially salted infant foods may predispose infants to hypertension. Two groups of black male infants were fed identical foods with and without added salt for 5 mo. starting at 3 mo. of age. These diets, which provided 1.93 .+-. 0.10 and 9.25 .+-. 0.05 meq Na/100 kcal did not result in a significant difference in blood pressure at 8 mo. or 8 yr of age. Blood pressure was significantly correlated with weight factors particularly at 8 yr, but not with Na intake, Na or Na/K excretion or plasma renin at 8 mo. Significantly increased Na and K excretion was noted on the salted diet and significantly increased aldosterone excretion was noted on the unsalted diet. A 6% expansion in extra-cellular fluid volume for the high Na group was statistically significant but was not correlated with blood pressure or urine volume and did not result in edema or increased weight. There was no indication that the salted foods imprinted a preference for salt at 8 yr. A salt intake representing the 99th percentile of Na intake by USA infants in 1969 had no hypertensive effect in infancy or at 8 yr of age and it did not imprint a preference for salt at 8 yr.