Ambulatory Blood Pressure Patterns in Children and Adolescents: Influence of Renin-Sodium Profiles

Abstract

A renin-sodium nomogram for normotensive children and adolescents was developed at our institution. The ambulatory blood pressure patterns of subjects classified by the nomogram were then compared. A biracial sample of 159 children and adolescents were classified as having a low, intermediate, or high renin-sodium profile based on the relationship between their plasma renin activity and 24-hour urinary sodium excretion. Casual (106/58 vs 107/61 vs 106/62 mm Hg) and awake (116/69 vs 117/69 vs 116/70 mm Hg) blood pressure values were comparable among subjects with low, intermediate, and high renin-sodium profiles. Subjects with high renin-sodium profiles, however, had a smaller decline in systolic blood pressure with sleep than did subjects with low renin-sodium profiles (7 vs 11 mm Hg; P < .04), and higher diastolic blood pressure readings during sleep than subjects with intermediate renin-sodium profiles (65 vs 62 mm Hg; P < .05). Subjects with high renin-sodium profiles also had greater variance of diastolic blood pressure readings during sleep than either subjects with low renin-sodium profiles (P < .01) or those with intermediate renin-sodium profiles (P < .02). The blunted nocturnal decline and increased nocturnal variance of blood pressure among subjects with high renin-sodium profiles may be a marker or mechanism for the future development of essential hypertension.