Abstract MP62: Beneficial Effects of Dietary Potassium on Adolescent Blood Pressure

Childhood blood pressure (BP) is an important predictor of adult blood pressure. Identification of modifiable risk factors for elevated blood pressure levels during adolescence has the potential to reduce the risk of adult hypertension. Longitudinal data on the effects of dietary sodium and potassium on adolescent BP are lacking. The objective of the study was to examine the effects of dietary potassium, sodium, and the potassium:sodium ratio (K:Na) throughout adolescence on blood pressure at the end of that period and to determine whether these effects are modified by other dietary factors. Data from 2330 girls, initially ages 9-10, and followed for 10 years in the National Growth and Health Study, were used to address these questions. Mean potassium and sodium intakes were 3.1 and 2.0 g, respectively, from an average of 6.6 sets of 3-day diet records. Analysis of covariance (ANCOVA) models were used to estimate mean systolic (SBP) and diastolic (DBP) blood pressures at 18-20 yrs of age, controlling for height, race, TV/video viewing time, physical activity, total energy intake, and BMI. Girls in the highest tertile of potassium intake (vs. lowest) had the lowest adjusted mean SBP (108.46 vs. 109.43 mm Hg; p-trend=0.030) and DBP (65.18 vs. 65.94 mm Hg; p-trend=0.073) at the end of follow up. Similar results were observed for the K:Na ratio (SBP 108.07 vs. 109.50 mm Hg; p-trend=0.021; DBP 65.02 vs. 65.85; p-trend=0.151). Finally, mineral intake as a part of a healthy eating pattern was examined. In this analysis, girls with a higher K:Na ratio (≥0.7) combined with high intakes of total fruit and vegetable (FV), fiber, or dairy had SBP levels that were approximately 2 mm Hg lower at the end of follow up than those with lower intake (p<0.05 for all diet patterns). Adolescents with a higher K:Na ratio with higher total FV or fiber intakes also had the lowest DBP levels at the end of follow up. Dietary sodium intake was generally unrelated to BP levels regardless of other diet patterns. Adolescent girls who consumed a high potassium and K:Na alone and particularly in the context of healthy eating patterns throughout adolescence had lower SBP and DBP levels at the end of adolescence. This study suggests that dietary potassium may play a more important role than sodium in determining adolescent BP levels. Thus, increasing dietary potassium intakes during childhood may reduce the risk of hypertension later in life.