Abstract
Importance Identification of risk factors early in life for the development of high blood pressure is critical to the prevention of cardiovascular disease. Objective To study prospectively the effect of dietary sodium, potassium, and the potassium to sodium ratio on adolescent blood pressure. Design, Setting, and Participants The National Heart, Lung, and Blood Institute’s Growth and Health Study is a prospective cohort study with sites in Richmond, California; Cincinnati, Ohio; and Washington, DC. Participants included 2185 black and white girls initially aged 9 to 10 years with complete data for early-adolescent to midadolescent diet and blood pressure who were followed up for 10 years. The first examination visits were from March 1987 through February 1988 and follow-up continued until February 1999. Longitudinal mixed models and analysis of covariance models were used to assess the effect of dietary sodium, potassium, and the potassium to sodium ratio on systolic and diastolic blood pressures throughout adolescence and after 10 years of follow-up, adjusting for race, height, activity, television/video time, energy intake, and other dietary factors. Exposures Mean dietary sodium and potassium intakes and the mean potassium to sodium ratio in individuals aged 9 to 17 years. To eliminate potential confounding by energy intake, energy-adjusted sodium and potassium residuals were estimated. Main Outcomes and Measures Mean systolic and diastolic blood pressures throughout adolescence and at the end of follow-up (individuals aged 17-21 years). Results Sodium intakes were classified as less than 2500 mg/d (19.4% of participants), 2500 mg/d to less than 3000 mg/d (29.5%), 3000 mg/d to less than 4000 mg/d (41.4%), and 4000 mg/d or more (9.7%). Potassium intakes ranged from less than 1800 mg/d (36.0% of participants) to 1800 mg/d to less than 2100 mg/d (26.2%), 2100 mg/d to less than 2400 mg/d (18.8%), and 2400 mg/d or more (19.0%). There was no evidence that higher sodium intakes (3000 to <4000 mg/d and ≥4000 mg/d vs <2500 mg/d) had an adverse effect on adolescent blood pressure and longitudinal mixed models showed that those consuming 3500 mg/d or more had generally lower diastolic blood pressures compared with individuals consuming less than 2500 mg/d (P = .18). However, higher potassium intakes were inversely associated with blood pressure change throughout adolescence (P < .001 for systolic and diastolic) and at the end of follow-up (P = .02 and P = .05 for systolic and diastolic, respectively). While the potassium to sodium ratio was also inversely associated with systolic blood pressure (P = .04), these effects were generally weaker compared with effects for potassium alone. Conclusions and Relevance In this study of adolescent girls, consumption of 3500 mg/d of sodium or more had no adverse effect on blood pressure. The beneficial effects of dietary potassium on both systolic and diastolic blood pressures suggest that consuming more potassium-rich foods during childhood may help suppress the adolescent increase in blood pressure.
Generated Summary
This is a prospective cohort study that investigated the effects of dietary sodium, potassium, and the potassium to sodium ratio on blood pressure in adolescent girls. The study utilized data from the National Heart, Lung, and Blood Institute’s Growth and Health Study, which followed 2185 black and white girls aged 9 to 10 years over a 10-year period, from early-adolescence to midadolescence. Data on dietary intake and blood pressure were collected, and longitudinal mixed models and analysis of covariance models were used to assess the relationships between dietary sodium, potassium, the potassium to sodium ratio, and systolic and diastolic blood pressures, adjusting for various factors. The primary aim was to understand how these dietary components influence blood pressure during adolescence and the potential implications for cardiovascular health.
Key Findings & Statistics
- The study classified sodium intakes as:
- Less than 2500 mg/d (19.4% of participants)
- 2500 mg/d to less than 3000 mg/d (29.5%)
- 3000 mg/d to less than 4000 mg/d (41.4%)
- 4000 mg/d or more (9.7%)
- Potassium intakes were categorized as:
- Less than 1800 mg/d (36.0% of participants)
- 1800 mg/d to less than 2100 mg/d (26.2%)
- 2100 mg/d to less than 2400 mg/d (18.8%)
- 2400 mg/d or more (19.0%)
- Higher sodium intakes (3000 to <4000 mg/d and ≥4000 mg/d vs <2500 mg/d) did not have an adverse effect on blood pressure
- Higher potassium intakes were inversely associated with blood pressure change throughout adolescence (P < .001 for systolic and diastolic) and at the end of follow-up (P = .02 and P = .05 for systolic and diastolic, respectively).
- The potassium to sodium ratio was also inversely associated with systolic blood pressure (P = .04), but these effects were generally weaker compared with effects for potassium alone.
Other Important Findings
- Higher potassium intakes were inversely associated with blood pressure changes throughout adolescence and at the end of the follow-up period.
- The potassium to sodium ratio was inversely associated with systolic blood pressure, but this effect was less pronounced compared to the effect of potassium alone.
Limitations Noted in the Document
- The study’s limitations were not explicitly mentioned in the provided text, but the study focuses on adolescent girls, which limits the generalizability of the findings to other populations. Additionally, the reliance on dietary recall and self-reporting could introduce inaccuracies or biases in the collected data.
Conclusion
The study’s findings suggest that dietary potassium intake plays a beneficial role in managing blood pressure in adolescent girls, while the effect of sodium appears to be less significant within the observed intake ranges. The absence of an adverse effect of higher sodium intakes, up to 3500 mg/d, on blood pressure suggests that other factors, such as potassium intake, may be more critical in influencing adolescent blood pressure. The beneficial impact of potassium on both systolic and diastolic blood pressures implies that increasing the consumption of potassium-rich foods during childhood could help prevent the rise in blood pressure often seen in adolescence. This research underscores the importance of dietary potassium in promoting cardiovascular health during a critical period of development and highlights the need for further investigation into dietary strategies for blood pressure management in young populations. The study underscores that while the impact of sodium intake on blood pressure may not be adverse in this specific demographic, focusing on increasing the intake of potassium-rich foods could be an effective approach to mitigate rising blood pressure in adolescents.