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Potassium intake and cardiovascular reactivity in children with risk factors for essential hypertension
Insights
White children excrete more potassium than black children due to higher vegetable intake. Family history of hypertension, not race, is a stronger predictor of cardiovascular reactivity (CVR) in children.
Area of Science:
- Pediatric Nephrology
- Cardiovascular Health
- Nutritional Science
Background:
- Dietary potassium intake influences cardiovascular health.
- Cardiovascular reactivity (CVR) may differ between racial groups and those with a family history of hypertension.
- Understanding factors affecting CVR in children is crucial for early hypertension detection.
Purpose of the Study:
- To compare urinary potassium excretion between black and white children.
- To investigate the relationship between dietary potassium intake and CVR.
- To determine if CVR is higher in black children versus white children and in children with a family history of hypertension.
Main Methods:
- Studied 39 children (aged 7-15) measuring 24-hour urinary sodium, potassium, and creatinine.
- Assessed dietary intake via questionnaire and measured resting and stress blood pressure.
- Administered potassium citrate or placebo for 1 week each in a randomized order.
Main Results:
- White children showed higher potassium excretion and vegetable intake than black children.
- A higher urinary potassium/creatinine ratio correlated with lower diastolic CVR in white children.
- Potassium supplementation did not measurably attenuate CVR; family history of hypertension predicted higher CVR, not race.
Conclusions:
- Higher vegetable intake explains greater urinary potassium excretion in white children.
- Dietary potassium may modulate CVR, especially in white children with a family history of hypertension.
- Family history of hypertension is a stronger predictor of enhanced CVR than race in children.
Objectives:
Our study objectives were as follows: (1) to determine whether urinary excretion of potassium is lower in black than in white children, (2) to determine whether cardiovascular reactivity (CVR) varies inversely with dietary intake of potassium, and (3) to confirm that CVR is greater in black than in white children, and in children with a family history of hypertension than in those without such a history.
Study Design:
Baseline measurements included 24-hour urinary sodium, potassium, and creatinine levels and food intake (by questionnaire). Resting and stress blood pressure were measured during blood sampling, cold water foot immersion, and a video game before and after 1 week each of supplementation with potassium citrate, 1.5 mmol/kg per day, and placebo administered in random order.
Results:
Thirty-nine children aged 7 to 15 years were studied. White subjects had higher baseline excretion of potassium than black subjects (p < 0.001) and higher vegetable intake (p < 0.01), which were positively correlated (r = 0.53, p < 0.001). At baseline, the 24-hour urinary potassium/creatinine ratio varied inversely with diastolic CVR to the video game stressor in white children (r = -0.55, p = 0.02). Cardiovascular reactivity was not attenuated measurably by potassium supplementation compared with placebo. The CVR was greater in children with a family history of hypertension than in those without, but was not greater in black children than in white children.
Conclusions:
The urinary potassium/creatinine ratio is higher in white than black children because their intake of vegetables is greater; dietary potassium intake may modulate CVR, particularly in white children with a family history of hypertension, but may need to be supplemented for more than 1 week to demonstrate attenuation of CVR; and a family history of hypertension may be a stronger predictor of enhanced CVR than is race.