This review examines epidemiologic, physiological, and molecular evidence that the interplay between sodium and potassium is central to the development of hypertension. The review concludes with recommendations for reducing sodium and increasing potassium in the diet.

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Sodium and Potassium in the Pathogenesis of Hypertension

OBJECTIVE--To determine whether the estimates of the size of the association between blood pressure and sodium intake derived from studies of individuals within populations can be quantitatively reconciled with our estimates derived from comparisons of the average blood pressure and sodium intake between different populations. DESIGN--Examination of data from 14 published studies that correlated blood pressure recordings in individuals against measurements of their 24 hour sodium intake (within population studies). MAIN OUTCOME MEASURE--Comparison of observed differences in blood pressure per 100 mmol/24 h difference in sodium intake in each within population study with predicted differences calculated from the between population data, after allowing for the underestimation of the true association of blood pressure with sodium intake caused by the large day to day variation in 24 hour sodium intake within individuals. RESULTS--The underestimation bias inherent in the within populations studies reduced the regression slope of blood pressure on single measures of 24 hour sodium intake to between a half and a quarter of the true value (for example, in one study from 6.0 to 2.4 mm Hg/100 mmol/24 h). Estimates from between population comparisons of the regression slope of blood pressure on sodium intake, after adjustment to take this underestimation bias into account, were similar to the values actually observed in the within population studies. CONCLUSION--The within population studies confirm our estimates from between population comparisons of the magnitude of the association between blood pressure and sodium intake.

https://www.bmj.com/content/bmj/302/6780/811.full.pdf

By how much does dietary salt reduction lower blood pressure? II--Analysis of observational data within populations.

—Normotensive salt sensitivity, a putative precursor of hypertension, might be quite frequent in African Americans (blacks) and less frequent in Caucasian Americans (whites), but only when ...

Normotensive Salt Sensitivity: Effects of Race and Dietary Potassium

The T235 allele of the angiotensinogen gene (AGT) has been associated with hypertension. Blood pressure increases faster over time in black children than in white children, and in adults hypertension is more prevalent in blacks. We sought evidence for a role for angiotensinogen to contribute to racial differences in blood pressure in a study of 148 white and 62 black normotensive children (mean age, 14.8 yr). The frequency of the T235 allele was 0.81 in blacks and 0.42 in whites (chi 2 = 77.3, P = 0.0001). The mean angiotensinogen level was 19% higher in blacks than in whites (P = 0.0001 for males, P = 0.004 for females). Genotype was positively related to serum angiotensinogen in white children (P = 0.0001 for males, P = 0.004 for females), but a similar relationship was absent in blacks where the frequency of M235 may have been too low to discern an association. Longitudinal blood pressure (measured twice yearly) adjusted for body mass index showed a marginally significant relationship to the angiotensinogen level (P = 0.07). An independent relationship of serum angiotensinogen with body mass index (P = 0.0001) and race (P = 0.0003) was also observed. In summary, T235 was more frequent, and the level of angiotensinogen was higher in blacks than in whites. Such a racial difference in the renin-angiotensin system may contribute to the disparity in blood pressure levels of white and black young people.

/pdf/the-serum-angiotensinogen-concentration-and-variants-of-the-ld93qaawv0.pdf

The serum angiotensinogen concentration and variants of the angiotensinogen gene in white and black children.

Epidemiologic studies suggest an inverse relation between potassium intake and the prevalence of hypertension. To investigate the effect of dietary potassium restriction on blood pressure,...

H.D. Battarbee

Papers

Racial differences in blood pressure in Evans County, Georgia: relationship to sodium and potassium intake and plasma renin activity.