Effects of Oral Calcium, Potassium, Digoxin, and Nifedipine on Natriuresis in Normal Humans

Luft, Friedrich C.; Aronoff, George R.; Fineberg, Naomi S.; Weinberger, Myron H.

doi:10.1093/ajh/2.1.14

Cited by 13 publications

(6 citation statements)

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“…11,26,27 In the current study, when dietary potassium was marginally deficient, the salt-induced increase in body weight predicted the salt-induced increase in SBP and DBP, and the increase in body weight correlated negatively with the urinary excretion of sodium and chloride. Salt loading induced not only a lesser increase in urinary excretion of sodium in blacks than in whites, as previously observed, 8,28 but also an increase in the urinary excretion of potassium only in blacks, despite their prior and ongoing marginally deficient dietary intake of potassium.…”

Section: Discussionmentioning

confidence: 54%

Normotensive Salt Sensitivity

et al. 1999

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Abstract-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 dietary potassium is deficient and not when maintained well within the normal range. We tested this hypothesis in 41 metabolically controlled studies of 38 healthy normotensive men (24 blacks, 14 whites) who ate a basal diet low in sodium (15 mmol/d) and marginally deficient in potassium (30 mmol/d) for 6 weeks. Throughout the last 4 weeks, NaCl was loaded (250 mmol/d); throughout the last 3, potassium was supplemented (as potassium bicarbonate) to either mid-or high-normal levels, 70 and 120 mmol/d. Salt sensitivity, defined as an increase in mean arterial blood pressure Ն3 mm Hg with salt loading, was deemed "moderate" if increasing Յ10 mm Hg and "severe" if increasing more. When dietary potassium was 30 mmol/d, salt loading induced a mean increase in blood pressure only in blacks (PϽ0.001), and salt sensitivity occurred in most blacks but not whites (79% vs 36% (PϽ0.02). Supplementing potassium only to 70 mmol/d attenuated moderate salt sensitivity similarly in blacks and whites; 120 mmol/d abolished it, attenuated severe salt sensitivity, which occurred in a quarter of affected blacks, and suppressed the frequency and severity of salt sensitivity in blacks to levels similar to those observed in whites. These observations demonstrate that in most normotensive black men but not white men, salt sensitivity occurs when dietary potassium is even marginally deficient but is dose-dependently suppressed when dietary potassium is increased within its normal range. Such suppression might prevent or delay the occurrence of hypertension, particularly in the many blacks, in whom dietary potassium is deficient. (Hypertension. 1999;33:18-23.)

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Section: Discussionmentioning

confidence: 54%

Normotensive Salt Sensitivity

et al. 1999

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“…Potassium supplements are well known to cause natriuresis and lower BP. [21][22][23] Calcium has also been shown to blunt the pressure effects of dietary sodium. 24 Other unidentified substances contained in the DASH diet may also have exerted the diuretic action.…”

Section: Discussionmentioning

confidence: 99%

Effects of the Dietary Approaches to Stop Hypertension (DASH) Diet on the Pressure-Natriuresis Relationship

et al. 2003

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Abstract-Blood pressure-lowering mechanisms of the Dietary Approaches to Stop Hypertension (DASH) diet, rich in fruits, vegetables, and low-fat dairy foods, were analyzed based on the pressure-natriuresis relationship. Participants (nϭ375) were randomly assigned to control or DASH diet groups by using a parallel-group design. They then ate their assigned diet for 3 consecutive 30-day intervention feeding periods, during which sodium intake varied among 3 levels by a randomly assigned sequence. Urinary sodium excretion rate and mean arterial pressure were measured at the end of each sodium intake level. Mean arterial pressure and urinary sodium excretion were plotted on x and y axes, respectively, for participants eating control and DASH diets and were modeled as linear relationships for simplicity to allow the estimation of the extrapolated x-intercept and slope of the relationships. he Dietary Approaches to Stop Hypertension (DASH) diet, rich in fruits, vegetables, and low-fat dairy foods, has been proved to have substantial blood pressure (BP)-lowering action 1,2 and is now recommended as one of the most important nonpharmacological measures to control BP. 3,4 However, the mechanisms of the action remain unsolved. We have theoretically shown that the mechanisms of BP-lowering action can be analyzed based on the pressurenatriuresis curve, 5-7 which may be drawn using data from the DASH-Sodium Trial. 2 Effects of different types of antihypertensive agents, including angiotensin-converting enzyme inhibitors, ␤-blockers, calcium antagonists, and diuretics, on the pressure-natriuresis curve are also known. 5,6,8 In this article, we studied the effect of the DASH diet on the pressure-natriuresis relationship to clarify the mechanisms of its BP-lowering action. MethodsThis was a study ancillary to the DASH-Sodium Trial, a multicenter, randomized feeding trial comparing the effects on BP of 3 levels of sodium intake and 2 dietary patterns, 2,9 and as such, was designed, conducted, and analyzed by the coauthors only. Study DesignThe 412 participants were 22 years of age or older and had systolic BP (SBP) of 120 to 159 mm Hg and diastolic BP (DBP) of 80 to 95 mm Hg without BP-lowering medication. After a 2-week run-in period, by using a parallel-group design, the participants were randomly assigned to one of the 2 dietary patterns: a control diet typical of what many Americans eat and the DASH diet, which emphasizes fruits, vegetables, and low-fat dairy foods, 1,10 with same number of calories as the control diet. Participants ate their assigned diet for 3 consecutive 30-day intervention feeding periods, during which sodium intake varied among the 3 levels by a randomly assigned sequence. The 3 levels of sodium intake (lower, intermediate, and higher) were 50, 100, and 150 mmol/d, respectively, for a 2100-kcal diet. Measurement ProtocolTrained staff measured BP at each of 3 screening visits on 2 days during the run-in period and on 5 of the last 9 days of each intervention feeding period. 2,9 Baseline BP was defined as ...

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“…The acute intravenous administration of the digitalis glycosides digoxin or ouabain caused either a small and transient increase in blood pressure [19,20] or had no effect on blood pressure [21,22]. Chronic administration of digoxin had no effect on casual blood pressure measurements in normal subjects [23,24] or caused a slight increase in systolic blood pressure without effects on dynamic exercise [25]. In patients with coronary artery disease, 2 weeks of digoxin treatment also had no effect on casual blood pressure but blunted the response to isometric handgrip exercise [26].…”

Section: Discussionmentioning

confidence: 99%