Chronic Effect of KCl on Black - White Differences in Plasma Renin Activity, Differences in Plasma Renin Activity

Langford, Herbert G.; Cushman, W; Hsu, Henry

doi:10.1093/ajh/4.5.399

Cited by 32 publications

(22 citation statements)

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“…Black patients have been consistently found to have significantly lower urinary potassium excretion [14,30,31,32,33,34,35]. One potential reason for this observation is the consumption by blacks of a diet that contains less potassium leading to a chronic potassium-depleted state [15,30,36], but the lower urinary excretion of potassium in blacks seemed to persist in studies that corrected for dietary differences by administering potassium supplements [14,16,36] or when black and white participants were administered identical diets under controlled circumstances [15]. Further contradicting the notion that potassium depletion is solely responsible for the low urinary potassium excretion of blacks was a study showing that total body potassium is in fact higher in blacks on a free-living diet [37].…”

Section: Discussionmentioning

confidence: 99%

“…Racial differences in potassium intake and excretion have been implicated as a potential mechanism, whereby blacks experience more severe hypertension, cardiovascular and renal disease in the general population [11,12,13,14,15,16,17]. While black patients are overrepresented in ESRD relative to their proportions in the general population [18,19], mortality in blacks with ESRD and NDD-CKD is paradoxically lower compared to whites [20,21].…”

Section: Introductionmentioning

confidence: 99%

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Association of Hypo- and Hyperkalemia with Disease Progression and Mortality in Males with Chronic Kidney Disease: The Role of Race

Hayes

Kalantar-Zadeh²,

Lü³

et al. 2011

Nephron Clin Pract

135

111

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Background/Aims: Abnormal serum potassium is associated with higher mortality in dialysis patients, but its impact on outcomes in predialysis chronic kidney disease (CKD) is less clear. Furthermore, blacks with normal kidney function have lower urinary potassium excretion, but it is unclear if such differences have a bearing on race-associated outcomes in CKD. Methods: We studied predialysis mortality and slopes of estimated glomerular filtration rate, eGFR) associated with serum potassium in 1,227 males with CKD. Mortality was examined in time-dependent Cox models, and slopes of eGFR in linear mixed effects models with adjustments for case mix and laboratory values. Results: Both hypo- and hyperkalemia were associated with mortality overall and in 933 white patients, but in 294 blacks hypokalemia was a stronger death predictor. Hypokalemia was associated with loss of kidney function independent of race: a 1 mEq/l lower potassium was associated with an adjusted difference in slopes of eGFR of -0.13 ml/min/1.73 m²/year (95% CI: -0.20 to -0.07), p < 0.001. Conclusion: Hypo- and hyperkalemia are associated with higher mortality in CKD patients. Blacks appear to better tolerate higher potassium than whites. Hypokalemia is associated with faster CKD progression independent of race. Hyperkalemia management may warrant race-specific consideration, and hypokalemia correction may slow CKD progression. This is a work of the US Government and is not subject to copyright protection in the USA. Foreign copyrights may apply. Published by S. Karger AG, Basel

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Association of Hypo- and Hyperkalemia with Disease Progression and Mortality in Males with Chronic Kidney Disease: The Role of Race

Hayes

Kalantar-Zadeh²,

Lü³

et al. 2011

Nephron Clin Pract

135

111

View full text Add to dashboard Cite

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“…We note, however, that it is well established that without and with potassium supplementation, urinary excretion of potassium is lower in blacks than in whites. [11][12][13][14][15] This racial difference has been attributed to low potassium intake in blacks, albeit no data have been provided to substantiate this idea. This topic is addressed in detail in a recent communication.…”

Section: Kimura Et Al Potassium and Platelet Reactivity 971mentioning

confidence: 99%

Potassium Chloride Supplementation Diminishes Platelet Reactivity in Humans

Kimura¹,

Xiao-bin²,

Skurnick³

et al. 2004

Hypertension

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Abstract-The prevalence of occlusive stroke is inversely correlated with potassium intake. We explored the hypothesis that a high potassium intake attenuates platelet reactivity, as expressed in ADP-evoked platelet aggregation. We studied healthy men (nϭ31) and women (nϭ42), blacks (nϭ33) and whites (nϭ40). In this cohort, we supplemented the habitual intake of 17 men and 21 women with 60 mmol KCl/70 kg body weight per day for 3 days and maintained 14 men and 21 women on their habitual intake. We then compared the change in ADP concentration causing 50% of the maximal initial rate (EC 50 ) of platelet aggregation in the potassium-supplemented versus control groups. Potassium supplementation attenuated platelet reactivity, expressed by an increase in EC 50 of platelet aggregation (Pϭ0.0005), which was primarily attributable to an increase in EC 50 in whites (Pϭ0.0004). Urinary potassium excretion was significantly lower in blacks than in whites under basal conditions and after potassium supplementation. We conclude that potassium supplementation diminishes platelet reactivity, a phenomenon that provides a link between platelet biology and occlusive stroke. Key Words: stroke Ⅲ cardiovascular disease Ⅲ atherosclerosis T he potential cardiovascular benefits of dietary potassium in the general population have been considered primarily from the perspectives that potassium may serve as a sodium substitute in the diet and that a high potassium intake enhances natriuresis. 1 Accordingly, the beneficial effect of a high dietary potassium intake on the cardiovascular system would presumably be mediated by the concomitant reduction in dietary sodium intake, coupled with enhanced sodium excretion, as well as other mechanisms that may ultimately lower blood pressure. 2 The question that follows is whether or not the cardiovascular effect of a high potassium intake may also be mediated through blood pressure-independent mechanisms, given that large-scale studies strongly suggest that dietary potassium intake is inversely correlated with occlusive stroke, a relationship that is independent of the effect of potassium intake on blood pressure. [3][4][5][6][7] Further, in the Systolic Hypertension in the Elderly Program (SHEP) within the treatment group, the risk for cardiovascular events, including stroke and myocardial infarction, was significantly higher in subjects with hypokalemia (serum potassium Ͻ3.5 mmol/L) associated with diuretic use. 8 Collectively, these findings suggest a link between systemic potassium homeostasis and atherosclerosis and thrombosis. 9,10 We note, however, that potassium is primarily an intracellular ion, so that dietary intake and diuretic use are likely to have an effect on intracellular potassium pool even without detectable changes in serum potassium.Because thromboembolic processes largely depend on platelet biology, we hypothesized that a high potassium intake would diminish platelet reactivity. This concept was explored in the present work. Materials and Methods SubjectsWe studied healthy men (...

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“…49,50 One interpretation of these results is that potassium supplementation has a greater natriuretic effect in blacks than in whites. Alternatively, a lower potassium intake may lead to a greater sodium retention in blacks.…”

Section: Dietary Sodium and Potassium Intakementioning

confidence: 99%

Why is plasma renin activity lower in populations of African origin?

Sagnella

2000

J Hum Hypertens

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Plasma renin activity is significantly lower in black people compared with whites independent of age and blood pressure status. The lower PRA appears to be due to a reduction in the rate of secretion of renin but the exact mechanistic events underlying such differences in renin release between blacks and whites are still not fully understood. Nevertheless, given the paramount importance of the renin-angiotensin system in the control of sodium balance, a most likely explanation is that the lower renin is a consequence of differences in renal sodium handling between blacks and whites. The lower PRA does not reflect differences in dietary sodium intake but the evidence available suggests that the low PRA could be part of the corrective mechanisms designed to maintain sodium balance in the presence of an increased tendency for sodium retention in black people. While it is possible that several factors may contribute to the reduced PRA, more recent investigation at

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Chronic Effect of KCl on Black - White Differences in Plasma Renin Activity, Differences in Plasma Renin Activity

Cited by 32 publications

References 0 publications

Association of Hypo- and Hyperkalemia with Disease Progression and Mortality in Males with Chronic Kidney Disease: The Role of Race

Association of Hypo- and Hyperkalemia with Disease Progression and Mortality in Males with Chronic Kidney Disease: The Role of Race

Potassium Chloride Supplementation Diminishes Platelet Reactivity in Humans

Why is plasma renin activity lower in populations of African origin?

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