The role of potassium in the pathogenesis and treatment of hypertension

Food Sources of Potassium in the Average Polish Diet

The aim of this study was to identify the food sources of potassium in the average Polish diet based on the data from the 2016 Household Budget Survey conducted on the representative sample of the Polish population (36,886 households, n = 99,230). This survey is organized by the Central Statistical Office and is related to the expenditures, quantitative consumption and revenues in households. We analyzed 91 sub-groups (i.e., milk, red meat) from 13 food categories (i.e., milk and dairy products, meat and products). Our findings indicated that the daily supply of potassium in the average Polish diet was 2617.9 mg, which meant covering the average allowance in 83%. Vegetables provided 32.5% of potassium, of which potatoes accounted for 16.2% of supply, and other vegetables for 16.2%. Tomatoes as well as other vegetables and mushrooms provided a total of 8.2% of potassium among vegetables. The next position was taken by the meat and meat products category (17.7%), with the largest share of meat products (6.7%) and red meat (5.2%). Cereal products supplied 16.64% of potassium, of which bread, rolls and bread products (12.2%) were of the greatest importance. Milk and dairy products turned out to be the fourth product category as a source of potassium (11.9%), with the highest share of milk (6.8%) and yoghurts and milk drinks (3.9%).

Salty taste in dairy foods: can we reduce the salt?

Sodium can be found in many sources of the US diet. Dietary guidelines currently suggest a maximum intake of 2,300 mg of sodium (6g of sodium chloride) per day, whereas the average consumer intake is 3,600 mg of sodium (9 g of sodium chloride) per day. The main health concern with high consumption of sodium is hypertension. The objectives of this study were to identify the salty taste intensity of sodium chloride in water and various dairy food matrices, and to identify the just-noticeable difference in concentration at which consumers noticed a decrease in salty taste in these food products. Solutions and food products (water, cheese sauce, cottage cheese, and milk-based soup) were prepared with sodium chloride ranging in concentration from 0.008 to 0.06 M. Seventeen panelists evaluated the salty intensity of each product in triplicate using a magnitude estimation scale. In subsequent tests, panelists (n=50) evaluated salty intensity of these food products in separate sessions using an ascending force choice method to determine the just-noticeable difference. Consumer acceptance tests (n=75 consumers) were conducted with cottage cheeses with and without sodium reductions and under conditions with and without health benefits of sodium reduction. The magnitude estimation scale data were log-transformed, and all data were analyzed by ANOVA with Fisher's least significant difference for means separation. The linear proportion of the power function in the salty taste intensity curve for sodium chloride solutions and the 3 foods was between 0.03 and 0.20 M. Consumers were able to notice and correctly identify reductions in salt concentration of less than 20% in all products. When consumers were informed of sodium reduction and its health benefits before tasting cottage cheese with lower sodium (4-12%), overall liking scores for the lower sodium cottage cheeses were not different from higher sodium cottage cheeses. These results suggest that reducing sodium in cheese sauce, cottage cheese, and milk-based soups may be challenging and that exploration of sodium chloride alternatives in these foods is warranted. Appropriate product positioning or advertising may be beneficial to consumer acceptance of lower sodium types of products.

Effects of fully and partial substitution of NaCl by KCl on physico-chemical and sensory properties of white pickled cheese

White pickled cheeses were produced with different salting treatments, vacuum-packed in polyethylene containers, and stored at 4 +/- 1 degree C for 90 days. Five different concentrations of NaC1, KC1 or NaCl/KCl mixtures (sample A, 100% NaCl; sample B, 100% KCl; sample C, 75% NaCl + 25% KCl; sample D, 50% NaC1+50% KCl; sample E, 25% NaCl+75% KCl) were applied in the production of cheeses. Some physical, chemical and sensory properties of the samples were monitored at 0, 15, 30, 60 and 90 days of ripening. The results obtained indicated that the cheese could be produced with the mixture of 75% NaCl + 25% KCl without negative effects on cheese quality.

Influence of sodium replacement on physicochemical properties of dry-cured loin

The consumption of cured meat products is not recommended to hypertensive consumers due to its high sodium content. This constitutes an important restriction for this industry, which is becoming more and more important due to the current trends in consumption. The partial replacement of sodium chloride by potassium chloride has been proposed as a possible strategy to reduce the sodium content of this type of products. The aim of this study was to evaluate the effect brought about by partial replacement of sodium chloride with potassium chloride (up to 70%) on physicochemical and microbiological parameters of dry-cured pork loin after the curing and drying process. The results showed that it is possible to obtain low sodium dry-cured loin, up to a 50% replacement of sodium by potassium, with similar physicochemical characteristics to the commercial product with usual amounts of sodium.

Lactotripeptides and antihypertensive effects: a critical review

Hypertension or high blood pressure is a significant health problem worldwide. Typically, lifestyle changes, including adopting a healthy diet, are recommended for people with an elevated blood pressure. Lactotripeptides are bioactive milk peptides with potential antihypertensive properties in man. These peptides, as part of a food product or as nutraceutical, may contribute to the prevention and treatment of hypertension. This paper reviews the current evidence of the blood pressure control properties of lactotripeptides in man. Blood pressure-lowering effects of lactotripeptides are typically measured after 4-6 weeks of treatment. However, in some cases, a blood pressure response has been observed after 1-2 weeks. Maximum blood pressure reductions approximate 13 mmHg (systolic blood pressure) and 8 mmHg (diastolic blood pressure) after active treatment compared with placebo, and are likely reached after 8-12 weeks of treatment. Effective dosages of lactotripeptides range from 3.07 to 52.5 mg/d. Evidence indicates that lactotripeptides are only effective at elevated blood pressure; no further lowering of normal blood pressure has been observed. Concomitant intake of antihypertensive medication does not seem to influence the potency of lactotripeptides to lower blood pressure. Similarly, ethnicity has not been found to influence the extent of lactotripeptide-induced blood pressure lowering. Based on the currently available data, lactotripeptides appear to be safe and effective. Thus, they can be part of a healthy diet and lifestyle to prevent or reduce high blood pressure.

Effects of exercise, diet and weight loss on high blood pressure

High blood pressure (BP) is a major health problem in the US, affecting more than 50 million people. Although high BP is among the most common reasons for outpatient visits, BP control is often inadequate. It is well established that BP can be lowered pharmacologically in hypertensive individuals; however, anti-hypertensive medications are not effective for everyone, and may be costly and result in adverse effects that impair quality of life and reduce adherence. Moreover, abnormalities associated with high BP, such as insulin resistance and hyperlipidaemia, may persist or may even be exacerbated by some anti-hypertensive medications. Consequently, there has been a great deal of interest in the development and application of behavioural interventions in the management of high BP. The main behavioural interventions that are recommended to reduce BP are exercise and the Dietary Approaches to Stop Hypertension (DASH) diet. Weight loss is also recommended for BP reduction in overweight individuals. Exercise alone is associated with reductions of approximately 3.5 and 2.0mm Hg in systolic (SBP) and diastolic blood pressure (DBP), respectively. Patients fed a DASH diet (a diet high in low-fat dairy products and fibre, including fruits and vegetables) had reductions in SBP and DBP of 5.5 and 3.0mm Hg, respectively, compared with those consuming a standard US diet. Reductions of approximately 8.5mm Hg SBP and 6.5mm Hg DBP accompany weight loss of 8 kg. In overweight hypertensive patients, a combined exercise and weight-loss intervention has been shown to decrease SBP and DBP by 12.5 and 7.9 mm Hg, respectively. There is evidence to suggest that these decreases in BP are associated with improvements in left ventricular structure and function, and peripheral vascular health. Both exercise training and weight loss have been shown to decrease left ventricular mass and wall thickness, reduce arterial stiffness and improve endothelial function. These data support the role of behavioural interventions in the treatment of patients with elevations in BP.

Level of hydration and renal function in healthy humans

BACKGROUND

High hydration is commonly used in renal studies to improve the completeness of urine collection. The renal effects of hydration are not well defined.

METHODS

Renal function was studied under fasting conditions (baseline) and after a meat meal (2 g of protein/kg body weight) in 12 healthy adults on a low and high hydration regimen of 0.5 and 4 mL of oral water per kg body weight/30 min, respectively.

RESULTS

Urine flow, urinary and plasma Na, K, urea, and osmolality were stably different on low and high hydration regimens. At baseline, there were significant or borderline significant correlations of plasma and urine osmolality with glomerular filtration rate (GFR; inulin clearance) only in the low hydration regimen. GFR was higher in the low than the high hydration regimen at all time points. The difference was significant at baseline (19.2%) and at 90 to 180 minutes after the meal (14.4%). After the meal, GFR increased significantly over baseline values only in the high hydration regimen (30.0% at peak time). Urinary excretion of Na, urea, and osmoles was lower in the low than the high hydration regimen at all time points: The difference was significant for Na (at baseline) and osmoles (all time points). Urinary K excretion was not different in the two regimens. After the meal, there were significant increases in urinary excretion of Na (in the low hydration regimen) and urea (90 to 180 min after the meal).

CONCLUSIONS

In fasting adults, high hydration lowered GFR and increased natriuresis. After a meat meal, GFR increased only in the high hydration regimen and natriuresis only in the low hydration regimen. Hydration affects GFR and natriuresis under fasting conditions and after a meat meal.

The role of gender and family support on dietary compliance in an African American adolescent hypertension prevention study

Social support experiences vary markedly across gender groups, and little is known about the role of social support in promoting healthy dietary compliance in African American adolescents who are at increased risk for developing hypertension. This study examined the relation between gender, dietary social support, and compliance to a low sodium diet. Casual blood pressures were also examined in relation to dietary compliance and gender One hundred eighty-four healthy African American adolescents (83 boys, 101 girls) participated in an intensive 5-day low sodium diet (50 mEq/24 hr) as part of a hypertension prevention program. Emotional dietary social support from family members and friends was measured at baseline. Compliance was defined as urinary sodium excretion of < or = 50 mEq/24 hr at postsodium restriction. The results indicated a significant Gender x Compliance effect for positive family support (p < .05). Girls who were compliant reported higher levels of dietary support from family members (19.2 +/- 7.8) than boys who were compliant (16.9 +/- 7.0). In contrast, boys who were compliant reported lower levels of dietary support from family members (16.9 +/- 7.0) than boys who were not compliant (20.2 +/- 7.5). Systolic blood pressure showed a trend toward decreasing in compliant participants (104.4 +/- 8.4 vs. 101.7 +/- 8.0, mm Hg, p < .06), but the effect diminished when Quetelet Index (kg/m2) was controlled for in the analyses (p < .12). These results suggest that higher levels of emotional dietary support from family members are associated with better adherence to short-term sodium restriction for African American girls as compared to boys. Further research is needed to determine the long-term impact of social support on sodium restriction in adolescent populations.

Individualizing the dialysate in the hemodialysis patient

In most outpatient centers the dialysate is prepared centrally such that the composition of the dialysate is the same for all patients. When delivered in this manner most patients tolerate the procedure well. However, there are patients who tolerate the procedure poorly, which has prompted a great deal of research focused on individualizing the composition of the dialysate in order to improve patient tolerability. Prescribing a patient-specific dialysate will become increasingly important as the age of and number of comorbid conditions increase in the dialysis population. Patients with end-stage renal disease (ESRD) depend on dialysis to maintain fluid and electrolyte balance. Hemodialysis allows for solutes to diffuse between blood and dialysate such that, over the course of the procedure, plasma composition is restored toward normal values. The makeup of the dialysate is of paramount importance in accomplishing this goal. In most out-patient settings patients receive hemodialysis using dialysate prepared in bulk and delivered via a central delivery system so that the composition of the dialysate is the same for all patients. While most patients tolerate the procedure when administered in this fashion, many patients suffer from hemodynamic instability or symptoms of dialysis disequilibrium. One strategy to improve the clinical tolerance to dialysis is to adjust the dialysate composition according to the individual characteristics of the patient. This article reviews recent developments on how the dialysate can be manipulated in order to improve patient tolerance. Individualizing the dialysate composition is likely to gain increasing importance given the advancing age and increasing number of comorbid conditions found in ESRD patients.

Dietary potassium and magnesium supplementation in cyclosporine-induced hypertension and nephrotoxicity

BACKGROUND

Cyclosporine A (CsA)-induced hypertension and nephrotoxicity are aggravated by high sodium intake. Accumulating evidence suggests that potassium and magnesium supplementation could protect against the detrimental effects of dietary salt. In the present study, we tested the hypothesis of whether concurrent supplementation with potassium and magnesium could protect against the development of CsA-induced hypertension and nephrotoxicity more effectively than supplementation with one mineral alone.

METHODS

Eight-week-old spontaneously hypertensive rats (SHRs) were divided into four groups (N = 10 in each group): (1) CsA group (5 mg/kg subcutaneously) receiving high-sodium diet (Na 2.6%, K 0.8%, Mg 0.2% wt/wt); (2) CsA group receiving a high-sodium, high-potassium diet (Na 2.6%, K 2.4%, Mg 0.2%); (3) CsA group receiving high-sodium, high-magnesium diet (Na 2.6%, K 0.8%, Mg 0.6%); and (4) CsA group receiving high-sodium, high-potassium, high-magnesium diet (Na 2.6%, K 2.4%, Mg 0.6%).

RESULTS

CsA induced severe hypertension and deteriorated renal functions in SHRs on high-sodium diet. Histologically, the kidneys showed severe thickening of the media of the afferent artery with fibrinoid necrosis. Potassium supplementation lowered blood pressure (198 +/- 5 vs. 212 +/- 2 mm Hg, P < 0.05) and partially prevented the development of proteinuria (-25%, P < 0.05). Magnesium supplementation decreased blood pressure to the same extent but improved renal functions more effectively than potassium. The greatest protection against CsA toxicity was achieved when dietary potassium and magnesium supplementations were combined. Urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion, a marker for renal proximal tubular damage, increased progressively in CsA-treated SHRs on the high-sodium diet. Neither potassium nor magnesium influenced urinary NAG excretion. We also estimated the activity of the renal dopaminergic system by measuring 24-hour urinary dopamine excretion rates. CsA suppressed the renal dopaminergic system during high-sodium diet. Magnesium supplementation, alone and in combination with potassium, protected against the development of renal dopaminergic deficiency in CsA-treated SHRs on high-sodium diet. Magnesium supplementation increased plasma-free ionized magnesium (iMg) and bone magnesium by 50 and 16%, respectively.

CONCLUSIONS

Our findings indicate that both potassium and magnesium supplementations showed beneficial effects against CsA-induced hypertension and nephrotoxicity. The protective effect of magnesium clearly exceeded that of potassium. The greatest protection against CsA toxicity was achieved when potassium and magnesium were combined. We also provide evidence that the development of CsA-induced glomerular, tubular, and vascular lesions are associated with renal dopaminergic deficiency.

Natural bioactive substances in milk and colostrum: effects on the arterial blood pressure system

High blood pressure is a significant public health problem worldwide which is associated with increased risk of cardiovascular disease, stroke, and renal disease. The development of this disease is influenced by genetic and environmental factors. The results of many studies have linked increased consumption of milk and milk products with lower blood pressure and reduced risk of hypertension. The intake of several minerals found in milk has been demonstrated to have an inverse relationship with blood pressure. Peptides formed during the digestion of milk proteins have also been demonstrated to have a blood pressure lowering effect. Other components in milk that have been examined for their effects on blood pressure have been less promising. More recent data indicate that a dietary pattern that is low in fat, with fruits, vegetables, and low fat dairy products can significantly reduce blood pressure and lower risk of developing high blood pressure.

Beneficial effects of dietary magnesium and potassium on cardiac and renal morphologic features in cyclosporin A-induced damage in spontaneously hypertensive rats

BACKGROUND

Cyclosporin A-induced hypertension is dependent on the level of dietary salt. We investigated whether dietary magnesium or potassium could protect against cyclosporin A-induced cardiac and renal damage in spontaneously hypertensive rats (SHRs) on high-sodium diet.

METHODS

Eight-week-old SHRs were divided into 4 groups: (1) receiving a high-sodium diet, (2) receiving a high-sodium, high-potassium diet, (3) receiving a high-sodium, high-magnesium diet, and (4) receiving a high-sodium, high-potassium, high-magnesium diet. The effects of cyclosporin A in SHRs on a relatively low-sodium diet and in normotensive Wistar-Kyoto rats were also examined. Cardiac and renal morphologic condition was assessed, and tissue damage was scored by light microscopy after 6 weeks of cyclosporin A treatment.

RESULTS

In SHRs on a high-sodium diet, cyclosporin A caused luminal narrowing of the coronary arteries, left ventricular scarring, and damage in the renal arterioli and glomeruli. Dietary magnesium supplementation alone and in combination with potassium protected against these changes, whereas potassium alone was less effective. Cyclosporin A treatment caused only minor histopathologic changes in SHRs receiving a low-sodium diet. Interestingly, the detrimental interaction between cyclosporin A and a high-sodium diet was also observed in normotensive Wistar-Kyoto rats.

CONCLUSIONS

Dietary magnesium, especially in combination with potassium, protects against cyclosporin A-induced cardiac and renal damage.

Role of dietary potassium in the hyperaldosteronism and hypertension of the remnant kidney model

The remnant kidney model of progressive renal disease is marked by arterial hypertension, especially when produced by nephrectomy and partial infarction. Hyperaldosteronism sustains much of the hypertension, but the stimuli to the increased aldosterone levels are uncertain. It is hypothesized that the hyperaldosteronism attending this model stems from the combination of fixed dietary potassium load in the face of reduced filtration on the one hand, and persistent renin secretion from the scarred remnant kidney on the other. This hypothesis predicted that dietary potassium restriction would lower aldosterone and BP in this model. To test this prediction, two groups of rats with a remnant kidney were studied. Group 1 consumed 0.4 +/- 0.06 mEq (mean +/- SD) of potassium chloride daily, and group 2 ate 4.8 +/- 1.0 mEq daily. Two sham-operated groups with intact kidneys also were studied. Group 3 consumed 1.7 +/- 0.2 mEq daily and group 4 ate 15.2 +/- 1.4 mEq daily. These levels of intake were designed to provide at least as much potassium per liter of GFR in the sham groups as in the remnant kidney rats. Systolic BP (SBP), 24-h protein excretion, plasma aldosterone levels, 24-h urinary aldosterone excretion, and plasma renin activity (PRA) were determined in all groups at 2 wk. At 4 wk, after SBP and protein excretion measurements, remnant kidneys were perfusion-fixed for morphometric analysis. SBP was normal in both sham-operated groups and was not different between the groups (113 +/- 13 versus 117 +/- 2 mmHg, group 3 versus group 4). In the remnant animals, SBP at 2 wk followed potassium intake: Group 1 had a lower SBP than group 2 (140 +/- 26 versus 170 +/- 34 mmHg, P = 0.005). The same SBP pattern persisted at 4 wk (153 +/- 25 versus 197 +/- 27 mmHg, group 1 versus group 2, P = 0.0006). However, 24-h urinary protein excretion was not different between the two groups with remnant kidneys at either 2 or 4 wk. Both plasma and 24-h urinary aldosterone excretion at 2 wk followed potassium intake (120 +/- 124 versus 580 +/- 442 pg/ml for plasma aldosterone, group 1 versus group 2, P = 0.03, and 2.6 +/- 1.8 versus 23.2 +/-9.8 ng/d for urinary aldosterone, group 1 versus group 2, P = 0.0001). PRA, however, followed a reverse pattern in which dietary potassium restriction resulted in higher levels (16 +/- 6 versus 6 +/- 3 ng angiotensin I/ml per h, group 1 versus group 2, P = 0.01). A similar pattern for PRA and aldosterone excretion was also observed in the sham groups, in which lower potassium intake also resulted in a significantly higher PRA and lower aldosterone excretion. The constancy of BP in the sham groups likely reflects their lack of nephron reduction and greater sodium excretory capacity. Morphometric analysis in remnant animals revealed no significant difference between the two dietary groups in the prevalence of glomerular sclerosis, glomerular volume, or interstitial volume. It is concluded that dietary potassium is a potent determinant of hypertension in the remnant kidney model probably through the actions of aldosterone and that the high aldosterone secretion in this model is a function of the dietary potassium load. In this model, reduction in nephron number is also critical in promoting hypertension in conjunction with hyperaldosteronism.

Finding consensus in the dietary calcium-blood pressure debate

No single study or avenue of investigation can resolve the scientific controversies that entangle efforts to determine the effects of specific nutrients on medical conditions. To reach consensus in this area requires a substantial body of plausible, reproducible and consistent data from various investigative approaches--such as the data that now exist regarding the relationship between dietary calcium and blood pressure. In this paper we describe the plethora of epidemiological and clinical studies and analyses that have been published in the last two years and which cumulatively reveal the consistency of the available data regarding the influence of dietary calcium on blood pressure regulation. Nearly 20 years of investigation in this area has culminated in remarkable and compelling agreement in the data, confirming the need for and benefit of regular consumption of the recommended daily levels of dietary calcium.

Effects of potassium on blood pressure in salt-sensitive and salt-resistant black adolescents

This study examined the effects of increasing dietary potassium on ambulatory blood pressure nondipping status (<10% decrease in blood pressure from awake to asleep) and cardiovascular reactivity in salt-sensitive and salt-resistant black adolescents. A sample of 58 normotensive (blood pressure, 101/57+/-9/4 mm Hg) black adolescents (aged 13 to 16 years) participated in a 5-day low sodium diet (50 mmol/24 h) followed by a 10-day high sodium diet (150 mmol/24 h NaCl supplement) to determine salt-sensitivity status. Participants showed a significant increase in urinary sodium excretion (24+/-19 to 224+/-65 mmol/24 h) and were identified as salt-sensitive if their mean blood pressure increase was >/=5 mm Hg from the low to high sodium diet. Sixteen salt-sensitive and 42 salt-resistant subjects were then randomly assigned to either a 3-week high potassium diet (80 mmol/24 h) or usual diet control group. Urinary potassium excretion significantly increased in the treatment group (35+/-7 to 57+/-21 mmol/24 h). At baseline, a significantly greater percentage of salt-sensitive (44%) compared with salt-resistant (7%) subjects were nondippers on the basis of diastolic blood pressure classifications (P<0.04). After the dietary intervention, all of the salt-sensitive subjects in the high potassium group achieved dipper status as a result of a drop in nocturnal diastolic blood pressure (daytime, 69 versus 67 mm Hg; nighttime, 69 versus 57 mm Hg). No significant group differences in cardiovascular reactivity were observed. These results suggest that a positive relationship between dietary potassium intake and blood pressure modulation can still exist even when daytime blood pressure is unchanged by a high potassium diet.

Nonpharmacologic therapy in hypertension: from single components to overall dietary management

Improved lifestyle and dietary practices are now recognized as essential factors in the optimal management of high blood pressure. This chapter discusses the nonpharmacologic approaches that are generally recommended for hypertension treatment as well as prevention, including summaries of the evidence on which these recommendations are based. For many of these approaches, specifically dietary modifications, the evidence is strong but not yet definitive. Potential sources of the conflicting data and the lack of scientific consensus are addressed, as well as recent findings of the effects of the total diet and dietary patterns that may ultimately resolve much of the controversy regarding nonpharmacologic means of treating and preventing hypertension.

End-stage renal disease (ESRD) and vascular access grafting: a critical review

End-Stage Renal Disease (ESRD) is a major disease state, costing the U.S. $9.5 billion in 1992, and increasing 10% yearly. The growth in the number of ESRD patients can be attributed principally to demographic trends: the aging of the general population and the improved treatment and increased survival rate of patients with diabetes, hypertension, and other illnesses that lead to ESRD. Moreover, improved dialysis technology has enabled older patients and those who previously could not tolerate dialysis due to other illnesses to benefit from this treatment. Three modalities exist for the treatment of ESRD: hemodialysis, peritoneal dialysis, and kidney transplant. This article reviews the medical treatments and the synthetic polymers used in the manufacture of vascular access grafts. We report on the development of a new, polyurethane-based microporous vascular graft, which displays self-sealing and improved compliance characteristics for use in vascular access grafting.

Dietary factors in the pathogenesis and treatment of hypertension

Data accumulated from epidemiological observations, intervention trials and studies on experimental animals provide a growing body of evidence of the influence of various dietary components on blood pressure. Dietary sodium, usually taken in the form of sodium chloride (common salt), is positively associated with blood pressure, and in many hypertensive patients reduction in sodium intake lowers blood pressure. On the other hand, in certain patients potassium, calcium and magnesium may be protective electrolytes against hypertension. Dietary fats, especially n-3 polyunsaturated fatty acids, may also influence blood pressure, whereas the possible role of other macronutrients, such as proteins and carbohydrates, or vitamins in the regulation of blood pressure is less well understood. Occasional ingestion of coffee transiently increases blood pressure, but the effects of habitual coffee consumption are controversial. Excessive use of alcohol on a regular basis has been associated with elevated blood pressure. It has also been shown in case reports that large amounts of liquorice lead to the development of hypertension. Thus, with appropriate dietary modifications, it is possible to prevent the development of high blood pressure and to treat hypertensive patients with fewer drugs and with lower doses. In some patients antihypertensive medication may not be at all necessary.

The effects of potassium depletion and supplementation on blood pressure: a clinical review

Nonpharmacologic treatment currently is recognized as an important part in the treatment of hypertension, and the role of dietary potassium intake in blood pressure (BP) control is becoming quite evident. Clinical studies have examined the mechanism by which hypokalemia can increase BP and the benefit of a large potassium intake on BP control. Epidemiologic data suggest that potassium intake and BP are correlated inversely. In normotensive subjects, those who are salt sensitive or who have a family history of hypertension appear to benefit most from the hypotensive effects of potassium supplementation. The greatest hypotensive effect of potassium supplementation occurs in patients with severe hypertension. This effect is pronounced with prolonged potassium supplementation. The antihypertensive effect of increased potassium intake appears to be mediated by several factors, which include enhancing natriuresis, modulating baroreflex sensitivity, direct vasodilation, or lowering cardiovascular reactivity to norepinephrine or angiotensin II. Potassium repletion in patients with diuretic-induced hypokalemia improves BP control. An increase in potassium intake should be included in the nonpharmacologic management of patients with uncomplicated hypertension.

Acute decreases in serum potassium augment blood pressure

Potassium depletion is a risk factor for cardiovascular diseases, including hypertension, and frequently is encountered in patients with end-stage renal disease. Since the treatment of end-stage renal disease might result in K+ depletion and postdialysis hypokalemia, we investigated the relationship between acute K+ removal by hemodialysis and changes in blood pressure at the completion of treatment compared with predialysis and 1-hour postdialysis blood pressure. The effects of three different dialysate potassium concentrations ([K+]d; 1.0, 2.0, and 3.0 mmol/L) were investigated in 11 patients. Hemodialysis-induced K+ removal, serum [K+], total body K+, and blood pressure were measured. The use of 1.0, 2.0, or 3.0 mmol/L [K+]d resulted in the removal of 77.0 +/- 6.5, 54.5 +/- 7.9, and 42.5 +/- 9.9 mmol of K+ per treatment, respectively (P < 0.05, [K+]d 1.0 v [K+]d 3.0). Predialysis and postdialysis serum [K+] were 4.9 +/- 0.2 and 3.6 +/- 0.1 mEq/L for 1.0 mmol/L [K+]d, 5.1 +/- 0.3 and 3.9 +/- 0.1 mEq/L for 2.0 mmol/L [K+]d, and 5.3 +/- 0.3 and 4.2 +/- 0.2 mEq/L for 3.0 mmol/L [K+]d, respectively (P < 0.001 for each [K+]d). The baseline total body K+ corrected for gender, age, and race was 92% of predicted normal level and did not change significantly with the use of different [K+]d. Blood pressure decreased during hemodialysis as excess fluid was removed, regardless of [K+]d. Significant increases in blood pressure did occur 1 hour postdialysis compared with levels measured at the completion of treatment ("rebound hypertension") when hemodialysis was performed with 1.0 and 2.0 mmol/L, but not with 3.0 mmol/L [K+]d.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of potassium supplementation in persons with a high-normal blood pressure. Results from phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group

We conducted a randomized, double-blind, placebo-controlled trial of oral potassium chloride supplementation (60 mmol/d) in 353 men and women with an initial average diastolic blood pressure between 80 and 89 mm Hg. In the active (n = 178) compared to the placebo (n = 175) treatment group, the urinary potassium level was significantly (p < 0.001) increased by an average of 44.0 and 42.3 mmol/24 h following 3 and 6 months of therapy, respectively. Compared to placebo, active treatment was associated with a small (mean = 1.8 mm Hg) but significant (p = 0.04) reduction in diastolic blood pressure following 3 months of therapy. Following 6 months, however, this apparent treatment effect had virtually disappeared (mean reduction in diastolic blood pressure = 0.3 mm Hg). There was no significant effect of potassium supplementation on systolic blood pressure at either follow-up visit. There was a significant, independent, dose-response relationship between change in both 24-hour urinary potassium excretion and urinary sodium-potassium ratio and the corresponding change in diastolic blood pressure (-1.49 mm Hg for the highest versus the lowest quartile of change in urinary potassium excretion.

Micronutrient effects on blood pressure regulation

Five micronutrients have been shown to directly influence blood pressure: sodium, calcium, potassium, magnesium, and chloride. The data presented here are based on accumulated findings from epidemiologic, laboratory, and clinical investigations, many of which focused primarily on a single nutrient. However, as also discussed here, nutrients are not consumed in isolation, and their physiologic interactions and combined effects on blood pressure are the subjects of much of the current research in the area of diet and hypertension.

Evidence for high risk of cerebral hemorrhage in chronic dialysis patients

One-half of the total deaths in chronic dialysis patients are due to cardiovascular disease; however, the precise incidence and relative risk of those compared to normals are not known. Therefore, we sought to determine the annual incidence of cardiovascular disease and relative risk of those on chronic dialysis to the general population. Both the general population (1.2 million, Census 1990) and chronic dialysis patients (N = 1,609) in Okinawa, Japan were studied prospectively from April, 1988, to March, 1991. Diagnosis of stroke was made by symptoms and brain CT scan, and acute myocardial infarction was done by changes in electrocardiogram and serum enzymes. The relative risk (observed/expected ratio) was calculated by using the standardized morbidity rate obtained in both sexes and age-class every 10 years in the general population. Forty-one stroke (8 cerebral infarction, 31 cerebral hemorrhage, and 2 subarachnoid hemorrhage) and four acute myocardial infarction cases were registered during the study period in chronic dialysis patients. The incidence per 1,000 person-year was 11.5 in stroke, 2.2 in cerebral infarction, 8.7 in cerebral hemorrhage, 0.6 in subarachnoid hemorrhage, and 1.1 in acute myocardial infarction. The relative risk compared to normals was 5.2 in stroke, 2.0 in cerebral infarction, 10.7 in cerebral hemorrhage, 4.0 in subarachnoid hemorrhage, and 2.1 in acute myocardial infarction. Cerebral hemorrhage occurred at 10 years younger than that of the general population (P < 0.001) and was associated with high prevalence of hypertension and low levels of serum albumin and cholesterol. Our results confirm the importance of blood pressure control and nutritional status in chronic dialysis patients.

Childhood prevention of essential hypertension

Childhood prevention of essential hypertension requires knowledge of alterable determinants of blood pressure in children; these include obesity and sodium intake and perhaps physical activity and intake of potassium and calcium. Altering these determinants may involve two general preventive strategies. The first is a population strategy, which attempts to lower blood pressure (or keep it from rising) among all children. Population strategies may require educating children to active participants in changing their behaviors (active approach) or may merely change their environment (passive approach). The second general strategy aims to focus on children at high risk of developing hypertension as adults. To determine the usefulness of this high-risk strategy, more information is needed about prediction of adult blood pressure from childhood values and about the efficacy of interventions to control blood pressure levels in high-risk children.