Oral Potassium Supplementation Research Articles

Efeitos da suplementação de potássio via sal de cozinha sobre a pressão arterial e a resistência à insulina em pacientes obesos hipertensos em uso de diuréticos

OBJETIVO: Avaliar os efeitos da suplementação de potássio, por intermédio do sal de cozinha contendo cloreto de potássio, associada à dieta hipocalórica e à atividade física aeróbica, sobre a pressão arterial e índices de resistência à insulina em pacientes hipertensos com obesidade abdominal. MÉTODOS: Estudo prospectivo duplo-cego, randomizado, em 22 pacientes hipertensos com excesso de peso (índice de massa corporal >27kg/m²) e controle insatisfatório da pressão arterial durante o uso de diuréticos pressão arterial sistólica >140 e <160mmHg e/ou pressão arterial diastólica >90 e <105mmHg. O estudo teve duração de 12 semanas, durante as quais, os pacientes, divididos em dois grupos (grupo sal normal, n=10; grupo sal de potássio, n=12), receberam sal contendo 100% de cloreto de sódio, ou sal contendo 50% de cloreto de sódio e 50% de cloreto de potássio. No início e ao final do estudo, os pacientes foram submetidos à determinação do índice de massa corporal, da circunferência da cintura, dos níveis séricos e da excreção urinária de sódio e potássio, à monitorização ambulatorial da pressão arterial nas 24 horas, ao teste oral de tolerância à glicose com determinação dos níveis séricos de insulina em jejum e aos 120 minutos, à determinação do perfil lipídico do plasma e à medida da composição corporal. RESULTADOS: No grupo sal de potássio, os níveis do potássio sérico não se elevaram, como no grupo sal normal, embora se elevasse de 38,8±18,6 para 62,3±29,7mEq/g a excreção de creatinina urinária (p<0,05). A perda de peso, semelhante nos dois grupos (3,5% no grupo sal normal e 2,7% no grupo sal de potássio), associou-se às reduções na pressão arterial sistólica durante a monitorização ambulatorial da pressão arterial; de 134,7 ±14,8 para 130,2±12,6mmHg (p<0,05) no grupo sal normal e de 128,2±7,4 para 122,9±5,7mmHg (p<0,05) no grupo sal de potássio, e às reduções na pressão arterial diastólica durante a monitorização ambulatorial da pressão arterial, de 84,4±10,2 para 81,4 ± 8,9mmHg no grupo sal normal e de 84,0±5,7 para 79,5±3,9mmHg (p<0,05) no grupo sal de potássio. As variações da pressão arterial sistólica, semelhantes nos dois grupos, correlacionaram-se com as variações das medidas da circunferência da cintura em todos os pacientes analisados em conjunto (r s=0,624; p=0,002). Os índices de resistência à insulina e o perfil lipídico do plasma não se alteraram e não diferiram entre os grupos. CONCLUSÃO: Nossos resultados indicam que as perdas de peso induzidas por alterações no estilo de vida promovem reduções na pressão arterial, proporcionais às reduções na gordura abdominal. A suplementação de potássio a partir da utilização do sal de cozinha contendo cloreto de potássio, em pacientes hipertensos obesos em uso de diurético, se mostrou insuficiente para impedir a queda dos níveis séricos de potássio e não resultou em nenhum efeito sobre a resistência à insulina ou sobre a pressão arterial, além daquele obtido pela perda de peso.

Postpartum Preeclampsia Management With Furosemide: A Randomized Clinical Trial

This investigation was undertaken to estimate whether a brief postpartum course of furosemide for patients with preeclampsia benefits recovery and shortens hospitalization by enhancing diuresis, lessening severe hypertension, and reducing the need for antihypertensive therapy. Two hundred sixty-four patients with preeclampsia were enrolled. After spontaneous onset of postpartum diuresis and discontinuation of intravenous magnesium sulfate, patients were randomly assigned to receive either no therapy or 20 mg oral furosemide daily for 5 days with oral potassium supplementation. Patient outcomes were compared between treatment groups with regard to classification of hypertensive disease. Only postpartum patients with severe preeclampsia (n = 70) who received furosemide compared with controls had significantly lower systolic blood pressure by postpartum day 2 (142 +/- 13 mm Hg compared with 153 +/- 19 mm Hg, P < .004) and required less antihypertensive therapy during hospitalization (14% compared with 26%, P = .371) and at discharge (6% compared with 26%, P = .045). No benefit was shown for patients with mild preeclampsia (n = 169) or superimposed preeclampsia (n = 25). Neither length of hospitalization nor frequency of delayed postpartum complications was positively affected by the intervention. Brief postpartum furosemide therapy for patients with severe preeclampsia seems to enhance recovery by normalizing blood pressure more rapidly and reducing the need for antihypertensive therapy. Shortening of hospitalization and reduction of delayed postpartum complications were not benefitted.

A new oral therapy for long QT syndrome: Long-term oral potassium improves repolarization in patients with HERGmutations

ObjectivesWe sought to determine whether oral potassium supplementation safely increases serum K+and results in sustained improvement of repolarization parameters in long QT syndrome type 2 (LQT2) subjects. BackgroundMutations in HERG(LQT2), the gene encoding the rapid delayed rectifier K+current IKr, account for a significant proportion of congenital long QT syndrome (LQTS). The magnitude of IKris paradoxically increased by an increase in extracellular K+. We tested the hypothesis that long-term oral potassium supplementation results in a mild, sustainable increase in serum K+that improves repolarization abnormalities in subjects with LQT2. MethodsAfter an initial evaluation consisting of electrocardiography, electrolytes, blood urea nitrogen, and creatinine, escalating doses of potassium chloride (KCl) and spironolactone were administered to eight subjects with six distinct HERGmutations. Medications were continued for four weeks, at which time, the final evaluation was undertaken. Beta-adrenergic blocking therapy was maintained. ResultsThe subjects ranged in age from 11 to 52 years. The average daily KCl and spironolactone dose was 3.3 ± 1.5 mEq/kg and 3.5 ± 1.2 mg/kg, respectively, and this regimen resulted in an increase in serum K+from 4.0 ± 0.3 to 5.2 ± 0.3 mEq/l. There were no serious complications associated with therapy. The increase in serum K+resulted in a decrease in the corrected QT interval from 526 ± 94 to 423 ± 36 ms (mean ± SD; lead V2). Both QT dispersion and T-wave morphology improved in most subjects. ConclusionsLong-term oral potassium administration increases serum K+in patients with LQT2. This can be achieved safely and results in improvement in repolarization. Further studies are warranted to determine whether this will reduce the incidence of life-threatening events in LQTS patients.

Argon laser peripheral iridoplasty versus conventional systemic medical therapy in treatment of acute primary angle-closure glaucoma: A prospective, randomized, controlled trial

Objective To study whether argon laser peripheral iridoplasty (ALPI) is as effective and safe as conventional systemic medications in treatment of acute primary angle-closure glaucoma (PACG) when immediate laser peripheral iridotomy is neither possible nor safe. Design Prospective, randomized, controlled trial. Participants Seventy-three eyes of 64 consecutive patients with their first presentation of acute PACG, with intraocular pressure (IOP) levels of 40 mmHg or more, were recruited into the study. Intervention The acute PACG eye of each consenting patient received topical pilocarpine (4%) and topical timolol (0.5%). The patients were then randomized into one of two treatment groups. The ALPI group received immediate ALPI under topical anesthesia. The medical treatment group was given 500 mg of intravenous acetazolamide, followed by oral acetazolamide 250 mg four times daily, and an oral potassium supplement until IOP levels normalized. Intravenous mannitol also was administered to the latter group if the presenting IOP was higher than 60 mmHg. The acute PACG eye of both groups continued to receive topical pilocarpine (1%) until peripheral iridotomy could be performed. Main outcome measures Intraocular pressure profile, corneal clarity, symptoms, visual acuity, angle status by indentation gonioscopy, and complications of treatment. Results Thirty-three acute PACG eyes of 32 patients were randomized to receive immediate ALPI, whereas 40 acute PACG eyes of 32 patients had conventional systemic medical therapy. Both treatment groups were matched for age, duration of attack, and IOP at presentation. The ALPI-treated group had lower IOP levels than the medically treated group at 15 minutes, 30 minutes, and 1 hour after the start of treatment. The differences were statistically significant. The difference in IOP levels became statistically insignificant from 2 hours onward. The duration of attack did not affect the efficacy of ALPI in reducing IOP in acute PACG. No serious laser complications occurred, at least in the early postlaser period. Conclusions Argon laser peripheral iridoplasty significantly is more effective than conventional systemic medications in reducing IOP levels in acute PACG in eyes not suitable for immediate laser peripheral iridotomy within the first 2 hours from the initiation of treatment. Argon laser peripheral iridoplasty is a safe and more effective alternative to conventional systemic medications in the management of acute PACG not amenable to immediate laser peripheral iridotomy.

Effect of oral potassium supplementation on QT dispersion in anorexia nervosa

The aim of this study was to evaluate the degree of QT dispersion in a group of young women with anorexia nervosa and its changes after oral potassium supplementation. Twenty‐eight patients with self‐induced starvation were matched with 20 thin and 20 normal‐weight women (body mass index ≪20). All participants underwent a complete clinical examination, including electrocardiogram (ECG) for QT interval measurements. QT dispersion was defined as the difference between the longest and the shortest QT interval occurring in the 12‐lead ECG. QT dispersion was corrected (QTc) with Bazett's formula. Anorexic patients were later allocated two subgroups of 14 to receive or not to receive potassium aspartate (2 vials K‐Flebo d‐1= 60 mEq d‐1, per os). ECG was repeated in both the subgroups of anorexic patients after 4 wk. QT dispersion was significantly greater in starving patients than in thin or normal‐weight women (QT dispersion = 62.2 ± 12.4 vs 33.4 ± 7.1 or 31.7 ± 6.3 ms; QTc dispersion = 56.5 ± 12 vs 34 ± 9.1 or 33.2 ± 11 ms, p &gt; 0.001). After 4 wk, anorexic women treated with oral potassium aspartate supplementation, compared with untreated patients, showed an increased kalaemia (4.21 ± 0.16 vs 3.91 ± 0.32 mmol 1‐1, p &gt; 0.05) and a significant reduction in the QT interval dispersion (QT dispersion = 44.2 ± 8.1 vs 63.2 ± 9.1 ms, QTc dispersion = 41.3 ± 9.7 vs 57.4 ± 9 ms, p &gt; 0.001). Conclusion: Patients with anorexia nervosa have greater QT dispersion than constitutionally thin and normal‐weight women, and oral potassium supplementation tends to reduce it. This suggests that the reduction in the pool of potassium may be the critical factor inducing the enhancement of the QT dispersion in anorexia nervosa.

Value of aldosterone receptor blockade in diuretic therapy of patients with chronic heart failure

All forms of chronic heart failure (high-output and low-output failure) are accompanied by an "arterial underfilling" inducing the activation of various neurohumoral systems (renin-angiotensin-aldosterone system, sympathic nervous system, non-osmotic stimulation of vasopressin). Elevated levels of those neurohormones detrimentally modulate renal function. Subsequently, renal salt and volume retention occurs leading to the main symptoms of heart failure, edema formation and dyspnea. Diuretics, which have been discovered more than 40 years ago, beneficially influence renal salt- and volume retention by their effects on tubular sodium reabsorption. While thiazides are recommended in mild forms, loop diuretics are used in severe stages of congestive heart failure. The clinician has to consider the changed pharmacokinetic and -dynamic properties during the application of diuretics in patients with chronic heart failure. In addition, increased sodium reabsorption occurs immediately after cessation of diuretic action often nullifying the preceding diuresis. Thus, salt- and volume restriction should be guaranteed, and a regular application of loop diuretics during the day should be preferred due to the short-acting nature of currently available loop diuretics. Sometimes, diuresis does not longer occur during the treatment with one substance (diuretic resistance), although the therapeutic goals of water excretion have not been achieved. After ruling out factors reducing the actions of diuretics (non-compliance, hyponatremia, etc.), a sequential nephron blockade should be initiated (combination of loop diuretics and a thiazide or an aldosterone-receptor antagonist) to increase diuresis and to elevate symptoms of volume overload. Loop diuretics and thiazides often induce mild hypokalemia, which has been demonstrated to be not as benign as thought before. Chronic treatment with oral potassium supplements has several drawbacks, as urine excretion of potassium is subsequently increased and supplementation is not as effective as believed. Diuretic-induced hypokalemia seems to be aldosterone dependent. As aldosterone levels increase during diuretic therapy even during chronic treatment with an angiotensin-converting enzyme (aldosterone-escape) a combined treatment including an aldosterone-receptor antagonist has been suggested. Beneficial effects of aldosterone-receptor blockade on mortality (RALES trial) appear to be mediated be extrarenal and renal mechanisms. The suggested beneficial renal mechanisms of aldosterone receptor blockade are discussed in detail in the review. In conclusion, diuretic therapy of patients with congestive heart failure is effective to relieve symptoms and, presumably, to prolong life. As renal function and pharmacokinetics and -dynamics of diuretics are changed in heart failure, diuretic treatment has to be adapted to provide optimal treatment. Increased levels of aldosterone appear to play an important role in diuretic-induced hypokalemia, and in the progression of heart and renal failure. Thus, aldosterone receptor antagonists should be used in the treatment of heart failure more frequently.

Endocrinology: Hyperaldosteronism in a cat with metastasised adrenocortical tumour

Summary In a 12‐year‐old male shorthaired cat with attacks of hypo‐kalaemic muscular weakness in spite of oral potassium supplementation, highly elevated plasma aldosterone concentrations in combination with low plasma renin activity pointed to primary hyperaldosteronism. Ultrasonography and computed tomography revealed a large left‐sided adrenal tumour growing into the phrenicoabdominal vein and the caudal vena cava. The tumour and its intravascular extension were surgically removed, but the subsequent stenosis of the caudal vena cava caused congestion and renal failure. At autopsy pulmonary micrometastases of the aldosteronoma were found.

Clinical Disorders of Potassium Homeostasis: Hyperkalemia and Hypokalemia

Potassium plays an important role in cell metabolism and membrane excitability. Disorders of potassium balance can have profound clinical effects, particularly on the cardiovascular and neuromuscular systems. Chronic hyperkalemia invariably results from impaired renal potassium excretion. Hyperkalemia can be a potentially life-threatening disturbance requiring emergency intervention. Treatment is usually directed at correcting the defect in potassium excretion. Hypokalemia has become closely linked with in cats. Clinical signs include muscle weakness and renal dysfunction, which usually respond well to oral potassium supplementation.

DOES ORAL POTASSIUM LOWER BLOOD PRESSURE

Several studies have suggested that oral potassium supplementation can help reduce blood pressure, but most randomized trials have been too small to show definitive results. This meta-analysis pooled data from 33 randomized controlled trials involving …

Safety of large-volume leukapheresis for collection of peripheral blood progenitor cells

Large volume leukapheresis (LVL) reduces the number of procedures required to obtain adequate peripheral blood progenitor cells (PBPCs) for autologous hematopoietic reconstitution. LVL involves the processing of > 15 L or 5 patient blood volumes using high flow rates. We report our experience with LVL evaluating its efficiency and adverse effects in 71 adult patients with hematologic or solid organ malignancies. All were mobilized with chemotherapy and granulocyte colony-stimulating factor (G-CSF). All collections used a double lumen apheresis catheter. Mean values per LVL were as follows: blood processed, 24.6 L; patient blood volumes processed, 5.9; ACD-A used, 1,048 ml; heparin used, 6,148 units; collect time, 290 min; blood flow rate, 89 ml/min. Eighty percent of the collections were completed in one or two procedures to obtain > or = 6.0 x 10(8) MNCs/kg body weight. The most frequent side effect (39%) was parasthesia due to citrate-related hypocalcemia. This was managed with oral calcium supplements and/or slower flow rates. Post-LVL electrolyte changes were generally asymptomatic. Prophylactic oral potassium supplements were administered in 57% of cases. Other reactions included hypotension (4%), prolonged parasthesia (1.4%), and headache (1.4%). Catheter problems in 9 (13%) of the procedures were attributed to clot formation (37%) or positional effects (63%). No bleeding occurred. Post-LVL decreases in hematocrit and platelet count averaged 3.5% and 46%, respectively. Six (4%) of the procedures required red blood cell transfusions. Platelet transfusions were given in 19 (13%) of the procedures. We conclude that adverse reactions with LVL are similar to those reported for conventional PBPC collections, making it safe and efficacious as an outpatient procedure.

Potassium supplements prevent serious hypokalaemia in colon cleansing

The association between colonic cleansing and hypokalaemia was studied prospectively by monitoring the serum potassium levels in four groups of patients: groups 1 (55 patients), 2 (72 patients), and 3 (97 patients) received the same 2-day preparation of 15 g magnesium sulphate and 10 mg bisacodyl twice daily; group 4 (96 patients) received a 1-day preparation of 2.4 mg sennoside per kg of bodyweight. Groups 1 and 2 were on diuretics, but only group 2 received potassium supplementation. Serum potassium levels were measured before and after bowel preparation. Hypokalaemia was present prior to cleansing in six (11%), and after cleansing in 20 (36%) of the 55 patients in the group 1 patients on diuretics but without potassium supplements. There was, after cleansing, no significant fall in serum potassium in the group 2 patients on diuretics who received potassium supplements. No hyperkalaemia resulted from supplementation. A significant fall of the mean level of serum potassium occurred in patients in both group 3 (2-day-preparation) and group 4 (1-day-preparation). We conclude that both 1 day and 2 days of cleansing with cathartics may result in a significant fall in serum potassium, which can be prevented by oral potassium supplements. Potassium supplements (three times a day 15 ml of potassium chloride with 0.9 mmol K per ml during the preparation) in patients on diuretics may be prudent to avoid the risk of cardiac arrhythmia.

Does potassium supplementation lower blood pressure? A meta-analysis of published trials.

Both epidemiologic and clinical studies have suggested that an increase in potassium intake may lower blood pressure. However, the results of prospective clinical trials looking at the effect of oral potassium supplements on blood pressure have yielded conflicting results. For this reason, we reviewed 19 clinical trials examining the same end-point and involving a total of 586 participants (412 of whom had essential hypertension). Overall, the results of the trials indicate that oral potassium supplements significantly lower systolic blood pressure [-5.9 mmHg, -6.6 to -5.2 mmHg (mean, 95% confidence interval)] and diastolic blood pressure (-3.4 mmHg, -4.0 to 2.8 mmHg). The magnitude of the blood pressure lowering effect is greater in patients with high blood pressure (-8.2 mmHg, -9.1 to -7.3 mmHg for systolic and -4.5 mmHg, -5.2 to -3.8 mmHg for diastolic blood pressure) and appears to be more pronounced the longer the duration of the supplementation (P less than 0.05 and P less than 0.01 for systolic and diastolic, respectively). Based on this analysis, an increase in potassium intake should be included in the recommendations for a non-pharmacological approach to the control of blood pressure in uncomplicated essential hypertension.

Protective Effect by Potassium Chloride against Gastric Carcinogenesis Induced by N‐Methyl‐N'‐nitro‐N‐nitrosoguanidine in Spontaneously Hypertensive Rats

The effects of oral potassium supplementation on the enhanced induction of gastric carcinogenesis by N‐methyl‐N'‐nitro‐N‐nitrosoguanidine (MNNG) in spontaneously hypertensive rats (SHR), and the norepinephrine concentration in their gastric wall were investigated. The SHR and normotensive Wistar Kyoto rats (WKY) as controls were given a solution of the carcinogen for 25 weeks and then 1% KCl solution or tap water to drink. In Week 52, the incidence of gastric cancers and their number per rat and the norepinephrine concentration in the gastric wall were significantly greater in SHR than in WKY. Prolonged oral treatment of SHR with potassium significantly reduced the incidence of gastric cancers and their number per rat, as well as the blood pressure and the norepinephrine concentration in the antral portion of the gastric wall. These findings indicate that prolonged treatment with KCl attenuated the enhancement of gastric carcinogenesis by MNNG in SHR.

Bartter's syndrome and diabetes mellitus

We here report a case of Bartter's syndrome occurring in association with diabetes mellitus. The patient, an insulin-dependent diabetic, presented with hypokalaemia, inappropriate kaliuresis and metabolic alkalosis. He had high plasma renin activity, relatively low plasma aldosterone, and resistance to infused angiotensin II. A high potassium diet raised total body potassium and serum potassium, did not affect plasma renin activity, but raised plasma aldosterone significantly and did not alter the resistance to angiotensin II. Indomethacin administered acutely reduced urinary potassium and kallikrein excretion and, on chronic administration, lowered plasma renin activity, urinary chloride excretion, and raised serum potassium. Salt restriction resulted in a prompt and significant reduction in urinary sodium and chloride excretion. Urinary kallikrein excretion was very high throughout, increased with sodium restriction, and decreased with sodium loading. Oral potassium supplementation partially corrected the hypokalaemia, but did not affect blood sugar control. In this patient the primary defect appears to have been primary urinary potassium wasting, rather than sodium or chloride wasting. The striking effects of indomethacin suggest that prostaglandins may play a fundamental role in the genesis of the syndrome.

Plasma electrolyte concentration in food-deprived goats orally supplemented with potassium chloride

The aim of the present study was to investigate whether oral potassium supplementation during food deprivation could stimulate rumen electrolyte absorption and maintain plasma electrolyte concentration. Eight goats were subjected to food deprivation in combination with intrarumen loads of potassium chloride or, as a control, mannitol in a change-over design. In addition, four KCl- and four mannitol-treated goats were given an extra KCl load towards the end of the experiment. Food-deprived goats which were given KCl maintained their plasma concentration of Na and Cl, while plasma K concentration increased from 3.6 mM to 4.4 mM. In control goats receiving mannitol during food deprivation, the plasma concentration (mM) decreased from 144 to 140 for Na, 105 to 100 for Cl and from 3.8 to 3.6 for K, but concentrations were restored when these goats were given a load of KCl. The plasma renin activity was suppressed in food-deprived goats receiving KCl, while those given mannitol showed increased activity. It is suggested that the hyponatraemia which occurs in food-deprived ruminants is mainly caused by diminished K intake.

Placebo-Controlled Trial of Potassium Supplements in Black Patients with Mild Essential Hypertension

Forty-eight black patients with mildly increased blood pressure (BP) that had not yet been subjected to treatment took part in a double-blind clinical trial of the efficacy and tolerability of oral potassium supplements (64 mmol daily) versus a matching placebo (made of starch with coating) in a 16-week study. Potassium supplements produced a significant decrease in mean supine and standing BP within 4 weeks after treatment inception. Urinary potassium excretion increased significantly in the 24 patients who received potassium supplements (p less than 0.001). No significant changes occurred in plasma sodium and potassium concentrations or in urinary excretion of sodium during the study. All patients completed the trial without experiencing any notable untoward effects. These results are consistent with the premise that oral potassium supplements may exert hypotensive effects of clinically significant degree in patients with mild hypertension.

Oral potassium supplements

Oral potassium supplements

Hypokalemic periodic paralysis with unusual responses to acetazolamide and sympathomimetics

Five members in three generations of a family were affected by an illness that had many clinical features of the hypokalemic form of periodic paralysis (HPP). The serum potassium was either moderately reduced or normal during attacks, and there was no evidence of myotonia or cold-intolerance. All of the patients improved to a variable degree with oral potassium supplements, and 3 responded favorably to triamterene. The usually beneficial drug acetazolamide, however, invariably caused weakness in these patients, an effect previously described in only one other family with HPP. In addition, amphetamine-like sympathomimetic drugs effectively aborted or prevented paralysis in several members. Muscle biopsy in two patients revealed some unusual features, and electromyography showed myopathic potentials. There was no evidence of diabetes. The urine electrolyte concentrations during glucose tolerance tests, however, were different from those previously reported in HPP. This family may represent a variant form of HPP.

Controlled trial of long term oral potassium supplements in patients with mild hypertension

Controlled trial of long term oral potassium supplements in patients with mild hypertension

Comparative effects of three delivery systems of oral potassium on upper gastrointestinal mucosa

SummaryForty‐five healthy volunteers were recruited into a single‐blind randomly allocated parallel group study to determine the effects on the gastric mucosa of three different oral potassium supplements — (K‐Contin ContinusR) tablets, (Napp); Slow‐K tablets, (Ciba); Micro‐K Extencaps, (A H Robins).The volunteers were gastroscoped initially and after one week of treatment with one of the potassium tablets taken in conjunction with glycopyrrolate to delay gastric emptying. Post‐treatment, seven out of 15 volunteers taking Slow‐K tablets showed erosions and two showed hyperaemia only. Of the 15 taking Micro‐K, one showed erosions and two showed hyperaemia only. None of those given K‐Contin tablets showed erosions, but four showed hyperaemia only.