Effects of extreme potassium stress on blood pressure and renal tubular sodium transport.

We characterized mouse blood pressure and ion transport in the setting of commonly used rodent diets that drive K+ intake to the extremes of deficiency and excess. Male 129S2/Sv mice were fed either K+-deficient, control, high-K+ basic, or high-KCl diets for 10 days. Mice maintained on a K+-deficient diet exhibited no change in blood pressure, whereas K+-loaded mice developed an ~10-mmHg blood pressure increase. Following challenge with NaCl, K+-deficient mice developed a salt-sensitive 8 mmHg increase in blood pressure, whereas blood pressure was unchanged in mice fed high-K+ diets. Notably, 10 days of K+ depletion induced diabetes insipidus and upregulation of phosphorylated NaCl cotransporter, proximal Na+ transporters, and pendrin, likely contributing to the K+-deficient NaCl sensitivity. While the anionic content with high-K+ diets had distinct effects on transporter expression along the nephron, both K+ basic and KCl diets had a similar increase in blood pressure. The blood pressure elevation on high-K+ diets correlated with increased Na+-K+-2Cl- cotransporter and γ-epithelial Na+ channel expression and increased urinary response to furosemide and amiloride. We conclude that the dietary K+ maneuvers used here did not recapitulate the inverse effects of K+ on blood pressure observed in human epidemiological studies. This may be due to the extreme degree of K+ stress, the low-Na+-to-K+ ratio, the duration of treatment, and the development of other coinciding events, such as diabetes insipidus. These factors must be taken into consideration when studying the physiological effects of dietary K+ loading and depletion.

Nonadherence to potassium replacement protocol leads to prolonged management of diabetic ketoacidosis.

Introduction Diabetic ketoacidosis is a life-threatening condition that requires prompt management. Objectives We aimed to assess the impact of adherence to potassium replacement protocol according to the guidelines of Diabetes Poland on the duration of diabetic ketoacidosis (DKA) treatment. Patients and methods This retrospective analysis included 242 adults (median age, 27 years; range, 21-38 years). Nonadherence to potassium replacement protocol was assessed, along with the relationship between nonadherence and duration of DKA management. Nonadherence to the protocol was defined as too low or too high doses of potassium compared with the recommended potassium replacement protocol. Results The median duration of DKA treatment was longer in the nonadherent group than in the adherent group: 37 hours (interquartile range [IQR], 27-48) and 30 hours (IQR, 17-43), respectively (P = 0.005). Treatment duration correlated positively with nonadherence to potassium replacement protocol (r = 0.18; P = 0.005) and severity of DKA (r = 0.52; P <0.0001). Stepwise multivariate linear regression analysis indicated nonadherence to the protocol (ß = 0.14; P = 0.02) and severity of DKA (ß = 0.43; P <0.0001) as predictors of treatment duration, after adjustment for body mass index and age (R2 = 0.28; P <0.0001). Conclusions Nonadherence to potassium replacement protocol leads to prolongation of DKA management. Medical staff should be educated about the benefits of potassium replacement and precision in potassium administration and dosing in patients with DKA.

K+ and Mg2+ Dyshomeostasis in Acute Hyperadrenergic Stressor States.

Acute stressor states are linked to neurohormonal activation that includes the adrenergic nervous system. Elevations in circulating epinephrine and norepinephrine unmask an interdependency that exists between K+ and Mg2+ based on their regulation of a large number of Mg2+-dependent Na+-K+-ATPase pumps present in skeletal muscle. The hyperadrenergic state accounts for a sudden translocation of cations into muscle with the rapid appearance of hypokalemia and hypomagnesemia. The resultant hypokalemia and hypomagnesemia will cause a delay in myocardial repolarization and electrocardiographic QTc prolongation raising the propensity for supraventricular and ventricular arrhythmias. In this review, we focus on the interdependency between K+ and Mg2+, which is clinically relevant to acute hyperadrenergic stressor states found in patients admitted to intensive care units.

Dietary Intake and Sources of Potassium and the Relationship to Dietary Sodium in a Sample of Australian Pre-School Children.

The aim of this study was to determine the intake and food sources of potassium and the molar sodium:potassium (Na:K) ratio in a sample of Australian pre-school children. Mothers provided dietary recalls of their 3.5 years old children (previous participants of Melbourne Infant Feeding Activity and Nutrition Trial). The average daily potassium intake, the contribution of food groups to daily potassium intake, the Na:K ratio, and daily serves of fruit, dairy, and vegetables, were assessed via three unscheduled 24 h dietary recalls. The sample included 251 Australian children (125 male), mean age 3.5 (0.19) (SD) years. Mean potassium intake was 1618 (267) mg/day, the Na:K ratio was 1.47 (0.5) and 54% of children did not meet the Australian recommended adequate intake (AI) of 2000 mg/day for potassium. Main food sources of potassium were milk (27%), fruit (19%), and vegetable (14%) products/dishes. Food groups with the highest Na:K ratio were processed meats (7.8), white bread/rolls (6.0), and savoury sauces and condiments (5.4). Children had a mean intake of 1.4 (0.75) serves of fruit, 1.4 (0.72) dairy, and 0.52 (0.32) serves of vegetables per day. The majority of children had potassium intakes below the recommended AI. The Na:K ratio exceeded the recommended level of 1 and the average intake of vegetables was 2 serves/day below the recommended 2.5 serves/day and only 20% of recommended intake. An increase in vegetable consumption in pre-school children is recommended to increase dietary potassium and has the potential to decrease the Na:K ratio which is likely to have long-term health benefits.

The Effect of the Sodium to Potassium Ratio on Hypertension Prevalence: A Propensity Score Matching Approach.

This study investigated the effect of the sodium to potassium ratio on hypertension prevalence and blood pressure. The study population was constructed by pooling the Korean National Health and Nutrition Examination Surveys between 2010 and 2014. The study population was divided into quartiles based on the sodium to potassium ratio, and the effect was inferred by the difference in hypertension prevalence across quartiles by six pairwise comparisons using a propensity score matching technique. The quartiles with the higher sodium to potassium ratio had higher hypertension prevalence rates based on the following pairwise comparisons: the first vs. third quartile, the first vs. fourth quartile, the second vs. third quartile, and the second vs. fourth quartile. The prevalence differences were 2.74% point (p < 0.05), 3.44% point (p < 0.01), 2.47% point (p < 0.05), and 2.95% point (p < 0.01), respectively. In addition, statistically significant higher systolic (p < 0.05) and diastolic blood pressure (p < 0.01) was observed in the second quartiles compared to the first quartiles. Because a strong association was also detected between the sodium to potassium ratio and blood pressure even at a low level of sodium to potassium ratio, a lower sodium to potassium ratio diet than a usual diet is recommended to control high blood pressure in Korea.

[Hypomagnesaemia severe in patients with high flow ileostomy]. / Hipomagnesemia severa en paciente con ileostomía de alto débito.

The need to create a stoma is frequent in the daily clinical practice. Usually ileostomies work well within the first 24 hours. However, many times they are associated with important morbidity up to 76%. Although the complications derived from this technique may be surgical, metabolic complications, which are preceded by large losses through the stoma, are the ones going undetected. It is not rare to see patients carrying an ileostomy that come repeatedly to the hospital with severe metabolic impairments and in whom the underlying cause remains untreated. The case reported herein is just one of a series published in this journal making us aware of the need for a multidisciplinary approach of the ileostomies and the prevention of major complications derived from their poor functioning.

[Diet low in potassium]. / Dieta pobre en potasio. Gestión por raciones y puntos.

After confirming the high prevalence rates in our hemodialysis unit of the following nursing diagnoses: nutritional imbalances--both excesses and shortages, willingness to improve nutrition and fear related to the consequences of excessive intake of potassium and manifested by the inhibition in some people towards the enjoyment of food, we decided to plan an educational strategy which later resulted in a nursing intervention for these diagnoses, with the objective of providing adequate resources for the monitoring of balanced diets with a restriction of potassium. Inspired by dietary rations, as well as recognized dietary programs of learning by points, we decided to incorporate these ideas to design an educational tool to facilitate advice to our patients on how to follow diet plans as well as the choice of appropriate foods. The result was a set of cards incorporating nutritional information of various kinds, aimed at our patients covering different aspects of the diet appropriate food rations using household measurements, promoting good food preparation, appropriate dietary advice for different chronic diseases and a scoring system of foods according to their potassium content. Together they form a board game available during the hemodialysis sessions that also takes into consideration other issues of importance related to conditions such as cognitive stimulation, coping with the disease, improving the therapeutic performance or resources to increase patient motivation. Although initially it was only an educational exercise, the result has turned out to be both enjoyable and entertaining.

Prolonged QT interval in bulimia nervosa.

A 39-year-old woman with an unremarkable history presented to the emergency department with three episodes of collapse. Each episode was witnessed by her son who described a loss of consciousness followed by rapid and complete recovery. The patient appeared well and examination was unremarkable. Her ECG showed a marked QTc prolongation of 642 ms (normal <470 ms) and low serum potassium at 1.8 mmol/l (3.5-5.3 mmol/l). The patient was moved to the coronary care unit and started on potassium replacement. On the ward a thorough history was taken and the patient confessed to being very conscious about his body shape and weight and admitted to episodes of binge eating and self induced vomiting. Her history suggested bulimia nervosa which is known to cause electrolyte disturbances and cardiac arrhythmia. Over the following 2 days the patient's potassium increased and the QTc interval normalised; the patient was discharged with an outpatient referral for a psychiatric opinion.

Potassium restriction, high protein intake, and metabolic acidosis increase expression of the glutamine transporter SNAT3 (Slc38a3) in mouse kidney.

Kidneys produce ammonium to buffer and excrete acids through metabolism of glutamine. Expression of the glutamine transporter Slc38a3 (SNAT3) increases in kidney during metabolic acidosis (MA), suggesting a role during ammoniagenesis. Potassium depletion and high dietary protein intake are known to elevate renal ammonium excretion. In this study, we examined SNAT3, phosphate-dependent glutaminase (PDG), and phosphoenolpyruvate carboxykinase (PEPCK) regulation during a control (0.36%) or low-K(+) (0.02%) diet for 7 or 14 days or a control (20%) or high-protein (50%) diet for 7 days. MA was induced in control and low-K(+) groups by addition of NH(4)Cl. Urinary ammonium excretion increased during MA, after 14-day K(+) restriction alone, and during high protein intake. SNAT3, PDG, and PEPCK mRNA abundance were elevated during MA and after 14-day K(+) restriction but not during high protein intake. SNAT3 protein abundance was enhanced during MA (both control and low K(+)), after 14-day low-K(+) treatment alone, and during high protein intake. Seven-day dietary K(+) depletion alone had no effect. Immunohistochemistry showed SNAT3 staining in earlier parts of the proximal tubule during 14-day K(+) restriction with and without NH(4)Cl treatment and during high protein intake. In summary, SNAT3, PDG, and PEPCK mRNA expression were congruent with urinary ammonium excretion during MA. Chronic dietary K(+) restriction, high protein intake, and MA enhance ammoniagenesis, an effect that may involve enhanced SNAT3 mRNA and protein expression. Our data suggest that SNAT3 plays an important role as the glutamine uptake mechanism in ammoniagenesis under these conditions.

A primary Sjögren's syndrome patient with distal renal tubular acidosis, who presented with symptoms of hypokalemic periodic paralysis: Report of a case study and review of the literature.

Although renal tubular acidosis (RTA), secondary to autoimmune interstitial nephritis, develops in a large proportion of patients with Sjögren's syndrome (SS), most of the subjects are asymptomatic. Here, we shall present a 39-year-old female patient who came to us with hypokalemic periodic paralysis (HPP), and who was later diagnosed with distal RTA. The patient, who had xerostomia and xerophthalmia for a long period of time, was diagnosed with primary SS from serologic and histologic findings. The patient recovered by being prescribed potassium replacement therapy. Although renal biopsy was not performed, corticosteroids were administered because HPP indicated severe interstitial nephritis. HPP did not reoccur during a 2-year follow-up period. We also review cases with SS-related distal RTA and HPP.

Thyrotoxic periodic paralysis: an unusual presentation of weakness.

Thyrotoxic periodic paralysis is a rare endocrine disorder seen predominantly in men of Asian origin. The case is reported of a patient who presented to the accident and emergency department with sudden onset of weakness of his lower limbs. Hypokalaemia was identified and treated with resolution of symptoms. Additional tests identified the patient as being thyrotoxic. He was treated with oral antithyroid drugs. It is important to consider the diagnosis of thyrotoxic periodic paralysis in patients presenting with acute onset of weakness. The report discusses the epidemiology, presentation, treatment, and complications of this condition.

Potassium depletion and salt sensitivity in essential hypertension.

To evaluate the actual role of potassium depletion on blood pressure, 11 hypertensive patients were placed on a 10-day isocaloric diet providing a daily potassium intake of either 18 or 80 mmol, with each subject serving as his or her own control; the intake of sodium (220 mmol/day) and other minerals was kept constant. On day 11 each patient was also subjected to central volume expansion by water immersion associated with either normal or low potassium intake. After a 10-day period of low potassium intake, systolic blood pressure increased (P < 0.02) by 5 mm Hg, whereas serum potassium decreased (P < 0.001) by 0.9 mmol/L; no significant changes in urinary sodium and a marked increase in urinary calcium excretion (P < 0.001) were found during the 10-day low potassium intake. PRA (P < 0.02) and plasma aldosterone (P < 0.04) concentrations also decreased during low potassium intake in hypertensive patients. Even though an identical natriuretic response was found during the water immersion experiments with either high or low potassium in the whole hypertensive group, the evaluation of hypertensive subjects in relation to salt sensitivity enabled us to disclose pronounced differences in the natriuretic and calciuretic response. In fact, although an impaired natriuretic ability and moderate calcium loss were particularly found during water immersion in those hypertensive subjects exhibiting a lower salt sensitivity index, a predominant calcium depletion appeared to be the most important consequence of potassium depletion in the hypertensive subjects with a higher salt sensitivity index. By confirming that potassium depletion may exacerbate essential hypertension, our data also suggest that not only sodium restriction, but also potassium and calcium supplementation, could be particularly advisable in salt-sensitive hypertensive patients.

Potassium contents of northeastern Thai foods.

From our previous nutritional assessment, low potassium (K) intake among northeastern Thai males has been clearly demonstrated. This prompted us to undertake a survey of the K content of local foods. Food samples comprised of 57 animal and 142 plant products which were collected from various places in the northeast of Thailand. The dry ashing method was used to prepare the samples for K analysis using an atomic absorption spectrophotometer. Foods could be divided into 7 groups according to their K levels. Foods containing K > or = 1000 mg per 100 g fresh food were categorized in group 1. These were mainly foods in the legume group, i.e., soybean, cowpea and mungbean. While rice (polished) and rice products, the main staple, were in group 7, the lowest K group of less than 100 mg per 100 g fresh food. Comparison studies of the natural foods between those collected from the northeast and from the central regions of the country, and between the cooked foods purchased from the rural villages and from the urban areas of Khon Kaen municipality, showed that, for most food items, the K content was similar wherever it came from. However, when the K content in various parts or in different stages of growth of the same kind of plants or animals was compared, a great variation was clearly seen, for example, young tamarind leaves contained K in group 6 whereas ripe tamarind fruit contained K in group 1. According to our food consumption data, the analysis of food components of 48 meals taken during the hot season by 13 rural volunteers revealed that food items eaten with the highest frequencies and in the largest amount were those in the low K food groups, i.e., glutinous rice (group 7) and green papaya (group 6). Our results suggest that the low K intake of these northeast rural Thai people is not due to a low K content of foods in this region, but rather that their food habits and low socioeconomic status restricts consumption of those food items with higher K contents.

[The effect of elevated environmental temperature on the development of a potassium deficiency in the body]. / Vliianie povyshennoi temperatury okruzhaiushchei sredy na razvitie defitsita kaliia v organizme.

Electron microscopy and roentgen microanalysis were used to study the ultrastructure and electrolytic balance of K+, Na+ and Cl- of the animal myocardial tissue during general body hyperthermia. It was established that long-term effect of heating microclimate causes a distinct reduction of K+ in the cardiomyocytes accompanied by essential changes of the ultrastructure of ischemic character.