Markers of potassium homeostasis in salt losing tubulopathies- associations with hyperaldosteronism and hypomagnesemia.

BACKGROUND: Renal loss of potassium (K+) and magnesium (Mg2+) in salt losing tubulopathies (SLT) leads to significantly reduced Quality of Life (QoL) and higher risks of cardiac arrhythmia. The normalization of K+ is currently the most widely accepted treatment target, however in even excellently designed RCTs the increase of K+ was only mild and rarely normalized. These findings question the role of K+ as the ideal marker of potassium homeostasis in SLT. Aim of this hypothesis-generating study was to define surrogate endpoints for future treatment trials in SLT in terms of their usefulness to determine QoL and important clinical outcomes. METHODS: Within this prospective cross-sectional study including 11 patients with SLTs we assessed the biochemical, clinical and cardiological parameters and their relationship with QoL (RAND SF-36). The primary hypothesis was that QoL would be more dependent of higher aldosterone concentration, assessed by the transtubular-potassium-gradient (TTKG). Correlations were evaluated using Pearson's correlation coefficient. RESULTS: Included patients were mainly female (82%, mean age 34 ± 12 years). Serum K+ and Mg2+ was 3.3 ± 0.6 mmol/l and 0.7 ± 0.1 mmol/l (mean ± SD). TTKG was 9.5/3.4-20.2 (median/range). While dimensions of mental health mostly correlated with serum Mg2+ (r = 0.68, p = 0.04) and K+ (r = 0.55, p = 0.08), better physical health was associated with lower aldosterone levels (r = -0.61, p = 0.06). TTKG was neither associated with aldosterone levels nor with QoL parameters. No relevant abnormalities were observed in neither 24 h-ECG nor echocardiography. CONCLUSIONS: Hyperaldosteronism, K+ and Mg2+ were the most important parameters of QoL. TTKG was no suitable marker for hyperaldosteronism or QoL. Future confirmatory studies in SLT should assess QoL as well as aldosterone, K+ and Mg2+.

Severe hypokalemia secondary to abuse of ß-adrenergic agonists in a pediatric patient: Case report / Hipocalemia grave secundária a abuso de agonistas ß-adrenérgicos em paciente pediátrico: relato de caso

ABSTRACT This study reports a case of a 13-year-old male with a 3-year history of severe and intermittent hypokalemia episodes of unknown origin, requiring admission to the intensive care unit (ICU) for long QT syndrome (LQTS), finally diagnosed of redistributive hypokalemia secondary to the abuse of β-adrenergic agonists in the context of a probable factitious disorder.

RESUMO O presente estudo relata o caso de um jovem de 13 anos de idade com histórico, há três anos, de episódios de hipocalemia grave intermitente de origem desconhecida, internado em unidade de terapia intensiva (UTI) por síndrome do QT longo (SQTL). O paciente foi diagnosticado com hipocalemia por redistribuição secundária ao abuso de agonistas β-adrenérgicos, em contexto de provável transtorno factício.

Severe hypokalemia secondary to abuse of ß-adrenergic agonists in a pediatric patient: Case report.

This study reports a case of a 13-year-old male with a 3-year history of severe and intermittent hypokalemia episodes of unknown origin, requiring admission to the intensive care unit (ICU) for long QT syndrome (LQTS), finally diagnosed of redistributive hypokalemia secondary to the abuse of ß-adrenergic agonists in the context of a probable factitious disorder.

[My stomach, the monster under my bed]. / Mon ventre, ce monstre caché sous mon lit.

Care for patients with eating disorders is complex and plurimodal. Care plans need to be adapted in order to take into account the body in crisis. A series of hospital admissions combined with specific psychomotor approaches, can contribute to the patient being reappropriated with their own body.

"End-stage kidney" in longstanding bulimia nervosa.

OBJECTIVE: The extent of renal damage over long-term binge/purges has not been well documented in bulimia nervosa (BN). METHOD: We describe a 52-year-old woman with longstanding BN subsequent to an 8-year history of anorexia nervosa (AN). RESULTS: The patient showed chaotic binge/purges and chronic severe hypokalemia after recovery from AN at age 26 years, and renal biopsy showed juxtaglomerular hyperplasia, which was diagnosed as pseudo-Bartter's syndrome. DISCUSSION: Over the following 26 years, the patient's eating behaviors remained chaotic, and her renal function gradually deteriorated. After the patient died of pneumonia and sepsis at age 52 years, autopsy of her kidney showed chronic interstitial nephritis, proximal tubular swelling, and diffuse glomerular sclerosis, suggesting chronic glomerular injury associated with long-term binge/purges. To our knowledge, this is the first case report of a patient with BN with long-term binge/purges who developed an eventual "end-stage kidney" characterized by hypokalemic nephropathy and diffuse glomerulosclerosis.

Total body potassium and serum potassium among eating disorder patients.

OBJECTIVE: The purpose of the study was to determine body composition, including total body potassium (TBK+), serum potassium, and lean body mass (LBM), in anorexia nervosa. METHOD: TBK+ measurements, serum potassium levels, and anthropometric measurements were obtained from four anorectic patients in the first week after their hospital admission. All four patients had normal serum potassium levels but three of the four had significant depletion of total body potassium. Two methods of calculating LBM, based on TBK+ measures or anthropometric assessment, produced different results. RESULTS: TBK+ may be depleted even when serum potassium levels are normal. It was also concluded that the two methods of calculating LBM were inaccurate. DISCUSSION: Patients may be at risk for cardiac arrhythmias and other physiological abnormalities even when serum potassium is normal since TBK+ may be low. The need for comprehensive assessment of body composition based on four compartment models is discussed.

Renal failure associated with laxative abuse.

Eating disorder patients often abuse laxatives in an attempt to purge excess food. Laxative abuse can cause hypokalemia and volume depletion. Hypokalemia, in turn, can lead to rhabdomyolysis. Laxative-induced hypokalemia and volume depletion have been previously reported to cause renal insufficiency, but not severe enough to require hemodialysis. A 27-year-old woman with a long history of laxative abuse presented with severe renal failure associated with hypokalemia and volume depletion. She required acute hemodialysis for worsening acidosis (pH 7.05) despite assisted ventilation. A prior episode of hypokalemic rhabdomyolysis at age 23 had resulted in only mild renal insufficiency. Her later episode of severe renal failure was linked to profound volume depletion (blood urea nitrogen 135 mg/dl). This patient calls attention to a potentially life-threatening complication of laxative abuse and indicates that volume depletion can exacerbate laxative-associated renal failure.

Number impairments following hypokalemia: a case study.

A case study is reported of a 55 year old female (B.B.) who complained of significant difficulty manipulating and remembering numbers. Twenty-four years prior to the present complaint, B.B. had been hospitalized for idiopathic hypokalemia and secondary hyperaldosteronism. The present study examined the nature and extent of B.B.'s cognitive impairments. On standardized and experimental tests of intelligence and general cognitive ability, she scored quite well. However, she demonstrated significant impairments in digit span, number processing and calculation, memory for biographical details involving numbers and general number knowledge. The implications of such a constellation of impairments are discussed from both cognitive and neurological perspectives.

A neurobehavioral syndrome after failure to thrive on chloride-deficient formula.

Eleven of 13 children, who demonstrated a failure-to-thrive pattern in infancy attributable to chloride-deficient Neo-Mull-Soy formula, had distinctive cognitive impairments four to nine years later. These included: a language disorder primarily involving articulation, word finding and naming; visual-motor and fine motor difficulties; and attention deficit disorder, often featuring repetitive behaviours, withdrawal and perseveration ('overfocus'). In contrast, global intellectual abilities were within the normal range in all 11 children. This residual neurobehavioral syndrome is too rare in the developmentally disabled population to reflect a chance association. It has not been associated either with protein-calorie malnutrition or chloride-deficiency diseases.