Renal complications and quality of life in postsurgical hypoparathyroidism: a case-control study.

PURPOSE: Conventional therapy (calcium and activated vitamin D) does not restore calcium homeostasis in patients with chronic hypoparathyroidism (HypoPT) and is associated with renal complications and reduced quality of life (QoL). The aim of this study was to evaluate in a case-control, cross-sectional study, the rate of renal complications and QoL in two sex- and age-matched cohort of patients with differentiated thyroid cancer with (n = 89) and without (n = 89) chronic post-operative HypoPT (PoHypoPT) and their relationship with the biochemical control of the disease. METHODS: Serum and urinary parameters, renal ultrasound and QoL were assessed by SF-36 and WHO-5 questionnaires. RESULTS: Forty-three (48.3%) PoHypoPT patients reported symptoms of hypocalcemia. Twenty-six (29.2%) patients were at target for all 6 parameters, 46 (51.6%) for 5. The most frequently unmet targets were gender-specific 24-h urinary calcium (44.9%) and serum calcium (37.1%). Serum phosphate, magnesium and 25(OH)D were in the normal range in > 90% of patients. Renal calcifications were found in 26 (29.2%) patients, with no correlation with 24-h urinary calcium. eGFR did not differ between patients and controls. Conversely, patients had a significant higher rate of renal calcifications and a lower SF-36, but not WHO-5, scores. SF-36 scores did not differ between PoHypoPT patients who were, or not, hypocalcemic. CONCLUSIONS: Our study shows that the rate of renal calcifications was higher in patients with PoHypoPT than in those without. This finding, together with the reduced QoL and the presence of hypocalcemic symptoms in about half patients, underscores that the treatment of chronic HypoPT with conventional therapy is suboptimal.

Hypocalcemia in sepsis: analysis of the subcellular distribution of Ca2+ in septic rats and LPS/TNF-α-treated HUVECs.

INTRODUCTION: Hypocalcemia has been widely recognized in sepsis patients. However, the cause of hypocalcemia in sepsis is still not clear, and little is known about the subcellular distribution of Ca2+ in tissues during sepsis. METHODOLOGY: We measured the dynamic change in Ca2+ levels in body fluid and subcellular compartments, including the cytosol, endoplasmic reticulum and mitochondria, in major organs of cecal ligation and puncture (CLP)-operated rats, as well as the subcellular Ca2+ flux in HUVECs which treated by endotoxin and cytokines. RESULTS: In the model of CLP-induced sepsis, the blood and urinary Ca2+ concentrations decreased rapidly, while the Ca2+ concentration in ascites fluid increased. The Ca2+ concentrations in the cytosol, ER, and mitochondria were elevated nearly synchronously in major organs in our sepsis model. Moreover, the calcium overload in CLP-operated rats treated with calcium supplementation was more severe than that in the non-calcium-supplemented rats but was alleviated by treatment with the calcium channel blocker verapamil. Similar subcellular Ca2+ flux was found in vitro in HUVECs and was triggered by lipopolysaccharide (LPS)/TNF-α. CONCLUSIONS: Ca2+ influx from the blood into the intercellular space and Ca2+ release into ascites fluid may cause hypocalcemia in sepsis and that this process may be due to the synergistic effect of endotoxin and cytokines.

Uso inapropiado de diuréticos: Algunas características no tan conocidas / Diuretic misuse: Some not so well known characteristics

Entre las situaciones asociadas al uso inapropiado de diuréticos se encuentran los intentos por descencer rápidamente de peso, comunes en los desordenes de la alimentación, y los intentos por enmascarar el consumo de otras sustancias, en el caso de las competencias deportivas. El uso sin indicación ni supervisión médica de estos fármacos genera un desbalance electrolítico, que puede manifestarse con hiponatremia, hipocalemia, hipocalcemia e hipomagnesemia, hipercalemia, entre otras alteraciones. El objetivo de este trabajo fue investigar las caracteríscas del uso inapropiado de diuréticos a partir de la casuística del CENATOXA. Se realizó un estudio descriptivo restrospectivo sobre los análisis ingresados al CENATOXA con solicitud de investigación cualitativa de diuréticos en orina, entre los años 2002 y 2016. En dicho período ingresaron al CENATOXA 138 casos, de los cuales el 56 % resultó positivo para algún diurético. Del total de casos con resultado positivo, el 93,5 % fueron mujeres entre 25 y 55 años de edad y predominó la etiología intencional. Los diuréticos mayoritariamente encontrados fueron hidroclorotiazida y furosemida. El perfil de diuréticos hasta el año 2008 (hidroclorotiazida = 68% de los casos positivos) se diferenció del hallado entre 2009 y 2016 (furosemida + hidroclorotiazida = 60% de los casos positivos). Se observó recurrencia en el uso inapropiado en el 8% de los casos. El uso simultáneo de más de un diurético y la recurrencia son factores que pueden contribuir a la aparición de toxicidad. Estos resultados sugieren que el uso inapropiado de diuréticos es una situación que debería ser ob­servada más atentamente para establecer mejor su alcance y sus riesgos.

Among the situations associated with diuretics misuse are the attempts to lose weight fast, frequently observed in eating disorders, and the attempts to mask the consumption of other substances, in the case of sports competitions. The use of these drugs with no medical indication or supervision generates an electrolyte imbalance, leading to hyponatremia, hypokalemia, hypocalcemia and hypomagnesemia, hyperkalemia, among other alterations. The objective of this work was to investigate the characteristics of diuretics misuse from the CENATOXA database, where the qualitative investigation of diuretics in urine is per­formed. A descriptive retrospective study was conducted on the cases admitted to the CENATOXA with a request for qualitative diuretic investigation, between 2002 and 2016. During this period, 138 urine samples were received at the CENATOXA and 56% were positive for at least one diuretic. Of all cases with positive results, 93.5% were women between 25 and 55 years of age, and intentional etiology predominated. The most detected diuretics were hydrochlorothiazide and furosemide. The diuretic misuse pattern detected up to 2008 (hydrochlorothiazide = 68% of positive cases) differed from that detected between 2009 and 2016 (furosemide + hydrochlorothiazide = 60% of positive cases). Recurrence in misuse was observed in 8% of the cases. The simul­taneous misuse of more than one diuretic and the recurrence are factors that can contribute to the onset of toxicity. These results suggest that diuretic misuse is a situation that should be observed more closely to better assess its consequences and its risks.

Screening for parathyroid hormone resistance in patients with nonphenotypically evident pseudohypoparathyroidism.

OBJECTIVE: Hypocalcemia and hyperphosphatemia in the setting of elevated parathyroid hormone (PTH) and normal vitamin D metabolites, raises the possibility of PTH resistance. The idiopathic and inherited forms of PTH resistance are referred to as pseudohypoparathyroidism. Nonphenotypically evident pseudohypoparathyroidism can go undiagnosed for decades. We have designed a new test to diagnose PTH resistance and confirmed its clinical utility in the diagnosis of pseudohypoparathyroidism. METHODS: Our test consists of a subcutaneous injection of commercially available recombinant PTH and concomitant measurement of cyclic adenosine monophosphate in urine. We implemented the test in 2 patients with recalcitrant hypocalcemia and a healthy control subject. RESULTS: Our test unequivocally demonstrated PTH resistance in both patients. One of the patients had phenotypically evident pseudohypoparathyroidism type-1a hence, PTH resistance was suspected. The other patient with nonphenotypically evident disease, also showed PTH resistance and was later demonstrated to have pseudohypoparathyroidism type-1b at the genomic level and confirmed to be of familial type. CONCLUSION: Our results show for the first time the implementation of a simple new diagnostic tool designed to check for PTH resistance. This new test has already proven to be useful in few occasions at our institution. Larger populations, however, should be tested before implementation of such a test is considered a standard of care.

Phenotypic variation in a large family with autosomal dominant hypocalcaemia.

BACKGROUND/AIMS: Autosomal dominant hypocalcaemia (ADH) is caused by activating mutations in the calcium- sensing receptor (CASR). We aimed to describe the phenotypic variation within a large family with ADH, especially kidney and cerebral basal ganglia calcifications. METHODS: Fifteen related subjects carrying the CASR mutation T151M participated in a cross-sectional study of calcium homeostasis, renal ultrasonography, cerebral CT, bone mineral density, and health-related quality of life (HRQoL). RESULTS: Eight subjects had received vitamin D treatment (mean duration 15.3 years; range 11-20 years). Urinary calcium excretion was elevated in 5/8 vitamin-D-treated and in 3/7 untreated subjects. Serum magnesium, calcium and parathyroid hormone remained at the lower reference limit or below. Renal calcifications were found in 12 of 14 (86%) and basal ganglia calcifications in 5 of 11 (46%) subjects, independently of vitamin D therapy. The glomerular filtration rate was moderately reduced in 3 subjects. Mean bone mineral density and bone markers were normal. HRQoL was impaired in the vitamin-D-treated group despite correction of the hypocalcaemia. CONCLUSIONS: The impact of the CASR mutation on calcium homeostasis varied greatly. Kidney and basal ganglia calcifications are common in ADH independently of vitamin D treatment, which, however, increases urinary calcium excretion and may promote urolithiasis.

Calcium metabolism in the early posttransplantation period.

BACKGROUND AND OBJECTIVES: Information on the time course of serum calcium levels after renal transplantation is scanty, especially in the early posttransplantation period. Both the abrupt cessation of calcium-containing phosphorus binders and vitamin D (analogs) at the time of surgery and the recovery of renal function may be hypothesized to affect serum calcium levels in this period. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this prospective observational study, biointact parathyroid hormone, calcidiol, calcitriol, calcium, and phosphorus levels were monitored in 201 renal transplant recipients at the time of transplantation and 3 mo thereafter. In addition, the serum calcium nadir and peak in each individual patient within this time frame were identified and the urinary fractional calcium excretion was determined at month 3. RESULTS: Serum calcium levels followed a biphasic pattern with a significant decline during the first postoperative week, followed by a significant increase. High pretransplantation parathyroid hormone levels protect against hypocalcemia within the first postoperative week but put patients at risk for hypercalcemia later. These complications, occurring in 41 and 14% of the patients, respectively, most probably reflect inappropriate calcium release from the skeleton, rather than inappropriate renal calcium handling. CONCLUSIONS: Our data indicate that both hypo- and hypercalcemia are prevalent in the early posttransplantation period. Pretransplantation parathyroid function is an important predictor of posttransplantation calcium levels.

Treatment of hypocalcemia caused by hypoparathyroidism or pseudohypoparathyroidism with domestic-made calcitriol: a prospective and self-controlled clinical trial.

BACKGROUND: Parathyroid hormone deficiency or resistance may cause hypocalcemia with related symptoms and signs. Lifelong treatment of calcium combined with vitamin D or its metabolites is always necessary for these patients. Here we reported a prospective and open-label trial to investigate the efficacy and safety of domestic-made calcitriol in treatment of hypocalcemia caused by hypoparathyroidism or pseudohypoparathyroidism. METHODS: Twenty-four patients with confirmed hypoparathyroidism or pseudohypoparathyroidism aged (36.5 +/- 11.0) years old were studied. Among them, 16 patients had idiopathic hypoparathyroidism, 2 had pseudohypoparathyroidism and 6 had hypoparathyroidism secondary to cervical surgery. Serum calcium levels were lower than 1.88 mmol/L. Oral calcitriol was administered twice or three times with elemental calcium 1.2 g per day. All patients were followed every 4 weeks throughout the 12-week period. Dose adjustments of calcitriol were based on serum and urinary calcium levels and symptoms of hypocalcemia. RESULTS: Twenty patients were included by the end of this study. Muscular weakness, cramps, extremity paresthesia, Chovestek's sign and Trousseau's sign were relieved in 76.9%, 100%, 94.4%, 93.3% and 78.9% of patients, respectively. Serum calcium, plasma ionized calcium and serum phosphorus levels were (1.54+/-0.25) mmol/L, (0.64+/-0.10) mmol/L and (2.00+/-0.46) mmol/L at baseline, and reached (2.20+/-0.20) mmol/L, (0.95+/-0.06) mmol/L and (1.68+/-0.25) mmol/L (P<0.01) at the 12th week of treatment, respectively. Eighty percent of patients were assessed as effective and 20% as partly effective. Three, four and eight patients had hypercalciuria at the 4th, 8th and 12th week of treatment, respectively, which were reduced by thiazide diuretics. The final dose of calcitriol was (1.09+/-0.50) microg/d. CONCLUSIONS: Calcitriol combined with calcium can be used in treatment of hypocalcemia caused by hypoparathyroidism or pseudohypoparathyroidism effectively and safely. Serum and urinary calcium levels should be monitored during the course of the therapy.

Comparison of bone resorption markers during hypocalcemia in dairy cows.

This study investigated whether hydroxyproline, deoxypyridinoline, or the carboxyterminal telopeptide of type I collagen could be used as markers to provide evidence of bone resorption during hypocalcemia of dairy cows. Serum concentrations of the amino-terminal propeptide of type III procollagen were also analyzed to study the effect of parturition on type III collagen, which is a component of soft connective tissues. Urine and blood samples were collected on d 1 to 5, on d 9, and d 14 after parturition from 18 cows with symptoms of periparturient paresis (group 1) and 19 healthy control cows without symptoms (group 2). Urine concentrations of hydroxyproline and deoxypyridinoline were measured with a colorimetric assay and an enzyme immunoassay, respectively. Serum concentrations of the amino-terminal propeptide of type III procollagen were measured using a commercially available radioimmunoassay. A radioimmunoassay was developed to analyze serum concentrations of the carboxyterminal telopeptide of bovine type I collagen. The mean corrected urinary hydroxyproline concentrations in group 1 increased from parturition to d 14; concentrations in group 1 were significantly higher for group 2 after d 5. Mean corrected deoxypyridinoline concentrations in urine increased after parturition to reach a peak at d 9, and serum concentrations of the carboxyterminal telopeptide of type I collagen peaked at d 5. However, mean concentrations of deoxypyridinoline and the carboxyterminal telopeptide of type I collagen did not differ significantly between groups. The variation in the behavior of the three markers is likely a reflection of the different phases and aspects of the bone collagen degradation. In conclusion, assays for urinary deoxypyridinoline and serum carboxyterminal telopeptide of type I collagen determinations are useful tools to follow the course of degradation of bone collagen in dairy cows.

[Physiology and pathophysiology of calcium and phosphate metabolism in newborn infants. Personal study results and literature references]. / Physiologie und Pathophysiologie des Kalzium- und Phosphatstoffwechsels im Neugeborenenalter.

This description of the physiology and pathophysiology of the calcium and phosphate balance in neonates is based on our own studies and a short review of the literature. In general, the higher the calcium concentration in the umbilical cord blood the greater its decrease during the first two days of life. With asphyxiated newborns the decrease in the serum level of both the total calcium and the ionized calcium surpasses that in nonasphyxiated newborns by approximately a third. There are various causes for neonatal hypocalcemia. The most striking causes for the early form of hypocalcemia are likely to be a transient hypoparathyroidism or a failure of end-organ responsiveness. In nearly all newborns we found a low urinary cAMP excretion on the first day of life increasing significantly until the fourth day. Measurements of the urinary cAMP excretion are an appropriate parameter for recognizing the parathormone effect. By measuring both the parathormone level in the serum and the urinary cAMP excretion it is possible to distinguish hypoparathyroidism from pseudoparathyroidism . Several cases with different forms of hypocalcemia are discussed.

Familial hypocalciuric hypercalcemia. Report of a new family.

We report a new family with familial hypocalciuric hypercalcemia (FHH) composed by 55 living members. Of 38 studied, 10 have been found to be affected by FHH. Differences between FHH and primary hyperparathyroidism are emphasized; lack of clinical features, relative hypocalciuria for the concomitant hypercalcemia and low phosphate excretion index. The PTH and urinary cAMP are normal. It is noteworthy that the disease is benign. None of our patients have undergone surgery, and all of them are asymptomatic.

Urinary content of 3',5'-adenosine monophosphate (cAMP) and creatinine in full-term and premature infants.

Cyclic 3',5'-monophosphate (c-AMP) and creatinine were measured in full-term and premature infants. In normals, values for c-AMP were highest on days 1 and 2 (1.3-1.5 nmol/ml) and decreased thereafter. In prematures the c-AMP values were significantly lower than in the full-term infants. There was a rough correlation with birth weight. Creatinine values were closely reflected by the c-AMP levels. Changes found in neonatal jaundice, hypocalcaemia, respiratory distress syndrome, and anoxia could be attributed to prematurity. No diurnal variation in c-AMP values was found.

Urinary cyclic AMP analyzed as a function of the serum calcium and parathyroid hormone in the idfferential diagnosis of hypercalcemia.

Urinary cyclic AMP (UcAMP) appropriate for the serum calcium concentration was determined in normal subjects during the base-line state and during alteration in their serum calcium concentrations by saline and calcium infusions. This was compared to the UcAMP in 76 patients with hypercalcemia and 5 patients with hypocalcemia. In 54 of 56 patients with primary hyperparathyroidism, the UcAMP was inappropriately high for their serum calcium concentration, the 2 exceptions having renal failure. In four patients with vitamin D intoxication, sarcoidosis, milkalkali syndrome, and thiazide-induced hypercalcemia and in five patients with hypocalcemia due to hypoparathyroidism, the UcAMP was appropriately low for their serum calcium concentration. In 16 patients with nonparathyroid neoplasms, 10 had UcAMP levels that were inappropriately high suggesting ectopic parathyroid hormone (PTH)-mediated hypercalcemia and 6 had UcAMP levels that were appropriately low suggesting that their hypercalcemia was due to osteolytic factors other than PTH. Correlations between UcAMP, serum calcium concentration, and carboxyl-terminal immunoreactive PTH suggest that random UcAMP is a sensitive accurate reflection of circulating biologically active PTH. If there is adequate renal function (serum creatinine concentration less than 2.0 mg/dl), a random UcAMP expressed as mumol/g creatinine and analyzed as a function of the serum calcium concentration completely separates patients with PTH and non-PTH-mediated hypercalcemia.

[Primary hyperparathyroidism (1st degree HPT): plasma vitamin D and urinary cyclic AMP during the postoperative phase]. / Primärer Hyperparathyreoidismus (1 degree HPT): Vitamin D im Plasma und cyclisches AMP im Urin in der postoperativen Phase

In 30 controls and 30 patients with primary hyperparathyroidism 25-OH-vitamin D in serum and urinary cyclic AMP were determined by competitive protein binding assays. Removal of hyperplastic or adenomatous parathyroid glands resulted in hypocalcemia with 1. low urinary cyclic AMP in surgical hypoparathyreoidism 2. high urinary cyclic AMP in skeletal calcium deficiency, 3. high urinary cyclic AMP in 25-OH-vitamin D deficiency. In calcium or vitamin D deficiency, therapy with calcium or calcium and vitamin D corrected hypocalcemia and urinary cyclic AMP.