Effect of Cellulose Phosphate and Dietary Calcium Restriction in Primary Hyperparathyroidism

1975 ◽  
Vol 49 (2) ◽  
pp. 91-98 ◽  
Author(s):  
A. M. Parfitt
Keyword(s):  
Primary Hyperparathyroidism ◽  
Urinary Calcium ◽  
Tubular Reabsorption ◽  
Plasma Calcium ◽  
Cation Binding ◽  
Published Data ◽  
Small Contribution ◽  
Bivalent Cation ◽  
Cellulose Phosphate ◽  
Low Calcium Diet

1. The bivalent cation-binding agent, cellulose phosphate, together with a low calcium diet was given for 6 days to nine patients with primary hyperparathyroidism subsequently verified at surgery. 2. Urinary calcium fell promptly by 8·4 mmol/24 h, and by 70%, and reached amounts below 4·0 mmol/24 h in five of the nine patients. The magnitude of fall may have been related to increased synthesis of vitamin D by the skin in a sub-tropical environment. Plasma magnesium fell steadily and urinary magnesium fell by 80%. 3. The plasma calcium showed two types of response. In five patients there was no significant change because a reduction in calcium load was offset by a further increase in the already high tubular reabsorption of calcium. In the remaining four patients, the tubular reabsorption of calcium was at a higher level initially and failed to increase further on the experimental regime, with a corresponding fall in plasma calcium. 4. The hypercalcaemia of primary hyperparathyroidism can be explained by increased gastrointestinal absorption and increased renal tubular reabsorption of calcium; net bone resorption makes only a small contribution but an additional factor dependent on the blood-bone equilibrium is not ruled out. 5. Comparison with other published data suggests that the fall in urinary calcium in response to a calcium-depleting regimen is prevented by concurrent depletion of inorganic phosphate and may be enhanced by concurrent depletion of magnesium. 6. Persistence of hypercalcaemia combined with an increase in tubular reabsorption of calcium in response to cellulose phosphate may be of diagnostic value in suspected primary hyperparathyroidism. 7. Cellulose phosphate may be of value in stone prevention in patients with primary hyperparathyroidism who are unsuitable for surgical treatment.

Effect of Cellulose Phosphate on Calcium and Magnesium Homeostasis: Studies in Normal Subjects and Patients with Latent Hypoparathyroidism

1975 ◽  
Vol 49 (2) ◽  
pp. 83-90 ◽  
Author(s):  
A. M. Parfitt
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Normal Subjects ◽  
Urinary Calcium ◽  
Tubular Reabsorption ◽  
Plasma Calcium ◽  
Cellulose Phosphate ◽  
Parathyroid Function ◽  
Edta Infusion

1. The bivalent cation-binding agent, cellulose phosphate, was given for 6 days to four normal subjects and six patients with latent hypoparathyroidism (diagnosed by impaired response to EDTA infusion), all of whom were on a moderately low calcium diet. 2. In normal subjects, there was a prompt and sustained fall in urinary calcium with no change in plasma calcium, indicating increased tubular reabsorption. Plasma and urinary magnesium fell, without increase in tubular reabsorption. The urinary total hydroxyproline increased and Tm,P/ glomerular filtration rate fell after 2 days; these changes were transient and were consistent with a transient increase in parathyroid hormone secretion. 3. In the hypoparathyroid patients, urinary calcium fell more slowly and a fall in plasma calcium occurred in several subjects, the extent and duration of which corresponded with parathyroid status determined by EDTA infusion. Urinary conservation of calcium was impaired but plasma and urinary magnesium fell as in normal subjects. Urinary total hydroxyproline did not change and Tm,P/glomerular filtration rate fell more slowly than in the normal subjects. 4. The relative contributions of increased tubular reabsorption and reduced filtered load to calcium conservation in response to calcium depletion depend on the prevailing level of parathyroid function; the former is more important when parathyroid function is normal, the latter when parathyroid function is impaired. 5. In the detection of reduced parathyroid reserve, the assessment based on the plasma calcium response to cellulose phosphate agrees closely with the assessment based on the degree of recovery from EDTA-induced hypocalcaemia.

PRE-OPERATIVE LOCALIZATION OF HYPERFUNCTIONING PARATHYROID TISSUE BY PARATHYROID SCINTIGRAPHY

1976 ◽  
Vol 81 (2) ◽  
pp. 298-309 ◽  
Author(s):  
P. Burckhardt ◽  
A. Bischof-Delaloye ◽  
B. Ruedi ◽  
B. Delaloye
Keyword(s):  
Primary Hyperparathyroidism ◽  
False Positive ◽  
Parathyroid Tissue ◽  
Tubular Reabsorption ◽  
Plasma Calcium ◽  
Parathyroid Scintigraphy ◽  
Biochemical Screening ◽  
Parathyroid Adenomas ◽  
Positive Results ◽  
Positive Focus

ABSTRACT In 22 patients who underwent surgery suspected of primary hyperparathyroidism, the surgical findings were compared with the results obtained by pre-operative parathyroid scanning and biochemical screening. Thirteen of 15 parathyroid adenomas were localized by pre-operative scanning, but in five of them a false positive focus was also described. The technique was less useful in primary hyperplasia. Comparable results were reported by other investigators. In both instances the best results were obtained in patients with high parathyroid activity as measured by plasma calcium, plasma alkaline phosphatase and tubular reabsorption of phosphorus (TRP). Parathyroid scintigraphy was especially helpful in the presence of ectopic adenomas and in patients who had undergone previous parathyroid surgery. Unfortunately, the possibility of false positive results makes it unreliable for the diagnosis of primary hyperparathyroidism.

EFFECT OF CALCIUM DEPRIVATION ON PARATHYROID HORMONE-MEDIATED BONE AND KIDNEY CONTRIBUTIONS TO THE MAINTENANCE OF PLASMA CALCIUM IN RATS

1975 ◽  
Vol 64 (2) ◽  
pp. 299-304 ◽  
Author(s):  
D. N. KALU ◽  
A. HADJI-GEORGOPOULOS ◽  
G. V. FOSTER
Keyword(s):  
Parathyroid Hormone ◽  
Urinary Calcium ◽  
Normal Diet ◽  
Plasma Calcium ◽  
Urinary Hydroxyproline ◽  
Deficient Diet ◽  
Adult Rats ◽  
Low Calcium Diet ◽  
Hydroxyproline Excretion ◽  
Plasma Calcium Level

SUMMARY This study was designed to investigate the roles of bone and kidney in the acute regulation of plasma calcium by parathyroid hormone (PTH) during prolonged calcium deprivation. The effect of PTH was assessed by gland ablation. Animals were thyroparathyroidectomized or sham-operated and their urine was collected for 3 h. Subsequently they were anaesthetized and bled from the abdominal aorta. In rats fed on a low calcium diet, urinary hydroxyproline excretion was enhanced and, unlike animals fed on a normal diet, decreased 3 h after thyroparathyroidectomy (TPTX). In addition TPTX decreased plasma calcium by 0·45 mg/100 ml in normal rats compared with 1·94 mg/100 ml in animals fed on a calcium-deficient diet. Urinary calcium increased by 161 and 12 μg and accounted for 82 and 1·4% of the fall in plasma calcium in normal and calcium-deprived animals respectively. The corresponding contributions of bone were 18 and 98·6%. These findings support the view that with prolonged calcium deprivation in adult rats, the relative contributions of bone and kidney to the acute regulation of the plasma calcium level by PTH are reversed. As a result, bone rather than kidney becomes the more important organ. At the same time non-PTH-mediated kidney reabsorption of calcium is increased.

Treatment of Severe Hypercalcemia in Primary Hyperparathyroidism with Aminopropylidene Diphosphonate

1992 ◽  
Vol 8 (4) ◽  
pp. 155-157
Author(s):  
Harold W. de Valk ◽  
Anton K.M. Bartelink ◽  
Onno J.J. Cluysenaer ◽  
Matthieu M. Tjoeng
Keyword(s):  
Primary Hyperparathyroidism ◽  
Calcium Concentration ◽  
Extracellular Fluid ◽  
Urinary Calcium ◽  
Plasma Calcium ◽  
Cardiac Conduction ◽  
Calcium Excretion ◽  
Hypercalcemic Crisis ◽  
Severe Hypercalcemia ◽  
Plasma Calcium Concentration

Objective: To test the clinical usefulness and potency for decreasing plasma calcium concentration of an intravenously administered diphosphonate (aminopropylide diphosphonate [APD]) in a patient with hypercalcemic crisis secondary to primary hyperparathyroidism, unresponsive to hydration and furosemide, and who was ineligible for surgery because of cardiac conduction defects. Design: Case report. Setting: Referred care setting. Intervention: The patient received APD 15 mg/d, dissolved in 100 mL of isotonic NaCl 0.9% and infused in one hour. Main Outcome Measure: Plasma calcium concentration. Results: The patient's plasma calcium concentration fell considerably in a few days. The concomitant decrease in urinary calcium excretion indicates that this fall is caused by a decreased entry of calcium to the extracellular fluid and not to increased renal calcium excretion. After nine days, a parathyroid adenoma was removed; plasma calcium concentration remained normal during the following three years. Conclusions: APD is a useful adjunct to medical therapy in patients with hypercalcemic crisis secondary to primary hyperparathyroidism.

The Effect of Cellulose Phosphate on Plasma and Urinary Magnesium at Different Levels of Parathyroid Function in Man

1976 ◽  
Vol 51 (2) ◽  
pp. 161-168 ◽  
Author(s):  
A. M. Parfitt
Keyword(s):  
Parathyroid Hormone ◽  
Lower Limit ◽  
Hormone Secretion ◽  
Normal Subjects ◽  
Tubular Reabsorption ◽  
Published Data ◽  
Cellulose Phosphate ◽  
Parathyroid Function ◽  
Magnesium Excretion ◽  
Plasma Magnesium

1. Previously published data obtained by magnesium infusion in man were found to conform to a Tm/glomerular filtration rate (GFR) model on the assumption of 80% diffusibility of plasma magnesium. The lower limit of Tm,Mg/GFR was 625 μmol/l. 2. Previously published data concerning the effect of cellulose phosphate on magnesium metabolism in normal subjects, patients with latent hypoparathyroidism and patients with primary hyperparathyroidism were found to conform to the same model, with the same lower limit for Tm,Mg/GFR for all three levels of parathyroid function. 3. The threshold for magnesium excretion is sharper with less ‘splay’ than for phosphate, but as for phosphate it is close to the normal blood concentration. 4. Because of the geometrical relationship between different methods of presentation of data, at a constant value for Tm,Mg/GFR changes in magnesium load or in GFR automatically produce changes in fractional magnesium clearance. This is the explanation for the increase in fractional magnesium clearance which occurs with diminishing renal function. 5. Renal conservation of magnesium is a passive consequence of the fall in plasma magnesium. There was no evidence of augmented tubular reabsorption of magnesium in response to magnesium deprivation in any of the three groups of subjects. 6. The tubular reabsorption of magnesium was not altered detectably by a moderate deficiency or excess of parathyroid hormone. Changes in parathyroid hormone secretion are probably not concerned in normal magnesium homeostasis.

scholarly journals Primary Hyperparathyroidism in Homozygous Sickle Cell Patients: A Hemolysis-Mediated Hypocalciuric Hypercalcemia Phenotype?

2021 ◽  
Vol 10 (21) ◽  
pp. 5179
Author(s):  
Edmat Akhtar Khan ◽  
Lynda Cheddani ◽  
Camille Saint-Jacques ◽  
Rosa Vargas-Poussou ◽  
Vincent Frochot ◽  
...  
Keyword(s):  
Primary Hyperparathyroidism ◽  
Sickle Cell ◽  
Fractional Excretion ◽  
Urinary Calcium ◽  
High Rate ◽  
Calcium Handling ◽  
Control Group ◽  
Calcium Excretion ◽  
Calcium Reabsorption ◽  
Chronic Hemolysis

Primary hyperparathyroidism (pHPT) has been reported to have a higher prevalence in sickle cell disease (SCD) patients, including a high rate of recurrence following surgery. However, most patients are asymptomatic at the time of diagnosis, with surprisingly infrequent hypercalciuria, raising the issue of renal calcium handling in SCD patients. We conducted a retrospective study including (1) 64 hypercalcemic pHPT non-SCD patients; (2) 177 SCD patients, divided into two groups of 12 hypercalcemic pHPT and 165 non-pHPT; (3) eight patients with a diagnosis of familial hypocalciuric hypercalcemia (FHH). Demographic and biological parameters at the time of diagnosis were collected and compared between the different groups. Determinants of fasting fractional excretion of calcium (FeCa2+) were also analyzed in non-pHPT SCD patients. Compared to non-SCD pHPT patients, our data show a similar ionized calcium and PTH concentration, with a lower plasmatic calcitriol concentration and a lower daily urinary calcium excretion in pHPT SCD patients (p < 0.0001 in both cases). Fasting FeCa2+ is also surprisingly low in pHPT SCD patients, and thus inadequate to be considered hypercalcemia, recalling the FHH phenotype. FeCa2+ is also low in the non-pHPT SCD control group, and negatively associated with PTH and hemolytic biomarkers such as LDH and low hemoglobin. Our data suggest that the pHPT biochemical phenotype in SCD patients resembles the FHH phenotype, and the fasting FeCa2+ association with chronic hemolysis biomarkers strengthens the view of a potential pharmacological link between hemolytic by-products and calcium reabsorption, potentially through a decreased calcium-sensing receptor (CaSR) activity.

scholarly journals A novel CASR variant in a family with familial hypocalciuric hypercalcaemia and primary hyperparathyroidism

2020 ◽  
Vol 2020 ◽  
Author(s):  
Satyanarayana V Sagi ◽  
Hareesh Joshi ◽  
Jamie Trotman ◽  
Terence Elsey ◽  
Ashwini Swamy ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Organ Damage ◽  
Urinary Calcium ◽  
Interesting Case ◽  
List Type ◽  
Loss Of Function ◽  
Clearance Ratio ◽  
Hormone Levels ◽  
Severe Hypercalcaemia

Summary Familial hypocalciuric hypercalcaemia (FHH) is a dominantly inherited, lifelong benign disorder characterised by asymptomatic hypercalcaemia, relative hypocalciuria and variable parathyroid hormone levels. It is caused by loss-of-function pathogenic variants in the calcium-sensing receptor (CASR) gene. Primary hyperparathyroidism (PHPT) is characterised by variable hypercalcaemia in the context of non-suppressed parathyroid hormone levels. Unlike patients with FHH, patients with severe hypercalcaemia due to PHPT are usually symptomatic and are at risk of end-organ damage affecting the kidneys, bone, heart, gastrointestinal system and CNS. Surgical resection of the offending parathyroid gland(s) is the treatment of choice for PHPT, while dietary adjustment and reassurance is the mainstay of management for patients with FHH. The occurrence of both FHH and primary hyperparathyroidism (PHPT) in the same patient has been described. We report an interesting case of FHH due to a novel CASR variant confirmed in a mother and her two daughters and the possible coexistence of FHH and PHPT in the mother, highlighting the challenges involved in diagnosis and management. Learning points: Familial hypocalciuric hypercalcaemia (FHH) and primary hyperparathyroidism (PHPT) can coexist in the same patient. Urinary calcium creatinine clearance ratio can play a role in distinguishing between PHPT and FHH. Genetic testing should be considered in managing patients with PHPT and FHH where the benefit may extend to the wider family. Family segregation studies can play an important role in the reclassification of variants of uncertain significance. Parathyroidectomy has no benefit in patients with FHH and therefore, it is important to exclude FHH prior to considering surgery. For patients with coexisting FHH and PHPT, parathyroidectomy will reduce the risk of complications from the severe hypercalcaemia associated with PHPT.

scholarly journals Clinical Presentation of Primary Hyperparathyroidism in Older Adults

2019 ◽  
Vol 3 (12) ◽  
pp. 2305-2312 ◽  
Author(s):  
Elena Castellano ◽  
Roberto Attanasio ◽  
Alberto Boriano ◽  
Giorgio Borretta
Keyword(s):  
Older Adults ◽  
Primary Hyperparathyroidism ◽  
Older Patients ◽  
Clinical Presentation ◽  
Renal Involvement ◽  
Age Groups ◽  
Urinary Calcium ◽  
Interquartile Range ◽  
Younger Patients ◽  
Vitamin D Levels

Abstract Background The clinical presentation of primary hyperparathyroidism (PHPT) has changed greatly during the past few decades. Our aim was to evaluate whether the clinical presentation at diagnosis differed according to age. Methods We evaluated retrospectively a monocentric series of 462 consecutive patients with PHPT, dividing them according to a cutoff of 65 years of age. Results No differences were found in the mean serum PTH, calcium, or vitamin D levels. In older patients (n = 212; 45.9%), the urinary calcium levels were significantly lower (median, 205 mg/24 hour; interquartile range, 220 mg/24 hour) compared with those in younger patients (median, 308 mg/24 hour; interquartile range, 233 mg/24 hour). In addition, renal involvement was significantly less frequent (25% vs 49.2%), and bone involvement significantly more frequent (58% vs 44%) in older patients compared with younger patients. The clinical presentation was significantly different between the two age groups, with a lower frequency of symptomatic forms and a greater frequency of asymptomatic forms not meeting surgical criteria in the older patients (44.4% vs 57.2% and 18.4% vs 5.6%, respectively). Osteoporosis was significantly more frequent in the older adults than in their younger counterparts. The most affected bone site was the forearm in older adults and the lumbar spine in younger ones (50.3% and 50.5%, respectively). Conclusion The clinical presentation of PHPT differs according to age, and this difference can affect the selection of management modalities.

Urinary calcium indices in primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcaemia (FHH): which test performs best?

2020 ◽  
pp. postgradmedj-2020-137718
Author(s):  
Muhammad Fahad Arshad ◽  
James McAllister ◽  
Azhar Merchant ◽  
Edmund Rab ◽  
Jacqueline Cook ◽  
...  
Keyword(s):  
Primary Hyperparathyroidism ◽  
International Workshop ◽  
Significant Proportion ◽  
Urinary Calcium ◽  
Calcium Excretion ◽  
Clearance Ratio ◽  
Urine Calcium ◽  
Genetic Studies ◽  
Urine Calcium Excretion ◽  
Control Study

AimPrimary hyperparathyroidism (PHPT) is much more common than familial hypocalciuric hypercalcaemia (FHH), but there is considerable overlap in biochemical features. Urine calcium indices help with the differential diagnosis, but their reliability in making this distinction is not clear. The aim of this study was to compare urinary calcium values in patients with PHPT and FHH.MethodsThis was a case–control study of patients with PHPT who had successful surgery and genetically proven FHH between 2011 and 2016. Due to low FHH numbers, patients from neighbouring hospitals and outside study period (2017–2019) were allowed to improve power. Data on demographics and urinary calcium were obtained from electronic records and compared between the two groups.ResultsDuring the study period, 250 patients underwent successful PHPT surgery, while in the FHH arm, 19 genetically proven cases were included. The median (IQR) 24-hour urine calcium excretion (UCE) in the PHPT group was 8.3 (5.6–11.2) mmol/24 hours compared with 3.2 (2.1–6.1) mmol/24 hour in the FHH group (p<0.001). Median (IQR) calcium to creatinine clearance ratio (CCCR) in the PHPT and FHH groups was 0.020 (0.013–0.026) and 0.01 (0.002–0.02), respectively (p=0.001). The sensitivity of urinary tests for PHPT was 96% for UCE (cut-off ≥2.5 mmol/24 hour) and 47% for CCCR (cut-off >0.02). The specificity of the urinary tests for FHH was 29.4% for UCE (cut-off <2.5 mmol/24 hour) and 93% for CCCR (cut-off <0.02).Conclusions24-hour UCE is more sensitive in diagnosing PHPT; however, it is less specific in ruling out FHH as compared with CCCR, when the cut-offs suggested by the International guidelines from the fourth international workshop are used. A significant proportion of patients with PHPT would have also required genetic studies if the guidelines were followed.

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