Factors associated with glomerular filtration rate variation in primary hyperparathyroidism after parathyroidectomy

Clinical effect of regional citrate anticoagulation continuous renal replacement therapy in three patients with hypercalcemic crisis

In this study, we investigated the effectiveness of regional citrate anticoagulation continuous renal replacement therapy (RCA-CRRT) in reducing blood calcium levels in three patients with hypercalcemia crisis caused by different etiologies. The sodium citrate chelation of calcium ions was utilized as an anticoagulant for treating severely affected patients. By adjusting the citrate anticoagulant dose and monitoring treatment indicators, RCA-CRRT parameters were actively modified to alleviate the hypercalcemia crisis and provide time for surgery or specialized treatment. Two patients experienced rapid and effective reductions in blood calcium levels, allowing for further treatment, while the third patient exhibited a repeated increase in blood calcium, which eventually decreased after parathyroid adenoma resection, leading to clinical discharge. Our findings suggest that RCA-CRRT can help alleviate hypercalcemia crisis, stabilize the patient's internal environment, and provide valuable time for clinical treatment in cases of various medical conditions causing abnormal blood calcium elevations.

Estimated Effect of Parathyroidectomy on Long-Term Kidney Function in Adults With Primary Hyperparathyroidism

BACKGROUND

Multidisciplinary guidelines recommend parathyroidectomy to slow the progression of chronic kidney disease in patients with primary hyperparathyroidism (PHPT) and an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2. Limited data address the effect of parathyroidectomy on long-term kidney function.

OBJECTIVE

To compare the incidence of a sustained decline in eGFR of at least 50% among patients with PHPT treated with parathyroidectomy versus nonoperative management.

DESIGN

Target trial emulation was done using observational data from adults with PHPT, using an extended Cox model with time-varying inverse probability weighting.

SETTING

Veterans Health Administration.

PATIENTS

Patients with a new biochemical diagnosis of PHPT in 2000 to 2019.

MEASUREMENTS

Sustained decline of at least 50% from pretreatment eGFR.

RESULTS

Among 43 697 patients with PHPT (mean age, 66.8 years), 2928 (6.7%) had a decline of at least 50% in eGFR over a median follow-up of 4.9 years. The weighted cumulative incidence of eGFR decline was 5.1% at 5 years and 10.8% at 10 years in patients managed with parathyroidectomy, compared with 5.1% and 12.0%, respectively, in those managed nonoperatively. The adjusted hazard of eGFR decline did not differ between parathyroidectomy and nonoperative management (hazard ratio [HR], 0.98 [95% CI, 0.82 to 1.16]). Subgroup analyses found no heterogeneity of treatment effect based on pretreatment kidney function. Parathyroidectomy was associated with a reduced hazard of the primary outcome among patients younger than 60 years (HR, 0.75 [CI, 0.59 to 0.93]) that was not evident among those aged 60 years or older (HR, 1.08 [CI, 0.87 to 1.34]).

LIMITATION

Analyses were done in a predominantly male cohort using observational data.

CONCLUSION

Parathyroidectomy had no effect on long-term kidney function in older adults with PHPT. Potential benefits related to kidney function should not be the primary consideration for PHPT treatment decisions.

PRIMARY FUNDING SOURCE

National Institute on Aging.

The importance of hypophosphatemia in the clinical management of primary hyperparathyroidism

AIM

The levels of serum phosphorus (P) are low or low-normal in primary hyperparathyroidism (PHPT), and there is an inverse relationship between the levels of parathormone (PTH) and P. However, when considering the diagnostic and surgical indication criteria of PHPT, serum P levels are generally ignored. The aim of this study was to retrospectively evaluate the association of serum P levels with the clinical outcomes of PHPT.

MATERIALS AND METHODS

A retrospective evaluation was made of the data of 424 consecutive patients (370 females, 54 males) with PHPT who presented at our centre.

RESULTS

The mean age of the study population was 57 ± 11.68 years. The mean P was 2.57 ± 0.53 mg/dl. Asymptomatic disease was determined in 199 (47%) patients. Male patients had significantly lower levels of P. Symptomatic patients and patients with renal stones, vitamin D < 20 µg/l, calcium level ≥ 11.2 mg/dl, 24 h urinary calcium > 400 mg/day, or hypomagnesemia, were seen to have significantly lower levels of P (p < 0.05). Hypophosphatemia (hypoP) was found in 202 of 424 patients (47%), and these patients had a higher rate of symptomatic disease (63% to 44%, p < .0001). Of the 61 (88%) patients with moderate hypoP, 54 (88%) had at least one of the surgical criteria. A statistically significant increase in the incidence of hypoP was determined in symptomatic and male patients. In the patients with hypoP, serum PTH and urine calcium levels were found to be higher, and lumbar T-scores and serum vitamin D levels were lower. The patients with hypoP had higher rates of renal stones and osteoporosis (p < 0.05).

CONCLUSIONS

The current study results show that hypoP is associated with a higher risk of osteoporosis and renal stones in PHPT patients. Even if patients are asymptomatic, moderate hypoP may be associated with poor outcomes of PHPT. Therefore, moderate hypoP may be a new criterion for parathyroidectomy, regardless of hypercalcemia level.

Spectrum of renal dysfunction after curative parathyroidectomy in symptomatic primary hyperparathyroidism

OBJECTIVE

The long-term renal consequences of curative parathyroidectomy (PTX) in symptomatic primary hyperparathyroidism (sPHPT) are not well characterized. We aimed to assess renal glomerular and tubular functions in an sPHPT cohort at ≥1 year's follow-up.

DESIGN

Retrospective-prospective study.

METHODS

sPHPT patients with preoperative eGFR ≥60mL/min/1.73m² and in remission (normocalcemic) for ≥1 year after PTX underwent clinical and biochemical assessment (calcium profile, renal parameters). Ammonium chloride and bicarbonate loading tests were performed in patients with renal tubular dysfunction (RTD).

RESULTS

Forty-eight patients (31 females) with median plasma PTH 1,029 (338-1604) pg/mL and mean eGFR 109.2±26.0mL/min/1.73m² at diagnosis were evaluated at 5.62±3.66 years after curative PTX. At follow-up, eGFR was <60mL/min/m² in 5 patients (10.4%). Patients with >10% drop in eGFR (n=31) had significantly higher pre-PTX plasma PTH (1,137 vs. 687pg/mL), and longer time to post-PTX evaluation (6.8 vs. 3.4 years). RTD was seen in 11 patients (22.9%): urinary low molecular weight proteinuria (14.6%), distal renal tubular acidosis (12.5%), hypophosphatemia (8.3%), and hypokalemia (8.3%); RTD was associated with significantly lower post-PTX eGFR (72.7 vs. 95.4mL/min/m²). Five of the 7 RTD patients undergoing loading test had impaired urinary acidification, whereas none had impaired bicarbonate resorption.

CONCLUSIONS

Reduction in eGFR and subclinical RTD were prevalent at long-term follow-up in the present Asian-Indian cohort with cured sPHPT. Further studies are warranted to understand the clinical implications of these various renal abnormalities.

Effects of parathyroidectomy on kidney function in patients with primary hyperparathyroidism: Results of a prospective study

BACKGROUND

Altered glomerular filtration rate is a controversial indication for parathyroidectomy in patients with primary hyperparathyroidism. The objective of this study was to evaluate the estimated glomerular filtration rate change 12 months after parathyroidectomy for primary hyperparathyroidism according to preoperative kidney function.

METHOD

Patients who underwent parathyroidectomy for primary hyperparathyroidism between 2016 and 2021 (n = 381) were enrolled in a monocentric prospective cohort. Patients without 1-year follow-up or with missing data were excluded (n = 135, 35%). Patients were dichotomized according to their baseline estimated glomerular filtration rate: <60 mL/min (group 1) and ≥60 mL/min (group 2). Parameters were measured before and then at 6 and 12 months after parathyroidectomy.

RESULTS

Out of 246 included patients, 27 (11%) were assigned to group 1 and 219 (89%) to group 2. The mean baseline estimated glomerular filtration rate was 46.8 ± 11.5 and 87.3 ± 14.7 mL/min in groups 1 and 2, respectively. Group 1 patients were older (P = .0006) and had a higher median serum parathyroid hormone level (P = .021). At 6 months postoperative, 224 patients (91%) were normocalcemic. The estimated glomerular filtration rate raw change after parathyroidectomy was significantly higher in group 1 than in group 2 (4.2 ± 7.8 vs -2.2 ± 9.1 mL/min, P = .0004). In group 1, 13/27 patients (48%) improved their chronic kidney disease stage after parathyroidectomy, including 6/13 (46%) with postoperative estimated glomerular filtration rate ≥60 mL/min, whereas 2/27 (7%) worsened. The baseline estimated glomerular filtration rate <60 mL/min and elevated serum calcium level were associated with postoperative estimated glomerular filtration rate improvement in multivariable analysis (P = .0023 and .039, respectively).

CONCLUSION

Parathyroidectomy for primary hyperparathyroidism is more likely to improve kidney function in patients with preoperative estimated glomerular filtration rate <60 mL/min. These results strengthen the current guidelines for surgery.

Clinical features of sporadic multigland parathyroid disease

Background. Sporadic multigland parathyroid disease (MGD) account for 1/4 of all cases of primary hyperparathyroidism (PHPT). There are no specific signs of MGD in comparison with single-gland parathyroid disease in PHPT. The only radical treatment is surgical, therefore, determining the number of excessively functioning parathyroid glands at the preoperative stage is important for choosing the extent of the operation and the success of the treatment in general.The aim. To identify the specific signs of multigland parathyroid disease in patients who underwent surgery for primary hyperparathyroidism. Methods. We conducted a single-center prospective study including 126 cases of surgical treatment of PHPT from December 2019 to June 2021. The study included an analysis of demographic, clinical, laboratory parameters and visual methods of topical diagnosis of parathyroid glands (ultrasound, scintigraphy, multislice computed tomography). The main endpoint of the study was the identification of characteristic signs of MGD in patients with PHPT.Results. Lower values of creatinine (p ≤ 0.01; Mann – Whitney U-test), albuminadjusted calcium (p ≤ 0.05; Mann – Whitney U-test), parathyroid hormone (p ≤ 0.01; Mann – Whitney U-test), glomerular filtration rate (p ≤ 0.01; Mann – Whitney U-test) and inconsistency of two methods of preoperative imaging (p ≤ 0.01; χ2) were set as specific signs of multigland compared with single-gland parathyroid disease. Conclusion. The results of preoperative biochemical and imaging studies can become the basis for differentiating single-gland and multigland parathyroid disease in primary hyperparathyroidism.

Therapy-Resistant Hypercalcemia in a Patient with Inactivating CYP24A1 Mutation and Recurrent Nephrolithiasis: Beware of Concomitant Hyperparathyroidism

We describe a case harboring a homozygous CYP24A1 mutation with mild loss of function, first presenting with recurrent nephrolithiasis from the age of 22 onward, initially associated with hypercalcemia and low PTH concentrations. Over the years, hyperparathyroidism developed, resulting in more severe hypercalcemia. Also, kidney function deteriorated, most probably as a consequence of biopsy-proven nephrocalcinosis. Conventional treatment options for CYP24A1 mutation were not effective and/or tolerated (avoidance of sun exposure, diet, pamidronate, itraconazole). A total parathyroidectomy was performed resulting in a normocalcemic hypoparathyroidism without need for treatment with vitamin D analogs, a positive bone mineral balance and an improved kidney function.