Secondary Hyperparathyroidism in Chronic Hemodialysis Patients: Prevalence and Race

Secondary hyperparathyroidism is a common complication of renal failure. The exact prevalence in chronic hemodialysis patients in not known. We evaluated 122 patients who were receiving maintenance hemodialysis for at least 12 months in 2 dialysis centers in mid Michigan. Seventy-eight percent of the patients had iPTH above 200 pg/mL (mean 481 pg/mL), 19% had iPTH within the accepted normal range (mean 155 pg/mL), while 3% had level below 100 (mean 53 pg/mL). Phosphate, calcium, calcium phosphate product, age and time on dialysis are the important factors correlating with elevated iPTH. There was no significant difference in iPTH between diabetic and nondiabetic patients with mean iPTH of 403 pg/mL and 407 pg/mL respectively. Black patients had a statistically significant elevated iPTH compared with white patients with a mean iPTH of 438 pg/mL and 283 pg/mL respectively (p ≤ 0.004). Factors that predict the response to vitamin D therapy need to be evaluated to help reduce the high prevalence of secondary hyperparathyroidism. The patterns of bone disease in black patients need to be evaluated to further define the accepted normal iPTH range for this population.     

Postoperative Hungry Bone Syndrome in Patients with Secondary Hyperparathyroidism of Renal Origin

Background  

Hungry bone syndrome (HBS) is a postoperative condition of severe hypocalcemia that can be seen in patients who have undergone parathyroidectomy (PTX) for secondary hyperparathyroidism (2HPT) of renal origin. This study examines HBS in patients after PTX for 2HPT.     

Red Blood Cell Deformability and Secondary Hyperparathyroidism in Uremic Patients on Maintenance Hemodialysis

Abstract: The possible relationship between red blood cell (RBC) deformability and secondary hyperparathyroidism (HPT) in 23 patients on maintenance hemodialysis was examined. Secondary HPT was evaluated by means of serum biochemistry (parathyroid hormone, calcium, phosphorus, and alkaline phosphatase) and radiographic examinations. This study showed that RBC deformability is markedly reduced in hemodialyzed patients when compared with normal controls. No significant correlation between RBC deformability and the hemato-chemical changes associated with secondary HPT was found. No difference in RBC deformability was observed as far as the activity (alkaline phosphatase) and the severity (radiographic findings) of secondary HPT are concerned. Effective treatment of secondary HPT by either pharmacological means (1α, 25-dihydroxycholecalciferol therapy) or surgical removal was not associated with consequent improvement in RBC deformability. It is concluded that secondary HPT is probably not a major factor influencing RBC deformability in uremic patients on maintenance hemodialysis.     

Risk Factors of Severe Hypocalcemia After US-Guided Percutaneous Microwave Ablation of the Parathyroid Gland in Patients with Secondary Hyperparathyroidism

Our aim was to identify potential risk factors associated with severe hypocalcemia (SH) after microwave ablation (MWA) in patients with secondary hyperparathyroidism (SHPT). This retrospective cross-sectional study enrolled 204 consecutive patients (with 387 parathyroid glands) who underwent MWA between July 2015 and May 2018. Clinical parameters, laboratory indices, and parathyroid gland characteristics were analyzed to assess risk factors associated with SH after MWA. SH was defined as serum calcium level lower than 1.875 mmol/L (7.5 mg/dL) after MWA. Two models (I and II) for pre-MWA and post-MWA prediction were established, respectively. In accordance with the KDIGO guidelines, the target value for intact parathyroid hormone (iPTH) less than 300 pg/mL within 7 days after MWA was considered as a successful procedure. The success rate of MWA was 71.6% (146/204). The incidence of hypocalcemia and SH after MWA was 35.8% and 22.06%, respectively. The pre-MWA prediction models I and II showed that high pre-MWA iPTH, a dramatic reduction in iPTH, low pre-MWA serum calcium, multiple ablated gland, and lack of pruritus symptoms were risk factors for developing SH. The accuracy (82.23% versus 83.25% in models I and II, respectively), sensitivity (34.88% versus 44.19%), specificity (95.45% versus 94.59%), positive predictive value (PPV) (68.18% versus 70.37%), and negative predictive value (NPV) (84% versus 85.37%) of both models were promising. The logistic regression fitting of the nomograms showed high prediction efficiency (0.845 and 0.863). High pre-MWA iPTH, dramatic reductions in iPTH, low pre-MWA serum calcium, multiple gland ablation, and no pruritus symptoms were predictors of SH. © 2019 American Society for Bone and Mineral Research.     

Calcimimetics and Bone Mineral Density in Renal Transplant Patients With Persistent Secondary Hyperparathyroidism

Background

The persistence of secondary hyperparathyroidism plays an important role in posttransplant bone loss. Calcimimetics are efficient to control metabolic alterations associated with this problem, but there are few publications that assess their effects on bone density.

Patients and Methods

This prospective study assessed the effects of a single daily dose of cinacalcet on calcemia, phosphatemia, parathyroid hormone (PTH), and bone densitometry (femur and spine) values of 27 renal transplant patients with stable kidney function, calcium > 10.5 mg/dL, and PTH > 65 pg/mL.

Results

A preliminary study after 6 months showed decreased calcemia (11.05 ± 0.5 to 10.18 ± 0.6 mg/dL; P < .0001), reduced levels of intact PTH (iPTH; 258 ± 104 to 209.61 ± 127 pg/mL; P < .05), and increased phosphatemia (2.38 ± 0.45 to 2.54 ± 0.3 mg/dL; P < .05). We also observed an increase in femoral neck bone mass with improved T score (−1.36 ± 1.19 to −1.05 ± 0.84 g/cm²; P < .05).

Conclusions

Cinacalcet was effective in the management of posttransplant persistent secondary hyperparathyroidism, resulting in decreased calcemia and iPTH, while also improving femoral neck bone loss. Longer-term studies with control groups are needed to determine the drug's influence on overall bone mineral density.     

Hyperparathyroidism in Patients With X-Linked Hypophosphatemia

X-linked hypophosphatemia (XLH) is characterized by increased activity of circulating FGF23 resulting in renal phosphate wasting and abnormal bone mineralization. Hyperparathyroidism may develop in XLH patients; however, its prevalence, pathogenesis, and clinical presentation are not documented. This observational study (CNIL 171036 v 0) recruited XLH adult patients in a single tertiary referral center. Each patient was explored in standardized conditions and compared with two healthy volunteers, matched for sex, age, and 25-OH vitamin D concentrations. The primary endpoint was the proportion of patients with hyperparathyroidism. The secondary endpoints were the factors influencing serum parathyroid hormone (PTH) concentrations and the prevalence of hypercalcemic hyperparathyroidism. Sixty-eight patients (51 women, 17 men) were enrolled and matched with 136 healthy volunteers. Patients had higher PTH concentrations compared with healthy controls (53.5 ng/L, interquartile range [IQR] 36.7–72.7 versus 36.0 ng/L, IQR 27.7–44.0, p < .0001). Hyperparathyroidism was observed in 17 patients of 68 (25%). In patients, a positive relationship between PTH and calcium concentrations and a negative relationship between PTH and phosphate concentrations were observed. Seven (10%) patients (3 premenopausal women, 1 postmenopausal woman, and 3 men) were diagnosed with hypercalcemic hyperparathyroidism. All underwent parathyroid surgery, with consecutive normalization of calcium and PTH concentrations. Hyperparathyroidism is a frequent complication in XLH adult patients. Disruption of the physiological regulation of PTH secretion contributes to parathyroid disease. Early-onset hypercalcemic hyperparathyroidism can be effectively and safely cured by surgical resection. © 2020 American Society for Bone and Mineral Research.     

Treatment With Cinacalcet of Secondary Hyperparathyroidism After Renal Transplantation

Background

The treatment of posttransplant secondary hyperparathyroidism (SHP) with vitamin D analogues is determined by their effectiveness to reverse hypercalcemia. Calcimimetics inhibit parathyroid hormone (PTH) secretion by modulating the calcium-sensing receptor in the parathyroid gland. Cinacalcet, a calcimimetic drug, has proven its effectiveness for the treatment of SHP among patients in phase V of chronic renal disease.

Patients and Methods

This retrospective analysis included 48 patients with SHP who were treated with cinacalcet. The initial dose of 30 mg/d could be increased to 180 mg, administering calcitriol also, depending on the serum calcium and PTH levels. The objectives were a PTH level between 75 and 125 pg/mL or a decrease >40%, and a serum calcium level below 10.5 mg/dL.

Results

The average PTH at baseline was 244 pg/mL, decreasing to 131 pg/mL at 1 year (P < .01). The average calcium at baseline was 10.1 mg/dL descending to 9.2 mg/dL at 1 year (P < .01). Among patients with hypercalcemia, the calcium decreased from 11 to 9.6 mg/dL at 1 year (P < .01). Seventy percent of patients without hypercalcemia reached the desired value of PTH, and 100% of those with hypercalcemia. Among patients with hypercalcemia, the desired calcium level was reached in 91% of cases. Ten patients developed hypocalcemia. In 3 cases we stopped the treatment with cinacalcet due to digestive intolerance.

Conclusions

Treatment with cinacalcet controlled hyperparathyroidism and hypercalcemia among patients with posttransplant SHP. It was a safe drug, with a low incidence of side effects.     

Long-Term Outcomes in Patients With Calciphylaxis From Hyperparathyroidism

Background Calciphylaxis is a rare condition associated with chronic renal failure and entails a very poor prognosis. Pathogenesis is poorly understood but involves abnormalities in calcium and phosphorus metabolism that lead to vascular and extravascular calcification. Patients present with painful ulcerating plaques that progress to gangrenous wounds. Parathyroidectomy has been advanced as a life-saving intervention in these patients, but long-term results with wound healing and survival after parathyroidectomy are not well described. Methods Between January 1987 and October 2003, 15 patients with biopsy-confirmed calciphylaxis were treated at the University of Wisconsin. Of these 15 patients, 9 were treated with medical therapy (bisphosphonates and phosphate binders), whereas 6 underwent parathyroidectomy. The medical records were reviewed, and patients or relatives were interviewed. Survival was determined by Kaplan-Meier analysis. Results Four patients underwent subtotal parathyroidectomy, and two patients underwent total parathyroidectomy. All had reductions in the intact parathyroid hormone level (mean ± SD, 25.2 ± 4.5 pg/mL). Whereas all six patients treated with parathyroidectomy had partial/complete wound healing, only two of nine in the medical group had any improvements in the skin lesions (P = .006). With up to 80 months of follow-up, patients who underwent parathyroidectomy had a longer median survival compared with those who did not have surgery (39 vs. 3 months; P = .017). Conclusions On the basis of our long-term follow-up of this patient population, subtotal or total parathyroidectomy was associated with long-term survival and was more likely to promote healing if performed earlier in the course of disease. Therefore, patients with calciphylaxis from secondary hyperparathyroidism should be referred promptly for potential parathyroidectomy.     

Removal of Autografted Parathyroid Tissue for Recurrent Renal Hyperparathyroidism in Hemodialysis Patients

Background  

Recurrent renal hyperparathyroidism (HPT) is a serious problem after parathyroidectomy (PTx). We evaluated the frequency of graft-dependent recurrent HPT and the clinical outcomes after removal of the autograft.     

Effect of Cinacalcet in Kidney Transplant Patients With Hyperparathyroidism

ObjectiveIn dialysis patients, cinacalcet could be an effective alternative to parathyroidectomy for treating hyperparathyroidism. In the present study, we aimed to determine the characteristics of subjects with persistent hyperparathyroidism who require parathyroidectomy despite the use of cinacalcet.MethodsNine kidney transplant patients (7 men, 2 women; mean age 53.2 [SD, 8.9] years) who had tertiary hyperparathyroidism were reviewed in a single center. Pre- and postcinacalcet levels of calcium, phosphorous, intact parathyroid hormone (iPTH), and renal function were analyzed to evaluate the effect of cinacalcet treatment in these patients. The baseline parameters before cinacalcet treatment were compared in patients who did and did not undergo parathyroidectomy.ResultsCinacalcet reduced serum calcium levels in all patients (11.48 [SD, 0.73] mg/dL to 10.20 [0.70] mg/dL; P = .008). Serum phosphorous levels significantly increased from 2.28 (SD, 0.77) mg/dL to 3.02 (SD, 0.65) mg/dL (P = .03). The iPTH levels in 7 patients decreased, while the mean level remained unchanged in total subjects. The iPTH levels increased even with cinacalcet treatment in 2 patients. In 3 patients, serum calcium levels abruptly increased after cinacalcet withdrawal. Five patients who showed persistent hypercalcemia due to hyperparathyroidism underwent parathyroidectomy. These 5 patients had significantly different characteristics compared with 4 patients who did not undergo parathyroidectomy: hypercalcemia (11.92 [SD, 0.68] mg/dL vs 10.93 [SD, 0.26] mg/dL; P = .02), hypophosphatemia (1.74 [SD, 0.36] mg/dL vs 2.95 [SD, 0.58] mg/dL; P = .03), and hyperparathyroidism (252.2 [SD, 131.4] pg/dL vs 101.5 [SD, 18.4] pg/dL; P = .02).ConclusionCinacalcet reduced hypercalcemia due to hyperparathyroidism in the transplant patients. However, patients who had pre-existing higher iPTH, hypercalcemia, and hypophosphatemia needed parathyroidectomy. Therefore, cinacalcet could be considered an alternative to parathyroidectomy in selected patients.