[Clinical protocol and therapeutic guidelines for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease]

Effect of parathyroidectomy on bone tissue biomarkers and body composition in patients with chronic kidney disease and secondary hyperparathyroidism

BACKGROUND/OBJECTIVE

Loss of renal function may induce secondary hyperparathyroidism (s-HPT), which triggers several complications leading to an extreme decline in quality of life and increased mortality in affected patients. We evaluated whether parathyroidectomy (PTx), as surgical treatment for s-HPT, modifies body composition, and hormones involved in the protein-energy metabolism of affected patients.

SUBJECTS/METHODS

Overall, 30 s-HPT patients were evaluated at two times, before PTx (pre PTx) and 6 months after PTx (post PTx). Patients were evaluated by biochemistry analysis, anthropometry, electrical bioimpedance (BIA), food intake diary, handgrip strength, and modified global subjective nutritional assessment (SGA).

RESULTS

After PTx, patients showed decreased serum levels of total and ionic calcium, as well as decreased alkaline phosphatase and PTH, and increased 25 (OH) vitamin D. These results demonstrate that PTx was efficient to correct part of the mineral disorder. We also observed an increase in caloric intake, body weight, body mass index (BMI), phase angle, handgrip strength, SGA score, and a decreasing in the percentage of weight loss. The osteocalcin concentration of both carboxylated (cOC) and undercarboxylated form was diminished post PTx. The cOC correlated with bone metabolism markers and SGA score.

CONCLUSIONS

PTx modified body composition improving nutritional status and preventing the progression of weight loss with increased of energy intake, BMI, handgrip strength, phase angle of BIA, and SGA score. The present study also suggests an association of cOC with bone markers and SGA score. Further studies are needed to better clarify these associations with larger sample size.

Association between hypocalcemia and rivaroxaban in coagulation disorders: a case report

We describe a patient with tertiary hyperparathyroidism with history of three episodes of deep vein thrombosis and on rivaroxaban. The patient underwent a subtotal parathyroidectomy, developing cervical hematoma with airway compression. Therefore, emergency surgical decompression was necessary. Later, on the ninth postoperative day, the serum ionized calcium levels were low. Medical team knowledge about preexisting diseases and their implication in the coagulation state are essential conditions to reduce morbidity and mortality of surgeries. However, no reports were found in literature about the association of hypocalcemia with the use of the new class of anticoagulants, which act as factor X inhibitors (Stuart-Prower factor), predisposing to increased bleeding in the immediate postoperative period.

The impact of cinacalcet in the mineral metabolism markers of patients on dialysis with severe secondary hyperparathyroidism

Introduction:

Treating secondary hyperparathyroidism (SHPT), a common condition associated with death in patients with chronic kidney disease, is a challenge for nephrologists. Calcimimetics have allowed the introduction of drug therapies no longer based on phosphate binders and active vitamin D. This study aimed to assess the safety and effectiveness of cinacalcet in managing chronic dialysis patients with severe SHPT.

Methods:

This retrospective study included 26 patients [age: 52 ± 12 years; 55% females; time on dialysis: 54 (4-236) months] on hemodialysis (N = 18) or peritoneal dialysis (N = 8) with severe SHPT (intact parathyroid hormone (iPTH) level > 600 pg/mL) and hyperphosphatemia and/or persistent hypercalcemia treated with cinacalcet. The patients were followed for 12 months. Their serum calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and iPTH levels were measured at baseline and on days 30, 60, 90, 180, and 365.

Results:

Patients with hyperphosphatemia (57.7%), hypercalcemia (23%), or both (19.3%) with iPTH > 600 pg/mL were prescribed cinacalcet. At the end of the study, decreases were observed in iPTH (1348 ± 422 vs. 440 ± 210 pg/mL; p < 0.001), Ca (9.5 ± 1.0 vs. 9.1 ± 0.6 mg/dl; p = 0.004), P (6.0 ± 1.3 vs. 4.9 ± 1.1 mg/dl; p < 0.001), and ALP (202 ± 135 vs. 155 ± 109 IU/L; p = 0.006) levels. Adverse events included hypocalcemia (26%) and digestive problems (23%). At the end of the study, 73% of the patients were on active vitamin D and cinacalcet. Three (11.5%) patients on peritoneal dialysis did not respond to therapy with cinacalcet, and their iPTH levels were never below 800 pg/mL.

Conclusion:

Cinacalcet combined with traditional therapy proved safe and effective and helped manage the mineral metabolism of patients with severe SHPT.

The shift from high to low turnover bone disease after parathyroidectomy is associated with the progression of vascular calcification in hemodialysis patients: A 12-month follow-up study

Parathyroidectomy (PTX) may cause low levels of PTH, leading to an excessive reduction of bone turnover, which is associated with poor outcomes in dialysis patients, including vascular calcification (VC). We aimed to prospectively investigate the impact of PTX on bone remodeling and its potential consequence on the progression of VC in hemodialysis patients. In this prospective study, 19 hemodialysis patients with severe secondary hyperparathyroidism (sHPT) were evaluated. All patients underwent laboratorial tests and coronary tomography at baseline and, 6 and 12 months after PTX; bone biopsy was performed at baseline and 12-month. At baseline, all patients had increased PTH levels up to 2500 pg/mL and high turnover bone disease in their bone biopsies. Fourteen (74%) patients had VC. During the follow-up, there was a significant decrease of PTH at 6 and 12-month. At 12-month, 90% of the patients evolved to low turnover bone disease. During the period of the hungry bone syndrome (first 6 months), no change of coronary calcium score was observed. However, calcium score increased significantly thereafter (12th month). There was an association between VC progression and the severity of low turnover bone disease. In conclusion, the shift from high to low turnover bone disease after PTX occurs in parallel to VC progression, contributing to the understanding of the complex pathophysiology involving mineral metabolism and cardiovascular disease in hemodialysis patients.