-
Clinical Journal of the American... Jun 2018Secondary hyperparathyroidism develops in CKD due to a combination of vitamin D deficiency, hypocalcemia, and hyperphosphatemia, and it exists in nearly all patients at... (Review)
Review
Secondary hyperparathyroidism develops in CKD due to a combination of vitamin D deficiency, hypocalcemia, and hyperphosphatemia, and it exists in nearly all patients at the time of dialysis initiation. There is insufficient data on whether to prefer vitamin D analogs compared with calcimimetics, but the available evidence suggests advantages with combination therapy. Calcium derangements, patient adherence, side effects, and cost limit the use of these agents. When parathyroid hormone level persists >800 pg/ml for >6 months, despite exhaustive medical interventions, monoclonal proliferation with nodular hyperplasia is likely present along with decreased expression of vitamin D and calcium-sensing receptors. Hence, surgical parathyroidectomy should be considered, especially if concomitant disorders exist, such as persistent hypercalcemia or hyperphosphatemia, tissue or vascular calcification including calciphylaxis, and/or worsening osteodystrophy. Parathyroidectomy is associated with 15%-57% greater survival in patients on dialysis, and it also improves hypercalcemia, hyperphosphatemia, tissue calcification, bone mineral density, and health-related quality of life. The parathyroidectomy rate in the United States declined to approximately seven per 1000 dialysis patient-years between 2002 and 2011 despite an increase in average parathyroid hormone levels, reflecting calcimimetics introduction and uncertainty regarding optimal parathyroid hormone targets. Hospitalization rates are 39% higher in the first postoperative year. Hungry bone syndrome occurs in approximately 25% of patients on dialysis, and profound hypocalcemia requires high doses of oral and intravenous calcium along with calcitriol supplementation. Total parathyroidectomy with autotransplantation carries a higher risk of permanent hypocalcemia, whereas risk of hyperparathyroidism recurrence is higher with subtotal parathyroidectomy. Given favorable long-term outcomes from observational parathyroidectomy cohorts, despite surgical risk and postoperative challenges, it is reasonable to consider parathyroidectomy in more patients with medically refractory secondary hyperparathyroidism.
Topics: Animals; Calcimimetic Agents; Humans; Hyperparathyroidism, Secondary; Parathyroidectomy; Renal Insufficiency, Chronic; Vascular Calcification
PubMed: 29523679
DOI: 10.2215/CJN.10390917 -
La Clinica Terapeutica May 2021Tertiary hyperparathyroidism (HPT III) occurs when an excess of parathyroid hormone (PTH) is secreted by parathyroid glands, usually after longstanding secondary... (Review)
Review
Tertiary hyperparathyroidism (HPT III) occurs when an excess of parathyroid hormone (PTH) is secreted by parathyroid glands, usually after longstanding secondary hyperparathyroidism. Some authorities reserve the term for secondary hyperparathyroidism that persists after successful renal transplantation. Long-standing chronic kidney disease (CKD) is associated with several metabolic disturbances that lead to increased secretion of PTH, including hyperphosphatemia, calcit-riol deficiency, and hypocalcaemia. Hyperphosphatemia has a direct stimulatory effect on the parathyroid gland cell resulting in nodular hyperplasia and increased PTH secretion. Prolonged hypocalcaemia also causes parathyroid chief cell hyperplasia and excess PTH. Af-ter correction of the primary disorder CKD by renal transplant, the hypertrophied parathyroid tissue fails to resolute, enlarge over and continues to oversecrete PTH, despite serum calcium levels that are within the reference range or even elevated. They also may become resistant to calcimimetic treatment. The main indication for treatment is persistent hypercalcemia and/or an increased PTH, and the primary treatment is surgery. Three procedures are commonly performed: total parathyroidectomy with or without autotransplantation, subtotal parathyroidectomy, and limited parathyroidectomy. It is important to remove superior parts of thymus as well. The most appropriate surgical procedure, whether it be total, subtotal, or anything less than subtotal including "limited" or "focused" parathyroidectomies, continues to be unclear and controversial. Surgical complications are rare, and para-thyroidectomy appears to be a safe and feasible treatment option for HPT III.
Topics: Humans; Hyperparathyroidism, Secondary; Hyperphosphatemia; Hyperplasia; Hypocalcemia; Kidney Transplantation; Parathyroid Glands; Parathyroid Hormone; Parathyroidectomy; Renal Insufficiency, Chronic; Transplantation, Autologous
PubMed: 33956045
DOI: 10.7417/CT.2021.2322 -
Kidney International May 2018Hyperphosphatemia has consistently been shown to be associated with dismal outcome in a wide variety of populations, particularly in chronic kidney disease (CKD).... (Review)
Review
Hyperphosphatemia has consistently been shown to be associated with dismal outcome in a wide variety of populations, particularly in chronic kidney disease (CKD). Compelling evidence from basic and animal studies elucidated a range of mechanisms by which phosphate may exert its pathological effects and motivated interventions to treat hyperphosphatemia. These interventions consisted of dietary modifications and phosphate binders. However, the beneficial effects of these treatment methods on hard clinical outcomes have not been convincingly demonstrated in prospective clinical trials. In addition, exposure to high amounts of dietary phosphate may exert untoward actions even in the absence of overt hyperphosphatemia. Based on this concept, it has been proposed that the same interventions used in CKD patients with normal phosphate concentrations be used in the presence of hyperphosphatemia to prevent rise of phosphate concentration and as an early intervention for cardiovascular risk. This review describes conceptual models of phosphate toxicity, summarizes the evidence base for treatment and prevention of hyperphosphatemia, and identifies important knowledge gaps in the field.
Topics: Animals; Biomarkers; Chelating Agents; Humans; Hyperphosphatemia; Phosphates; Phosphorus, Dietary; Recommended Dietary Allowances; Renal Insufficiency, Chronic; Risk Factors; Risk Reduction Behavior; Treatment Outcome
PubMed: 29580635
DOI: 10.1016/j.kint.2017.11.036 -
European Heart Journal Jun 2014Vascular calcifications (VCs) are actively regulated biological processes associated with crystallization of hydroxyapatite in the extracellular matrix and in cells of... (Review)
Review
Vascular calcifications (VCs) are actively regulated biological processes associated with crystallization of hydroxyapatite in the extracellular matrix and in cells of the media (VCm) or intima (VCi) of the arterial wall. Both patterns of VC often coincide and occur in patients with type II diabetes, chronic kidney disease, and other less frequent disorders; VCs are also typical in senile degeneration. In this article, we review the current state of knowledge about the pathology, molecular biology, and nosology of VCm, expand on potential mechanisms responsible for poor prognosis, and expose some of the directions for future research in this area.
Topics: Adult; Arteriosclerosis; Biomarkers; Calcium-Binding Proteins; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Humans; Hyperphosphatemia; Male; Monckeberg Medial Calcific Sclerosis; Phosphates; Prognosis; Renal Insufficiency, Chronic; Terminology as Topic; Tunica Intima; Tunica Media; Vascular Calcification
PubMed: 24740885
DOI: 10.1093/eurheartj/ehu163 -
JAMA May 2021Among patients with hyperphosphatemia undergoing dialysis, it is unclear whether non-calcium-based phosphate binders are more effective than calcium-based binders for... (Comparative Study)
Comparative Study Randomized Controlled Trial
Effect of Treating Hyperphosphatemia With Lanthanum Carbonate vs Calcium Carbonate on Cardiovascular Events in Patients With Chronic Kidney Disease Undergoing Hemodialysis: The LANDMARK Randomized Clinical Trial.
IMPORTANCE
Among patients with hyperphosphatemia undergoing dialysis, it is unclear whether non-calcium-based phosphate binders are more effective than calcium-based binders for reducing cardiovascular events.
OBJECTIVE
To determine whether lanthanum carbonate reduces cardiovascular events compared with calcium carbonate in patients with hyperphosphatemia at risk of vascular calcification undergoing hemodialysis.
DESIGN, SETTING, AND PARTICIPANTS
Open-label, randomized, parallel-group clinical trial with blinded end point adjudication performed in 2374 patients with chronic kidney disease from 273 hemodialysis facilities in Japan. Eligible patients had hyperphosphatemia and 1 or more risk factors for vascular calcification (ie, ≥65 years, postmenopausal, diabetes). Enrollment occurred from November 2011 to July 2014; follow-up ended June 2018.
INTERVENTIONS
Patients were randomized to receive either lanthanum carbonate (n = 1154) or calcium carbonate (n = 1155) and titrated to achieve serum phosphate levels of between 3.5 mg/dL and 6.0 mg/dL.
MAIN OUTCOMES AND MEASURES
The primary outcome was a composite cardiovascular event (cardiovascular death, nonfatal myocardial infarction or stroke, unstable angina, transient ischemic attack, or hospitalization for heart failure or ventricular arrhythmia). Secondary outcomes included overall survival, secondary hyperparathyroidism-free survival, hip fracture-free survival, and adverse events.
RESULTS
Among 2309 randomized patients (median age, 69 years; 40.5% women), 1851 (80.2%) completed the trial. After a median follow-up of 3.16 years, cardiovascular events occurred in 147 of 1063 patients in the lanthanum calcium group and 134 of 1072 patients in the calcium carbonate group (incidence rate, 4.80 vs 4.30 per 100 person-years; difference 0.50 per 100 person-years [95% CI, -0.57 to 1.56]; hazard ratio [HR], 1.11 [95%, CI, 0.88 to 1.41], P = .37). There were no significant differences in all-cause death (difference, 0.43 per 100 person-years [95% CI, -0.63 to 1.49]; HR, 1.10 [95% CI, 0.88 to 1.37]; P = .42) or hip fracture (difference, 0.10 per 100 person-years [95% CI, -0.26 to 0.47]; HR, 1.21 [95% CI, 0.62 to 2.35]; P = .58). The lanthanum carbonate group had an increased risk of cardiovascular death (difference, 0.61 per 100 person-years [95% CI, 0.02 to 1.21]; HR, 1.51 [95% CI, 1.01 to 2.27]; P = .045) and secondary hyperparathyroidism (difference, 1.34 [95% CI, 0.49 to 2.19]; HR, 1.62 [95% CI, 1.19 to 2.20]; P = .002). Adverse events occurred in 282 (25.7%) in the lanthanum carbonate group and 259 (23.4%) in the calcium carbonate groups.
CONCLUSIONS AND RELEVANCE
Among patients undergoing hemodialysis with hyperphosphatemia and at least 1 vascular calcification risk factor, treatment of hyperphosphatemia with lanthanum carbonate compared with calcium carbonate did not result in a significant difference in composite cardiovascular events. However, the event rate was low, and the findings may not apply to patients at higher risk.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT01578200; UMIN Clinical Trial Registry Identifier: UMIN000006815.
Topics: Aged; Calcium Carbonate; Cardiovascular Diseases; Female; Heart Disease Risk Factors; Hip Fractures; Humans; Hyperparathyroidism; Hyperphosphatemia; Incidence; Japan; Lanthanum; Male; Phosphates; Renal Dialysis; Renal Insufficiency, Chronic; Survival Analysis; Vascular Calcification
PubMed: 34003226
DOI: 10.1001/jama.2021.4807 -
Kidney & Blood Pressure Research 2020Tumor lysis syndrome (TLS) is an oncologic emergency due to a rapid break down of malignant cells usually induced by cytotoxic therapy, with hyperuricemia, hyperkalemia,... (Review)
Review
BACKGROUND
Tumor lysis syndrome (TLS) is an oncologic emergency due to a rapid break down of malignant cells usually induced by cytotoxic therapy, with hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and serious clinical consequences such as acute renal injury, cardiac arrhythmia, hypotension, and death. Rapidly expanding knowledge of cancer immune evasion mechanisms and host-tumor interactions has significantly changed our therapeutic strategies in hemato-oncology what resulted in the expanding spectrum of neoplasms with a risk of TLS.
SUMMARY
Since clinical TLS is a life-threatening condition, identifying patients with risk factors for TLS development and implementation of adequate preventive measures remains the most critical component of its medical management. In general, these consist of vigilant laboratory and clinical monitoring, vigorous IV hydration, urate-lowering therapy, avoidance of exogenous potassium, use of phosphate binders, and - in high-risk cases - considering cytoreduction before the start of the aggressive agent or a gradual escalation of its dose. Key Messages: In patients with a high risk of TLS, cytotoxic chemotherapy should be given in the facility with ready access to dialysis and a treatment plan discussed with the nephrology team. In the case of hyperkalemia, severe hyperphosphatemia or acidosis, and fluid overload unresponsive to diuretic therapy, the early renal replacement therapy (RRT) should be considered. One must remember that in TLS, the threshold for RRT initiation may be lower than in other clinical situations since the process of cell breakdown is ongoing, and rapid increases in serum electrolytes cannot be predicted.
Topics: Acute Kidney Injury; Animals; Disease Management; Humans; Hyperkalemia; Hyperphosphatemia; Hyperuricemia; Incidence; Risk Factors; Tumor Lysis Syndrome
PubMed: 32998135
DOI: 10.1159/000509934 -
Journal of Renal Nutrition : the... Jan 2021Bone and mineral metabolism becomes dysregulated with progression of chronic kidney disease (CKD), and increasing levels of parathyroid hormone serve as an adaptive...
Bone and mineral metabolism becomes dysregulated with progression of chronic kidney disease (CKD), and increasing levels of parathyroid hormone serve as an adaptive response to maintain normal phosphorus and calcium levels. In end-stage renal disease, this response becomes maladaptive and high levels of phosphorus may occur. We summarize strategies to control hyperphosphatemia based on a systematic literature review of clinical trial and real-world observational data on phosphorus control in hemodialysis patients with CKD-mineral bone disorder (CKD-MBD). These studies suggest that current management options (diet and lifestyle changes; regular dialysis treatment; and use of phosphate binders, vitamin D, calcimimetics) have their own benefits and limitations with variable clinical outcomes. A more integrated approach to phosphorus control in dialysis patients may be necessary, incorporating measurement of multiple biomarkers of CKD-MBD pathophysiology (calcium, phosphorus, and parathyroid hormone) and correlation between diet adjustments and CKD-MBD drugs, which may facilitate improved patient management.
Topics: Calcimimetic Agents; Chelating Agents; Diet; Humans; Hyperphosphatemia; Kidney Failure, Chronic; Vitamin D
PubMed: 32386937
DOI: 10.1053/j.jrn.2020.02.003 -
Frontiers in Cell and Developmental... 2021Hyperphosphatemia or even serum phosphate levels within the "normal laboratory range" are highly associated with increased cardiovascular disease risk and mortality in... (Review)
Review
Hyperphosphatemia or even serum phosphate levels within the "normal laboratory range" are highly associated with increased cardiovascular disease risk and mortality in the general population and patients suffering from chronic kidney disease (CKD). As the kidney function declines, serum phosphate levels rise and subsequently induce the development of hypertension, vascular calcification, cardiac valvular calcification, atherosclerosis, left ventricular hypertrophy and myocardial fibrosis by distinct mechanisms. Therefore, phosphate is considered as a promising therapeutic target to improve the cardiovascular outcome in CKD patients. The current therapeutic strategies are based on dietary and pharmacological reduction of serum phosphate levels to prevent hyperphosphatemia in CKD patients. Large randomized clinical trials with hard endpoints are urgently needed to establish a causal relationship between phosphate excess and cardiovascular disease (CVD) and to determine if lowering serum phosphate constitutes an effective intervention for the prevention and treatment of CVD.
PubMed: 33748139
DOI: 10.3389/fcell.2021.644363 -
Journal of the American Society of... Mar 2021In patients on maintenance dialysis, cardiovascular mortality risk is remarkably high, which can be partly explained by severe coronary artery calcification (CAC).... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
In patients on maintenance dialysis, cardiovascular mortality risk is remarkably high, which can be partly explained by severe coronary artery calcification (CAC). Hyperphosphatemia has been reported to be associated with the severity of CAC. However, the optimal phosphate range in patients on dialysis remains unknown. This study was planned to compare the effects on CAC progression of two types of noncalcium-based phosphate binders and of two different phosphate target ranges.
METHODS
We conducted a randomized, open-label, multicenter, interventional trial with a two by two factorial design. A total of 160 adults on dialysis were enrolled and randomized to the sucroferric oxyhydroxide or lanthanum carbonate group, with the aim of reducing serum phosphate to two target levels (3.5-4.5 mg/dl in the strict group and 5.0-6.0 mg/dl in the standard group). The primary end point was percentage change in CAC scores during the 12-month treatment.
RESULTS
The full analysis set included 115 patients. We observed no significant difference in percentage change in CAC scores between the lanthanum carbonate group and the sucroferric oxyhydroxide group. On the other hand, percentage change in CAC scores in the strict group (median of 8.52; interquartile range, -1.0-23.9) was significantly lower than that in the standard group (median of 21.8; interquartile range, 10.0-36.1; =0.006). This effect was pronounced in older (aged 65-74 years) versus younger (aged 20-64 years) participants ( value for interaction =0.003). We observed a similar finding for the absolute change in CAC scores.
CONCLUSIONS
Further study with a larger sample size is needed, but strict phosphate control shows promise for delaying progression of CAC in patients undergoing maintenance hemodialysis.
CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER
Evaluate the New Phosphate Iron-Based Binder Sucroferric Oxyhydroxide in Dialysis Patients with the Goal of Advancing the Practice of EBM (EPISODE), jRCTs051180048.
Topics: Adult; Aged; Calcinosis; Coronary Artery Disease; Disease Progression; Drug Combinations; Female; Ferric Compounds; Humans; Hyperphosphatemia; Lanthanum; Male; Middle Aged; Phosphates; Renal Dialysis; Sequestering Agents; Sucrose; Young Adult
PubMed: 33547218
DOI: 10.1681/ASN.2020050598