Parathyroidectomy and survival among Japanese hemodialysis patients with secondary hyperparathyroidism

Chronic Kidney Disease-Mineral and Bone Disorder in Asia

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is one of the most common complications in patients with CKD. As CKD-MBD is a systemic syndrome, prevention and management should be aimed at achieving better survival and less risk of cardiovascular events and fractures.

SUMMARY

Although target ranges for serum markers of mineral metabolism have been proposed in several global or local guidelines, these were mostly based on data from non-Asian patients. Additionally, there remain differences in medical and social systems as well as in economic status, even among Asian countries and areas.

KEY MESSAGE

Asian CKD patient data needs to be analyzed, published, and shared to establish optimal local strategies for CKD-MBD management.

Impact of Different Levels of iPTH on All-Cause Mortality in Dialysis Patients with Secondary Hyperparathyroidism after Parathyroidectomy

Background

Secondary hyperparathyroidism (SHPT) usually required parathyroidectomy (PTX) when drugs treatment is invalid. Analysis was done on the impact of different intact parathyroid hormone (iPTH) after the PTX on all-cause mortality.

Methods

An open, retrospective, multicenter cohort design was conducted. The sample included 525 dialysis patients with SHPT who had undergone PTX.

Results

404 patients conformed to the standard, with 36 (8.91%) deaths during the 11 years of follow-up. One week postoperatively, different levels of serum iPTH were divided into four groups: A: ≤20 pg/mL; B: 21–150 pg/mL; C: 151–600 pg/mL; and D: >600 pg/mL. All-cause mortality in groups with different iPTH levels appeared as follows: A (8.29%), B (3.54%), C (10.91%), and D (29.03%). The all-cause mortality of B was the lowest, with D the highest. We used group A as reference (hazard ratio (HR) = 1) compared with the other groups, and HRs on groups B, C, and D appeared as 0.57, 1.43, and 3.45, respectively.

Conclusion

The all-cause mortality was associated with different levels of iPTH after the PTX. We found that iPTH > 600 pg/mL appeared as a factor which increased the risk of all-cause mortality. When iPTH levels were positively and effectively reducing, the risk of all-cause mortality also decreased. The most appropriate level of postoperative iPTH seemed to be 21–150 pg/mL.

To assess the effects of parathyroidectomy (TPTX versus TPTX+AT) for Secondary Hyperparathyroidism in chronic renal failure: A Systematic Review and Meta-Analysis

BACKGROUND

Secondary Hyperparathyroidism (SHPT) requiring parathyroidectomy (PTX) occurs more commonly in patients with progressive chronic kidney disease and in those on long-term lithium therapy. Successful PTX often results in a dramatic drop of parathyroid hormone level, relieves the patient from clinical symptoms, and reduces mortality. However, there is an ongoing debate on the optimal surgical treatment of SHPT. Currently, no clinical guidelines or trials have definitely answered the question of whether Total Parathyroidectomy (TPTX) is superior or equal to Total Parathyroidectomy with Autotransplantation (TPTX + AT).

OBJECTIVE

The aims of the study were to compare the efficacy of two different surgical procedures and to develop evidence-based practice guidelines for the treatment of SHPT.

METHODS

Citations were identified in the Medline, Cochrane, EMBASE, and Chinese Biomedical Literature databases through November 2016. The Newcastle-Ottawa Scale (NOS) score was used to assess the methodological quality of the studies included. All data were analyzed using Review Manager 5.3.

RESULTS

A total of nine cohort studies and one Randomized Controlled Trials (RCT), comprising 1283 patients, were identified. The NOS score of all the studies included was 5 or above. Compared with TPTX + AT, patients in the TPTX group had lower rates of "recurrence" (OR = 0.20; 95%CI, 0.11-0.38; P < 0.01), "recurrence or persistence" (OR = 0.18; 95%CI, 0.10-0.33; P < 0.01), "reoperation due to recurrence or persistence" (OR = 0.17; 95%CI, 0.06-0.54; P = 0.002), and shorter "operative time" (WMD = -17.30; 95%CI, -30.53 to -4.06; P < 0.05), except for a higher risk of "hypoparathyroidism" (OR = 2.97; 95%CI, 1.09-8.08; P = 0.01). However, none of the patients had developed permanent hypocalcemia or adynamic bone disease. No significant difference was found for "symptomatic improvement", "complications", "drug requirements", and "hospital stay" (P > 0.05).

CONCLUSION

The findings indicate that TPTX is superior to TPTX + AT, while referring to the rate of recurrent SHPT. However, this conclusion needs to be tested in large-scale confirmatory trials. TPTX seems to be a feasible alternative therapeutic option for the surgical treatment of refractory SHPT.

Vitamin D Receptor Activator Use and Cause-specific Death among dialysis Patients: a Nationwide Cohort Study using Coarsened Exact Matching

Vitamin D receptor activators (VDRA) may exert pleiotropic effects on cardiovascular disease, malignancy, and infections among dialysis patients, but recent studies have mainly focused on cardiovascular outcomes. Among 8,675 patients who started dialysis in 2007 and who survived until January 1, 2010, listed in the Renal Data Registry of the Japanese Society for Dialysis Therapy, 5,365 VDRA users were matched to 3,203 non-users based on clinically relevant variables at the end of 2009 using the coarsened exact matching procedure. Until December 31, 2011, a total of 1,128 deaths occurred, of which 468 (42%) were cardiovascular deaths, 229 (20%) were infection-related deaths, and 141 (12%) were malignancy-related deaths. Multivariable survival analyses accounting for intra-region correlation revealed that VDRA use was significantly associated with lower rates of infection- and malignancy-related deaths [subhazard ratio 0.62 (95% CI, 0.52–0.73) and 0.70 (95% CI, 0.50–0.97), respectively] but not with cardiovascular death [subhazard ratio 0.86 (95% CI, 0.72–1.04)]. Future randomized clinical trials with a sufficient sample size and an adequate follow-up period are warranted to test the clinical effectiveness of VDRA on infection and malignancy, rather than cardiovascular disease, among dialysis patients.

Association of CKD-MBD Markers with All-Cause Mortality in Prevalent Hemodialysis Patients: A Cohort Study in Beijing

The relationships between all-cause mortality and serum intact parathyroid hormone (iPTH), calcium, and phosphate are fairly diverse in patients on maintenance hemodialysis according to prior studies. This study evaluated the association of chronic kidney disease-mineral and bone disorder (CKD-MBD) markers with all-cause mortality in prevalent hemodialysis patients from 2007 to 2012 in Beijing, China. A cohort, involving 8530 prevalent hemodialysis patients who had undergone a 6-70 months follow-up program (with median as 40 months) was formed. Related data was recorded from the database in 120 hemodialysis centers of Beijing Health Bureau (2007 to 2012). Information regarding baseline demographics, blood CKD-MBD markers and all-cause mortality was retrospectively reviewed. By using multivariate Cox regression model analysis, patients with a low iPTH level at baseline were found to have greater risk of mortality (<75pg/ml, HR = 1.36, 95% confidence interval (CI) 1.16-1.60) than those with a baseline iPTH level within 150-300 pg/ml. Similarly, death risk showed an increase when the baseline serum calcium presented a low level (<2.1mmol/L, HR = 1.54; 95% CI 1.37-1.74). Levels of baseline serum phosphorus were not associated with the risk of death. Similar results appeared through the baseline competing risks regression analysis. Patients with a lower level of serum iPTH or calcium are at a higher risk of all-cause mortality compared with those within the range recommended by Kidney Disease Outcome Quality Initiative (KDOQI) guidelines.

Management of secondary hyperparathyroidism: how and why?

Secondary hyperparathyroidism (SHPT) is a common complication in chronic kidney disease. Currently, various treatment options are available, including vitamin D receptor activators, cinacalcet hydrochloride, and parathyroidectomy. These treatment options have contributed to the successful control of SHPT, and recent clinical studies have provided evidence suggesting that effective treatment of SHPT leads to improved survival. Although bone disease is the most widely recognized consequence of SHPT and remains a major target for treatment of SHPT, there is increasing evidence that parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23), both of which are markedly elevated in SHPT, have multiple adverse effects on extraskeletal tissues. These actions may lead to the pathological development of left ventricular hypertrophy, renal anemia, immune dysfunction, inflammation, wasting, muscle atrophy, and urate accumulation. Given that treatment of SHPT leads to decreases in both PTH and FGF23, these data provide an additional rationale for treating SHPT. However, definitive evidence is still lacking, and future research should focus on whether treatment of SHPT prevents the adverse effects of PTH and FGF23.

Clinical features of CKD-MBD in Japan: cohort studies and registry

Randomized controlled trials (RCTs) are essential for evidence-based medicine; however, cohort studies and registries provide an important information about risk factors and, hence, shed light on the target of laboratory parameters. The uniqueness of the current Japanese CKD-MBD guidelines lies in the lower target range of intact parathyroid hormone levels than those used in other countries, which is based on analyses of the nationwide Japan Renal Data Registry. Cohort studies were also useful in exploring risk factors of renal outcome in predialysis patients. It was revealed that low vitamin D status (very prevalent in Japan) and high fibroblast growth factor 23 (FGF23) levels predict poor renal outcome. The reported association of FGF23 levels with left ventricular hypertrophy (LVH) and heart failure observed in cohort studies may support the idea of adding the 4th component of CKD-MBD, namely, "LVH" to the three original components. When it is not feasible to conduct RCTs regarding intervention, we have no choice but to rely on observational studies with sophisticated analysis methods, such as facility-level analysis and marginal structural model minimizing indication bias. Observational studies conducted in Japan revealed that the side effects of medications for CKD-MBD, resultant compliance, and effective doses in terms of hard outcome in Japanese patients were found to be different from those in other countries. For example, the MBD-5D study confirmed the benefit of cinacalcet in terms of mortality despite its median dose of only 25 mg/day. These data are very helpful for future guidelines specific to Japanese patients with CKD.

Geographic variation of parathyroidectomy in patients receiving hemodialysis: a retrospective cohort analysis

Background

Secondary hyperparathyroidism (SHPT) is associated with adverse outcomes in patients receiving maintenance dialysis. Parathyroidectomy is a treatment for SHPT; whether parathyroidectomy utilization varies geographically in the US is unknown.

Methods

A retrospective cohort analysis was undertaken to identify all patients aged 18 years or older who were receiving in-center hemodialysis between 2007 and 2009, were covered by Medicare Parts A and B, and had been receiving hemodialysis for at least 1 year. Parathyroidectomy was identified from inpatient claims using relevant International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. Patient characteristics and End-Stage Renal Disease Network (a proxy for geography) were ascertained. Adjusted odds ratios for parathyroidectomy were estimated from a logistic model.

Results

A total of 286,569 patients satisfied inclusion criteria, of whom 4435 (1.5%) underwent PTX. After adjustment for a variety of patient characteristics, there was a 2-fold difference in adjusted odds of parathyroidectomy between the most- and least-frequently performing regions. Adjusted odds ratios were more than 20% higher than average in four networks, and more than 20% lower in four networks.

Conclusions

Parathyroidectomy use varies substantially by geography in the US; the factors responsible should be further investigated.

Optimal management of bone mineral disorders in chronic kidney disease and end stage renal disease

PURPOSE OF REVIEW

The review summarizes recent studies on chronic kidney disease-mineral bone disorders, with a focus on new developments in disease management.

RECENT FINDINGS

The term chronic kidney disease-mineral bone disorder has come to describe an increasingly complex network of alterations in minerals and skeletal disorders that contribute to the significant cardiovascular morbidity and mortality seen in patients with chronic kidney disease and end stage renal disease. Clinical studies continue to suggest associations with clinical outcomes, yet current clinical trials have failed to support causality. Variability in practice exists as current guidelines for management of mineral bone disorders are often based on weak evidence. Recent studies implicate novel pathways for therapeutic intervention in clinical trials.

SUMMARY

Mineral bone disorders in chronic kidney disease arise from alterations in a number of molecules in an increasingly complex physiological network interconnecting bone and the cardiovascular system. Despite extensive associations with improved outcomes in a number of molecules, clinical trials have yet to prove causality and there is an absence of new therapies available to improve patient outcomes. Additional clinical trials that can incorporate the complexity of mineral bone disorders, and with the ability to intervene on more than one pathway, are needed to advance patient care.

Risk of acute coronary syndrome after parathyroidectomy in patients with end-stage renal disease: A population-based cohort study in Taiwan

Aim

Patients with end‐stage renal disease (ESRD) who received parathyroidectomy (PTX) had persistently reduced levels of parathyroid hormone. This study investigated the risk of acute coronary syndrome (ACS) in patients with ESRD who underwent PTX using a nationwide health insurance claims database.

Methods

Of all ESRD patients, we selected 1047 individuals who had undergone PTX between 2000 and 2008 as the PTX group and 4188 patients who did not undergo PTX (non‐PTX group) matched by propensity score. Multivariable Cox proportional hazards regression analysis was conducted for assessing the excess ACS risk for the PTX group compared to the non‐PTX group.

Results

The mean follow‐up periods were 4.63 and 4.04 years for the PTX and non‐PTX groups, respectively. A significant reduction in the risk of ACS (adjusted hazard ratio = 0.74, 95% confidence interval = 0.57–0.96) was observed for the ESRD patients after PTX.

Conclusions

Parathyroidectomy is associated with reduced risk of ACS in patients with ESRD.

From a national health insurance claims database, this study matched patients receiving dialysis who had a parathyroidectomy to patients who did not, using a propensity score method. They demonstrate that patients who had a parathyroidectomy were less likely to experience an acute coronary syndrome in the ensuing 4 years.

Feasibility of photodynamic therapy for secondary hyperparathyroidism in chronic renal failure rats

BACKGROUND

Feasibility of photodynamic therapy (PDT) for secondary hyperparathyroidism (SHPT) was examined in a rat model of SHPT.

METHODS

A photosensitizer, 5-aminolevulinic acid (5-ALA), was injected intraperitoneally, and the parathyroid glands were irradiated either after surgical exposure with 385-nm light or transdermally with 630-nm light from a light-emitting diode (LED) lamp.

RESULTS

PDT with high 5-ALA and irradiation doses caused severe hypoparathyroidism in SHPT rats within two days. Low-dose invasive PDT reduced intact parathyroid hormone (iPTH) levels in all rats from 748.9 ± 462.6 pg/mL at baseline to 138.7 ± 117.5 pg/mL at week 6, followed by a further decrease to 80.5 ± 54.0 pg/mL at week 9 in 60 % of rats or an increase to 970.0 ± 215.6 pg/mL at week 9 in 40 % of rats. Low-dose noninvasive PDT reduced iPTH levels from 1612.5 ± 607.8 pg/mL at baseline to 591.9 ± 480.1 pg/mL at week 4 in all rats. Thereafter, iPTH levels remained low in 43 % of rats and were 233.7 ± 51.6 pg/mL at week 9, whereas 57 % showed an increase, reaching 3305.9 ± 107.3 pg/mL at week 9. Control SHPT rats had iPTH levels of 2487.8 ± 350.9 and 2974.6 ± 372.1 pg/mL at week 4 and 9, respectively. The parathyroid glands of the rats with low iPTH levels were atrophied and had few parathyroid cells surrounded by fibrotic materials and no recognizable blood vessels. Those of the rats with high iPTH levels showed well-preserved gland structure, clusters of parathyroid cells, and blood vessels.

CONCLUSION

These results demonstrate that 5-ALA-mediated PDT for SHPT is feasible.

The deceptive concept of hypoparathyroidism and recurrence after parathyroidectomy in dialysis patients: are we offering a Procrustean bed to some patients?

ABSTRACT Objective: to analyze the frequency of hypoparathyroidism and of its recurrence after parathyroidectomy in dialysis patients according to different existing classifications. Methods: we conducted a retrospective study of 107 consecutive dialysis patients undergoing total parathyroidectomy with immediate autograft in a tertiary hospital from 2006 to 2010. We studied the changes in PTH levels in the postoperative period over time. Were grouped patients according to different PTH levels targets recommended according to the dosage method and by the American and Japanese Nephrology Societies, and by an International Experts Consortium. Results: after parathyroidectomy, there was sustained reduction in serum calcium and phosphatemia. The median value of PTH decreased from 1904pg/ml to 55pg/ml in 12 months. Depending on the considered target level, the proportion of patients below the target ranged between 17% and 87%. On the other hand, the proportion of patients with levels above the target ranged from 3% to 37%. Conclusion: the application of different recommendations for PTH levels after parathyroidectomy in dialysis patients may lead to incorrect classifications of hypoparathyroidism or recurrent hyperparathyroidism and resultin discordant therapeutic conducts.

Rates and Outcomes of Parathyroidectomy for Secondary Hyperparathyroidism in the United States

BACKGROUND AND OBJECTIVES

Secondary hyperparathyroidism is common among patients with ESRD. Although medical therapy for secondary hyperparathyroidism has changed dramatically over the last decade, rates of parathyroidectomy for secondary hyperparathyroidism across the United States population are unknown. We examined temporal trends in rates of parathyroidectomy, in-hospital mortality, length of hospital stay, and costs of hospitalization.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample, a representative national database on hospital stay regardless of age and payer in the United States, we identified parathyroidectomies for secondary hyperparathyroidism from 2002 to 2011. Data from the US Renal Data System reports were used to calculate the rate of parathyroidectomy.

RESULTS

We identified 32,971 parathyroidectomies for secondary hyperparathyroidism between 2002 and 2011. The overall rate of parathyroidectomy was approximately 5.4/1000 patients (95% confidence interval [95% CI], 5.0/1000 to 6.0/1000). The rate decreased from 2003 (7.9/1000 patients; 95% CI, 6.2/1000 to 9.6/1000), reached a nadir in 2005 (3.3/1000 patients; 95% CI, 2.6/1000 to 4.0/1000), increased again through 2006 (5.4/1000 patients; 95% CI, 4.4/1000 to 6.4/1000), and remained stable since that time. Rates of in-hospital mortality decreased from 1.7% (95% CI, 0.8% to 2.6%) in 2002 to 0.8% (95% CI, 0.1% to 1.6%) in 2011 (P for trend <0.001). In-hospital mortality rates were significantly higher in patients with heart failure (odds ratio [OR], 4.23; 95% CI, 2.59 to 6.91) and peripheral vascular disease (OR, 4.59; 95% CI, 2.75 to 7.65) and lower among patients with prior kidney transplantation (OR, 0.20; 95% CI, 0.06 to 0.65).

CONCLUSIONS

Despite the use of multiple medical therapies, rates of parathyroidectomy of secondary hyperparathyroidism have not declined in recent years.

Association of Increased Serum Leptin with Ameliorated Anemia and Malnutrition in Stage 5 Chronic Kidney Disease Patients after Parathyroidectomy

Leptin is an adipokine that regulates various metabolism, but its association with secondary hyperparathyroidism (SHPT), a clinical manifestation of chronic kidney disease-mineral and bone disorder (CKD-MBD), remains obscure. Parathyroidectomy (PTX) is recommended for severe SHPT patients. Here, the associations between circulating leptin and clinical characteristics in CKD patients were investigated. Effects of PTX on leptin production were analyzed in vivo and in vitro. Controls and CKD patients had approximate serum leptin levels in that a larger proportion of CKD patients with body mass index (BMI) <23 kg/m². Serum leptin was related to anemia, albumin, and bone metabolism disorders in CKD patients. Lower intact parathyroid hormone (PTH) was related with higher leptin in PTX patients group. Severe SHPT inhibited uremia-enhanced leptin production in 3T3-L1 adipocytes, which was attenuated after PTX. High levels of PTH were found to reduce Akt phosphorylation and leptin production in vitro but high levels of calcium and phosphorus were not. Successful PTX was found to improve anemia and malnutrition in severe SHPT patients, and this was correlated with increased circulating leptin levels via up-regulated Akt signaling in adipocytes. These findings indicated the therapeutic potential of leptin and related target pathway for improving survival and quality of life in CKD.

The Risk of Peripheral Arterial Disease after Parathyroidectomy in Patients with End-Stage Renal Disease

Purpose

The changes of the risk of peripheral arterial disease (PAD) in patients with end-stage renal disease after parathyroidectomy are scant.

Methods

We used a nationwide health insurance claims database to select all dialysis-dependent patients with end-stage renal disease aged 18 years and older for the study population in 2000 to 2006. Of the patients with end-stage renal disease, we selected 947 patients who had undergone parathyroidectomy as the parathyroidectomy group and frequency matched 3746 patients with end-stage renal disease by sex, age, years since the disease diagnosis, and the year of index date as the non-parathyroidectomy group. We used a multivariate Cox proportional hazards regression analysis with the use of a robust sandwich covariance matrix estimate, accounting for the intra-cluster dependence of hospitals or clinics, to measure the risk of peripheral arterial disease for the parathyroidectomy group compared with the non-parathyroidectomy group after adjusting for sex, age, premium-based income, urbanization, and comorbidity.

Results

The mean post-op follow-up periods were 5.08 and 4.52 years for the parathyroidectomy and non-parathyroidectomy groups, respectively; the incidence density rate of PAD in the PTX group was 12.26 per 1000 person-years, significantly lower than the data in the non-PTX group (24.09 per 1000 person-years, adjusted HR = 0.66, 95% CI = 0.46–0.94).

Conclusion

Parathyroidectomy is associated with reduced risk of peripheral arterial disease in patients with end-stage renal disease complicated with severe secondary hyperparathyroidism.

Phosphate-a poison for humans?

Maintenance of phosphate balance is essential for life, and mammals have developed a sophisticated system to regulate phosphate homeostasis over the course of evolution. However, due to the dependence of phosphate elimination on the kidney, humans with decreased kidney function are likely to be in a positive phosphate balance. Phosphate excess has been well recognized as a critical factor in the pathogenesis of mineral and bone disorders associated with chronic kidney disease, but recent investigations have also uncovered toxic effects of phosphate on the cardiovascular system and the aging process. Compelling evidence also suggests that increased fibroblastic growth factor 23 and parathyroid hormone levels in response to a positive phosphate balance contribute to adverse clinical outcomes. These insights support the current practice of managing serum phosphate in patients with advanced chronic kidney disease, although definitive evidence of these effects is lacking. Given the potential toxicity of excess phosphate, the general population may also be viewed as a target for phosphate management. However, the widespread implementation of dietary phosphate intervention in the general population may not be warranted due to the limited impact of increased phosphate intake on mineral metabolism and clinical outcomes. Nonetheless, the increasing incidence of kidney disease or injury in our aging society emphasizes the potential importance of this issue. Further work is needed to more completely characterize phosphate toxicity and to establish the optimal therapeutic strategy for managing phosphate in patients with chronic kidney disease and in the general population.

Diagnostic Accuracy Study of Intraoperative and Perioperative Serum Intact PTH Level for Successful Parathyroidectomy in 501 Secondary Hyperparathyroidism Patients

Parathyroidectomy (PTX) is an effective treatment for severe secondary hyperparathyroidism (SHPT); however, persistent SHPT may occur because of supernumerary and ectopic parathyroids. Here a diagnostic accuracy study of intraoperative and perioperative serum intact parathyroid hormone (iPTH) was performed to predict successful surgery in 501 patients, who received total PTX + autotransplantation without thymectomy. Serum iPTH values before incision (io-iPTH0), 10 and 20 min after removing the last parathyroid (io-iPTH10, io-iPTH20), and the first and fourth day after PTX (D1-iPTH, D4-iPTH) were recoded. Patients whose serum iPTH was >50 pg/mL at the first postoperative week were followed up within six months. Successful PTX was defined if iPTH was <300 pg/mL, on the contrary, persistent SHPT was regarded. There were 86.4% patients underwent successful PTX, 9.8% remained as persistent SHPT and 3.8% were undetermined. Intraoperative serum iPTH demonstrated no significant differences in two subgroups with or without chronic hepatitis. Receiver operating characteristic (ROC) curves showed that >88.9% of io-iPTH20% could predict successful PTX (area under the curve [AUC] 0.909, sensitivity 78.6%, specificity 88.5%), thereby avoiding unnecessary exploration to reduce operative complications. D4-iPTH >147.4 pg/mL could predict persistent SHPT (AUC 0.998, sensitivity 100%, specificity 99.5%), so that medical intervention or reoperation start timely.

Long-term mortality after parathyroidectomy among chronic kidney disease patients with secondary hyperparathyroidism: a systematic review and meta-analysis

Parathyroidectomy (PTx) and medical treatments are both recommended for reducing serum intact parathyroid hormone (iPTH) and curing secondary hyperparathyroidism (sHPT) in patients with chronic kidney disease (CKD), but their therapeutic effects on long-term mortality are not well-known. Thus, we aim to assess such therapeutic effect of PTx. Electronic literatures published on Pubmed, Embase, and Cochrane Central Register of Controlled Trials in any language until 27 November 2015 were systematically searched. All literatures that compared outcomes (survival rate or mortality rate) between PTx-treated and medically-treated CKD patients with sHPT were included. Finally, 13 cohort studies involving 22053 patients were included. Data were extracted from all included literatures in a standard form. The outcomes of all-cause and cardiovascular mortalities were assessed using DerSimonian and Laird's random effects model. We find PTx-treated versus medically-treated patients had a 28% reduction in all-cause mortality and a 37% reduction in cardiovascular mortality. Thus, PTx versus medical treatments might reduce the risks of all-cause and cardiovascular mortalities in CKD patients with sHPT. Further studies with prospective and large-sample clinical trials are needed to find out the real effect of PTx and to assess whether mortality rates differ among patterns of PTx.

Surgical management of secondary hyperparathyroidism: how to effectively reduce recurrence at the time of primary surgery

BACKGROUND

Successful parathyroidectomy (PTX) often results in a dramatic drop in the parathyroid hormone (PTH) levels, relieves the patient from clinical symptoms, and reduces mortality. Although PTX is generally a successful treatment for progressive secondary hyperparathyroidism (SHPT) patients subjected to surgery, a significant proportion develops recurrent SHPT following PTX.

KEY MESSAGE

SHPT requiring PTX occurs more commonly in progressive chronic kidney disease and in long-term lithium therapy. Operative approaches include subtotal PTX, total PTX with or without autotransplantation, and possible thymectomy. Each approach has its proponents, advantages, and disadvantages. Although PTX offers the highest percentage cure for SHPT, compared to all other medical and surgical treatment, recurrent hyperparathyroidism can be observed in some patients dependent on follow-up time. A literature review and analysis of recent data regarding how to reduce recurrence of SHPT at the time of primary surgery was performed. The current literature and our own experience in the field have confirmed that pre-operative imaging, thymectomy, stereo magnifier, and surgical procedure may effectively reduce recurrence of SHPT at the time of primary surgery.

[Management of secondary hyperparathyroidism-current impact of parathyroidectomy]

Parathyroidectomy still presents an adequate and efficient therapeutic option for the management of refractory secondary hyperparathyroidism (sHPT). Dependent on the selected surgical technique it allows the highest rate of "laboratory cure" of sHPT. The question remains as to whether these improvements translate into clinical long-term benefits regarding the sHPT-associated vascular calcification and the increased risk for cardiovascular morbidity and mortality as well as overall mortality. Recent large observational studies point in this direction but definite evidence through prospective randomized controlled trials is still lacking.

Parathyroidectomy Associates with Reduced Mortality in Taiwanese Dialysis Patients with Hyperparathyroidism: Evidence for the Controversy of Current Guidelines

Parathyroidectomy is recommended by the clinical guidelines for dialysis patients with unremitting secondary hyperparathyroidism (SHPT). However, the survival advantage of parathyroidectomy is debated because of the selection bias in previous studies. To minimize potential bias in the present nationwide cohort study, we enrolled only dialysis patients who had undergone radionuclide parathyroid scanning to ensure all patients had severe SHPT. The parathyroidectomized patients were matched with the controls based on propensity score for parathyroidectomy. Mortality hazard was estimated using multivariate Cox proportional hazard models adjusting for comorbidities before scanning (model 1) or over the whole study period (model 2). Our results showed that among the 2786 enrolled patients, 1707 underwent parathyroidectomy, and the other 1079 were controls. The crude mortality rates were lower in the parathyroidectomized patients than in the controls. In adjusted analyses for the population matched on propensity score, parathyroidectomy was associated with a significant 20% to 25% lower risk for all-cause mortality (model 1: hazard ratio 0.76, 95% confidence interval 0.61 to 0.94; model 2: hazard ratio 0.80, 95% confidence internal 0.64 to 0.98). We concluded that parathyroidectomy was associated with a reduced long-term mortality risk in dialysis patients with severe SHPT.

A Randomized Study Comparing Parathyroidectomy with Cinacalcet for Treating Hypercalcemia in Kidney Allograft Recipients with Hyperparathyroidism

Tertiary hyperparathyroidism is a common cause of hypercalcemia after kidney transplant. We designed this 12-month, prospective, multicenter, open-label, randomized study to evaluate whether subtotal parathyroidectomy is more effective than cinacalcet for controlling hypercalcemia caused by persistent hyperparathyroidism after kidney transplant. Kidney allograft recipients with hypercalcemia and elevated intact parathyroid hormone (iPTH) concentration were eligible if they had received a transplant ≥6 months before the study and had an eGFR>30 ml/min per 1.73 m(2) The primary end point was the proportion of patients with normocalcemia at 12 months. Secondary end points were serum iPTH concentration, serum phosphate concentration, bone mineral density, vascular calcification, renal function, patient and graft survival, and economic cost. In total, 30 patients were randomized to receive cinacalcet (n=15) or subtotal parathyroidectomy (n=15). At 12 months, ten of 15 patients in the cinacalcet group and 15 of 15 patients in the parathyroidectomy group (P=0.04) achieved normocalcemia. Normalization of serum phosphate concentration occurred in almost all patients. Subtotal parathyroidectomy induced greater reduction of iPTH and associated with a significant increase in femoral neck bone mineral density; vascular calcification remained unchanged in both groups. The most frequent adverse events were digestive intolerance in the cinacalcet group and hypocalcemia in the parathyroidectomy group. Surgery would be more cost effective than cinacalcet if cinacalcet duration reached 14 months. All patients were alive with a functioning graft at the end of follow-up. In conclusion, subtotal parathyroidectomy was superior to cinacalcet in controlling hypercalcemia in these patients with kidney transplants and persistent hyperparathyroidism.

The effect of parathyroidectomy on patient survival in secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism is a common condition in patients with end-stage renal disease and is associated with osteoporosis and cardiovascular disease. Despite improved medical treatment, parathyroidectomy (PTX) is still necessary for many patients on renal replacement therapy. The aim of this study was to evaluate the effect of PTX on patient survival.

METHODS

A nested index-referent study was performed within the Swedish Renal Registry (SRR). Patients on maintenance dialysis and transplantation at the time of PTX were analysed separately. The PTX patients in each of these strata were matched for age, sex and underlying renal diseases with up to five referent patients who had not undergone PTX. To calculate survival time and hazard ratios, indexes and referents were assigned the calendar date (d) of the PTX of the index patient. The risk of death after PTX was calculated using crude and adjusted Cox proportional hazards regressions.

RESULTS

There were 20 056 patients in the SRR between 1991 and 2009. Of these, 579 (423 on dialysis and 156 with a renal transplant at d) incident patients with PTX were matched with 1234/892 non-PTX patients. The adjusted relative risk of death was a hazard ratio (HR) of 0.80 [95% confidence interval (CI) 0.65-0.99] for dialysis patients at d who had undergone PTX compared with matched patients who had not. Corresponding results for the patients with a renal allograft at d were an HR of 1.10 (95% CI 0.71-1.70).

CONCLUSIONS

PTX was associated with improved survival in patients on maintenance dialysis but not in patients with renal allograft.

Fifty shades of gray: Bone disease in renal transplantation

Kidney transplantation is the renal replacement therapy of choice for patients with end stage renal disease. Advances in technology, surgical techniques and pharmacotherapy have improved renal allograft survival. Increasingly, we are seeing long term side effects related to renal transplantation, bone disease being a major one amongst them. Renal transplant patients have a higher risk of fragility fractures even when compared to those who remain on dialysis. This is likely to be related to pre-existing underlying bone disease and the emergence of new metabolic bone problems post-transplant. Conditions such as persistent hyperparathyroidism and the use of certain immunosuppressive agents have a deleterious effect on the post renal transplant bone.

Remarkable advances in the field of metabolic bone research have been made in the last decade and newer imaging techniques, biomarkers and therapeutic options are now available for osteoporosis in the general population. Interest is being focused on attempting to extrapolate these new discoveries to the management of bone disease post renal transplant. This review will briefly describe the metabolic bone changes that occur after transplantation and will provide an update on the currently available investigative options and therapeutic strategies for the management of post renal transplant bone disease.

Survival after parathyroidectomy in chronic hemodialysis patients with severe secondary hyperparathyroidism

INTRODUCTION

The life for end-stage renal disease patients has remarkably improved in the last years. Although mineral and bone disorders remain as unsolved complication, in severe secondary hyperparathyroidism (sHPT), the ultimate treatment is parathyroidectomy (PTX). It is an old treatment, but there are still insufficient data regarding survival after PTX. The study goals were to compare 2-year mortality and morbidity after PTX in surgically versus medically treated sHPT and to compare the efficacy and safety in subtotal versus total PTX in a cohort of patients receiving hemodialysis (HD).

METHODS

This prospective, longitudinal study was carried out on a cohort of chronic HD patients with severe sHPT (iPTH over 700 pg/ml). Among the overall HD population, 26 patients underwent PTX. This group was compared to a control group treated with specific drugs. Laboratory parameters, specific symptoms and mortality were registered after 24 months of follow-up for each group. The subgroups of subtotal and total PTX patients were also compared.

RESULTS

All average values of mineral markers were significantly reduced after PTX, as a proof that surgical treatment was effective. The reduction in mineral markers and the improvement in symptoms and mortality rates were similar after total and subtotal PTX. Bone pain was significantly lower in patients after PTX than in those drug treated (p = 0.0005), but not muscle weakness and itching. Survival at 2 years was better in patients surgically treated (PTX) despite significantly higher mean baseline values of iPTH, Ca and ALP compared to patients medically treated (p = 0.03).

CONCLUSIONS

We compared clinical and laboratory outcomes in HD patients with severe sHPT. Mortality, bone pain and mineral markers were improved by PTX. Total and subtotal PTX had similar clinical outcomes.

When there will never be a randomized controlled trial

There are many unanswered questions about how to manage secondary hyperparathyroidism and associated alterations in mineral metabolism in patients with end-stage renal disease. We provide commentary on an observational study by Komaba et al. that presents interesting new insights into the long-standing controversy related to the impact of parathyroidectomy on survival of hemodialysis patients.

Parathyroidectomy Is Associated with Reduced Mortality in Hemodialysis Patients with Secondary Hyperparathyroidism

Secondary hyperparathyroidism increases morbidity and mortality in hemodialysis patients. The Kidney Disease Outcomes Quality Initiative Guidelines recommend parathyroidectomy for patients with chronic kidney disease and parathyroid hormone concentrations exceeding 800 pg/mL; however, this concentration represents an arbitrary cut-off value. The present study was conducted to identify factors influencing mortality in hemodialysis patients with parathyroid hormone concentrations exceeding 800 pg/mL and to evaluate the effects of parathyroidectomy on outcome for these patients. Two hundred twenty-one hemodialysis patients with parathyroid hormone concentrations > 800 pg/mL from July 2004 to June 2010 were identified. 21.1% of patients (n = 60) received parathyroidectomy and 14.9% of patients (n = 33) died during a mean follow-up of 36 months. Patients with parathyroidectomy were found to have lower all-cause mortality (adjusted hazard ratio [aHR]: 0.34). Other independent predictors included age ≥ 65 years (aHR: 2.11) and diabetes mellitus (aHR: 3.80). For cardiovascular mortality, parathyroidectomy was associated with lower mortality (HR = 0.31) but with a marginal statistical significance (p = 0.061). In multivariate analysis, diabetes was the only significant predictor (aHR: 3.14). It is concluded that, for hemodialysis patients with parathyroid hormone concentrations greater than 800 pg/mL, parathyroidectomy is associated with reduced all-cause mortality.