Parathyroidectomy in patients with chronic kidney disease: Impacts of different techniques on the biochemical and clinical evolution of secondary hyperparathyroidism

Regulatory mechanism of FCGR2A in macrophage polarization and its effects on intervertebral disc degeneration

Intervertebral disc degeneration (IDD) poses a significant health burden, necessitating a deeper understanding of its molecular underpinnings. Transcriptomic analysis reveals 485 differentially expressed genes (DEGs) associated with IDD, underscoring the importance of immune regulation. Weighted gene co-expression network analysis (WGCNA) identifies a yellow module strongly correlated with IDD, intersecting with 197 DEGs. Protein-protein interaction (PPI) analysis identifies ITGAX, MMP9 and FCGR2A as hub genes, predominantly expressed in macrophages. Functional validation through in vitro and in vivo experiments demonstrates the pivotal role of FCGR2A in macrophage polarization and IDD progression. Mechanistically, FCGR2A knockdown suppresses M1 macrophage polarization and NF-κB phosphorylation while enhancing M2 polarization and STAT3 activation, leading to ameliorated IDD in animal models. This study sheds light on the regulatory function of FCGR2A in macrophage polarization, offering novel insights for IDD intervention strategies. KEY POINTS: This study unveils the role of FCGR2A in intervertebral disc (IVD) degeneration (IDD). FCGR2A knockdown mitigates IDD in cellular and animal models. Single-cell RNA-sequencing uncovers diverse macrophage subpopulations in degenerated IVDs. This study reveals the molecular mechanism of FCGR2A in regulating macrophage polarization. This study confirms the role of the NF-κB/STAT3 pathway in regulating macrophage polarization in IDD.

The effect of intradialytic exercise on calcium, phosphorus and parathyroid hormone: a randomized controlled trial

BACKGROUND

Patients with kidney failure experience derangements of circulating markers of mineral metabolism and dysregulation of skeletal and cardiovascular physiology which results in high mortality rate in these patients. This study aimed to evaluate the effect of intradialytic exercise on regulation of these abnormalities in patients receiving chronic hemodialysis (HD).

METHODS

In this randomized controlled trial conducted in an HD center in Iran, adult patients receiving chronic HD were randomized to intradialytic exercise (60 min) in the second hour of thrice weekly dialysis for 6 months (intervention) or no intradialytic exercise (control). The primary outcomes were serum calcium, serum phosphorous and parathyroid hormone levels. Secondary outcomes were serum alkaline phosphatase and calcium-phosphorous product.

RESULTS

The study included 44 participants randomized to intervention (n = 22) or control (n = 22). During the 6-month intervention period, significant between-group changes were observed in all primary and secondary outcomes between the intervention and control groups. Statistical analyses reveal a significant increase in serum calcium (P < 0.05) as well as a significant decrease in serum phosphorous, parathyroid hormone, alkaline phosphatase and calcium-phosphorous product (P < 0.05).

CONCLUSION

Intradialytic exercise performed for at least 60 min during thrice weekly dialysis sessions improves bone mineral metabolism in adult patients receiving HD. Further studies should focus on observing and comparing the effect of different types of exercise on bone mineral disorders and all-cause mortality in HD patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04916743, Registered on 08/06/2021. Registered trial name: The Effect of Intradialytic Exercise on Calcium, Phosphorous and Parathyroid Hormone: A Randomized Controlled Trial.

Advances in the treatment of secondary and tertiary hyperparathyroidism

Secondary hyperparathyroidism (SHPT) and tertiary hyperparathyroidism (THPT) are common and complicated clinical endocrine diseases. The parathyroid glands maintain endocrine homeostasis by secreting parathyroid hormone to regulate blood calcium levels. However, structural alterations to multiple organs and systems occur throughout the body due to hyperactivity disorder in SHPT and THPT. This not only decreases the patients' quality of life, but also affects mortality. Since current treatments for these diseases remains unclear, we aimed to develop a comprehensive review of advances in the treatment of SHPT and THPT according to the latest relevant researches.

Use of 99mTc-sestamibi SPECT/CT imaging in predicting the degree of pathological hyperplasia of the parathyroid gland: semi-quantitative analysis

Background

Previous studies have demonstrated that ^99mTc-sestamibi (^99mTc-MIBI) Single-Photon Emission Computed Tomography/ Computed Tomography (SPECT/CT) imaging is an effective isotopic technique for locating the parathyroid in secondary hyperparathyroidism (SHPT). This study aimed to explore further the correlation between ^99mTc-MIBI SPECT/CT imaging and SHPT to demonstrate the value of ^99mTc-MIBI SPECT/CT in evaluating the degree of pathological hyperplasia of the parathyroid gland (PG).

Methods

The demographics, surgical records, and follow-up information of 91 patients were recorded and analyzed. A total of 216 paraffin-embedded PGs of 54 patients were obtained and analyzed.

Results

Patients with ^99mTc-MIBI negative PG(s) had significantly lower preoperative serum phosphorus and higher serum calcium levels at 6 months postoperatively compared to those with ^99mTc-MIBI positive PG(s) (P<0.05). We also found a higher total uptake ratio of the region of interest (URRI) and higher URRI max in the hypocalcemia group than in the non-hypocalcemia group. Both URRI total (P=0.003) and URRI max (P=0.028) were independent risk factors for hypocalcemia 6 months postoperatively. The URRI values of the PGs were significantly positively correlated with glandular weight (R²=0.343, P<0.001), glandular volume (R²=0.240, P<0.001), and degree of pathological hyperplasia (P<0.001). However, the URRI value of the PGs exhibited a notably weak correlation with proliferating cell nuclear antigen (PCNA) (R²=0.035, P=0.006). The area under the receiver operating characteristic curve showed a URRI evaluative value of 0.771 for diffuse and nodular types in 216 PGs (P<0.001). We further evaluated 167 nodular-type PGs, distinguishing between nodular hyperplasia and a single nodule; the URRI evaluative value reached 0.819, which was higher than the volume or weight (P<0.001).

Conclusions

The ^99mTc-MIBI SPECT/CT scintigraphy results were related to serum calcium levels at 6 months after total parathyroidectomy with autotransplantation (TPTX+AT), suggesting the occurrence of hypocalcemia (6 months after TPTX+AT). More importantly, this technique effectively evaluated the pathological hyperplasia of PGs preoperatively, and therefore, could assist surgeons in selecting the PGs with the lowest degree of hyperplasia intraoperatively.

The effect of vitamin D supplementation on fibroblast growth factor-23 in patients with chronic kidney disease: A systematic review and meta-analysis

This is a meta-analysis of randomized controlled trials (RCTs) investigating the effects of oral vitamin D supplementation on serum fibroblast growth factor-23 (FGF23) concentrations in patients with chronic kidney disease (CKD). Manuscripts were extracted from PubMed/MEDLINE, Scopus, and ISI Web of Science through February 2020. Subgroup analyses, sensitivity analysis, and meta-regression assessments were performed. A total of eight clinical trials with nine treatment arms were included in the final analysis. The pooled results showed no significant changes in circulating FGF23 following vitamin D supplementation compared to the control group (Standardized mean difference (SMD): 0.24; 95% confidence intervals (CIs): -0.03 to 0.50, p > 0.05). Subgroup analyses found that studies which had participants with a body mass index (BMI) higher than 25 kg/m² , with an intervention duration shorter than 15 weeks, using phosphate binder medications, and trials that were on both patients with CKD undergoing hemodialysis and patients without hemodialysis treatment produced significant increases in FGF23 when concentration compared with the control group. This meta-analysis provides evidence that vitamin D supplementation does not have a significant effect on plasma FGF23 levels. However, further high-quality trials are required to identify the influence of oral vitamin D supplementation on FGF23 levels in patients with CKD.

Surgery for Renal Hyperparathyroidism in the Era of Cinacalcet: A Single-Center Experience

BACKGROUND AND AIMS

There are only few data on the influence of cinacalcet on the outcome of parathyroidectomy in patients with renal hyperparathyroidism. Indication and timing of surgery have changed since its introduction, especially with regard to kidney transplantation. Therefore, we retrospectively analyzed patients undergoing parathyroidectomy for renal hyperparathyroidism in our institution.

MATERIAL AND METHODS

Between 2008 and 2015, 196 consecutive operations in 191 patients were analyzed. About 80 operations (41%) were performed in patients receiving cinacalcet compared with 116 operations (59%) in patients without cinacalcet. Clinical data, preoperative medication, pre- and postoperative laboratory values, type and details of surgery including complications, as well as cardiovascular complications and kidney transplantation with graft function were recorded.

RESULTS

Demographical data were similar in patients with or without cinacalcet treatment. A total of 54% of patients received a kidney graft before or after parathyroidectomy. Pre- and postoperative parathormone levels were similar in both groups (preoperatively 755 vs 742 ng/L, postoperatively 50 vs 46 ng/L, p > 0.10), whereas patients with cinacalcet showed significantly lower calcium levels preoperatively (2.28 vs 2.41 mmol/L, p = 0.0002). There was no difference in recurrence or persistence of hyperparathyroidism, duration of surgery, hospital stay, or complication rate. Creatinine levels in patients with tertiary hyperparathyroidism were similar after 1-year follow-up.

CONCLUSION

Cinacalcet did not influence outcome of patients with parathyroidectomy for renal hyperparathyroidism and can be safely offered to patients not responding to medical treatment.

Type of subtotal parathyroidectomy and evolution of parathyroid hormone levels in end-stage renal disease patients: a retrospective cohort study

PURPOSE

Parathyroidectomy (PTX) is performed in end-stage renal disease (ESRD) for the treatment of secondary hyperparathyroidism. Whether and how the number of glands removed affects parathyroid hormone (PTH) levels remain controversial. The objective of this study is to compare the biochemical and pharmacological evolution after subtotal PTX according to the number of glands removed in ESRD.

METHODS

This is a unicenter longitudinal retrospective cohort study of ESRD patients who have undergone PTX [< 3 glands (group 1) vs ≥ 3 glands (group 2)] from April 2006 to October 2014 at CHU de Québec, Canada. Demographic data, comorbidities, pharmacological and biochemical parameters were collected before, 3, 6, 12 and 24 months after PTX. Linear mixed model was performed to compare the biochemical and pharmacological evolution.

RESULTS

We included 37 (13 in group 1, 24 in group 2) ESRD patients with a median age of 53 (46-58) years. The population is 68% male with a median dialysis vintage of 30.7 (18.0-61.2) months. The two groups were similar in terms of demographics and comorbidities. Compared to baseline, PTH levels in groups 1 and 2 dropped significantly at 2 years (1239-361 ng/L and 1542-398 ng/L, p < 0.05) but the evolution was comparable between the two groups.

CONCLUSIONS

Our results show the efficacy of subtotal PTX in lowering PTH levels in our ESRD cohort. However, the results were not different according to the number of glands removed.

Network meta-analysis of surgical treatment for secondary hyperparathyroidism

BACKGROUND

Main surgical treatments for secondary hyperparathyroidism (SHPT) include subtotal parathyroidectomy (sPTX), total parathyroidectomy with autotransplantation (tPTX+AT), and total parathyroidectomy (tPTX); however, determining the best treatment is debatable. We conducted a network meta-analysis (NMA) comparing three treatments in terms of postoperative hypocalcemia (or hypoparathyroidism), postoperative recurrence, and reoperation.

METHODS

We searched PubMed, Medline, the Cochrane Library, and Embase for relevant research from inception to July 30, 2019. We performed our Bayesian NMA using R 3.51 software to assess odds ratios (OR) and 95% confidence intervals (CI). Network and forest plots displayed study outputs. Potential publication bias was assessed with funnel plots using software Stata/MP 13.0.

RESULTS

Twenty-six articles comprising 5063 patients were included in our NMA, which showed that postoperative hypocalcemia (or hypoparathyroidism) occurred more frequently in tPTX than in sPTX (OR = 3.50, 95% CI 1.10-11.0) or tPTX+AT patients (OR = 1.80, 95% CI 0.66-5.20). Regarding postoperative hypocalcemia (or hypoparathyroidism), there was no significant difference between sPTX and tPTX+AT (OR = 0.53, 95% CI 0.24-1.10). As for recurrence rates, statistically significant differences were observed between sPTX and tPTX (OR = 25.0, 95% CI 5.1-260), tPTX+AT and tPTX (OR = 20.0, 95% CI 4.2-200), and sPTX and tPTX+AT (OR = 1.30, 95% CI 0.65-2.50). Regarding reoperation rates, sPTX experienced higher incidence compared with tPTX+AT (OR = 1.20, 95% CI 0.53-2.70) or tPTX patients (OR = 2.70, 95% CI 1.20-14.00).

CONCLUSIONS

TPTX+AT is recommended as the most efficient and safe surgical SHPT treatment with minimal adverse effects. Large-scale randomized controlled trials are recommended to confirm the NMA results.

Effect of parathyroid hormone levels on the functional capacity and pulmonary function of patients on dialysis

Abstract Introduction: Chronic kidney disease is characterized as the gradual loss of kidney function, with patients on dialysis experiencing a decline in functional capacity and pulmonary function. One of the non-traditional risk factors is parathyroid hormone (PTH), which influences metabolism and the status of the disease. Objective: Assess the effect of parathyroid hormone levels on functional capacity and pulmonary function in patients on dialysis. Method: Cross-sectional study with hemodynamically stable dialysis patients of both sexes, aged 18 to 59 years, who did not gain more than 2.5kg between dialysis sessions. Two groups were created according to PTH blood levels: PTH (A), with values outside the normal range, and PTH (C), who exhibited normal levels of the hormone. Pulmonary function (PF) was assessed by spirometry and functional capacity (FC) via the six-minute walk test (6MWT). Results: The PTH A group displayed a negative association between PTH levels and PF, based on the values obtained for the spirometric variables forced expiratory volume in 1 second (FEV1) (r = -0.54) and forced vital capacity (FVC) (r= -0.69). The average distance walked by the PTH (C) group was 343.85 ± 98.14 meters. Conclusion: The results suggest that high PTH levels have a negative effect on the PF of patients on dialysis.

Long-term outcomes and management considerations after parathyroidectomy in the dialysis patient

Parathyroidectomy (PTX) remains an important intervention for dialysis patients with poorly controlled secondary hyperparathyroidism (SHPT), though there are only retrospective and observational data that show a mortality benefit to this procedure. Potential consequences that we seek to avoid after PTX include persistent or recurrent hyperparathyroidism, and parathyroid insufficiency. There is considerable subjectivity in defining and diagnosing these conditions, given that we poorly understand the optimal PTH targets (particularly post PTX) needed to maintain bone and vascular health. While lowering PTH after PTX decreases bone turnover, long-term changes in bone activity have been poorly explored. High turnover bone disease, usually present at the time a PTX is considered, often swings to a state of low turnover in the setting of sufficiently low PTH levels. It remains unclear if all low bone turnover equate with disease. However, such changes in bone turnover appear to predispose to vascular calcification, with positive calcium balance after PTX being a potential contributor. We know little of how the post-PTX state resets calcium balance, how calcium and VDRA requirements change or what kind of adjustments are needed to avoid calcium loading. The current consensus cautions against excessive reduction of PTH although there is insufficient evidence-based guidance regarding the management of chronic kidney disease - mineral bone disease (CKD-MBD) parameters in the post-PTX state. This article aims to compile existing research, provide an overview of current practice with regard to PTX and post-PTX chronic management. It highlights gaps and controversies and aims to re-orient the focus to clinically relevant contemporary priorities in CKD-MBD management after PTX.

Preoperative calcitriol reduces postoperative intravenous calcium requirements and length of stay in parathyroidectomy for renal-origin hyperparathyroidism

BACKGROUND

Patients undergoing subtotal parathyroidectomy for renal-origin hyperparathyroidism often develop postoperative hypocalcemia, requiring calcitriol and intravenous calcium (Postop-IVCa). We hypothesized that in subtotal parathyroidectomy for renal-origin hyperparathyroidism, preoperative calcitriol treatment reduces the use of postoperative administration of intravenous calcium.

METHODS

A retrospective chart review compared subtotal parathyroidectomy for renal-origin hyperparathyroidism patients who received preoperative calcitriol treatment with those patietns who did not receive preoperative calcitriol treatment at one institution. Preoperative calcitriol treatment loading doses were 0.5 mcg twice daily for 5 days. All patients received postoperative calcitriol and oral calcium carbonate. Postoperative administration of intravenous calcium was given for symptoms, calcium <7.0 mg/dL, or surgeon preference. The Fisher exact test was used to compare proportions. The Wilcoxon test was used to compare continuous data. Multivariable logistic regression adjusted for confounders.

RESULTS

Included were 81 patients who received subtotal parathyroidectomy for renal-origin hyperparathyroidism (41 patients who received preoperative calcitriol treatment, 40 patients who did not receive preoperative calcitriol treatment). Preoperative calcitriol treatment use increased over time (0% 2004-2010, 69% 2011-2016). Groups who received preoperative calcitriol treatment and groups who did not receive preoperative calcitriol treatment were similar in preoperative serum calcium, vitamin D, parathyroid hormone, and median age (P > .05 for all). Patients who received preoperative calcitriol treatment less often required postoperative administration of intravenous calcium (34% vs 90% of patients who did not receive preoperative calcitriol treatment, P < .001). Median length of stay was 2.0 days shorter for patients who received preoperative calcitriol treatment versus patients who did not receive preoperative calcitriol treatment patients (P < .001). Factors associated with postoperative administration of intravenous calcium included not receiving preoperative calcitriol treatment, low preoperative calcium, and high preoperative parathyroid hormone. After multivariable adjustment, preoperative calcitriol treatment remained independently associated with reduced postoperative administration of intravenous calcium (OR 0.02, P < .001).

CONCLUSION

Preoperative calcitriol therapy lowered use of postoperative administration of intravenous calcium by 56% and length of stay by 50% in subtotal parathyroidectomy for renal-origin hyperparathyroidism patients. We believe preoperative calcitriol treatment should become standard of care for subtotal parathyroidectomy for renal-origin hyperparathyroidism.