The optimal range of serum intact parathyroid hormone for a lower risk of mortality in the incident hemodialysis patients

Association between serum intact parathyroid hormone and survival in dialysis patients

PURPOSE

To examine the relationship between serum intact parathyroid hormone (iPTH) levels and survival in maintenance dialysis patients.

METHODS

We retrospectively reviewed the data of patients who began and continued dialysis from January 2013 to December 2022. Patients were categorized based on their baseline and time-averaged (TA) iPTH levels into three groups: low (iPTH < 150 pg/ml), medium (150 ≤ iPTH < 300 pg/ml), and high (iPTH ≥ 300 pg/ml). We utilized the Kaplan-Meier method to assess survival differences, the Cox proportional hazards regression model to identify risk factors impacting adverse outcomes and the restricted cubic spline model to evaluate the association between iPTH levels and the all-cause mortality.

RESULTS

We included a total of 1023 participants, comprising 524 hemodialysis and 499 peritoneal dialysis. Kaplan-Meier analysis showed that high baseline group had higher survival and low baseline group had poorer survival, compared with medium baseline group, respectively (χ2 = 44.974, P < 0.001). The three TA groups showed similar results (χ2 = 67.316, P < 0.001). Multivariate COX regression analysis showed that low TA iPTH was an independent risk factor for all-cause death (hazard ratio [HR] = 1.655, 95% CI 1.159-2.365, P = 0.006). The restricted cubic spline model revealed an L-shaped connection between TA iPTH level and the all-cause mortality with an inflection point of 193 pg/ml.

CONCLUSION

The survival for maintenance dialysis patients varies significantly based on their baseline and time-averaged iPTH levels, with time-averaged iPTH emerges as an independent risk factor for all-cause death in these patients.

PTH may predict early mortality in incident patients on hemodialysis: results from a large cohort

PURPOSE

Parathyroid hormone (PTH) is merit as a risk factor for mortality in patients with chronic kidney disease in prevalent hemodialysis patients in a U shape. Most studies, however, do not focus on incident patients and those who died within the first 90 days of therapy. We evaluated PTH as a risk factor for mortality in a large cohort population in Brazil.

METHODS

This is an observational cohort study that included 4317 adult patients who initiated hemodialysis between July 1st, 2012 and June 30, 2017. The main outcome was all-cause mortality. Fine-gray sub-distribution hazard models were used to evaluate survival in the presence of a competing event (kidney transplant).

RESULTS

Median PTH levels of 252 (118, 479) pg/mL. There were 331 deaths during the first 90 days of therapy (6.7%), 430 in a 1-year follow-up (10.7%) and 1282 (32%) during the 5-year study period. Deaths according to PTH < 150, 150-600 and > 600 pg/mL corresponded to 38.1%, 33.0% and 28.5%, respectively (p < 0.001). In an adjusted model, patients who started dialysis with PTH < 150 pg/mL had a higher mortality risk within the first 90 days, but not in 1 year and 5 years after starting dialysis. Analyses in a subset of patients with a repeated PTH in 1 year (N = 1954) showed that although persistent PTH low levels (< 150 pg/mL) at 1 year were significantly associated with all-cause mortality, this result was not sustained after multiple adjustments.

CONCLUSION

PTH < 150 pg/mL confers a high mortality risk in the first 90 days of dialysis. If this result reflects poor nutritional conditions, it deserves further investigations.

The efficacy and safety of cuttlebone for lowering serum phosphate in patients with end-stage renal disease: a meta-analysis of randomized controlled trials

Background: The efficacy of cuttlebone for treating hyperphosphatemia in patients with end-stage renal disease and its safety remained unclear. Methods: Randomized controlled trials comparing the efficacy of cuttlebone with conventional interventions were retrieved from MEDLINE, EMBASE, Cochrane Library, Airiti Library, and other major Chinese databases until 1 February 2023. The primary outcome was circulating phosphate concentration, while secondary outcomes included circulating calcium and intact parathyroid hormone levels, calcium-phosphorus product, and treatment-related side-effects. Results: Analysis of nine studies published between 2000 and 2019 including 726 participants showed a lower circulating phosphate concentration in the cuttlebone group than in controls [mean difference (MD) = -0.23, 95% CI: -0.39 to -0.06, p = 0.006, I2 = 94%, 726 patients] and a dose-dependent effect of cuttlebone against hyperphosphatemia. Therapeutic benefits were noted after both short-term (1-2 months) and long-term (3-6 months) treatments. Besides, patients receiving hemodialysis showed a better response to cuttlebone than those receiving peritoneal dialysis. There was no difference in circulating calcium level (mean difference = 0.03, 95% CI: -0.01 to 0.07, p = 0.17, I2 = 34%, 654 patients), while patients receiving cuttlebone showed lower circulating iPTH level and calcium-phosphorus product (MD = -43.63, 95% CI: -74.1 to -13.16, p = 0.005, I2 = 76%, 654 patients), (MD = -0.38, 95% CI: -0.38 to -0.01, p = 0.04, I2 = 83%, 520 patients). No difference in the risks of constipation, gastrointestinal discomfort, and elevated blood calcium was noted between the two groups. Conclusion: Compared with conventional phosphate-binding agents, cuttlebone more efficiently suppressed hyperphosphatemia with a dose-dependent effect. The limited number of included studies warrants further clinical investigations to verify our findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023396300.

Low Parathyroid Hormone Versus Secondary Hyperparathyroidism and Survival in Patients Undergoing Hemodialysis: A Propensity-Matched Analysis

Introduction

Low serum parathyroid hormone (PTH) and secondary hyperparathyroidism (SHPT) are very common in patients undergoing hemodialysis. However, it remains unclear which of these has a lower mortality.

Objective

In this study, we compared outcomes between hemodialysis patients with low PTH and those with SHPT.

Methods

This was a multi-center, retrospective, matched cohort study. Median intact PTH (iPTH) was used as the cutoff for allocating participants to low PTH (iPTH<100 pg/mL) and SHPT groups (iPTH ≥600 pg/mL). Sex, diabetes, age, and dialysis vintage were matched between the groups. The primary outcome was all-cause death at 72 months.

Results

The study cohort comprised 2282 patients (1166 in each study group). Prior to matching, the primary outcome occurred in 429/1166 patients (36.79%) in the low PTH group and in 284/1116 (25.45%) in the SHPT group. There were no significant differences in all-cause death between the groups according to multivariable Cox regression (P=0.423). The hazard ratio for low PTH versus SHPT was 1.08 (95% confidence interval, 0.90-1.30). Propensity matching created 619 pairs of patients. Baseline characteristics, including age, sex, diabetes, and dialysis vintage were comparable between the groups. The primary outcome occurred in 195/619 patients (31.50%) in the low PTH group and in 193/619 (31.18%) in the SHPT group. There were no significant differences in all-cause death between the groups according to multivariable Cox regression (P=0.43). The adjusted hazard ratio for low PTH versus SHPT was 1.10 (95% confidence interval, 0.87-1.39).

Conclusions

Hemodialysis patients with low PTH have similar all-cause death rates to the rates for those with SHPT.

Optimal targets of chronic kidney disease-mineral and bone disorder markers for Chinese patients with maintenance peritoneal dialysis: a single-center retrospective cohort study

Background

The chronic kidney disease-mineral and bone disorder（CKD-MBD) is known to be associated with increased mortality in dialysis patients, but whether current global guidelines for CKD-MBD, which were primarily developed from hemodialysis, are suitable for peritoneal dialysis (PD) patients practice require further investigation.

Methods

This is a single-center retrospective cohort study. In total 491 prevalent PD patients (median follow-ups: 34 months) from Peking Union Medical College Hospital (PUMCH) from January 2004 to December 2017 were included and followed until 30 June 2018. In the first dialysis year, the average levels of serum calcium, albumin-corrected calcium (CorCa), phosphorus, and parathyroid hormone (PTH) levels were the interested predictors in Cox proportional regression model.

Results

Of these PD patients (age 58 ± 17 years), 52% were male and 36% had diabetic nephropathy. In Cox regression over first-year mean parameters, PTH <100 pg/mL (HR = 1.97, 95% CI 1.32 to 2.94, p < 0.001) and ≥300 pg/mL (HR = 2.24, 95% CI 1.32 to 3.81, p = 0.003) were associated with increased all-cause mortality than that of PTH 100–200 pg/mL. Patients with albumin-corrected serum calcium level < 2.13 mmol/L also had higher risk of death than patients with level of 2.13 to 2.38 mmol/L (HR = 2.06, 95% CI 1.06 to 4.01, p = 0.02). Serum phosphorus ≥1.45 mmol/L were associated with increased all-cause mortality. However, lacking of data on 25-hydroxy vitamin D, alkaline phosphatase, and activated vitamin-D are limitations of our analysis.

Conclusions

As one of the largest PD cohort study focusing on CKD-MBD, we demonstrated that the level of CKD-MBD markers in the first PD year are independent predictors of all-cause mortality. PTH 100–300 pg/mL might be the best target for Chinese PD patients.