Parathyroidectomy is associated with slow progression of vascular calcification in maintenance haemodialysis patients: A propensity score-matched case-control study.

Parathyroidectomy has been the mainstay of treatment of severe hyperparathyroidism in patients with kidney failure until the introduction of calcimimetic. Several large observational studies demonstrated the improvement in patient outcomes after parathyroidectomy. The benefit of parathyroidectomy on vascular calcification remains largely unexplored. AIM: To examine the association between parathyroidectomy and the progression of vascular calcification as well as overall survival in maintenance haemodialysis patients. METHOD: This is a matched case-control study undertaken between 2012 and 2020. Patients who underwent parathyroidectomy were identified and matched 1:1 to non-parathyroidectomized (non-PTX) haemodialysis patients using propensity score matching method resulting in 120 patients in each arm. Aortic arch calcification (AoAC) score was determined annually in the posteroanterior chest x-ray. The average follow-up period was 38 months. RESULTS: Baseline demographic, laboratory data and AoAC score were comparable among the two groups of patients. The prevalence of AoAC was 59% in the PTX group and 54% in the non-PTX group (p = .43). Progression of AoAC occurred in 33% in the PTX group and 47% in the non-PTX group (p = .04). Multivariate generalized linear model revealed parathyroidectomy as an independent protective factor [ß (95% CI) -1.04 (-1.68, -0.41)] and increased serum calcium as a potentiating factor [ß (95% CI) 0.62 (0.25, 0.1)] for progression of AoAC. Linear mixed models revealed an increase in AoAC score in both groups but between group comparisons indicated substantially slower progression in the PTX group. Rapid progression of AoAC was also observed more frequently among non-PTX patients. Death occurred in 7 and 16% in the PTX and non-PTX groups, respectively. Kaplan-Meier survival curve revealed better survival associated with parathyroidectomy (p = .01). More rapid progression of AoAC also correlated with worse survival. CONCLUSION: Parathyroidectomy was associated with slow progression of vascular calcification in maintenance haemodialysis patients.

Improvement of nutritional status after parathyroidectomy in patients receiving maintenance hemodialysis.

Aims/Introduction: Parathyroidectomy is associated with improved survival in patients with end-stage kidney disease. Protein-energy wasting (PEW) is common in patients with kidney failure and predicts poor outcomes. Recent clinical trials have linked hyperparathyroidism to PEW. The present retrospective cohort study examined whether parathyroidectomy was associated with improvement in nutritional status in maintenance hemodialysis patients. Materials and methods: One hundred twenty-nine maintenance hemodialysis patients who had successful parathyroidectomy during 2012-2018 were identified (PTX group) and matched 1:1 to 479 patients with parathyroid hormone (PTH) levels ≤1,000 pg./mL (non-PTX control group) and 187 patients with PTH levels >1,000 pg./mL (pre-PTX control group) by propensity score. The matchings yielded 120 matched pairs from PTX and non-PTX groups (cohort 1) and 76 matched pairs from PTX and pre-PTX groups (cohort 2). Baseline and follow-up nutritional parameters associated with PEW were compared over the 12-month study period. Results: In cohort 1, substantially lower serum albumin and serum creatinine/body surface area (Cr/BSA) and higher proportions of patients with serum albumin ≤38 g/L (low albumin) and serum Cr/BSA ≤380 µmol/L/m2 (low Cr/BSA) were observed in the PTX group. These parameters improved significantly after parathyroidectomy. Total lymphocyte count (TLC) was comparable at baseline but the percentage of patients with TLC <800 cells/mm3 (low TLC) decreased substantially after parathyroidectomy. At follow-up, serum albumin, serum Cr/BSA and proportions of patients with low albumin and Cr/BSA became comparable with the non-PTX control group. The percentage of patients with low TLC became lower in the PTX group. Mixed-models analysis confirmed significant differences in the changes in serum albumin, serum Cr/BSA, and proportions of patients with low albumin and TLC between the two groups. In cohort 2, nutritional parameters were comparable at baseline. At follow-up, serum Cr/BSA was higher and proportions of patients with body mass index ≤18.5 kg/m2, low TLC and low Cr/BSA were lower in the PTX group. Weight gain was more frequent and of greater magnitude in the PTX group in both cohorts. A substantial reduction in blood pressure was also observed in the PTX group. Conclusion: Severe hyperparathyroidism was associated with nutritional impairment which improved considerably after parathyroidectomy.

Severe hyperparathyroidism is associated with nutritional impairment in maintenance hemodialysis patients.

Severe hyperparathyroidism predicts poor outcomes in patients with kidney failure. Mechanisms underlying the relationship between high parathyroid hormone (PTH) and decreased survival other than bone loss are largely unexplored. Recent evidence suggests the role of excess PTH in adipose tissue browning resulting in protein-energy wasting. The present retrospective observational study examined nutritional status among patients receiving maintenance hemodialysis with different degree of hyperparathyroidism. Seven hundred forty-five patients were categorized into four groups according to PTH levels: group 0, < 200; group 1, 200-599; group 2, 600-1,499; and group 3, ≥1,500 pg/ml. Group 0 was excluded because of the relationship between low PTH with aging and malnutrition. Patients in groups 1 and 2 were matched to group 3 by propensity score yielding 410 patients in the final analysis. Nutritional parameters at baseline and the preceding 1 and 2 years were examined. At baseline, lower serum albumin, creatinine/body surface area (Cr/BSA), height in female and higher percentage of patients with serum albumin < 38 g/L were observed in group 3 compared to groups 1 and 2. Higher PTH level was independently associated with serum albumin < 38 g/L and Cr/BSA < 380 µmol/L/m2. The longitudinal decline in serum albumin and Cr/BSA and the increase in the frequency of patients with serum albumin < 38 g/L were observed among patients in group 3. Between group comparisons confirmed a significant decline in serum albumin and Cr/BSA in association with an increase in the proportion of patients with serum albumin < 38 g/L and Cr/BSA < 380 µmol/L/m2 in group 3 compared to groups 1 and 2. Weight loss was more significant and was of greater magnitude among patients in group 3 compared to groups 1 and 2. Normalized protein catabolic rate in 3 groups were comparable. There was no significant difference in any of the nutritional parameters between groups 1 and 2. In conclusion, patients receiving maintenance hemodialysis with severe hyperparathyroidism showed deterioration of nutritional status compared to patients with moderate hyperparathyroidism and patients with PTH level in the recommended range. These findings support the role of extreme PTH level in protein-energy wasting emphasizing the importance of early management of hyperparathyroidism.