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Aberrant serum parathyroid hormone, calcium, and phosphorus as risk factors for peritonitis in peritoneal dialysis patients.
Liao, CT, Zheng, CM, Lin, YC, Wu, MY, Lin, YF, Hsu, YH, Hsu, CC, Wu, MS
Scientific reports. 2021;(1):1171
Abstract
Identifying modifiable risk factors of peritoneal dialysis (PD)-related peritonitis is of clinical importance in patient care. Mineral bone disease (MBD) has been associated with mortality and morbidity in end-stage kidney disease (ESKD) patients. However, its influence on PD related peritonitis due to altered host immunity remains elusive. This study investigated whether abnormal biomarkers of MBD are associated with the development of peritonitis in patients undergoing maintenance PD. We conducted a retrospective observational cohort study, analysing data derived from a nationwide dialysis registry database in Taiwan, from 2005 to 2012. A total of 5750 ESKD patients commencing PD therapy during this period were enrolled and followed up to 60 months or by the end of the study period. The patients were stratified based on their baseline serum parathyroid hormone (PTH) levels, calcium (Ca) levels or phosphorus (P) levels, respectively or in combinations. The primary outcome was the occurrence of first episode of peritonitis, and patient outcomes such as deaths, transfer to haemodialysis or receiving renal transplantation were censored. Peritonitis-free survival and the influence of PTH, Ca, P (individual or in combination) on the peritonitis occurrence were analysed. A total of 5750 PD patients was enrolled. Of them, 1611 patients experienced their first episode of peritonitis during the study period. Patients with low PTH, high Ca or low P levels, respectively or in combination, had the lowest peritonitis-free survival. After adjusting for age, sex and serum albumin levels, we found that the combinations of low PTH levels with either high Ca levels or low/normal P levels were significant risk factors of developing peritonitis. Abnormal mineral bone metabolism in maintenance PD patients with low serum PTH levels, in combination with either high Ca levels or low/normal P levels, could be novel risk factors of PD-related peritonitis.
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Paradoxical Response of Parathyroid Hormone to Vitamin D-Calcium Supplementation in Indian Children.
Mandlik, RM, Mughal, ZM, Khadilkar, AV, Ekbote, VH, Kajale, NA, Patwardhan, VG, Khadilkar, VV, Padidela, R
The Journal of pediatrics. 2020;:197-203
Abstract
OBJECTIVES To investigate the effect of oral vitamin D-calcium supplementation on serum intact parathyroid hormone (PTH), calcium, phosphorous, and alkaline phosphatase (ALK-P) concentrations in children with habitually low calcium intakes. STUDY DESIGN In this follow-up study to a randomized controlled trial that aimed to assess the effect of vitamin D-calcium supplementation on immunity, data related to dietary intake, anthropometry, and biochemistry [serum 25(OH)D and bone profile] were collected from 178 children-79 in the vitamin D group and 99 in the non-vitamin D group. RESULTS Dietary calcium to phosphorus intake ratio was 0.4:1. Baseline serum 25(OH)D concentration was 58.2 ± 10.9 nmol/L; 66% children were vitamin D sufficient and none deficient. After supplementation, vitamin D group, compared with the non-vitamin D group, had significantly (P < .05) greater 25(OH)D (83.9 ± 30.1 nmol/L vs 58.3 ± 15.7 nmol/L), significantly greater PTH (6.7 ± 3.6 pmol/L vs 5.5 ± 3.2 pmol/L), and positive correlation (rs = 0.24) between serum 25(OH)D and PTH (vs negative correlation [rs = -0.1] in non-vitamin D group). Mean concentrations of serum bone measures in the vitamin D group were calcium (2.2 ± 0.1 mmol/L), phosphorus (1.7 ± 0.2 mmol/L), and ALK-P (178.7 ± 40.7 IU/L). At follow-up, 1-year post-supplementation, in the vitamin D group, PTH concentrations continued to remain high (but not significantly different from levels at 6 months), with low normal serum calcium, high normal phosphate, and ALK-P in reference range. CONCLUSIONS In children who are vitamin D sufficient but with habitually low dietary calcium intake, vitamin D-calcium supplementation paradoxically and significantly increased serum PTH concentrations with no apparent effect on other bone biochemistry. Chronic low dietary calcium to phosphorus ratio is likely to have caused this paradoxical response.
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The medical and surgical treatment in secondary and tertiary hyperparathyroidism. Review.
Cocchiara, G, Fazzotta, S, Palumbo, VD, Damiano, G, Cajozzo, M, Maione, C, Buscemi, S, Spinelli, G, Ficarella, S, Maffongelli, A, et al
La Clinica terapeutica. 2017;(2):e158-e167
Abstract
INTRODUCTION Hyperparathyroidism is an alteration of the pathophysiological parathyroid hormone (PTH) secretion due or an independent and abnormal release (primary or tertiary hyperparathyroidism) by the parathyroid or an alteration of calcium homeostasis that stimulates the excessive production of parathyroid hormone (secondary hyperparathyroidism). AIMS There is not a standard, clinical or surgical, treatment for hyperparathyroidism. We review current diagnostic and therapeutic methods. DISCUSSION In secondary hyperparathyroidism (2HPT) there is a progressive hyperplasia of the parathyroid glands and an increased production of parathyroid hormone. Several causes are proposed: chronic renal insufficiency, vitamin D deficiency, malabsorption syndrome. The tertiary hyperparathyroidism (3HPT) is considered a state of excessive autonomous secretion of PTH due to long-standing 2HPT and it's usually the result of a lack of suppression in the production of PTH. The pathophysiological implications are both skeletal and extraskeletal: it damages the cardiovascular system, nervous system, immune, hematopoietic and endocrine system. The introduction of new drugs has improved the survival of these patients, allowing the inhibition of the synthesis of PTH. Indication for surgical treatment is unresponsive medical therapy. CONCLUSIONS There are no large prospective studies that comparing the medical and surgical treatment. The choice is not unique and we have to consider the singolar case and the clinical condition of the patient.
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[New definition of optimal vitamin D status and redefening serum parathyroid hormone reference range].
Cormier, C, Souberbielle, JC
La Revue de medecine interne. 2006;(9):684-9
Abstract
SCOPE Knowledge concerning vitamin D has greatly improved during the past few years. Vitamin D can no longer be considered only as a preventive therapy for rickets-osteomalacia. Indeed, beside its role in the prevention of osteoporotic fractures in the elderly, many data suggest that it may be involved in the prevention of various diseases including cancers and auto-immune diseases. CURRENT SITUATION AND SALIENT POINTS Vitamin D status may be easily assessed by the measurement of 25OHD serum concentration. However, many specialists in the field regard most 25OHD reference values as being too low, and believe that the 25OHD threshold below which vitamin D status can be considered as insufficient is somewhere between 50 and 100 nmol/L (20 to 40 ng/mL). It then appears that usually recommended amounts of supplemental vitamin D may be too low to reach these 25OHD concentrations, and thus need to be revised. We have proposed that PTH reference values should be established in healthy subjects with a normal vitamin D status. This supposes that 25OHD is measured in the reference population beforehand, and that the subjects with vitamin D insufficiency are eliminated from the reference group. PERSPECTIVES Although more complicated than the usual way to establish normative data, we have shown that it decreases the upper limit of normal by 25-35%, enhancing thus the diagnostic sensitivity for hyperparathyroidism without a decrease in specificity.
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[Population genetic correlation of vitamin D receptor polymorphisms with clinical disorders].
Gyórffy, B, Szabó, A, Vásárhelyi, B
Orvosi hetilap. 2003;(41):2011-5
Abstract
Calcitriol, the active metabolite of Vitamin D (1,25(OH)2D3) has several major roles in the body: hormonal regulation of calcium and phosphate-homeostasis, regulation of parathormone synthesis and modulation of the immune and endocrine systems. Due to its antiproliferative effects it also plays a role in tumour development. The calcitriol can have these differential effects as it is modulating gene expression in the cell nucleus. The effects of vitamin D are mediated by the nuclear vitamin D receptor, which heterodimerizes with the retinoid X receptor and changes gene transcription. Until now 5 single nucleotide polymorphisms of the vitamin D receptor gene have been identified. This review summarizes the identified effects of vitamin D receptor polymorphisms on bone homeostasis, on the parathyroid function, on diversal tumours and on diabetes.
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A placebo-controlled trial to evaluate immunomodulatory effects of paricalcitol.
Moe, SM, Zekonis, M, Harezlak, J, Ambrosius, WT, Gassensmith, CM, Murphy, CL, Russell, RR, Batiuk, TD
American journal of kidney diseases : the official journal of the National Kidney Foundation. 2001;(4):792-802
Abstract
Calcitriol has shown a benefit in various small uncontrolled studies of ex vivo immune function. We hypothesized that paricalcitol, a new vitamin D derivative, will have a positive effect on the immune system with minimal adverse effects on calcium homeostasis. Thirty-one hemodialysis patients not administered vitamin D because of low intact parathyroid hormone (PTH) levels were randomized to placebo or 4 microg of paricalcitol intravenously with the hemodialysis session three times weekly for 12 weeks. Effects on in vivo and ex vivo assessments of immune function were evaluated. All patients achieved the target dose of paricalcitol. Twenty patients were anergic at the start of the study; 4 of 11 patients in the paricalcitol group and 0 of 9 patients in the placebo group converted to reactive (P = 0.09). The in vivo response to standard hepatitis B booster vaccine and in vitro proliferation and release of interleukin-2 (IL-2), IL-6, tumor necrosis factor-alpha, and interferon-gamma from stimulated lymphocytes were not different between the groups. In contrast to clinical immune effects, paricalcitol increased serum calcium levels and decreased PTH and bone alkaline phosphatase levels (all P < 0.05). However, hypercalcemia was infrequent. In vitro experiments showed that paricalcitol led to greater dose-dependent thymidine uptake than calcitriol in lymphocytes isolated from either dialysis patients or control subjects. Paricalcitol has a tendency toward improving delayed hypersensitivity reactions, but did not have other proimmune effects. However, as expected, paricalcitol had significant effects on calcium homeostasis compared with placebo. Thus, patients with low PTH levels are unlikely to experience the proimmune effects of vitamin D therapy without more profound and potentially adverse oversuppression of PTH.