Low Intact Parathyroid Hormone Levels Research Articles

Neonate with Respiratory Distress, Bilateral Microtia, Hypocalcemia, and Lymphopenia.

Neonate with Respiratory Distress, Bilateral Microtia, Hypocalcemia, and Lymphopenia.

Infantile hypercalcemia with novel compound heterozygous mutation in SLC34A1 encoding renal sodium-phosphate cotransporter 2a: a case report.

Idiopathic infantile hypercalcemia is characterized by hypercalcemia, dehydration, vomiting, and failure to thrive, and it is due to mutations in 24-hydroxylase (CYP24A1). Recently, mutations in sodium-phosphate cotransporter (SLC34A1) expressed in the kidney were discovered as an additional cause of idiopathic infantile hypercalcemia. This report describes a female infant admitted for evaluation of nephrocalcinosis. She presented with hypercalcemia, hypercalciuria, low intact parathyroid hormone level, and high 1,25-dihydroxyvitamin D3 level. Exome sequencing identified novel compound heterozygous mutations in SLC34A1 (c.1337G>A, c.1483C>T). The patient was treated with fluids for hydration, furosemide, a corticosteroid, and restriction of calcium/vitamin D intake. At the age of 7 months, the patient's calcium level was within the normal range, and hypercalciuria waxed and waned. Renal echogenicity improved on the follow-up ultrasonogram, and developmental delay was not noted. In cases of hypercalcemia with subsequent hypercalciuria, DNA analysis for SLC34A1 gene mutations and CYP24A1 gene mutations should be performed. Further studies are required to obtain long-term data on hypercalciuria and nephrocalcinosis.

Aortic Arch Calcification as a Predictor of Repeated Arteriovenous Fistula Failure within 1-Year in Hemodialysis Patients.

Objectives The aim of the study was to identify the factors associated with repeated arteriovenous fistula (AVF) failure within 1-year, especially the impact of aortic arch calcification (AAC) on patency of AVF. Materials and Methods We retrospectively assessed chest radiography in hemodialysis patients who had undergone initial AVF. The extent of AAC was categorized into four grades (0–3). The association between AAC grade, other clinical variables, and repeated failure of AVF was then analyzed by binary logistic regression analysis. Results This study included 284 patients (158 males, mean age 61.7 ± 13.1 years). Patients with higher AAC grade were older, had more frequently diabetes mellitus and cardiovascular disease, had lower diastolic blood pressure, and had higher corrected calcium and lower intact parathyroid hormone levels. In multivariate analysis, the presence of higher AAC grade (odds ratio (95% confidence interval): 2.98 (1.43–6.23); p = 0.004), lower mean corrected calcium (p = 0.017), and mean serum albumin level (p = 0.008) were associated with repeated failure of AVF. Conclusions The presence of higher AAC grade, lower mean corrected calcium and mean serum albumin level were independently associated with repeated AVF failure within 1 year in hemodialysis patients.

Effect Modifying Role of Serum Calcium on Mortality-Predictability of PTH and Alkaline Phosphatase in Hemodialysis Patients: An Investigation Using Data from the Taiwan Renal Registry Data System from 2005 to 2012.

Predicting mortality in dialysis patients based on low intact parathyroid hormone levels is difficult, because aluminum intoxication, malnutrition, older age, race, diabetes, or peritoneal dialysis may influence these levels. We investigated the clinical implications of low parathyroid hormone levels in relation to the mortality of dialysis patients using sensitive, stratified, and adjusted models and a nationwide dialysis database. We analyzed data from 2005 to 2012 that were held on the Taiwan Renal Registry Data System, and 94,983 hemodialysis patients with valid data regarding their intact parathyroid levels were included in this study. The patient cohort was subdivided based on the intact parathyroid hormone and alkaline phosphatase levels. The mean hemodialysis duration within this cohort was 3.5 years. The mean (standard deviation) age was 62 (14) years. After adjusting for age, sex, diabetes, the hemodialysis duration, serum albumin levels, hematocrit levels, calcium levels, phosphate levels, and the hemodialysis treatment adequacy score, the single-pool Kt/V, the crude and adjusted all-cause mortality rates increased when alkaline phosphatase levels were higher or intact parathyroid hormone levels were lower. In general, at any given level of serum calcium or phosphate, patients with low intact parathyroid hormone levels had higher mortality rates than those with normal or high iPTH levels. At a given alkaline phosphatase level, the hazard ratio for all-cause mortality was 1.33 (p < 0.01, 95% confidence interval 1.27–1.39) in the group with intact parathyroid hormone levels < 150 pg/mL and serum calcium levels > 9.5 mg/dL, but in the group with intact parathyroid hormone levels > 300 pg/mL and serum calcium levels > 9.5 mg/dL, the hazard ratio was 0.92 (95% confidence interval 0.85–1.01). Hence, maintaining albumin-corrected high serum calcium levels at > 9.5 mg/dL may correlate with poor prognoses for patients with low intact parathyroid hormone levels.

A Rare Cause of Hypercalcemia: &amp;#147;Immobilization&amp;#148; A Case Report and Literature Review

Immobilization hypercalcemia (IH) mainly results from rapid bone turnover and may be seen after spinal cord injury or long bone fracture in particular in children and adolescents. The pathophysiology of this entity is entirely unknown. A-19 year-old, male quadriplegic adolescent was referred to our outpatient clinic by a family physician. At presentation he had some vague symptoms due to hypercalcemia including fatigue, nausea, vomiting, anorexia, constipation and dehydration. Laboratory investigations for hypercalcemia revealed low intact parathyroid hormone level, low 25-0H vitamin D, and high 24-hour urine calcium. He was diagnosed as having IH after all other causes of hypercalcemia were excluded. The pathophysiology of IH remains unclear. Treatment is directed towards lowering the serum calcium level. Up to date, intravenous hydration with isotonic saline, furosemide and salmon calcitonin have been the conventional therapies. Other treatment options include bisposphonates (such as etidronate, zoledronate or pamidronate) or, an inhibitor of receptor activator of nuclear factor kappa-B ligand (RANKL), denosumab. IH is a rare cause of hypercalcemia. Physicians should be aware of this condition when seeing patients with restricted physical activity.

Associations between the levels of sclerostin, phosphate, and fibroblast growth factor-23 and treatment with vitamin D in hemodialysis patients with low intact PTH level.

Serum sclerostin levels could be closely associated with serum phosphate and fibroblast growth factor-23 levels in hemodialysis patients with low intact parathyroid hormone (PTH) levels. Further study is required to indicate whether these close associations are present in patients with spontaneously low PTH levels without any vitamin D treatment. Intact parathyroid hormone (iPTH) is involved in the interaction between sclerostin and phosphate/fibroblast growth factor-23 (FGF23) in animal models. However, their relationship in patients on hemodialysis (HD) is unclear. Data of 102 HD patients were collected regarding clinical and laboratory parameters and mineral bone disorder medications. The patients were divided into subgroups according to the iPTH level (A, <70 pg/mL; B, 70-150 pg/mL; C, 150-300 pg/mL; and D, ≥ 300 pg/mL). The sclerostin level was significantly and positively correlated with phosphate and log of FGF23 levels in subgroups A, B, and combined A and B. Multiple linear regression analysis in the combined A and B subgroup revealed that male sex (t = 3.24, P = 0.01; 95% confidence interval [CI] 11.78 to 50.43) and phosphate level (t = 2.13, P = 0.04; 95% CI, 1.08 to 36.91) were independent factors for serum sclerostin level. The log of serum FGF23 level (t = 1.90, P = 0.06, 95% CI -1.85 to 63.50) appeared to be an important factor for serum sclerostin level. The frequency of patients using vitamin D treatment was not significantly different among subgroups A (93.1%), B (88.0%), C (85.2%), and D (90.5%). Serum sclerostin levels were associated with serum phosphate and FGF23 levels in patients with low iPTH levels. Further study is required to indicate whether these close associations are present in patients with spontaneously low iPTH levels without vitamin D treatment.

Early predictors of hypocalcemia after total thyroidectomy: an analysis of 304 patients using a short-stay monitoring protocol.

Postoperative hypocalcemia is common after total thyroidectomy, and perioperative monitoring of serum calcium levels is arguably the primary reason for overnight hospitalization. Confidently predicting which patients will not develop significant hypocalcemia may allow for a safe earlier discharge. To examine associations of patient characteristics with hypocalcemia, duration of hospitalization, and postoperative intact parathyroid hormone (IPTH) level after total thyroidectomy. Retrospective study of consecutive patients who underwent total thyroidectomy by a single high-volume surgeon between February 1, 2010, and November 30, 2012. Postoperative serum 25-hydroxyvitamin D (vitamin D), calcium, and IPTH levels were tested within 6 to 8 hours after surgery. Mild hypocalcemia was defined as any postoperative serum calcium level of less than 8.4 to 8.0 mg/dL. Significant hypocalcemia was defined as any postoperative serum calcium level of less than 8.0 mg/dL or the development of hypocalcemia-related symptoms. Total thyroidectomy. Associations of patient demographic and clinical characteristics and laboratory values with postoperative mild and significant hypocalcemia were examined using univariate analysis, and independent predictors of hypocalcemia, duration of hospitalization, and IPTH level were determined using multivariate analysis. Overall, 304 total thyroidectomies were performed. Mild and significant hypocalcemia occurred in 68 (22.4%) and 91 (29.9%) patients, respectively, of which the majority were female (P = .003). The development of significant hypocalcemia was associated with postoperative IPTH level (P < .001). On multivariate analysis, males had a decreased risk of developing mild (odds ratio, 0.37 [95% CI, 0.16-0.85]) and significant (odds ratio, 0.57 [95% CI, 0.09-0.78]) hypocalcemia. Every 10-pg/mL increase in postoperative IPTH level predicted a 43% decreased risk of significant hypocalcemia (P < .001) and an 18% decreased risk of hospitalization beyond 24 hours (P = .03). Presence of malignant neoplasm carried a 27% risk of mild hypocalcemia (P = .02). There was a progressively increasing risk of lower IPTH levels for each parathyroid gland inadvertently resected or autotransplanted. Male sex and African American race were independently predictive of higher IPTH levels. Low postoperative IPTH level, female sex, and presence of malignant neoplasm are all significant, independent predictors of hypocalcemia after total thyroidectomy. Clinicians should consider these variables when deciding how to best manage or prevent postoperative hypocalcemia.

Persistently low intact parathyroid hormone levels predict a progression of aortic arch calcification in incident hemodialysis patients

Recent observational studies have found that low intact parathyroid hormone (iPTH) is related with mortality in hemodialysis patients and these findings may be considered to be the result of accelerated cardiovascular calcifications in adynamic bone disease. This study was aimed to determine the relationship between persistently low iPTH and aortic arch calcification (AAC) in incident hemodialysis patients. From January 2004 to December 2008, a total of 94 incident hemodialysis patients were enrolled in this study. They were divided into three groups according to the changing patterns of iPTH during the first year of hemodialysis. ACC was scored on posterior-anterior plain chest X-rays using a specific scale at the initiation of dialysis and followed till May 2011. The median follow-up periods were 46.9 months. The prevalence of baseline AAC and its progression were the highest in the persistently low iPTH group. Also, all-cause mortality was the highest in this group. Age, baseline calcification score and persistently low iPTH independently contributed to the progression of calcification by multivariate logistic regression analyses (HR 1.083, 95% CI 1.023-1.147, P = 0.006; HR 3.320, 95% CI 1.023-10.789, P = 0.046; HR 5.207, 95% CI 1.027-26.412, P = 0.046, respectively). Also, mortality was relatively higher in calcification progressor compared to non-progressor (39.3, 18.2%, P = 0.030). Persistently low iPTH was an independent risk factor for both AAC and mortality in incident hemodialysis patients.

Vitamin K2 Alters Bone Metabolism Markers in Hemodialysis Patients with a Low Serum Parathyroid Hormone Level

Background: A low level of intact parathyroid hormone (PTH) is an indicator of adynamic bone disease in hemodialysis patients, and is associated with a significant increase of all-cause mortality. Thus, effective treatment for adynamic bone disease is required. We previously investigated the effect of vitamin K₂ on adynamic bone disease. In this study, we assessed the efficacy of oral vitamin K₂ in a controlled trial. Methods: Forty hemodialysis patients with low intact PTH levels (<100 pg/ml) were randomly divided into two groups, which were a vitamin K₂ group receiving oral menatetrenone (45 mg/day) for 1 year and a control group without vitamin K₂. Venous blood samples were collected at baseline and during the study for measurement of bone metabolism parameters. Results: Thirty-three patients completed follow-up. There was a significant increase of the serum intact osteocalcin level after 1 month of vitamin K₂ administration. Serum levels of intact PTH, bone alkaline phosphatase, and cross-linked N-terminal telopeptide of type I collagen increased significantly after 12 months in the vitamin K₂ group. The serum osteoprotegerin level was decreased after 12 months in the vitamin K₂ group, but the change was not significant. Conclusion: Vitamin K₂ therapy improves bone remodeling in hemodialysis patients with a low intact PTH level.

Sevelamer Hydrochloride Improves Hyperphosphatemia in Hemodialysis Patients With Low Bone Turnover Rate and Low Intact Parathyroid Hormone Levels

Sevelamer improves hyperphosphatemia without increasing the calcium load. However, it remains unknown whether sevelamer restores bone metabolism in hemodialysis patients with low bone turnover osteodystrophy and hypoparathyroidism. We investigated the changes in serum intact parathyroid hormone (iPTH) and bone metabolic marker levels after replacing calcium carbonate with sevelamer in these patients. We also conducted stratified analysis based on patient background and multivariate analysis to determine the factors affecting these parameters. During sevelamer replacement therapy, serum calcium and phosphate concentrations, and the calcium phosphate product were measured at 0, 1, 3, and 6 months. Serum iPTH, bone alkaline phosphatase and osteocalcin concentrations were measured at 0 and 6 months. In hemodialysis patients (71 men and 46 women, 63 +/- 12 years old) serum calcium levels and the calcium phosphate product decreased significantly at 1 month. Serum iPTH, bone alkaline phosphatase and osteocalcin levels increased significantly at 6 months. Increases in serum iPTH concentrations were observed in all stratified groups. Significant increases in serum bone alkaline phosphatase and osteocalcin concentrations were found only in the relative hypoparathyroidism group (iPTH levels > or =51.5 pg/mL, the median pretreatment level). Multivariate analysis showed that the factors affecting change in serum iPTH level are baseline serum iPTH, baseline calcium level (> or =9.5 mg/dL), and dialysis duration of 10 years or longer. Sevelamer appears useful for the treatment of hyperphosphatemia in these patients. Particularly, in the relative hypoparathyroidism group, the iPTH secretory response is probably enhanced and bone turnover may have been improved as a result of reducing the calcium load.

Persistent hypoparathyroidism following magnesium repletion in burn-injured children.

Children suffering severe burns develop hypocalcemia, magnesium (Mg) depletion, hypoparathyroidism, and renal resistance to parathyroid hormone (PTH) infusion. We hypothesized that Mg depletion accounted for both the hypoparathyroidism and the renal resistance to PTH, and that Mg repletion would improve both. Due to a lack of PTH for infusion, we studied only the effect of Mg repletion on the relationship between ionized Ca (iCa) and PTH in the serum of 14 sequentially recruited children burned > or =40% total body surface area. All received a urinary Mg retention test a median of 20 days post burn (range 8-137 days). Seven (50%) of the children remained Mg depleted, which was not attributable to burn size or to time from burn to study. Combined enteral and parenteral Mg intakes were not different between the depleted and repleted groups, 12.2+/-4.4 (SD) mg/kg per day and 14.2+/-6.2 mg/kg per day, respectively. Both groups had low intact PTH levels in relation to serum iCa concentration, indicating persistent hypoparathyroidism. We conclude that Mg depletion is not the chief cause of hypoparathyroidism following thermal injury and we postulate that the persistent hypoparathyroidism is consistent with a reduced set-point for Ca suppression of PTH secretion.