Associations between serum levels of calcium, parathyroid hormone and future risk of venous thromboembolism: the Tromsø study

Primary Hyperparathyroidism and Pulmonary Embolism in Patients With a Fractured Neck of Femur

Two patients aged 82 and 77, with a fractured neck of the femur, were found to have primary hyperparathyroidism, characterized by hypercalcemia and hypercalciuria. Post-surgery, both developed pulmonary embolism (PE), highlighting a possible link between hypercalcemia and increased hypercoagulation risk. There have been few case reports suggesting the association between hypercalcemia due to hyperparathyroidism and the increase in tendency of hypercoagulation and subsequent risk of venous thromboembolism (VTE). This case series offers insights into how ionized calcium influences thrombin formation, platelet activation and aggregation, and activation of clotting factors such as factor VII and factor X, raising questions about the role of chronic hypercalcemia in VTE. Further research is needed to 1) establish whether chronic hypercalcemia in the absence of fracture can modulate the risk of hypercoagulation; 2) determine whether chronic hypercalcemia in individuals with bone fracture may represent a significantly higher hypercoagulability risk during the postoperative periods.

Calcium Prevents Enhanced Degradation of Factor VIII in the Condition of Motion

Background: Hemophilia A and B induce recurrent bleeding episodes, mainly in skeletal muscles and joints that are in intermittent motion. We have previously demonstrated that intermittent motion contributes to increased degradation of factors VIII and IX. Objectives: Given that calcium ions are known to enhance factor VIII-von Willebrand factor (vWF) interaction, the present study has investigated the role of these ions on factors VIII and IX in the condition of motion. Methods: The effects of calcium ions were assessed using purified proteins via Western blot, factor VIII activity, immunocytochemistry, and in Institute of Cancer Research (ICR) mice with no specific genetic background. Results: Calcium was found to prevent degradation of plasma-derived factor VIII but not that of factor IX, during intermittent motion. Calcium levels in the microcirculation of mouse striated muscles were elevated following movement, enabling prevention of factor VIII degradation in normal physiology. Calcium supplementation in drinking water increased factor VIII levels in blood and striated muscles of ICR mice during movement. Conclusions: calcium ions decrease factor VIII degradation in the condition of motion. Further research on the impact of calcium salt oral supplementation on hemophilia patients is warranted.

The Association between Admission Serum Phosphorus and Preoperative Deep Venous Thrombosis in Geriatric Hip Fracture: A Retrospective Study

OBJECTIVE

This study aimed to evaluate the association between serum phosphorus level and preoperative deep vein thrombosis (DVT) in geriatric hip fractures.

METHODS

Older adults with hip fractures were screened between January 2015 and September 2019. Demographic and clinical characteristics of the patients were collected. Multivariate binary logistic regression and generalized additive models were used to identify the linear and nonlinear associations between serum phosphorus levels and preoperative DVT. Analyses were performed using Empower Stats and R software.

RESULTS

In this study, 1818 patients were included, with an average age of 79.39 ± 6.87. Of these, 30.25% were males, and 580 patients had DVT. The study found that when serum phosphorus was used as a continuous variable, there was a statistically significant difference in the relationship between blood phosphorus and the occurrence of DVT (p < 0.05). Furthermore, we also found curvilinear relationships. Serum phosphorus = 0.71 mmol/L was the inflection point in the curve. When serum phosphorus was <0.71 mmol/L, the serum phosphorus was associated with DVT (OR = 1.64; 95% CI: 1.04-2.59; p = 0.0333). With a 0.1 mmol/L increase, the DVT increased 0.64 times. When phosphorus was >0.71 mmol/L, there was no significant difference in the correlation between serum phosphorus levels and DVT (OR = 1.03; 95% CI: 0.98-1.09; p = 0.186).

CONCLUSION

Serum phosphorus was nonlinearly associated with preoperative DVT in geriatric patients with hip fractures, and serum phosphorus level could be considered a predictor of DVT risk.

One-Year Postoperative Mortality in MEN1 Patients Operated on Gastric and Duodenopancreatic Neuroendocrine Tumors: An AFCE and GTE Cohort Study

IMPORTANCE

In MEN1 patients with gastric and duodenopancreatic neuroendocrine tumors (GPD-NET), surgery aims to control secretions or to prevent metastatic spread, but after GPD-NET resection, postoperative mortality may be related to the surgery itself or to other associated MEN1 lesions with their own uncontrolled secretions or metastatic behavior.

OBJECTIVE

To analyze the causes of death within 1 year following a GPD-NET resection in MEN1 patients.

DESIGN

An observational study collecting data from the Groupe d'étude des Tumeurs Endocrines (GTE) database. The analysis considered the time between surgery and death (early deaths [<1 month after surgery] versus delayed deaths [beyond 1 month after surgery]) and the period (before 1990 vs after 1990). Causes of death were classified as related to GDP surgery, related to surgery for other MEN1 lesions or not related to MEN1 causes.

SETTING

GTE database which includes 1220 MEN1 patients and 441 GPD-NET resections.

PARTICIPANTS

Four hundred and forty-one GPD-NET resections.

MAIN OUTCOME MEASURES

The primary end point was postoperative mortality within 1 year after surgery.

RESULTS

Twenty-four patients met the inclusion criteria (2%). Median age at death was 50.5 years. Sixteen deaths occurred in the 30-day postoperative period (76%). Among the 8 delayed deaths, 3 occurred as a result of medical complications between 30 and 90 postoperative days. After 1990, mean age at death increased from 48 to 58 years (p = 0.09), deaths related to uncontrolled acid secretion disappeared (p < 0.001) and deaths related to associated MEN1 lesions increased from 8 to 54% (p = 0.16).

CONCLUSION

Surgery and uncontrolled secretions remain the two main causes of death in MEN1 patients operated for a GPD-NET tumor. Improving the prognosis of these patients requires a strict evaluation of the secretory syndrome and MEN1 aggressiveness before GDP surgery.

Familial Hypocalciuric Hypercalcemia Type 1 and Autosomal-Dominant Hypocalcemia Type 1: Prevalence in a Large Healthcare Population

The calcium-sensing receptor (CaSR) regulates serum calcium concentrations. CASR loss- or gain-of-function mutations cause familial hypocalciuric hypercalcemia type 1 (FHH1) or autosomal-dominant hypocalcemia type 1 (ADH1), respectively, but the population prevalence of FHH1 or ADH1 is unknown. Rare CASR variants were identified in whole-exome sequences from 51,289 de-identified individuals in the DiscovEHR cohort derived from a single US healthcare system. We integrated bioinformatics pathogenicity triage, mean serum Ca concentrations, and mode of inheritance to identify potential FHH1 or ADH1 variants, and we used a Sequence Kernel Association Test (SKAT) to identify rare variant-associated diseases. We identified predicted heterozygous loss-of-function CASR variants (6 different nonsense/frameshift variants and 12 different missense variants) in 38 unrelated individuals, 21 of whom were hypercalcemic. Missense CASR variants were identified in two unrelated hypocalcemic individuals. Functional studies showed that all hypercalcemia-associated missense variants impaired heterologous expression, plasma membrane targeting, and/or signaling, whereas hypocalcemia-associated missense variants increased expression, plasma membrane targeting, and/or signaling. Thus, 38 individuals with a genetic diagnosis of FHH1 and two individuals with a genetic diagnosis of ADH1 were identified in the 51,289 cohort, giving a prevalence in this population of 74.1 per 100,000 for FHH1 and 3.9 per 100,000 for ADH1. SKAT combining all nonsense, frameshift, and missense loss-of-function variants revealed associations with cardiovascular, neurological, and other diseases. In conclusion, FHH1 is a common cause of hypercalcemia, with prevalence similar to that of primary hyperparathyroidism, and is associated with altered disease risks, whereas ADH1 is a major cause of non-surgical hypoparathyroidism.

Association of serum vitamin D and parathyroid hormone with subclinical atherosclerotic phenotypes: The Dong-gu Study

Background

Although previous studies reported an association between serum vitamin D and parathyroid hormone (PTH) with carotid atherosclerosis or arterial stiffness, these were inconsistent. We examined the independent association between serum vitamin D and PTH with multiple subclinical markers of atherosclerosis.

Methods

A total of 8,217 subjects who participated in the Dong-gu Study in Korea were included in the final analysis. The carotid artery structure, including intima-media thickness (IMT), plaques, and luminal diameter, was evaluated using a high-resolution B-mode ultrasound. The brachial-ankle pulse wave velocity (baPWV) was determined using an automatic waveform analysis device, and the mean of the left and right baPWV was used.

Results

The PTH concentration was positively associated with carotid luminal diameter and baPWV, but not with carotid IMT and plaques. The mean carotid luminal diameter of individuals with PTH levels in the second, third, and fourth quartiles was significantly larger compared with those in the first quartile (P-trend < 0.01). The mean baPWV of individuals with PTH levels in the fourth quartile was significantly greater than those with PTH levels in the first quartile (P-trend = 0.01). However, there was no significant association between vitamin D and any atherosclerotic phenotypes, including carotid IMT, plaques, luminal diameter, and baPWV.

Conclusion

This suggests that PTH might affect the development of atherosclerosis by altering vascular compliance.