Clinical Implication of Consistently Strict Phosphate Control for Coronary and Valvular Calcification in Incident Patients Undergoing Hemodialysis

Advances in Pathophysiological Mechanisms of Degenerative Aortic Valve Disease

Degenerative aortic valve disease (DAVD) represents the most prevalent valvular ailment among the elderly population, which significantly impacts their physical well-being and potentially poses a lethal risk. Currently, the underlying mechanisms of DAVD remain incompletely understood. While the progression of this disease has traditionally been attributed to degenerative processes associated with aging, numerous recent studies have revealed that heart valve calcification may represent a response of valve tissue to a specific initiating factor, involving the interaction of various genes and signaling pathways. This calcification process is further influenced by a range of factors, including genetic predispositions, environmental exposures, metabolic factors, and hemodynamic considerations. Based on the identification of its biomarkers, potential innovative therapeutic targets are proposed for the treatment of this complex condition. The present article primarily delves into the underlying pathophysiological mechanisms and advancements in diagnostic and therapeutic modalities pertaining to this malady.

The Diagnostic Value of Plasma NETs Levels and iCEB in Silent Myocardial Ischemia in Maintenance Hemodialysis Patients

Objective

This study evaluated the diagnostic value of plasma Neutrophil extracellular traps (NETs) levels and the index of cardiac electrophysiological balance (iCEB) in identifying silent myocardial ischemia (SMI) in maintenance hemodialysis (MHD) patients.

Methods

This cross-sectional observational study involved patients receiving MHD treatment. Data were collected on coronary angiography performed in our hospital from February 2023 to February 2024. Patients diagnosed with myocardial ischemia via coronary angiography but without obvious symptoms were grouped as the SMI group, while those without SMI were grouped as the control group. Plasma NETs levels were assessed using markers indicative of NETs components including double-stranded DNA (dsDNA), circulating free DNA (cfDNA) and myeloperoxidase, while iCEB (QT/QRS) and electrocardiographic findings were obtained. Additionally, echocardiographic parameters, inflammatory markers, and cardiac biomarkers were analyzed. Receiver operating characteristic (ROC) analysis were employed to evaluate the diagnostic accuracy of plasma NETs levels and iCEB in identifying SMI.

Results

A total of 114 patients were included, with 79 participants in the control group and 35 participants in the SMI group. The SMI group exhibited significantly elevated levels of NETs associated components (dsDNA(37.89±4.55 vs 31.64±5.32, P<0.001), cfDNA(11.27±2.03 vs 8.91±1.84, P<0.001), MPO-DNA(23.69±4.01 vs 17.52±3.41, P<0.001)), as well as higher iCEB compared to the control group(56.45±7.67 vs 45.89±6.23, P<0.001). Furthermore, electrocardiography findings, echocardiographic parameters, inflammatory markers, and cardiac biomarkers showed significant differences between the two groups. The ROC analysis demonstrated the potential diagnostic accuracies of NETs levels and iCEB, with an area under the curve (AUC) of 0.908, sensitivity of 0.987, and specificity of 0.829 for identifying SMI.

Conclusion

The study highlights the combined diagnostic value of plasma NETs levels and iCEB in identifying SMI in MHD patients, providing valuable insights into potential early detection and risk stratification strategies for this population.

Predictive nomogram model for severe coronary artery calcification in end-stage kidney disease patients

INTRODUCTION

The Agatston coronary artery calcification score (CACS) is an assessment index for coronary artery calcification (CAC). This study aims to explore the characteristics of CAC in end-stage kidney disease (ESKD) patients and establish a predictive model to assess the risk of severe CAC in patients.

METHODS

CACS of ESKD patients was assessed using an electrocardiogram-gated coronary computed tomography (CT) scan with the Agatston scoring method. A predictive nomogram model was established based on stepwise regression. An independent validation cohort comprised of patients with ESKD from multicentres.

RESULTS

369 ESKD patients were enrolled in the training set, and 127 patients were included in the validation set. In the training set, the patients were divided into three subgroups: no calcification (CACS = 0, n = 98), mild calcification (0 < CACS ≤ 400, n = 141) and severe calcification (CACS > 400, n = 130). Among the four coronary branches, the left anterior descending branch (LAD) accounted for the highest proportion of calcification. Stepwise regression analysis showed that age, dialysis vintage, β-receptor blocker, calcium-phosphorus product (Ca × P), and alkaline phosphatase (ALP) level were independent risk factors for severe CAC. A nomogram that predicts the risk of severe CAC in ESKD patients has been internally and externally validated, demonstrating high sensitivity and specificity.

CONCLUSION

CAC is both prevalent and severe in ESKD patients. In the four branches of the coronary arteries, LAD calcification is the most common. Our validated nomogram model, based on clinical risk factors, can help predict the risk of severe coronary calcification in ESKD patients who cannot undergo coronary CT analysis.

Determination of Serum Zinc and Phosphorus Levels in Patients with Hypothyroidism

Various studies reported that serum zinc (Zn) and phosphorus (P) levels altered in patients with hypothyroidism and vice versa, but results were found inconsistent. It was aimed to find the association between serum Zn and P in patients with hypothyroidism. In this case-control study, a total of 100 subjects (50 newly diagnosed patients of hypothyroidism and 50 controls) were enrolled aged between 25 and 60 years. Biochemical parameters such as thyroid profile, serum Zn, and P were estimated in each subject. A p < 0.05 was considered statistically significant. The mean level of body mass index (BMI), thyroid-stimulating hormone (TSH), and serum P was found significantly elevated in cases compared to controls (p < 0.001). However, the mean level of total triiodothyronine (T3), thyroxine (T4), and serum Zn was found significantly reduced in cases compared to controls (p < 0.001). The serum Zn has shown a significant negative correlation with T3 and BMI among cases (r =  - 0.313 p < 0.05, r =  - 0.338 p < 0.05, respectively). However, serum P has shown a significant positive correlation with TSH and BMI among cases (r = 0.310 p < 0.05, r = 0.449 p < 0.01, respectively). Regression analysis indicated that serum Zn significantly predicted hypothyroidism (p < 0.00). Similarly, serum P significantly predicted hypothyroidism (p < 0.007). Results showed that serum Zn levels were significantly reduced and serum P levels were significantly elevated in cases compared to controls. The serum Zn and serum P both significantly associated with hypothyroidism.

Effects of a single phosphate-enriched test meal on inflammasome activity and postprandial inflammatory markers in healthy subjects

PURPOSE

The consumption of highly processed food is often associated with a high intake of inorganic phosphate. Hyperphosphatemia is accompanied by an inflammatory status in patients with chronic kidney disease. However, the immune response to high phosphorus intake in healthy individuals is largely unknown. Therefore, the aim of the present study was to evaluate the effect of a single phosphate-enriched meal on inflammasome activity and plasma levels of inflammatory markers.

METHODS

The analysis included 28 participants who received a single dose of either 700 mg phosphorus or a placebo with a test meal. At baseline, 4 and 8 h post-meal, plasma interleukin (IL)-6, IL-1β, IL-10, c-reactive protein (CRP), soluble IL-6 receptor (sIL-6R) and glycoprotein 130 (sgp130) levels were determined. At baseline and 4 h post-meal, peripheral blood mononuclear cells were isolated to assess inflammasome activity. Subsequently, the effect of phosphate with or without glucose on IL-6 and IL-1β gene expression and secretion in U937 monocytes was examined.

RESULTS

While both groups showed a marked postprandial increase in IL-6 plasma levels, neither plasma levels of IL-6, IL-1β, CRP, IL-10, sIL-6R, and sgp130 nor inflammasome activity were affected by phosphate compared to placebo. In U937 cells, there was also no effect of phosphate on IL-6 expression, but the addition of glucose increased it. Phosphate, however, reduced the IL-1β secretion of these cells.

CONCLUSION

Postprandial inflammatory markers were not affected by dietary phosphate. However, IL-6 plasma levels were markedly increased post-meal, which appears to be a metabolic rather than a pro-inflammatory phenomenon.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT03771924, date of registration: 11th December 2018, retrospectively registered.

Food to Prevent Vascular Calcification in Chronic Kidney Disease

Vascular calcification (VC) is a consequence of chronic kidney disease (CKD) which is of paramount importance regarding the survival of CKD patients. VC is far from being controlled with actual medication; as a result, in recent years, diet modulation has become more compelling. The concept of medical nutritional therapy points out the idea that food may prevent or treat diseases. The aim of this review was to evaluate the influence of food habits and nutritional intervention in the occurrence and progression of VC in CKD. Evidence reports the harmfulness of ultra-processed food, food additives, and animal-based proteins due to the increased intake of high absorbable phosphorus, the scarcity of fibers, and the increased production of uremic toxins. Available data are more supportive of a plant-dominant diet, especially for the impact on gut microbiota composition, which varies significantly depending on VC presence. Magnesium has been shown to prevent VC but only in experimental and small clinical studies. Vitamin K has drawn considerable attention due to its activation of VC inhibitors. There are positive studies; unfortunately, recent trials failed to prove its efficacy in preventing VC. Future research is needed and should aim to transform food into a medical intervention to eliminate VC danger in CKD.