Longitudinal Effects of Serum Calcium and Phosphate Levels and Their Ratio on Incident Ischemic Heart Disease among Korean Adults

High Serum Phosphate Is Associated with Cardiovascular Mortality and Subclinical Coronary Atherosclerosis: Systematic Review and Meta-Analysis

(1) Background: Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. The aim of the study was to examine the existing published results of the association between elevated serum phosphate concentrations and cardiovascular mortality, along with the CVD incidence and subclinical coronary atherosclerosis, in primary prevention among non-selected samples of the general population. (2) Methods: A systematic review and meta-analysis were carried out using literature obtained from PubMed, SCOPUS, and the Web Of Science until March 2024 and following the PRISMA guidelines. Relevant information was extracted and presented. Random and fixed effects models were used to estimate the pooled odds ratio (OR) and hazard ratio (HR) with their 95% coefficient interval (CI), and I2 was used to assess heterogeneity. (3) Results: Twenty-five studies met our inclusion criteria and were included in the meta-analysis (11 cross-sectional and 14 cohort studies). For cardiovascular mortality, which included 7 cohort studies and 41,764 adults, the pooled HR was 1.44 (95% CIs 1.28, 1.61; I2 0%) when the highest versus the reference level of serum phosphate concentrations were compared. For CVDs, which included 8 cohort studies and 61,723 adults, the pooled HR was 1.12 (95% CIs 0.99, 1.27; I2 51%). For subclinical coronary atherosclerosis, which included 11 cross-sectional studies and 24,820 adults, the pooled OR was 1.44 (95% CIs 1.15, 1.79; I2 88%). (4) Conclusions: The highest serum phosphate concentrations were positively associated with a 44% increased risk of cardiovascular mortality and subclinical coronary atherosclerosis.

Rifampicin efficacy against doxorubicin-induced cardiotoxicity in mice

BACKGROUND

The toxic effect of doxorubicin on the heart limits its clinical usage in cancer therapy. This work intended to investigate, for the first time, the efficacy of rifampicin administration against doxorubicin-induction of cardiotoxicity in mice. Forty adult male albino mice were distributed into four sets: Control, Doxorubicin, Doxorubicin + Rifampicin 0.107, and Doxorubicin + Rifampicin 0.214, with n = 10 for each. Heart histopathology and biochemical assays for heart function tests [creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cardiac troponin I (cTnI), atrial natriuretic peptide (ANP), and vascular endothelial growth factor (VEGF)], oxidative stress [malondialdehyde (MDA) and superoxide dismutase (SOD)], and minerals [phosphorus, sodium, potassium, and calcium] were done.

RESULTS

Doxorubicin-induced cardiotoxicity using a total dose of 15 mg/kg was confirmed histologically. Cardiomyocytes showed congestion, necrosis, edema, and inflammatory cell infiltration. Biochemically, elevations in LDH, CK, and AST activities, p < 0.001, as well as increases in cTnI and ANP levels, p < 0.001, increased oxidative stress (MDA, p < 0.001), high minerals (Na, K, p < 0.001, P, p < 0.01, and Ca, p < 0.05), with reduced VEGF concentration, p < 0.001, and low antioxidant (SOD, p < 0.001) were observed in the Doxorubicin group compared to control. Co-treatment with rifampicin significantly (p < 0.001) reduced the increased oxidative stress, high Na and K, increased LDH, CK, AST, cTnI, and ANP, and elevated the low SOD toward the normal ranges. Our histological data supported our biochemical data; rifampicin dose 0.214 mg/kg showed better improvements than dose 0107.

CONCLUSIONS

Our results demonstrated that rifampicin could help protect the body against doxorubicin-induced cardiotoxicity through its antioxidative effect.

Glycine protects against doxorubicin-induced heart toxicity in mice

Doxorubicin (DOXO) is a well-known cancer chemotherapeutic. However, its toxic effect on the heart limits its clinical application. This study aimed to assess the effectiveness of glycine administration to counteract the DOXO-induction of cardiomyopathy in mice. Fifty male albino mice were divided into five groups (n = 10/group) as follows: control, DOXO, Gp100, Gp150, and Gp200. Histopathological examination of the heart, and biochemical examinations for heart function (creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST)), inflammation (tumor necrosis factor-alpha (TNF-α) and interleukin 10 (IL-10)), oxidative stress (malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase, nitric oxide (NO), and uric acid), kidney function (urea and creatinine), and minerals (calcium, phosphorus, sodium, and potassium) were carried out. Cardiomyopathy induced by DOXO treatment (15 mg/kg total dose) was ascertained via pathological alterations seen in heart tissue and verified biochemically via increases (P < 0.001) in CPK, LDH, AST, TNF-α, IL-10, MDA, NO, Na, and K levels along with decreases (P < 0.001) in GSH, SOD, catalase, and uric acid. Glycine co-treatment, using doses of 100, 150, and 200 mg/kg, in a dose-dependent manner, displayed ameliorated heart architecture, significantly (P < 0.001) improved biochemical heart function tests, reduced oxidative stress and inflammation, and controlled mineral levels. The positive actions of glycine in DOXO-induced cardiotoxicity amelioration via modulating oxidative stress, inflammation, and immunity are confirmed. Glycine antioxidative properties may be behind its positive outcomes. Finally, we present glycine as a worthy possible option against DOXO-induced heart damage after more validation.

Potential Association of Isolated γ-Glutamyltransferase Elevation with Incident Ischemic Heart Disease in Lean Koreans

Isolated elevation of γ-glutamyltransferase (GGT), a microsomal membrane-bound protein, is commonly observed in non-obese Koreans without diabetes, and its clinical implications are not well-known. Therefore, we aimed to investigate the longitudinal effect of isolated GGT on the incidence of ischemic heart disease (IHD) risk in a large cohort of lean non-diabetic Koreans. Data were obtained from the Health Risk Assessment Study (HERAS) and Korea Health Insurance Review and Assessment (HIRA) datasets. The participants were divided into four groups according to the GGT quartile after the exclusion of those participants with diabetes, a body mass index (BMI) ≥ 25 kg/m2, alanine aminotransferase (ALT) ≥ 40 IU/L, and aspartate aminotransferase (AST)/ALT > 1.5, as well as those positive for hepatitis B surface antigen or hepatitis C antibody. We prospectively assessed the hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD using multivariate Cox proportional hazard regression models over a 50-month period. During the follow-up period, 183 individuals (1.85%) developed IHD. After setting the lowest GGT quartile as a reference group, the HRs of IHD for GGT quartiles 2−4 were 1.66 (95% CI 0.95−2.89), 1.82 (95% CI 1.05−3.16), and 1.98 (95% CI 1.12−3.50), respectively, after adjusting for age, sex, body mass index, smoking status, alcohol consumption, physical activity, mean arterial blood pressure, fasting plasma glucose, and dyslipidemia. An isolated high GGT may be an additional measure for assessing and managing future IHD risks among lean Koreans without diabetes.

Genetically predicted phosphate and cardiovascular disease: A Mendelian randomization study

Background

Extensive epidemiological studies have highlighted the correlation between serum phosphate and cardiovascular diseases. The present study aims to determine whether genetically predicted serum phosphate is causally associated with the distinct subtypes of cardiovascular events through the use of Mendelian randomization (MR) analysis.

Methods

Independent and strongly correlated single-nucleotide polymorphisms (SNPs) for serum phosphate were extracted from publicly available genome-wide association studies. Summary statistics of cardiovascular diseases were derived from large-scale consortiums, including HERMES and FinnGen biobank. MR-Egger, weighted median, inverse variance weighted, pleiotropy residual sum and outlier (MR-PRESSO) methods and MR using robust adjusted profile score (MR-RAPS) were employed to analyze causality. The sensitivity analyses comprised heterogeneity, horizontal pleiotropy, and leave-one-out approaches; these were used to ensure the stability of the results.

Results

Our study demonstrated that increased genetically predicted serum phosphate is causally associated with a higher risk of valvular heart disease (VHD) [For VHD including rheumatic fever: odds ratio (OR) = 2.45; 95% confidence interval (CI), 1.52-3.94; p = 0.0002; for non-rheumatic VHD: OR = 6.58; 95% CI, 2.50-17.32; p = 0.0001]. However, no causal association was detected between serum phosphate and other common cardiovascular diseases (including coronary heart disease, heart failure, atrial fibrillation, and essential hypertension).

Conclusions

The results indicate strong causality between serum phosphate and valvular heart disease. Serum phosphate-lowering therapy within the physiological range may represent a novel therapeutic method for valvular heart disease.

Predictive Value of Serum Uric Acid to HDL Cholesterol Ratio for Incident Ischemic Heart Disease in Non-Diabetic Koreans

HDL cholesterol, besides its function in lipid metabolism, plays a role in suppressing blood oxidation reactions and protecting vascular endothelial cells. The uric acid/HDL cholesterol ratio (UHR) has recently attracted attention as a new biomarker for evaluating interactions between inflammatory and anti-inflammatory substances in the blood. This study aimed to investigate the longitudinal association between UHR and incident ischemic heart disease (IHD). Data from 16,455 participants without diabetes from the Health Risk Assessment Study (HERAS) and Korean Health Insurance Review and Assessment (HIRA) were assessed. Over 50 months after baseline enrolment, 321 (2.0%) participants developed IHD. The HRs of incident IHD were 0.85 (95% CI, 0.55–1.29), 1.42 (95% CI, 0.94–2.13), and 1.57 (95% CI, 1.01–2.45) in the second, third, and fourth UHR quartiles, respectively, after adjusting for potential confounding variables. In the subgroup analysis by sex-specific quartile, women tended to have higher HRs in the highest UHR quartile. We found that high UHR values were positively associated with incident IHD in Koreans without diabetes. An increased UHR may be a useful measure by which to assess cardiovascular risk in the preclinical stage.