Chronic Kidney Disease Distinctly Affects Relationship Between Selenoprotein P Status and Serum Thyroid Hormone Parameters

Associations between Plasma Essential Metals Levels and the Risks of All-Cause Mortality and Cardiovascular Disease Mortality among Individuals with Type 2 Diabetes

Epidemiological evidence regarding the possible link between multiple essential metals levels and all-cause mortality and cardiovascular disease (CVD) mortality among type 2 diabetes (T2D) patients is sparse. Here, we aimed to evaluate the longitudinal associations between 11 essential metals levels in plasma and all-cause mortality and CVD mortality among T2D patients. Our study included 5278 T2D patients from the Dongfeng-Tongji cohort. LASSO penalized regression analysis was used to select the all-cause and CVD mortality-associated metals from 11 essential metals (iron, copper, zinc, selenium, manganese, molybdenum, vanadium, cobalt, chromium, nickel, and tin) measured in plasma. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: With a median follow-up of 9.8 years, 890 deaths were documented, including 312 deaths of CVD. LASSO regression models and the multiple-metals model revealed that plasma iron and selenium were negatively associated with all-cause mortality (HR: 0.83; 95%CI: 0.70, 0.98; HR: 0.60; 95%CI: 0.46, 0.77), whereas copper was positively associated with all-cause mortality (HR: 1.60; 95%CI: 1.30, 1.97). Only plasma iron has been significantly associated with decreased risk of CVD mortality (HR: 0.61; 95%CI: 0.49, 0.78). The dose-response curves for the association between copper levels and all-cause mortality followed a J shape (P_{for nonlinear} = 0.01). Our study highlights the close relationships between essential metals elements (iron, selenium, and copper) and all-cause and CVD mortality among diabetic patients.

Association between Selenium Status and Chronic Kidney Disease in Middle-Aged and Older Chinese Based on CHNS Data

Background: The association between selenium and chronic kidney disease (CKD) remains controversial. Population studies with large samples facilitate the reliability of conclusions. Objective: In this study, we aimed to describe the prevalence of a CKD association with selenium intake in middle-aged and older Chinese. Methods: Data for this study were obtained from the China Health and Nutrition Survey (CHNS). A total of 5381 participants (aged ≥ 45) with biochemical test data were included in the study. Logistic regression models were used to examine the association between diet selenium intake (quartile) and the prevalence of CKD. Results: A total of 942 (17.01%) participants had CKD. The prevalence of CKD was 23.33%, 20.32%, 14.98%, and 9.25% among participants with average selenium intakes of 21.5 ± 4.82, 33.1 ± 2.79, 43.8 ± 3.70, and 67.0 ± 13.97 µg/day, respectively. In the fully adjusted model (Model 3), across the quartiles of selenium intake, the ORs for the prevalence of CKD were 1.00, 1.09 (95% CI 0.69–1.73), 0.82 (95% CI 0.49–1.38), and 0.43 (95% CI 0.22–0.85). The protein intake had a certain diagnostic significance for the selenium intake. Conclusions: An adequate selenium intake may have a positive effect on CKD. The influence of individual weight and location on the effect of selenium on CKD needs to be further explored.

Selenium Deficiency Leads to Changes in Renal Fibrosis Marker Proteins and Wnt/β-Catenin Signaling Pathway Components

Renal fibrosis is the final result of the progression of chronic kidney disease (CKD) to end-stage renal disease (ESRD). Earlier studies confirmed that selenium (Se) displays a close association with kidney diseases. However, the correlation between Se and fibrosis has rarely been explored. Thus, this article mainly aimed to investigate the effect of Se deficiency on renal fibrosis and the Wnt/β-catenin signaling pathway. Twenty BALB/c mice were fed a diet containing 0.02-mg/kg Se (Se-deficient diet) or 0.18-mg/kg Se (standard diet) for 20 weeks. A human glomerular mesangial cell (HMC) cell line was transfected with lentiviral TRNAU1AP-shRNA vector to establish a stable Se deficiency model in vitro. As indicated in this study, the glutathione (GSH) content in the Se-deficient group displayed an obvious decline compared with that in the control group, whereas the content of malondialdehyde (MDA) was obviously elevated. The results of Masson staining showed fibrosis around the renal tubules, and the results of immunohistochemistry showed that the area of positive fibronectin expression increased. In the Se-deficient group, the levels of collagen I, collagen III, matrix metalloproteinase 9 (MMP9), and other fibrosis-related proteins changed significantly in vivo and in vitro. Compared with the control group, the TRNAU1AP-shRNA group showed markedly reduced cell proliferation and migration abilities. Our data indicate that Se deficiency can cause kidney damage and renal fibrosis. Furthermore, the Wnt pathway is critical for the development of tissue and organ fibrosis. The data of this study demonstrated that the expression of Wnt5a, β-catenin, and dishevelled 1 (Dvl-1) was significantly upregulated in the Se-deficient group. Therefore, the Wnt/β-catenin pathway may play an important role in renal fibrosis caused by Se deficiency.

Impact of Selenium on Biomarkers and Clinical Aspects Related to Ageing. A Review

Selenium (Se) is an essential dietary trace element that plays an important role in the prevention of inflammation, cardiovascular diseases, infections, and cancer. Selenoproteins contain selenocysteine in the active center and include, i.a., the enzymes thioredoxin reductases (TXNRD1–3), glutathione peroxidases (GPX1–4 and GPX6) and methionine sulfoxide reductase, involved in immune functions, metabolic homeostasis, and antioxidant defense. Ageing is an inevitable process, which, i.a., involves an imbalance between antioxidative defense and reactive oxygen species (ROS), changes in protein and mitochondrial renewal, telomere attrition, cellular senescence, epigenetic alterations, and stem cell exhaustion. These conditions are associated with mild to moderate inflammation, which always accompanies the process of ageing and age-related diseases. In older individuals, Se, by being a component in protective enzymes, operates by decreasing ROS-mediated inflammation, removing misfolded proteins, decreasing DNA damage, and promoting telomere length. Se-dependent GPX1–4 and TXNRD1–3 directly suppress oxidative stress. Selenoprotein H in the cell nucleus protects DNA, and selenoproteins residing in the endoplasmic reticulum (ER) assist in the removal of misfolded proteins and protection against ER stress. In this review, we highlight the role of adequate Se status for human ageing and prevention of age-related diseases, and further its proposed role in preservation of telomere length in middle-aged and elderly individuals.

Association between albuminuria and thyroid function in patients with chronic kidney disease

PURPOSE

The relationship between proteinuria and thyroid function remains controversial in patients with chronic kidney disease (CKD). We prospectively investigated the association between kidney and thyroid function in thyroid antibody-negative patients through all CKD stages.

METHODS

We enrolled 184 nondialysis patients (mean age: 63.1 ± 16.9 years) without previous thyroid disease or thyroid-specific antibodies. Kidney function was assessed by estimating the glomerular filtration rate (eGFR) classified according KDIGO (CKD G1-5). Kidney damage was assessed by albuminuria (albumin-to-creatinine ratio, ACR) and classified as mild, moderate, or severe (ACR1: <300, ACR2: 300-3000, and ACR3: 3000 mg/g). To evaluate thyroid function, TSH, T4, fT4, T3, fT3, reverse T3 (rT3), and thyroxine-binding globulin (TBG) were measured.

RESULTS

rT3 concentrations correlated negatively with albuminuria (r = -0.286, p < 0.001) and were significantly lower in patients with severe albuminuria than in those with mild or moderate albuminuria (ACR3: 0.28 vs. ACR2: 0.32 vs. ACR1: 0.36 nmol/l, p < 0.001). The severity of albuminuria revealed no impact on TSH, fT4, T3, fT3, and TBG. EGFR correlated with increasing T4, fT4, T3, fT3, and TBG (T4: r = 0.289, p < 0.01; fT4: r = 0.196, p < 0.01; T3: r = 0.408, p < 0.01; fT3: r = 0.390, p < 0.01) but not with rT3.

CONCLUSIONS

In thyroid antibody-negative patients presenting advanced CKD (stages 4 and 5), even severe kidney protein loss failed to influence thyroid hormone status. However, albuminuria severity correlated negatively with rT3, which was significantly lower in patients with albuminuria in the nephrotic range.

Differential expression of MAP3K7 and TROPONIN C proteins and related perturbations in renal amyloidosis

OBJECTIVES

Renal amyloidosis (RA) is a rare protein misfolding disorder that prompts progressive renal insufficiency. This study aimed to decipher proteomic changes in human sera to understand the pathophysiology and molecular mechanisms underlying the disease development, hence assisting in the diagnosis of RA.

METHODS

Serum proteomic analysis was performed using a gel-based approach followed by MALDI-TOF MS. RA patients with age and sex matched healthy volunteers were recruited from Max Super Speciality Hospital, New Delhi, India.

RESULTS

Proteome profiles of serum revealed eight differentially expressed proteins namely, Zinc finger protein 624, Protein FAM183A, Calcium-binding mitochondrial carrier protein Scamc-3, V-type proton ATPase 116 kDa subunit A isoforms 2, Protein TXNRD3NB, ATP - dependent RNA helicase, Troponin C and Mitogen-activated protein kinase kinase kinase 7. These proteins were reported first time in RA. The increased levels of MAP3K7 and TROPONIN C were validated by bio-layer interferometry and their diagnostic accuracy was evaluated by ROC curve analysis. The differentially expressed proteins were predominantly associated with vesicular trafficking, transcriptional regulation, metabolic processes, apoptotic process and mitochondrial metabolism.

CONCLUSION

The results indicate that these proteomic signatures may be considered as potential molecular targets for RA diagnostics and therapeutics subject to validation on large sample size. Abbreviations: AβP= Amyloid-beta protein, Aβ=Amyloid-beta, AL= Light chain amyloidosis, AA= Amyloid A, ALECT2= LECT2 amyloidosis, APS= Ammonium persulfate CKD= Chronic Kidney Diseases, EBRT= external beam radiation therapy, ESRD= End-Stage Kidney Disease, Glis2= Gli-similar 2, JNK= c-Jun NH 2-terminal kinase, MAPK= Mitogen-Activated Protein Kinase, MM=Multiple Myeloma, PHD= Prolyl hydroxylase, RA = Renal Amyloidosis, SAA= Serum Amyloid A, SD= Standard Deviation, Sepp= Selenoprotein, SCC= Squamous cell carcinoma, SDS= Sodium dodecyl sulfate, TEMED = tetramethyl ethylenediamine, TGF-Beta-1=Transforming growth factor- Beta-1, Trx = Thioredoxin, TrxR= Thioredoxin reductase.

A prognostic role for non-thyroidal illness syndrome in chronic renal failure:a systematic review and meta-analysis

BACKGROUND

Chronic renal failure (CRF) is a serious disease that has become a burden on global and local economics and public health. In addition, non-thyroidal illness syndrome (NTIS) has become increasingly more prevalent in CRF patients.

MATERIALS AND METHODS

A data search was conducted on the PubMed/Medline, Cochrane Library, Web of Science, Embase, and CBM databases to identify studies up to November 1st, 2018, that compared low T3 and normal T3 levels in patients with CRF. Data analysis was done by calculating the relative risks (RR) and 95% confidence intervals (95% CI) and continuous variables were described by weighted mean difference (WMD) and 95% CI. The efficacy outcomes included renal function and mortality. The Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality scale were used to assess the quality of the cohort and cross-sectional studies, respectively. A funnel plot was used to identify publication bias.

RESULTS

Seventeen studies with a total of 4593 patients were finally included in the analysis. Among the 17 studies, 11 reported the mortality of CRF patients with low T3 and normal T3 levels. Subgroups were assigned according to different follow-up times and different methods of treatment. The mortality rate in the low T3 group was much higher than in the normal T3 group. 11 studies reported creatinine (Cr) results in patients with low T3 and normal T3 levels and our analysis found no significant differences between the two groups (95%CI: 0.46-0.25; P-heterogeneity = 0.000; P = 0.559). Five studies reported uric acid results and we found no significant differences between the two groups (95%CI: 0.08-0.22; P-heterogeneity = 0.438; P = 0.377). Five studies reported the urea levels in the two groups and our analysis found no significant differences (95%CI: 1.60-1.23; I² = 0.0%; P-heterogeneity = 0.498;P = 0.798).

CONCLUSION

Low T3 had a greater impact on the short-term prognosis of patients with CRF than on the long-term prognosis. NTIS did not cause substantial kidney damage.

Selenium, aging and aging-related diseases

Selenium is an essential trace element in the human body and plays an important role in the body via selenoprotein, which contains selenium. Selenoproteins (glutathione peroxidase, thioredoxin reductase, methionine sulfoxide reductase1 and endoplasmic reticulum-selenoproteins, etc.) have antioxidant effects and are involved in regulating antioxidant activities. Aging is an inevitable process and is always accompanied by aging-related diseases. Reactive oxygen species are important initial factors in aging and aging-related diseases. Selenium contributes to the alleviation of reduced reactive oxygen species-mediated inflammation, reduced DNA damage and prolonged telomere length and thereby plays roles in fighting aging and preventing aging-related diseases. In the elderly, aging-related diseases include neuropsychiatric diseases, tumors, cardiovascular diseases, and skin aging, among others. Selenium supplementation is an important strategy for anti-aging and the prevention of aging-related diseases and is of great significance for the elderly. However, with the accumulation of related research, selenium supplementation does not necessarily contribute to the prevention of aging and aging-related diseases. It is believed that a low level of selenium is beneficial to the human body. Thus, the effect of selenium on human aging and aging-related diseases is still controversial. This paper reviews the research progress and objective role of selenium in aging and aging-related diseases.

Circulating secreted frizzled-related protein 5 and chronic kidney disease in patients with acute ST-segment elevation myocardial infarction

Secreted frizzled-related protein-5 (Sfrp5) known as secreted antagonist binds to Wnt protein. It has been shown to be downregulated by histone acetylation and promoter methylation, and to function as a tumor suppressor gene by inducing apoptosis in renal cell cancer cells. However, its relationship with chronic kidney disease (CKD) has not been well studied. Our objective was to investigate the effect of plasma Sfrp5 levels in subjects with and without CKD. Plasma Sfrp5 levels were determined by enzyme-linked immunosorbent assays in 196 consecutive patients with acute ST-segment elevation myocardial infarction (STEMI). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m². For the purpose of this study, stage 1 or 2 CKD patients (eGFR ≥ 60 ml/min per 1.73 m²) were classified as not having CKD. With increasing Sfrp5 tertiles, the patients had higher frequencies of hypertension, stage 4 or 5 CKD, and waist-to-hip ratio, incrementally lower eGFRs and serum hemoglobin levels, and higher levels of blood urine nitrogen (BUN), creatinine, and adiponectin. Multivariate logistic regression analysis showed that an increased plasma Sfrp5 level was independently associated with CKD for all subjects (adjusted odds ratio (OR), 1.08; 95% confidence interval (CI), 1.02-1.14; p = 0.011). Sfrp5 was also significantly positively related to BUN, creatinine, and adiponectin, and significantly negatively related to eGFR and hemoglobin. When the patients were stratified by age, plasma Sfrp5 level was independently related to CKD for patients >65 years old (adjusted OR, 1.10; 95% CI, 1.00-1.20; p = 0.045), however, the association was not significant for those <65 years old. In addition, Sfrp5 was significantly positively related to BUN, creatinine, and adiponectin, and significantly negatively related to eGFR and hemoglobin in patients >65 years old. Our results suggest that Sfrp5 may play a role in the pathogenesis of CKD in acute STEMI patients who are older than 65 years.

Correlation of Thyroid Hormone Profile with Biochemical Markers of Renal Function in Patients with Undialyzed Chronic Kidney Disease

OBJECTIVE

The present study was conducted to evaluate the correlation of renal functions with thyroid hormone levels in patients with undialyzed chronic kidney disease (CKD). Literature shows significant alteration in thyroid hormone function tests in CKD patients who are receiving long-standing dialysis treatment. However, not much is described in those receiving conservative management without dialysis. Although CKD is associated with an increased prevalence of primary hypothyroidism, various studies on thyroid hormone status in uremic patients have reported conflicting results.

METHODOLOGY

Thyroid hormone levels and biochemical markers of renal function were estimated in 30 undialyzed CKD patients and similar number of age- and sex-matched healthy controls, followed by statistical analysis and correlation.

RESULTS

Free triiodothyronine (FT3) and free thyroxine (FT4) were found to be significantly reduced (P < 0.001 for each) in undialyzed CKD patients whereas thyroid-stimulating hormone (TSH) levels showed statistically insignificant alteration in both groups. We also observed that urea and creatinine were negatively correlated whereas creatinine clearance was positively correlated with both FT3 and FT4 having high statistical (two tailed) significance with P < 0.001. Nonsignificant correlation was seen between blood urea and TSH (r = 0.236, P = 0.069), creatinine clearance, and TSH (r = 0.206, P = 0.114 Pearson's correlation coefficient). There is just significant positive correlation between the serum creatinine values and TSH (r = 0.248, P = 0.049).

CONCLUSIONS

Thyroid hormones were significantly decreased in undialyzed CKD patients as compared to healthy controls.

Pathophysiology of Non Alcoholic Fatty Liver Disease

The physiopathology of fatty liver and metabolic syndrome are influenced by diet, life style and inflammation, which have a major impact on the severity of the clinicopathologic outcome of non-alcoholic fatty liver disease. A short comprehensive review is provided on current knowledge of the pathophysiological interplay among major circulating effectors/mediators of fatty liver, such as circulating lipids, mediators released by adipose, muscle and liver tissues and pancreatic and gut hormones in relation to diet, exercise and inflammation.

Thyroid Function Test Derangements and Mortality in Dialysis Patients: A Systematic Review and Meta-analysis

BACKGROUND

We evaluated current evidence associating thyroid function test result derangements with risk for mortality in patients with chronic kidney failure treated by long-term dialysis.

STUDY DESIGN

Systematic review and meta-analysis of cohort studies.

SETTING & POPULATION

Dialysis patients.

SELECTION CRITERIA FOR STUDIES

We searched PubMed, Web of Science, Science Citation Index, Cochrane Library, and Embase databases from inception through December 2015.

PREDICTORS

Hypothyroidism (thyrotropin level greater than reference range) and low triiodothyronine (T₃) and thyroxine (T₄) levels.

OUTCOMES

All-cause and cardiovascular mortality.

RESULTS

12 studies involving 14,766 participants (4,450 deaths) were identified. Of those, 6 studies provided data for cardiovascular mortality (2,772 participants with 327 cardiovascular deaths). Overall, confidence in the available evidence was moderate. Pooled adjusted HRs for all-cause mortality associated with hypothyroidism, low T₃ level, and low T₄ level were 1.24 (95% CI, 1.14-1.34), 1.67 (95% CI, 1.23-2.27), and 2.40 (95% CI, 1.47-3.93), respectively. Pooled adjusted HRs for cardiovascular mortality associated with low T₃ and T₄ levels were 1.84 (95% CI, 1.24-2.74) and 3.06 (95% CI, 1.29-7.24), respectively.

LIMITATIONS

Fewer studies reporting on T₄ and thyrotropin outcomes.

CONCLUSIONS

In patients treated with long-term dialysis, (cardiovascular) mortality is consistently higher in the presence of thyroid function test result derangements.