Hemodialysis (HD) patients are highly susceptible to COVID-19 infection. However, comprehensive assessments of current evidence regarding COVID-19 in HD patients remain incomplete. We systematically searched PUBMED and EMBASE for articles published on incidence or mortality of COVID-19 infection in HD patients until September 2020. Two independent researchers extracted data and study-level risk of bias across studies. We conducted meta-analysis of proportions for incidence and mortality rate. Study heterogeneity and publication bias were assessed. A total of 29 articles with 3261 confirmed COVID-19 cases from a pool of 396,062 HD patients were identified. Incidence of COVID-19 in these HD patients was 7.7% (95% CI: 5.0–10.9%; study heterogeneity: I2 = 99.7%, p < 0.001; risk of publication bias, Egger’s test, p < 0.001). Overall mortality rate was 22.4% (95% CI: 17.9–27.1%; study heterogeneity: I2 = 87.1%, p < 0.001; risk of publication bias, Egger’s test: p = 0.197) in HD patients with COVID-19. Reported estimates were higher in non-Asian than Asian countries. Quality of study may affect the reported incidence but not the mortality among studies. Both incidence and mortality of COVID-19 infection were higher in HD patients. Available data may underestimate the real incidence of infection. International collaboration and standardized reporting of epidemiological data should be needed for further studies.

Chronic kidney disease (CKD) is a growing concern worldwide. Exposure to xenoestrogens (XEs), such as phthalates, parabens, and phenols, lead to CKD. However, kidney function and its complex relationship with XEs, lifestyle, and dietary habits are not well understood. In the present cross-sectional community-based cohort study, we enrolled 887 subjects for a questionnaire-based interview and laboratory tests. XE exposure concerning lifestyle/dietary habits were evaluated using questionnaires. Urinary levels of 17XE metabolites were measured in 60 subjects with high exposure risk scores and 60 subjects with low exposure risk scores. Univariate and multivariate linear regression showed that a high exposure score (β ± SE: 4.226 ± 1.830, P = 0.021) was independently negatively associated with eGFR in 887 subjects. Univariate and multivariate linear regression to urinary XEs and urine albumin creatinine excretion ratio (UACR) in 120 subjects indicated that ethylparaben (EP) (β: 1.934, 95% CI: 0.135-3.733, P = 0.035) was significantly associated with increased UACR. Multivariate regression analyses of the CKD subgroup (n = 38), after adjusting for age, showed that higher levels of mono-(2-ethylhexyl) phthalate (MEHP), EP, nonylphenol (NP), and benzophenone-3 (BP-3) were significantly associated with lower estimated glomerular filtration rate (eGFR). Higher urinary levels of MEHP (OR: 3.037, 95% CI: 1.274-7.241) were more likely associated with high exposure scores (>5 points), after adjusting for diabetes, gender, eGFR, age, Na, Ca, albumin, vitamin D, systolic blood pressure (SBP), white blood cell count, total bilirubin, aspartate transaminase, and heart rate. MEHP (β ± SE: 0.033 ± 0.009, P < 0.001) was also significantly positively associated with total exposure scores after applying multivariate linear regression analyses. XE exposure scores obtained from the questionnaires were negatively associated with kidney function. Urinary metabolites of XEs, including EP, NP, BP-3, and MEHP, are potential risk factors for microalbuminuria and decline in kidney function. MEHP seemed to have the strongest correlation with high exposure scores and decline in kidney function.

Background: Micronutrients are essential in maintaining normal human physiology. Data regarding the association between micronutrients and renal outcomes in chronic kidney disease (CKD) are lacking. Methods: This prospective observational cohort study enrolled 261 patients with CKD stages 1–5 and 30 subjects with normal renal function. Baseline serum zinc (Zn), selenium (Se), chromium, manganese, and copper, and laboratory tests were performed at enrolment. The primary endpoint was the presence of end-stage renal disease (ESRD) requiring long-term renal replacement therapy. Results: The median follow-up periods of renal and non-renal survivals were 67.78 and 29.03 months, respectively. Multiple linear regression showed that Zn and Se (β ± SE: 24.298 ± 8.616, p = 0.005; 60.316 ± 21.875, p = 0.006, respectively) levels were positively correlated with renal function. Time to ESRD was significantly longer for those with Zn levels ≥1287.24 ng/g and Se levels ≥189.28 ng/g (both p < 0.001). Cox regression analysis identified a higher Zn level as an independently negative predictor of ESRD after adjusting for renal function (hazard ratio, 0.450, p = 0.019). Conclusion: Serum Se and Zn concentrations are positively associated with renal function and better renal outcomes. A higher Zn concentration could independently predict better renal survival.

Diabetic kidney disease is the most common primary disease of end-stage kidney disease globally; however, a sensitive and accurate biomarker to predict this disease remains awaited. microRNAs are endogenous single-stranded noncoding RNAs that have intervened in different post-transcriptional regulations of various cellular biological functions. Previous literatures have reported its potential role in the pathophysiology of diabetic kidney disease, including regulation of Transforming Growth Factor-β1-mediated fibrosis, extracellular matrix and cell adhesion proteins, cellular hypertrophy, growth factor, cytokine production, and redox system activation. Urinary microRNAs have emerged as a novel, non-invasive liquid biopsy for disease diagnosis. In this review, we describe the available experimental and clinical evidence of urinary microRNA in the context of diabetic kidney disease and discuss the future application of microRNA in routine practice.