Time-updated anion gap and cardiovascular events in advanced CKD: a cohort study

Dynamics of serum anion gaps with in-hospital mortality: Analysis of the multi-open databases

BACKGROUND

Few studies have investigated the relationship between the anion gap, including the corrected anion gap, and patient mortality in intensive care units (ICUs) without restricting the analysis to specific diseases or medical specialties. Our primary objective was to investigate the association between the anion gap and ICU mortality using multiple open-access databases.

METHODS

We identified 4229 subjects from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, whose entries were from between 2008 and 2019. For each patient, the anion gap and corrected anion gap were calculated, and the study sample was divided into tertile groups (T) according to these levels. The association between the anion gap and in-hospital mortality was assessed using hazard ratios (HRs) and 95% confidence intervals (CIs) derived from a multivariable-adjusted Cox proportional hazards model. Besides MIMIC-IV, we also incorporated study samples from two other databases (MIMIC-III and electronic ICU) to calculate summary HRs using a random-effects meta-analysis.

RESULTS

Within MIMIC-IV, 1015 patients (24%) died during an average follow-up period of 15.5 days. The fully adjusted HRs and 95% CIs for T2 and T3, relative to T1, were 1.31 (95% CI 1.08-1.58) and 1.54 (95% CI 1.24-1.90), respectively. When grouped by corrected anion gap, the results remained statistically significant. In the meta-analysis, the summary HRs and 95% CIs for T2 and T3 were 1.24 (95% CI 1.08-1.43) and 1.55 (95% CI 1.33-1.82), respectively.

CONCLUSIONS

Both the anion gap and corrected anion gap were associated with in-hospital mortality regardless of specific diseases or medical specialties.

An Overview of Chronic Kidney Disease Pathophysiology: The Impact of Gut Dysbiosis and Oral Disease

Chronic kidney disease (CKD) is a severe condition and a significant public health issue worldwide, carrying the burden of an increased risk of cardiovascular events and mortality. The traditional factors that promote the onset and progression of CKD are cardiometabolic risk factors like hypertension and diabetes, but non-traditional contributors are escalating. Moreover, gut dysbiosis, inflammation, and an impaired immune response are emerging as crucial mechanisms in the disease pathology. The gut microbiome and kidney disease exert a reciprocal influence commonly referred to as "the gut-kidney axis" through the induction of metabolic, immunological, and endocrine alterations. Periodontal diseases are strictly involved in the gut-kidney axis for their impact on the gut microbiota composition and for the metabolic and immunological alterations occurring in and reciprocally affecting both conditions. This review aims to provide an overview of the dynamic biological interconnections between oral health status, gut, and renal pathophysiology, spotlighting the dynamic oral-gut-kidney axis and raising whether periodontal diseases and gut microbiota can be disease modifiers in CKD. By doing so, we try to offer new insights into therapeutic strategies that may enhance the clinical trajectory of CKD patients, ultimately advancing our quest for improved patient outcomes and well-being.

Increased serum albumin corrected anion gap levels are associated with increased incidence of new-onset HF and poor prognosis in patients with acute myocardial infarction

BACKGROUND

There is scant evidence on a relationship between metabolic acid load and acute myocardial infarction (AMI). We evaluated the relationship between serum albumin corrected anion gap (ACAG), a metabolic acid load biomarker, and post-myocardial infarction heart failure (post-MI HF) in patients with AMI.

METHODS

This prospective, single-center study enrolled 3,889 patients with AMI. The primary endpoint was the incidence of post-MI HF. Serum ACAG levels were calculated with the following formula: ACAG = AG + (40 - [albuminemia in g/l]) × 0.25.

RESULTS

After correction for multiple confounding factors, patients in the fourth quartile of ACAG (highest serum ACAG levels) showed 33.5% higher risk of out-of-hospital HF [hazard ratio (HR) = 1.335, 95% CI = 1.034-1.724, p = 0.027], and 60% higher risk of in-hospital HF [odds ratio (OR) = 1.600, 95% CI = 1.269-2.017, p < 0.001] than those in the first quartile of ACAG (lowest serum ACAG levels). Altered levels of eGFR mediated 31.07% and 37.39% of the association between serum ACAG levels with out-of-hospital HF and in-hospital HF, respectively. Furthermore, altered levels of hs-CRP mediated 20.85% and 18.91% of the association between serum ACAG levels with out-of-hospital and in-hospital HF, respectively.

CONCLUSION

Our study showed that higher metabolic acid load was associated with increased incidences of post-MI HF in the AMI patients. Furthermore, deterioration of renal function and the hyperinflammatory state partially mediated the association between metabolic acid load and the incidence of post-MI HF.

Plant-Dominant Low Protein Diet: A Potential Alternative Dietary Practice for Patients with Chronic Kidney Disease

Dietary protein restriction has long been a cornerstone of nutritional therapy for patients with chronic kidney diseases (CKD). However, the recommended amount of dietary protein intake is different across guidelines. This is partly because previous randomized controlled trials have reported conflicting results regarding the efficacy of protein restriction in terms of kidney outcomes. Interestingly, a vegetarian, very low protein diet has been shown to reduce the risk of kidney failure among patients with advanced CKD, without increasing the incidence of hyperkalemia. This finding suggests that the source of protein may also influence the kidney outcomes. Furthermore, a plant-dominant low-protein diet (PLADO) has recently been proposed as an alternative dietary therapy for patients with CKD. There are several potential mechanisms by which plant-based diets would benefit patients with CKD. For example, plant-based diets may reduce the production of gut-derived uremic toxins by increasing the intake of fiber, and are useful for correcting metabolic acidosis and hyperphosphatemia. Plant proteins are less likely to induce glomerular hyperfiltration than animal proteins. Furthermore, plant-based diets increase magnesium intake, which may prevent vascular calcification. More evidence is needed to establish the efficacy, safety, and feasibility of PLADO as a new adjunct therapy in real-world patients with CKD.

Elevated albumin corrected anion gap is associated with poor in-hospital prognosis in patients with cardiac arrest: A retrospective study based on MIMIC-IV database

Background

Cardiac arrest(CA) is one of the most leading causes of death. Most of the indicators which used to predict the prognosis of patients with CA are not recognized. Previous studies have suggested that albumin corrected anion gap (ACAG) is associated with recovery of spontaneous circulation in patients with CA, but the predictive value of ACAG for prognosis has not been investigated. This study aims to explore the relationship between ACAG and prognosis during hospitalization in patients with CA.

Methods

The baseline data of adult patients with CA hospitalized in the intensive care unit (ICU) from 2008 to 2019 in the American Intensive Care Database (MIMIC-IV, version v2.0) were collected. According to the in-hospital prognosis, patients were divided into survival and non-survival group. Based on the criteria of ACAG level in the previous literature, patients enrolled were divided into normal ACAG (12-20 mmol/L) and high ACAG (>20 mmol/L) group. The basic information of patients during hospitalization were compared and analyzed between the two groups with propensity score matching (PSM). The Kaplan-Meier method was used to compare the cumulative survival rates of normal ACAG and high ACAG groups before and after matching. Restricted cubic spline (RCS) method and multivariate COX proportional hazards regressions were used to analyze whether elevated ACAG was associated with all-cause mortality during hospitalization.

Results

A total of 764 patients were included. A matched cohort (n = 310) was obtained after PSM analysis. The mortality rate before and after matching in the high ACAG group was higher than that in the normal ACAG group (χ ² = 25.798; P < 0.001; χ ² = 6.258; P = 0.012) The Kaplan-Meier survival analysis before and after matching showed that the cumulative survival rate of the high ACAG group was lower (P < 0.05). RCS analysis showed that ACAG had a non-linear relationship with the risk of in-hospital all-cause mortality (χ ² = 6.060, P < 0.001). Multivariate COX regression analysis before and after PSM suggested that elevated ACAG was an independent risk factor for all-cause mortality in patients with CA during hospitalization (P < 0.01).

Conclusions

Elevated ACAG is associated with increased all-cause mortality in patients with CA during hospitalization, it can be an independent risk factor for poor prognosis in patients with CA and remind clinicians to pay more attention to these patients.

The association between serum anion gap and all-cause mortality of unselected adult patients: A retrospective cohort study of >20,000 patients

BACKGROUND

Even though the serum anion gap (AG) is frequently measured in clinical practice, there is not much research that has examined long-term mortality in unselected adult patients. Our study's objective was to investigate how serum anion gap levels could be used to predict death in unselected participants.

METHODS

The relationship between baseline serum AG levels and short-, intermediate-, and long-term all-cause mortality in unselected adult patients is examined using the Cox proportional risk analysis, smoothed curve fitting, subgroup analysis, and Kaplan-Meier survival curves.

RESULTS

After screening the database using the appropriate method, a total of 26,270 patients were enrolled in our study for the final data analysis. Our study used smoothed curve fit plots and COX proportional risk regression models incorporating cubic spline functions to evaluate the association between AG levels and all-cause mortality in a non-selected population, and the results indicated a non-linear relationship. In the fully adjusted model, we found that AG levels were positively associated with 30-day, 90-day, 365-day, and 4-year all-cause mortality in unselected adult patients with HRs of 1.08 95% CIs (1.06, 1.09); 1.08 95% CIs (1.06, 1.09); 1.08 95% CIs (1.07, 1.08); 1.07 95% CIs (1.06, 1.07).

CONCLUSION

Serum anion gap levels were positively correlated with all-cause mortality in unselected adult patients, with increasing levels of serum anion gap increasing patient mortality.

The Anion Gap and Mortality in Critically Ill Patients with Hip Fractures

Objectives

Epidemiological evidence suggests that anion gap (AG) has been reported to serve as an independent predictor for mortality in different diseases. We studied the effect of AG on both short and long-term mortalities in critically ill patients with hip fracture.

Methods

A large clinical database was utilized to perform retrospective cohort analysis. AG was subdivided into three groups. The Cox proportional hazards regression model was employed to approximate the hazard ratio (HR) with a confidence interval (CI) of 95% for the link between AG and mortality. 30-day mortality is the primary outcome, while 90-day and 1-year mortalities represented our secondary outcomes for this study.

Results

The participants in this study were that who provided essential data on AG and the number of patients with hip fractures was 395, and they were all aged ≥16 years. The participants comprised 199 (50.4%) females as well as 196 (49.6%) males with an average age of 71.9 ± 19.4 years, and a mean AG of 12.4 ± 3.3 gmEq/L. According to an unadjusted model for 30-day all-cause mortality, the HR (95% CI) of AG ≥ 12.5 gmEq/L was 1.82 (1.11, 2.99), correspondingly, compared to the reference group (AG < 12.5 gmEq/L). This correlation was still remarkable after adjustment for r age, sex, race, SBP, DBP, WBC, heart failure, and serum chloride (HR = 1.70, 95% CI: 1.02–2.02; 2.82). For 90-day all-cause mortality, a similar correlation was observed.

Conclusions

We noted that AG was an independent indicator of both short and long-term mortalities among hip fractures individuals in this retrospective single-center cohort study. AG is a simple, readily available, and inexpensive laboratory variable that can serve as a possible risk stratification tool for hip fracture.