Does hyperglycemia affect arginine metabolites in critically ill patients? A prospective cohort and in vitro study

Association between stress hyperglycemia ratio and contrast-induced nephropathy in ACS patients undergoing PCI: a retrospective cohort study from the MIMIC-IV database

BACKGROUND

Contrast-induced nephropathy (CIN) is a significant complication in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). The role of the stress hyperglycemia ratio (SHR) as a predictor of CIN and mortality in these patients remains unclear and warrants investigation.

OBJECTIVE

To assess the relationship between SHR and CIN, as well as its impact on short-term mortality in ACS patients undergoing PCI.

METHODS

We conducted a retrospective cohort study using the MIMIC-IV database, including 552 ACS patients. SHR was calculated as the ratio of admission glucose to estimated average glucose from hemoglobin A1c. CIN was defined as a ≥ 0.5 mg/dL or ≥ 25% increase in serum creatinine within 48 h of PCI. Logistic regression and spline models were used to analyze the association between SHR and CIN, while Kaplan-Meier curves assessed 30-day mortality.

RESULTS

Higher SHR levels were independently associated with increased CIN risk (OR 2.36, 95% CI: 1.56-3.57, P < 0.0001). A J-shaped relationship was observed, with CIN risk rising sharply when SHR exceeded 1.06. SHR was also a predictor of higher 30-day mortality (P < 0.0001). Subgroup analysis revealed a stronger SHR-CIN association in non-diabetic patients.

CONCLUSION

SHR is an independent predictor of CIN and short-term mortality in ACS patients undergoing PCI. It offers potential for risk stratification and clinical decision-making, especially in non-diabetic patients.

Mechanisms of Homoarginine: Looking Beyond Clinical Outcomes

PURPOSE

Homoarginine (hArg) is an arginine metabolite that has been known for years, but its physiological role in the body remains poorly understood. For instance, it is well known that high hArg concentrations in the blood are protective against several disease states, yet the mechanisms behind these health benefits are unclear. This review compiles what is known about hArg, namely its synthetic pathways, its role in different diseases and conditions, and its proposed mechanisms of action in humans and experimental animals.

FINDINGS

Previous work has identified multiple pathways that control hArg synthesis and degradation in the body. Furthermore, endogenous hArg can modulate the cardiovascular system, with decreased hArg being associated with cardiovascular complications and increased mortality. Studies also suggest that hArg could serve as a diagnostic biomarker for a variety of immune, pancreatic, renal, and hepatic dysfunctions. Finally, in women, hArg concentrations rapidly increase throughout pregnancy and there are suggestions that alterations in hArg could indicate pregnancy complications like pre-eclampsia.

SUMMARY

Homoarginine is an under-appreciated amino acid with potential wide-ranging roles in systemic health, pregnancy, and pathophysiology. Although recent research has focused on its health or disease associations, there is a need for more investigations into understanding the mechanistic pathways by which hArg may operate. This could be aided using metabolomics, which provides a comprehensive approach to correlating multiple metabolites and metabolic pathways with physiological effects. Increasing our knowledge of hArg's roles in the body could pave the way for its routine use as both a diagnostic and therapeutic molecule.

Association between fasting stress hyperglycemia ratio and contrast-induced acute kidney injury in coronary angiography patients: a cross-sectional study

Aims

Stress hyperglycemia ratio (SHR), an emerging indicator of critical illness, exhibits a significant association with adverse cardiovascular outcomes. The primary aim of this research endeavor is to evaluate the association between fasting SHR and contrast-induced acute kidney injury (CI-AKI).

Methods

This cross-sectional study comprised 3,137 patients who underwent coronary angiography (CAG) or percutaneous coronary intervention (PCI). The calculation of fasting SHR involved dividing the admission fasting blood glucose by the estimated mean glucose obtained from glycosylated hemoglobin. CI-AKI was assessed based on elevated serum creatinine (Scr) levels. To investigate the relationship between fasting SHR and the proportion of SCr elevation, piecewise linear regression analysis was conducted. Modified Poisson's regression analysis was implemented to evaluate the correlation between fasting SHR and CI-AKI. Subgroup analysis and sensitivity analysis were conducted to explore result stability.

Results

Among the total population, 482 (15.4%) patients experienced CI-AKI. Piecewise linear regression analysis revealed significant associations between the proportion of SCr elevation and fasting SHR on both sides (≤ 0.8 and > 0.8) [β = -12.651, 95% CI (-23.281 to -2.022), P = 0.020; β = 8.274, 95% CI (4.176 to 12.372), P < 0.001]. The Modified Poisson's regression analysis demonstrated a statistically significant correlation between both the lowest and highest levels of fasting SHR and an increased incidence of CI-AKI [(SHR < 0.7 vs. 0.7 ≤ SHR < 0.9) β = 1.828, 95% CI (1.345 to 2.486), P < 0.001; (SHR ≥ 1.3 vs. 0.7 ≤ SHR < 0.9) β = 2.896, 95% CI (2.087 to 4.019), P < 0.001], which was further validated through subgroup and sensitivity analyses.

Conclusion

In populations undergoing CAG or PCI, both lowest and highest levels of fasting SHR were significantly associated with an increased occurrence of CI-AKI.