Acute Kidney Injury and Progressive Diabetic Kidney Disease: An Epidemiological Perspective

Delving into the complexities of the interplay between acute kidney injury and diabetic kidney disease: A focus on glycemic control and outcomes

Patients with diabetic kidney disease (DKD) face an elevated risk of experiencing acute kidney injury (AKI), exacerbating the progression of DKD. This article offers a comprehensive review of the literature and knowledge of the primary pathophysiologic mechanisms underlying kidney damage, as well as the biological implications of maladaptive kidney repair in the context of DKD complicated by AKI. Additionally, we examine in detail the findings of clinical trials evaluating the efficacy and safety of intensive insulin treatment for hyperglycemic patients in intensive care units, alongside the potential risks of hypoglycemia and mortality. Furthermore, through critical analysis of clinical trial results, opportunities for personalized safety-based approaches to mitigate side effects are identified. It is imperative to conduct randomized-controlled studies to assess the impact of intensive insulin treatment on diabetic patients with DKD, and to validate AKI biomarkers in this patient population. Such studies will help to tailor treatment strategies to improve patient outcomes and preserve kidney function.

Validation of plasma neutrophil gelatinase-associated lipocalin as a biomarker for diabetes-related acute kidney injury

OBJECTIVE

This retrospective study aimed to investigate the correlation between neutrophil gelatinase-associated lipocalin (NGAL) levels and the clinical progression and severity of diabetes-related acute kidney injury (AKI). The quantitative determination of NGAL in plasma on the Beckman Coulter AU480 analyzer was measured using the Bioporto NGAL TestTM, a particle-enhanced turbidimetric immunoassay with hospitalized patients at an East Central Georgia Medical Center.

METHODS

The clinical determination of plasma NGAL included a retrospective cohort study where 45 adult patients were selectively recruited. The selective criteria were patients with and without diabetes mellitus (DM) at risk for developing AKI admitted to the Medical Center between January and November 2023. All patients included in the study had pNGAL levels measured upon admission and up to 96 h post-admission. Receiver operating characteristics and likelihood ratio methods were used to determine optimal sensitivity, specificity, and cutoff value of pNGAL in AKI patients associated with and without DM.

RESULTS

The intra-assay and interassay imprecision percent relative standard deviation was between 2.7% and 4.2%. pNGAL levels were higher for patients with AKI compared to non-AKI patients, regardless of DM status. The optimal cutoff value for pNGAL to predict AKI for patients with DM was 293 ng/mL, with a sensitivity of 80% and specificity of 87%. In a multivariate logistic regression model, pNGAL levels at 48 h post-admission were determined to be associated with diabetes-related AKI patients.

CONCLUSION

Plasma NGAL levels at 48 h are associated with patients with diabetes-related AKI. The specific cutoff values for AKI for early diagnosis and risk stratification and its association with comorbidities must be determined to improve patient outcomes.

Evaluation of the Diagnostic Utility of Urine Biomarkers Tissue Inhibitor of Metalloproteinases-2 (TIMP-2) and Insulin-like Growth Factor Binding Protein-7 (IGFBP-7) in Predicting Acute Kidney Injury and Short-term Outcomes among High-risk, Critically Ill Patients in a Tertiary Government Hospital in the Philippines

BackgroundandObjectives

Acute kidney injury (AKI) is a common complication of critical illness that often leads to increased mortality and morbidity. Biomarkers detect AKI earlier, providing a window of opportunity for timely intervention. Of the recent biomarkers in literature, the cell cycle arrest biomarkers tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor binding protein-7 (IGFBP-7) were found to be superior in predicting AKI. Our study aimed to evaluate the diagnostic performance of urine TIMP-2/IGFBP-7 in its ability to predict AKI and major adverse kidney events within 30 days (MAKE30) among high-risk patients for AKI. MAKE30 is a composite outcome comprised of all-cause mortality, use of renal replacement therapy (RRT), or persistent renal dysfunction at hospital discharge truncated at 30 days.

Methods

We conducted a prospective, cross-sectional study which included 135 adult, non-COVID ICU patients. Baseline urine TIMP-2/IGFBP-7 results were used to dichotomize the population into low risk (<0.3 ng/mL) or high risk (≥0.3 ng/mL) for AKI. Participants were then observed for 30 days and monitored for MAKE30 outcomes. ROC curves were created to calculate the sensitivity, specificity, NPV, PPV, and the AUC of the 0.3 ng/mL cut-off to predict the AKI and MAKE30.

Results

Urine TIMP-2/IGFBP-7 cutoff of 0.3 ng/mL predicted AKI with a sensitivity of 82.4%, specificity of 79.2%, PPV of 57.1%, NPV of 93% and AUC of 0.81. MAKE30 was detected with a sensitivity of 62.8%, specificity of 76.1%, PPV of 55.1%, NPV of 81.4% and AUC of 0.69. Elevated levels of urine TIMP-2/IGFBP-7 were found to be associated with AKI (p<0.01), MAKE30 (p<0.01) and all of its subcomponents. Survival or discharge after 30 days were found to be associated with lower urine TIMP-2/IGFBP-7 levels (p<0.01).

Conclusions

Urine TIMP-2/IGFBP-7, at its current cut-off at 0.3 ng/mL, can predict the likelihood of developing AKI and major adverse kidney events among high-risk patients for AKI. It can serve as a useful adjunct to existing methods, such as serum creatinine, in the early diagnosis and prognosis of acute kidney injury and expanding the therapeutic window to prevent disease progression and improve outcomes.

Acute kidney injury in diabetic patients: A narrative review

Diabetes mellitus (DM) is the most common cause of chronic kidney disease, which leads to end-stage renal failure worldwide. Glomerular damage, renal arteriosclerosis, and atherosclerosis are the contributing factors in diabetic patients, leading to the progression of kidney damage. Diabetes is a distinct risk factor for acute kidney injury (AKI) and AKI is associated with faster advancement of renal disease in patients with diabetes. The long-term consequences of AKI include the development of end-stage renal disease, higher cardiovascular and cerebral events, poor quality of life, and high morbidity and mortality. In general, not many studies discussed extensively "AKI in DM." Moreover, articles addressing this topic are scarce. It is also important to know the cause of AKI in diabetic patients so that timely intervention and preventive strategies can be implemented to decrease kidney injury. Aim of this review article is to address the epidemiology of AKI, its risk factors, different pathophysiological mechanisms, how AKI differs between diabetic and nondiabetic patients and its preventive and therapeutic implications in diabetics. The increasing occurrence and prevalence of AKI and DM, as well as other pertinent issues, motivated us to address this topic.

Is there a relationship between the prevalence of autoimmune thyroid disease and diabetic kidney disease?

Autoimmune thyroid disease (AITD) is more common among diabetes mellitus (DM) patients and may impact its microvascular complications. The present study aimed to assess the relationship between AITD and the prevalence of diabetic kidney disease (DKD) in patients with diabetes mellitus type 1 (DM1). Anthropometric parameters, parameters of metabolic control of DM, thyreometabolic status, and the UACR were assessed. DKD was diagnosed if patients' UACR level was ≥30 mg/g or eGFR level was <60 mL/min. This study involved 144 patients with DM1 aged 36.2 ± 11.7 years: 49 men and 95 women. Significant differences in creatinine, eGFR, and UACR levels were found in patients with DKD. fT3 concentration was significantly lower among DKD patients. A significantly higher probability of DKD was found in DM1 patients with lower fT3 levels. Patients with DM1 and AITD had significantly lower creatinine levels than the control group. However, the study did not show any significant relationship between AITD and the occurrence of DKD in patients with DM1. Significantly lower fT3 concentrations in DKD patients may be caused by metabolic disorders in the course of DKD and require further cohort studies in a larger population of patients with DM1 and AITD.

Update on the Mechanisms of Tubular Cell Injury in Diabetic Kidney Disease

Increasing evidence supports a role of proximal tubular (PT) injury in the progression of diabetic kidney disease (DKD), in patients with or without proteinuria. Research on the mechanisms of the PT injury in DKD could help us to identify potential new biomarkers and drug targets for DKD. A high glucose transport state and mismatched local hypoxia in the PT of diabetes patients may be the initiating factors causing PT injury. Other mechanism such as mitochondrial dysfunction, reactive oxygen species (ROS) overproduction, ER stress, and deficiency of autophagy interact with each other leading to more PT injury by forming a vicious circle. PT injury eventually leads to the development of tubulointerstitial inflammation and fibrosis in DKD. Many downstream signaling pathways have been demonstrated to mediate these diseased processes. This review focuses mostly on the novel mechanisms of proximal renal tubular injury in DKD and we believe such review could help us to better understand the pathogenesis of DKD and identify potential new therapies for this disease.