Kidney injury molecule-1: A potential marker of renal recovery after laparoscopic sleeve gastrectomy

Recent Update on Acute Kidney Injury-to-Chronic Kidney Disease Transition

Acute kidney injury (AKI) is characterized by an abrupt decline of excretory kidney function. The incidence of AKI has increased in the past decades. Patients diagnosed with AKI often undergo diverse clinical trajectories, such as early or late recovery, relapses, and even a potential transition from AKI to chronic kidney disease (CKD). Although recent clinical studies have demonstrated a strong association between AKI and progression of CKD, our understanding of the complex relationship between AKI and CKD is still evolving. No cohort study has succeeded in painting a comprehensive picture of these multi-faceted pathways. To address this lack of understanding, the idea of acute kidney disease (AKD) has recently been proposed. This presents a new perspective to pinpoint a period of heightened vulnerability following AKI, during which a patient could witness a substantial decline in glomerular filtration rate, ultimately leading to CKD transition. Although AKI is included in a range of kidney conditions collectively known as AKD, spanning from mild and self-limiting to severe and persistent, AKD can also occur without a rapid onset usually seen in AKI, such as when kidney dysfunction slowly evolves. In the present review, we summarize the most recent findings about AKD, explore the current state of biomarker discovery related to AKD, discuss the latest insights into pathophysiological underpinnings of AKI to CKD transition, and reflect on therapeutic challenges and opportunities that lie ahead.

The Predicted Value of Kidney Injury Molecule-1 (KIM-1) in Healthy People

Purpose

Recent studies have focused on whether kidney injury molecule-1 (KIM-1) might serve as a marker of acute kidney tubular injury. Our study analyzed the levels of KIM-1 in the healthy population of different ages to explore the correlation between KIM-1 and age. Moreover, we constructed a model to predict kidney age.

Methods

A cross-sectional study was conducted by Huashan Hospital, Shanghai, China, between April 2020 and December 2020. KIM-1 and other kidney biomarkers were measured in 176 healthy individuals ranging from 26 to 91 years old. Statistical correlated analyses for urinary KIM-1, creatinine (uCREA), potassium (K), sodium (Na) and chlorine (Cl), plasmic renin, angiotensin-2 (AngII) and aldosterone (ALD), and serum microalbuminuria (MALB), β2-microglobulin (B2MG), cystatin C (CYSC), urea nitrogen (BUN), creatinine (CREA), and glucose (GLU) were performed to assess the correlation between age and kidney biomarkers. All variables were selected as independent variables for the prediction of age by multiple linear regression.

Results

KIM-1 positively correlated with age in kidney healthy people (r = 0.41, p < 0.05), whether among females (r = 0.51, p < 0.05) or males (r = 0.27, p < 0.05). It was much related to K (r = 0.34), B2MG (r = 0.28), and CL (r = 0.23). The predicted model was constructed with eGFR, Cl, ALD, CYSC, KIM-1, BUN, GLU and AngII, reaching an adjusted R² of 69.5% and a standard error of the estimated 7.84 years.

Conclusion

The level of urinary KIM-1 increases with age in healthy people. The model constructed by KIM-1 and the other 7 biomarkers can predict kidney age in healthy people.

Renal Function Following Bariatric Surgery: a Literature Review of Potential Mechanisms

Obesity is a major and independent risk factor for onset and progression of many renal diseases. Bariatric surgery (BS) improves renal function by improving obesity-related metabolic disorders. However, the procedure is also accompanied by renal risks, including acute kidney injury (AKI) and oxalate nephropathy. Here, we briefly review the history and principle of frequently applied technique for BS and summarize the comprehensive BS effect on kidney function. Importantly, we highlight the possible molecular mechanisms associated with the recovery of renal function to provide novel ideas for future studies and clinical applications.

Improvement of Renal Function After Bariatric Surgery: a Systematic Review and Meta-analysis

BACKGROUND/OBJECTIVE

The effect of bariatric surgery in renal function varies and the postoperative benefit time point remains unclear. We aim to assess the changes of renal function after bariatric surgery (BS) in different postoperative periods and subgroups.

METHODS

We searched the databases of PubMed and Cochrane from inception to December 14, 2020. Articles included in the study were drawn from all recipients of BS that provided assessments of renal function pre and post-surgery. Meta-analysis was performed to compare glomerular filtration rate (GFR), serum creatinine, albumin-to-creatinine ratio (ACR), and albuminuria before and after BS.

RESULTS

The study included 49 articles involving 8515 patients. Compared with pre-operative renal function, the overall analysis showed that bariatric surgery significantly reduced serum creatinine levels, ACR, and albuminuria. There was significant increase of GFR in the CKD subgroup, yet a noticeable decrease in the hyperfiltration subgroup. The most significant improvement in GFR was seen 6-12 months after BS, while ACR dropped most dramatically 12-24 months after BS.

CONCLUSIONS

Bariatric surgery can improve renal function in obese patients with kidney dysfunction, especially 1 year after surgery.