Kidney Injury Molecule Levels in Type 2 Diabetes Mellitus

Urinary NGAL is a Potential Biomarker for Early Renal Injury in Insulin Resistant Obese Non-diabetic Children

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) is one of the new biomarkers for detecting acute renal injury. There are studies showing the relationship between NGAL and renal injury in obese children. The aim of this study was to investigate whether urinary levels of NGAL, kidney injury molecule-1, and serum cystatin C are increased in insulin resistance (IR) patients before the development of diabetes.

METHODS

Cross-sectional, case-controlled study that included non-diabetic obese children and adolescent patients with IR and a non-diabetic obese control group with no IR, who attended a tertiary center pediatric endocrinology outpatient clinic between 2016-2018. Those with diabetes mellitus and/or known renal disease were excluded. NGAL and creatinine (Cr) levels were evaluated in the morning spot urine from all participants. Serum renal function was evaluated.

RESULTS

Thirty-six control and 63 IR patients were included in the study, of whom 68 (68.7%) were girls. The mean age of all participants was 13.12±2.64 years and no statistically significant difference was found between the two groups in terms of age or gender distribution. Median (range) spot urinary NGAL (u-NGAL) values in the IR group were significantly higher at 26.35 (7.01-108.7) ng/mL than in the control group at 19.5 (3.45-88.14) ng/mL (p=0.018). NGAL/Cr ratio was also significantly higher in the IR group compared to the control group (p=0.018).

CONCLUSION

Obese pediatric patients with IR were shown to have elevated levels of u-NGAL, a marker of renal injury. u-NGAL examination may show early renal injury before development of diabetes.

Patterns and risk factors associated with index Lower Extremity Amputations (LEA) among Type 2 Diabetes Mellitus (T2DM) patients in Fiji

AIM

To describe patterns of index (first ever) Lower Extremity Amputations (LEA) and to determine factors associated with their occurrence amongst Type 2 Diabetes Mellitus (T2DM) patients in Fiji.

METHODS

This cross-sectional study was conducted that adheres to the STROBE check lists for observational research among T2DM patients who experienced index LEA at the Colonial War Memorial Hospital (CWMH) in Fiji between 2011 and 2015. Demographic and clinical variables were extracted from patient folders. Univariate and multivariate logistic regression were used to determine factors associated with Major LEA. A p-value < 0.05 was considered significant.

RESULTS

A total of 649 study participants were studied with the average age of index amputation was 58.4 years (±9.6 years, range 30-91 years). The average duration of T2DM was 9.5 ± 5.7 years. LEAs were more common amongst males (55%) and indigenous Fijians (71.8%). One-third of index LEA (33%) were major amputations. Factors associated with occurrence of Major LEA were poor Random Blood Sugar (RBS) levels (OR = 1.68, 95% CI: 1.01, 2.81), midfoot lesion (OR = 9.38 95% CI: 4.95, 19.52), septicaemia (OR = 2.42, 95% CI: 1.28, 4.57), low haemoglobin level (OR = 0.78 95% CI: 0.72, 0.86), and history of hypertension (OR = 0.58, 95% CI: 0.40, 0. 84).

CONCLUSIONS

Results indicate that diabetic patients with foot infections present late to tertiary level care. Our findings also show an urgent need to strengthen primary care interventions and surveillance of both diabetes and diabetic LEA.

Diagnostic Performance of Biomarkers Urinary KIM-1 and YKL-40 for Early Diabetic Nephropathy, in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

There is a lack of prediction markers for early diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (T2DM). The aim of this systematic review and meta-analysis was to evaluate the performance of two promising biomarkers, urinary kidney injury molecule 1 (uKIM-1) and Chitinase-3-like protein 1 (YKL-40) in the diagnosis of early diabetic nephropathy in type 2 diabetic patients. A comprehensive search was performed on PubMed by two reviewers until May 2020. For each study, a 2 × 2 contingency table was formulated. Sensitivity, specificity, and other estimates of accuracy were calculated using the bivariate random effects model. The hierarchical summary receiver operating characteristic curve hsROC) was used to pool data and evaluate the area under curve (AUC). The sources of heterogeneity were explored by sensitivity analysis. Publication bias was assessed using Deek’s test. The meta-analysis enrolled 14 studies involving 598 healthy individuals, 765 T2DM patients with normoalbuminuria, 549 T2DM patients with microalbuminuria, and 551 T2DM patients with macroalbuminuria, in total for both biomarkers. The AUC of uKIM-1 and YKL-40 for T2DM patients with normoalbuminuria, was 0.85 (95%CI; 0.82–0.88) and 0.91 (95%CI; 0.88–0.93), respectively. The results of this meta-analysis suggest that both uKIM-1 and YKL-40 can be considered as valuable biomarkers for the early detection of DN in T2DM patients with the latter showing slightly better performance than the former.

Evaluation of Urinary Neutrophil Gelatinase Associated Lipocalin and Kidney Injury Molecule-1 as Diagnostic Markers for Early Nephropathy in Patients with Type 2 Diabetes Mellitus

PURPOSE

The purpose of this study was evaluating the early diagnostic value of two specific tubular markers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in diabetes nephropathy.

PATIENTS AND METHODS

Cross-sectional study was carried in three groups of patients from 10/2017 to 10/2018 in Military Hospital 103. Group I included 30 healthy peoples with estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m2 and urine albumin creatinine ratio (uACR) <30 mg/g. Group II included 30 type 2 diabetic patients having uACR <30 mg/g, eGFR >60 mL/min/1.73 m2. Group III included 30 type 2 diabetic patients having uACR >30 mg/g, eGFR >60 mL/min/1.73 m2.

RESULTS

Urine KIM-1 and NGAL increased progressively from control group (57.29 ± 25.91 pg/mL; 25.71 ± 13.69 ng/mL) to the group of diabetic patients with uACR <30 mg/g (167.06 ± 44.01 pg/mL; 37.42 ± 10.89 ng/mL) and the group of diabetic patients with uACR ≥30 mg/g) (p < 0.05). There were moderate correlations between KIM-1 (r = 0.48, p < 0.05) and NGAL (r = 0.45, p < 0.05) with uACR. There was a mild correlation between KIM-1 and NGAL (r = 0.29, p < 0.05). KIM-1 and NGAL are the independent tests to detect diabetic nephropathy. The sensivity and specificity of KIM-1 with cut-off value of 174.95 pg/mL were 62.37% and 73.48%, respectively; the sensivity and specificity of NGAL with cut-off value of 35.2 ng/mL were 60.45% and 70.37%, respectively.

CONCLUSION

KIM-1 and NGAL in urine are independent markers for early diagnostic diabetic nephropathy.

Hyperfiltration predicts long-term renal outcomes in humanized sickle cell mice

We previously reported that humanized sickle cell (HbSS) mice develop spontaneous nephropathy, a major cause of morbidity and mortality in sickle cell disease (SCD). Because sex-dependent protective mechanisms in SCD have been reported, we examined the course of nephropathy in male and female HbSS mice to determine contributors and/or predictors of disease severity. In male HbSS mice, glomerular filtration rate was characterized by a rapid onset of hyperfiltration and subsequent progressive decline of renal function over 20 weeks. Early tubular injury presented with increased excretion of kidney injury marker 1 (KIM-1), progressive loss of tubular brush border, and interstitial fibrosis that preceded the onset of glomerular damage, suggesting a tubuloglomerular mechanism of kidney injury in these mice. Additionally, we observed a strong association between the magnitude of hyperfiltration and the degree of long-term kidney injury in male HbSS mice. Unlike males, female HbSS mice did not demonstrate a significant loss of renal function or severe kidney damage during the time course of the study. These results suggest that magnitude of hyperfiltration predicts the onset of chronic kidney damage in male HbSS mice, whereas protective mechanisms in female HbSS mice delay the onset of SCD nephropathy.

Renal injury after uninephrectomy in male and female intrauterine growth-restricted aged rats

Epidemiological studies report an inverse association between birth weight and risk for kidney disease that may differ between males and females, but studies investigating this association are limited. This study tested the hypothesis that male intrauterine growth-restricted offspring in a model of low birth weight induced by placental insufficiency in the rat exhibit enhanced renal injury in response to a persistent secondary renal insult while female growth-restricted offspring are protected. For this study, control offspring from sham-operated dams and growth-restricted offspring from reduced uterine perfusion dams underwent uninephrectomy or a sham procedure at 18 months of age. One month later, urinary markers of renal injury, renal function, and histological damage were measured. Results were analyzed using 2-way ANOVA. Male and female offspring were assessed separately. Proteinuria and urinary neutrophil gelatinase-associated lipocalin were significantly elevated in male growth-restricted offspring exposed to uninephrectomy when compared to male uninephrectomized control. Urinary kidney injury marker-1 was elevated in male uninephrectomized growth-restricted offspring relative to male sham growth-restricted but not to male uninephrectomized controls. Likewise, urinary neutrophil gelatinase-associated lipocalin was elevated in female uninephrectomized growth-restricted offspring but only when compared to female sham growth-restricted offspring. Markers of renal function including glomerular filtration rate and serum creatinine were impaired after uninephrectomy in female offspring regardless of birth weight. Histological parameters did not differ between control and growth-restricted offspring. Collectively, these studies suggest that both male and female growth-restricted offspring demonstrate susceptibility to renal injury following uninephrectomy; however, only male growth-restricted offspring exhibited an increase in renal markers of injury in response to uninephrectomy relative to same-sex control counterparts. These findings further suggest that urinary excretion of protein, kidney injury marker-1, and neutrophil gelatinase-associated lipocalin may be early markers of kidney injury in growth-restricted offspring exposed to a secondary renal insult such as reduction in renal mass.

Baseline urinary KIM-1 concentration in detecting acute kidney injury should be interpreted with patient pre-existing nephropathy

Objectives

To determine whether pre-existing nephropathy impacts urinary KIM-1 levels, urinary KIM-1 were measured in patients with normal kidney filtration function but either with or without proteinuria. The reference intervals of urinary KIM-1 in adults with normal kidney filtration function but without urine proteinuria were established.

Design and methods

188 urine samples were obtained from adults with normal kidney filtration. 83 of the 188 showed negative urine protein, erythrocytes and leucocytes were used as normal controls. The remaining 105 samples showed at least one abnormal result suggesting possible pre-existing nephropathy. Urinary KIM-1 concentrations were measured using an enzyme-linked immunosorbent assay. Urinary KIM-1 was normalized with urine creatinine concentration. The reference interval for urinary KIM-1 was determined by non-parametric methodology on 147 individuals.

Results

The results showed significantly increased urinary KIM-1 concentration in protein positive (protein +, erythrocyte +/−, leucocyte+/-) samples compared to controls (protein-, erythrocyte -, leucocyte -). Urinary KIM-1 concentrations were significantly higher when proteinuria was at trace concentration (0.25 g/L) and correlated with the severity of proteinuria. The creatinine normalized urinary KIM-1 was significantly higher when urine protein was 1 + to 3+ (0.75–5 g/L). The reference interval for urinary KIM-1 was 0.00 (90%CI: 0-0) to 4.19 (90%CI: 3.11–5.62) μg/L, and for creatinine normalized urinary KIM-1 0.00 (90%CI: 0-0) to 0.58 (90%CI: 0.44–0.74) μg/mmol.

Conclusions

Baseline urinary KIM-1 concentrations were increased when there was detectable urine protein and correlated with its severity. The urinary KIM-1 concentrations should be interpreted with consideration of urine protein levels in individual patients.

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The correlation of urinary KIM-1 with pre-existing evidence of nephropathy such as proteinuria, hematuria and pyuria was investigated.

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Urinary KIM-1 was normalized to urine creatinine concentration.

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Urinary KIM-1 reference intervals for healthy adults with normal kidney filtration and without proteinuria were established.

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Age and sex effects on the urinary KIM-1 concentration were investigated.

Effect of Pinocembrin Isolated from Mexican Brown Propolis on Diabetic Nephropathy

Propolis is a resinous beehive product that has been used worldwide in traditional medicine to prevent and treat colds, wounds, rheumatism, heart disease and diabetes. Diabetic nephropathy is the final stage of renal complications caused by diabetes and for its treatment there are few alternatives. The present study aimed to determine the chemical composition of three propolis samples collected in Chihuahua, Durango and Zacatecas and to evaluate the effect of pinocembrin in a model of diabetic nephropathy in vivo. Previous research demonstrated that propolis of Chihuahua possesses hypoglycemic and antioxidant activities. Two different schemes were assessed, preventive (before renal damage) and corrective (once renal damage is established). In the preventive scheme, pinocembrin treatment avoids death of the rats, improves lipid profile, glomerular filtration rate, urinary protein, avoid increases in urinary biomarkers, oxidative stress and glomerular basement membrane thickness. Whereas, in the corrective scheme, pinocembrin only improves lipid profile without showing improvement in any other parameters, even pinocembrin exacerbated the damage. In conclusion, pinocembrin ameliorates diabetic nephropathy when there is no kidney damage but when it is already present, pinocembrin accelerates kidney damage.