Aniceta Brzozowska

Serum and Urinary NGAL in Septic Newborns

Neutrophil gelatinase-associated lipocalin (NGAL) is postulated to be a potentially new and highly specific/sensitive marker of acute kidney injury (AKI). The aim of this study was to assess the impact of inflammation on serum and urine NGAL in newborns that were treated due to infection. We determined serum and urine NGAL concentrations in 73 infants (51 with sepsis; 22 with severe sepsis) admitted to the Intensive Care Unit in the first month of life, for three consecutive days during the course of treatment for infection. 29 neonates without infection served as the control group. Septic patients, in particular, severe sepsis patients, had increased serum and urinary NGAL levels in the three subsequent days of observation. Five septic patients who developed AKI had elevated serum and urinary NGAL values to a similar extent as septic neonates without AKI. A strong correlation was found between the concentration of serum and urinary NGAL and inflammatory markers, such as CRP and procalcitonin. Serum and urinary NGAL levels were also significantly associated with NTISS (neonatal therapeutic intervention scoring system) values. We conclude that increased serum and urinary NGAL values are not solely a marker of AKI, and more accurately reflect the severity of inflammatory status.

Relationship between circulating visfatin/NAMPT, nutritional status and insulin resistance in an elderly population - results from the PolSenior substudy ☆

BACKGROUND Circulating visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT) levels according to some studies are related to nutritional status and insulin resistance. These associations have not been studied in large elderly populations. Therefore, the aim of our study was to assess the relationships between circulating visfatin/NAMPT levels, nutritional status, and insulin resistance in a large population of the elderly. MATERIALS AND METHODS Concentrations of glucose, albumin, creatinine, CRP, interleukin-6, insulin, and visfatin/NAMPT (by ELISA) were assessed, and HOMA-IR calculated in 3050 elderly participants of the PolSenior study. RESULTS The highest plasma visfatin/NAMPT levels were observed in obese, as well as in non-diabetic insulin resistant subjects; however there were only significant differences found in women. The regression models showed that plasma visfatin/NAMPT levels decline with age and increased with waist circumference, BMI, and hs-CRP. Waist circumference was better correlated than BMI for visfatin/NAMPT levels in statistical models not adjusted by sex, and just the opposite in models which were. We demonstrated a 0.023ng/mL increase of Visfatin/NAMPT levels for 1mg/L increase of hs-CRP, and a 0.007ng/mL decline for each year of age. CONCLUSION Our study revealed that in elderly subjects, circulating visfatin/NAMPT levels are related to age, nutritional status, especially visceral obesity, and inflammation.

Factors limiting usefulness of serum and urinary NGAL as a marker of acute kidney injury in preterm newborns

Abstract Background: Neutrophil gelatinase-associated lipocalin (NGAL) is postulated to be a highly sensitive and specific marker of acute kidney injury (AKI). The aim of this study was to assess the factors affecting serum and urine total NGAL in preterm newborns, limiting the role of this new potential marker of AKI. Methods: Serum and urinary total NGAL concentrations were determined in 57 preterm infants admitted to the Neonatal Intensive Care Unit in the following points of time: first week of life, between 8 and 14 days of life, and after the fourth week of life. Patients’ clinical conditions were evaluated based on NTISS (Neonatal Therapeutic Intervention Scoring System). Two gestational age subgroups were distinguished: ≤29 and 30 to 35 weeks of gestation. We sought correlation between total NGAL values and gestational age, birth weight, Apgar score and severity of clinical condition, with particular interest in inflammatory status. Results: Serum and urinary total NGAL concentration correlated with inflammatory markers, such as CRP and procalcitonin, as well as with NTISS values. Birth weight and gestational age influence urinary NGAL (uNGAL) values in the first two weeks of life. In AKI (N = 8) patients uNGAL values were significantly higher than in non-AKI newborns. Conclusions: We conclude that inflammatory status and prematurity limits the specificity of total NGAL measurement as a marker of AKI.

The relationship between circulating visfatin/nicotinamide phosphoribosyltransferase, obesity, inflammation and lipids profile in elderly population, determined by structural equation modeling.

Abstract Background: The available literature suggests that circulating visfatin/Nicotinamide Phosphoribosyltransferase (NAMPT) level variability in humans is related to obesity, insulin resistance, inflammation, and lipid profile. The aim of the study was to assess the relationship between circulating visfatin/NAMPT, obesity, insulin resistance, inflammation, and lipid profile in a large population-based, elderly cohort, applying structural equation modeling. Materials and methods: The analysis included 2983 elderly participants of the PolSenior study with assessed total blood count, fasting concentrations of lipids, glucose, insulin, hs-CRP, interleukin-6, and visfatin/NAMPT (by ELISA), and calculated HOMA-IR. Results: The circulating visfatin/NAMPT levels were higher in obese compared to normal weight subjects, in those with hs-CRP above 3 mg/L, with low serum HDL cholesterol, and in insulin resistant subjects. Based on results of the exploratory factor analysis, a baseline model of mutual relationship between four latent and measured variables was created and a final model was developed by maintaining only two significant categories. The important variables for ‘latent inflammation’ proved to be hs-CRP and IL-6 serum levels. In the case of ‘nutritional status’, important variables were BMI, waist circumference, and to a lesser extent insulin resistance. Additionally, the residual correlation between those two constructs was also statistically significant. Conclusion: The structural equation modeling provided support for the existence of a link between nutritional status, inflammation and circulating visfatin/NAMPT level. This indicates that circulating visfatin/NAMPT can be considered as a novel surrogate marker of systemic inflammation associated with fat depot, especially visceral, in the elderly population.

Plasma visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT) concentration is not related to kidney function in elderly subjects.

Abstract Background: Studies assessing plasma visfatin/nicotinamide phosphoribosyltransferase (NAMPT) concentrations in chronic kidney disease with the ELISA method are restricted mainly to subjects with end-stage kidney disease. Therefore, little is known about to what extent glomerular filtration rate (GFR) affects the plasma levels of visfatin/NAMPT. The aim of this study was to assess the relations between circulating visfatin/NAMPT levels and estimated GFR (eGFR), independently of potential confounders such as inflammation, nutritional status, and insulin resistance in the elderly population. Methods: The analysis included 3023 elderly subjects (1076 with impaired kidney excretory function – eGFR <60 mL/min/1.73 m2) who were participants of the PolSenior study. Serum insulin, glucose, creatinine, C-reactive protein, interleukin-6, and plasma visfatin/NAMPT concentrations were measured by a highly specific ELISA method. Insulin resistance was assessed on the basis of homeostasis model assessment for insulin resistance, and kidney excretory function was assessed using the full MDRD formula. Results: Similar plasma visfatin/NAMPT levels were found in subjects with eGFR ≥60 and <60 mL/min/1.73 m2 (0.96 ng/mL in both groups), and even in those subjects with eGFR 15–30 mL/min/1.73 m2 (0.83 ng/mL). Additionally, there was no association between plasma visfatin/NAMPT concentrations and eGFR values in models of regression analysis including confounding factors. Conclusions: The results of our study suggest that plasma visfatin/NAMPT levels are not affected by impaired kidney excretory function in elderly subjects.

Zonulin: A Potential Marker of Intestine Injury in Newborns

Introduction Zonulin (ZO), a new diagnostic biomarker of intestinal permeability, was tested in newborns presenting symptoms of infection and/or inflammation of the gut or being at risk of intestinal pathology. Material and Methods Serum ZO was assessed in 81 newborns diagnosed with sepsis, necrotizing enterocolitis (NEC), rotavirus infection, and gastroschisis, also in extremely low gestational age babies, and in controls (healthy newborns). ZO concentration was compared to C-reactive protein (CRP) and procalcitonin (PCT) values, leucocyte and platelet count, basic demographic data, and the value of the Neonatal Therapeutic Intervention Scoring System (NTISS). Results Median values of ZO were markedly higher in groups with rotavirus infection and gastroschisis (36.0 (1-3Q: 26.0–43.2) and 20.3 (1-3Q: 17.7–28.2) ng/ml, resp.) versus controls (3.5 (1-3Q: 2.7–4.8) ng/ml). Its concentration in the NEC group was twice as high as in controls but did not reach statistical significance. ZO levels were not related to NTISS, CRP, and PCT. Conclusions Zonulin is a promising biomarker of intestinal condition, markedly elevated in rotavirus infections. Its role in defining the severity of necrotizing enterocolitis and the risk for perforation is not well described and needs further evaluation. An increase in zonulin may not be parallel to the release of inflammatory markers, and low CRP should not exclude an injury to neonatal intestine.

Plasma Level of Retinol-Binding Protein 4, N-Terminal proBNP and Renal Function in Older Patients Hospitalized for Heart Failure

Background/Aim: Elevated plasma concentration of retinol-binding protein 4 (RBP4) has recently emerged as a potential new risk factor for cardiovascular diseases, including hypertension (HT) and coronary artery disease (CAD). Limited data suggest that RBP4 promotes inflammatory damage to cardiomyocytes and participates in the development of heart failure (HF). This study aimed to analyze the relationship between concentrations of plasma RBP4 and serum N-terminal proBNP (NT-proBNP), a powerful biomarker of left ventricle dysfunction, in the older Polish population. Methods: The study sample consisted of 2,826 (1,487 men) participants of the PolSenior study, aged 65 years and older, including a subgroup hospitalized for HF (n = 282). In all subjects, plasma concentrations of RBP4, interleukin-6 (IL-6), serum level of NT-proBNP, and hs-CRP were measured. Additionally, BMI, estimated glomerular filtration rate (eGFR), and HOMA-IR were calculated. The prevalence of HT, CAD, atrial fibrillation (AF), and medication were considered as potential confounders. Results: Similar RBP4 levels were found in subjects with NT-proBNP < 125 and ≥125 ng/mL, with and without AF, and in the subgroups hospitalized for HF with and without AF. Regression analysis revealed no association between log10(NT-proBNP) and log10(RBP4). Plasma levels of RBP4 were increased by HT occurrence and diuretic therapy, while diminished with regard to female gender, age, eGFR values, AF, and IL-6 levels. Conclusion: Our results show that RBP4 is affected by GFR but cannot be considered as an independent biomarker of heart muscle dysfunction.

Plasma concentration of Retinol Binding Protein 4 (RBP4) in relation to nutritional status and kidney function in older population of PolSenior Study

PURPOSE The aim of the study was to assess plasma RBP4 concentration in elderly subjects in relation to nutritional status and kidney function in the population of the PolSenior Study. MATERIAL AND METHODS We assessed RBP4, glucose, insulin, albumin, lipid profile, C-reactive protein, (hsCRP) and creatinine concentrations in 2614 PolSenior Study participants (1235 women and 1379 men). The study group was divided based on BMI and HOMA-IR values, and the occurrence of diabetes. RESULTS Plasma RBP4 concentration was similar in normal weight, overweight, and obese subgroups, both in women (40.4 vs 40.8 vs 41.8 ng/ml, respectively), and men (41.2 vs 40.3 vs 42.9 ng/ml, respectively). Similar values were found in subjects with HOMA-IR <2.5; ≥2.5 and diabetes, while those with decreased eGFR (<60 ml/min/1.73 m2) were characterized by increased RBP4 levels [46.0 (32.0-64.8) vs 39.4 (28.2-54.9) ng/ml; p < 0.001]. Plasma RBP4 level variability was explained by: age, waist circumference or BMI, and eGFR, but not HOMA-IR and/or hsCRP. The standardized coefficients β (slopes) for BMI and waist circumference were similar. CONCLUSIONS The results revealed that in older subjects, circulating RBP4 levels are mostly affected by kidney function and modestly by age, gender, and nutritional status, but not insulin resistance.