Resistin and all-cause and cardiovascular mortality: effect modification by adiponectin in end-stage kidney disease patients

Circulating and Adipose Tissue Adiponectin Level and Outcomes in Incident Peritoneal Dialysis Patients

Rationale & Objective

Cardiovascular disease is the major cause of mortality and morbidity in peritoneal dialysis (PD) patients. Adiponectin, a key adipokine, is related to obesity and insulin resistance. We determined the clinical and prognostic value of plasma adiponectin level and its adipose tissue messenger RNA (mRNA) expression in new PD patients.

Study Design

Retrospective analysis of a prospective observational study.

Setting & Participants

152 new PD patients from a single center; 6 adults undergoing abdominal surgeries without kidney disease served as controls.

Predictors

Plasma adiponectin level and its adipose tissue mRNA expression.

Outcomes

Body build and composition, patient and technique survival.

Analytical Approach

Adiponectin level and mRNA expression were grouped in quartiles for correlation analysis for body build and Cox regression for survival analysis.

Results

The median plasma adiponectin level was 31.98 μg/mL (IQR, 16.81-49.49 μg/mL), and adiponectin mRNA expression in adipose tissue was 1.65 times higher than in controls (IQR, 0.98-2.63). There was a modest but statistically significant correlation between plasma adiponectin and its adipose tissue mRNA expression (r = 0.40, P < 0.001). Plasma adiponectin level inversely correlated with body mass index, waist-hip ratio, mid-arm circumference, adipose tissue mass, plasma triglyceride (r = -0.39, -0.38, -0.41, -0.38, and -0.30, respectively; P < 0.001 for all), as well as serum insulin level (r = -0.24, P = 0.005). Similar correlations were present but less marked with adipose tissue adiponectin mRNA level. Neither plasma adiponectin level nor adipose tissue adiponectin mRNA level predicted patient or technique survival.

Limitations

Observational study, single center, single baseline measurement.

Conclusions

Plasma adiponectin level correlated with the degree of adiposity in new PD patients. However, neither plasma adiponectin level nor its adipose tissue mRNA expression was an independent prognostic indicator in kidney failure patients newly started on PD.

Oxidized LDL Modifies the Association between Proteinuria and Deterioration of Kidney Function in Proteinuric Diabetic Kidney Disease

Proteinuria is characterized by low accuracy for predicting onset and development of diabetic kidney disease (DKD) because it is not directly associated with molecular changes that promote DKD, but is a result of kidney damage. Oxidized low-density lipoprotein (ox-LDL) reflects oxidative stress and endothelial dysfunction, both underlying the development of proteinuria and loss of kidney function in DKD. We aimed to investigate whether ox-LDL modifies the association between proteinuria and progression of DKD in a cohort of 91 patients with proteinuric DKD and diabetic retinopathy, followed for 10 years. The primary endpoint was a combined kidney outcome of eGFR decline ≥30% or progression to end-stage kidney disease. After the end of the study, we considered the percentage change of eGFR over time as our secondary outcome. Proteinuria was associated with both outcomes, and ox-LDL amplified the magnitude of this link (p < 0.0001 for primary and p < 0.0001 for secondary outcome, respectively). After adjustment for duration of diabetes, history of cardiovascular disease and serum albumin, ox-LDL remained a significant effect modifier of the association between proteinuria and eGFR decline over time (p = 0.04). Our study shows that in proteinuric DKD, circulating ox-LDL levels amplified the magnitude of the association between proteinuria and progression of DKD.

Effect of Reduction Mammoplasty on Insulin and Lipid Metabolism in the Postoperative Third month: Compensatory Hip Enlargement

BACKGROUNDS

The positive effects of reduction mammoplasty on metabolic profile have been shown in a limited number of studies. This study objective to reveal the effects of reduction mammoplasty on metabolic profile and anthropometric measurements.

SUBJECTS AND METHOD

The study was prospectively conducted on 42 patients who were operated between April 2019 and March 2020. Fasting plasma glucose, fasting plasma insulin, total cholesterol, triglyceride, high-density lipoprotein and low-density lipoprotein cholesterol, HgA1c, homeostasis model assessment scores, adiponectin, leptin, and resistin levels were evaluated. In addition, age, height, weight, body mass index; breast, chest, waist, hip circumference; waist-hip ratio, and bilateral breast resection tissue weights were recorded. Data and blood samples were collected one hour before the operation, 6 and 12 weeks after the operation.

RESULT

The patients' mean age was 43.14±10.24, and their average height was 159.42±4.96 cm. The excised bilateral dermo fatty tissue weight was 1435.85±721.16 g. At the postoperative 40th day a decrease in leptin (p = 0.001), resistin (p =0.008), glucose (p = 0.021) and insulin resistance values (p=0.013) stated. There was an increase in adiponectin (p < 0.001) and HDL (p = 0.013) levels at the postoperative 40th day. In the postoperative third month, these data returned to the previous levels that were measured before operations. However, an increase in hip circumference (p = 0.034) and a decrease in waist-hip ratio (p < 0.001) was detected in third month. Also, there was no difference in body mass index and weight compared to pre-operation.

CONCLUSION

After reduction mammoplasty, compensatory fat growth in the hip area, an increase in the hip circumference, and a decrease in the waist-hip ratio were observed in the postoperative third month.

LEVEL OF EVIDENCE

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Analysis of serum inflammatory mediators in type 2 diabetic patients and their influence on renal function

Aim

To evaluate the serum concentrations of inflammatory mediators in patients with type 2 diabetes mellitus (T2DM) with or without renal alteration (RA) function.

Methods

Serum samples from 76 patients with T2DM and 24 healthy individuals were selected. Patients with T2DM were divided into two groups according to eGFR (> or < 60mL/min/1.73m²). Cytokines, chemokines and adipokines levels were evaluated using the Multiplex immunoassay and ELISA.

Results

TNFR1 and leptin were higher in the T2DM group with RA than in the T2DM group without RA and control group. All patients with T2DM showed increased resistin, IL-8, and MIP-1α compared to the control group. Adiponectin were higher and IL-4 decreased in the T2DM group with RA compared to the control group. eGFR positively correlated with IL-4 and negatively with TNFR1, TNFR2, and leptin in patients with T2DM. In the T2DM group with RA, eGFR was negatively correlated with TNFR1 and resistin. TNFR1 was positively correlated with resistin and leptin, as well as resistin with IL-8 and leptin.

Conclusion

Increased levels of TNFR1, adipokines, chemokines and decrease of IL-4 play important role in the inflammatory process developed in T2DM and decreased renal function. We also suggest that TNFR1 is a strong predictor of renal dysfunction in patients with T2DM.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Serum Resistin, Adenylate Cyclase-Associated Protein 1 Gene Expression, and Carotid Intima-Media Thickness in Patients with End-Stage Renal Disease and Healthy Controls

BACKGROUND

Human resistin is a proinflammatory cytokine with significant proatherogenic effects which acts through adenylyl cyclase-associated protein 1 (CAP1). Chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients have increased cardiovascular risk and resistin levels. Previous studies indicated resistin significance as a predictor of mortality in CKD.

AIMS

We sought to investigate plasma resistin levels, peripheral blood mononuclear cell (PBMC) resistin mRNA, and for the first time CAP1 mRNA levels in ESRD patients and healthy controls. We also sought to investigate the relation of resistin and CAP1 to carotid intima media thickness (CIMT), CD36 gene expression, and matrix metalloproteinase 9 (MMP-9) circulating levels in ESRD patients and healthy controls.

METHODS

This study included 33 patients with ESRD and 27 healthy controls. Resistin and MMP-9 levels were measured by ELISA. Resistin, CAP1, and CD36 PBMC mRNA were measured by quantitative PCR.

RESULTS

Our study showed that ESRD patients have significantly higher levels of circulatory resistin compared to healthy controls (p < 0.001), while there was no significant difference in resistin mRNA. A significant upregulation of CAP1 and CD36 was observed in the ESRD group (p < 0.001; p < 0.001). Resistin concentration correlated with CIMT in healthy controls (r = 0.512, p = 0.036), and with MMP-9 concentration in ESRD (r = 0.353, p = 0.044) and healthy controls (r = 0.463, p = 0.026). CAP1 correlated positively with CIMT (r = 0.464, p = 0.008) in ESRD, and with CD36 in healthy controls (r = 0.447, p = 0.022) and ESRD (r = 0.824, p < 0.001).

CONCLUSION

The obtained data suggest that high levels of circulating resistin acting upon cells with an upregulated CAP1 gene could contribute to the increased inflammation and accelerated atherosclerosis seen in CKD patients.

Resistin as a predictor of cardiovascular hospital admissions and renal deterioration in diabetic patients with chronic kidney disease

BACKGROUND

High resistin levels have been associated with cardiovascular disease (CVD). Cardiovascular hospitalizations are common, especially in diabetic and renal impaired patients. The purpose of this study is to determine the role of serum resistin as a predictor of cardiovascular hospitalizations in type 2 diabetic patients with mild to moderate chronic kidney disease (CKD).

METHODS

We conducted a prospective, observational study. 78 diabetic patients with mild to moderate CKD and no previous CVD were included. The population was divided in two groups: G-1 with cardiovascular related admission (n = 13) and G-2 without cardiovascular related admission (n = 65). A Student's t-test was conducted to determine correlations between laboratory findings and hospitalization. We used logistic regression to assess predictors of cardiovascular events requiring hospitalization and Cox regression to identify predictors of end-stage renal disease (ESRD).

RESULTS

eGFR, albumin, HbA1c, phosphorous, PTH, IR, CRP, resistin and active vitamin D, were related to cardiovascular admissions. In a multivariate regression model, resistin (OR = 2.074, p = 0.047) was an independent predictor of cardiovascular hospitalization. Cox regression showed that resistin (HR = 1.931, p = 0.031) and UACr (HR = 1.151, p = 0.048) were also independent predictors of renal disease progression.

CONCLUSION

Resistin demonstrated to be valuable in predicting hospital admissions and progression to ESRD.

Physical activity increases the resistin concentration in hemodialyzed patients without metabolic syndrome

BACKGROUND

Resistin (RES) concentration increases in end-stage renal disease patients. However, there have been no studies defining the role of physical activity in RES concentrations in hemodialyzed (HD) patients. This study was aimed to determine metabolic and inflammatory effects, including RES, of 4-week supervised rehabilitation program in HD patients, with or without metabolic syndrome (MS).

METHODS

The study was completed by 28 patients aged 56.9±13.3 years ( x ¯ ± SD ) who were HD for 50.6±73.4 months, and 30 controls aged 61.5±8.3 years with normal renal function. Both the groups were divided into two subgroups with respect to MS. Individualized supervised rehabilitation program based on physiotherapy, including exercises, was provided to each subject for 4 weeks. Baseline and post-intervention complete blood count, glycated hemoglobin (HbA1c) and levels of serum RES, leptin, adiponectin, cystatin C, erythropoietin, high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6, transforming growth factor- β1, plasminogen activator inhibitor-1 homocysteine, insulin, albumin, parathyroid hormone (PTH), and phosphorus were measured.

RESULTS

Compared to controls, HD patients showed higher baseline leucocytes count and higher serum concentrations of RES, leptin, cystatin C, hs-CRP, TNF-α, homocysteine, phosphorus, PTH while hemoglobin, glucose, and albumin concentrations. A positive correlation between serum albumin and RES concentrations was observed in HD patients. Post-intervention RES increase was observed in HD patients without MS (post-intervention 34.22±8.89 vs baseline 30.16±11.04 ng/mL; P=0.046) while no change was observed in patients with MS and in the control group.

CONCLUSION

MS modifies a RES response to the rehabilitation program in HD patients.

Effects of the inspiratory muscle training and aerobic training on respiratory and functional parameters, inflammatory biomarkers, redox status and quality of life in hemodialysis patients: A randomized clinical trial

Objective

Evaluate and compare the isolated and combined effects of Inspiratory Muscle Training (IMT) and Aerobic Training (AT) on respiratory and functional parameters, inflamatory biomarkers, redox status and health-related quality of life (HRQoL) in hemodialysis patients.

Methods

A randomised controlled trial with factorial allocation and intention-to-treat analysis was performed in hemodialysis patients. Volunteers were randomly assigned to performe 8-weeks of IMT at 50% of maximal inspiratory pressure (MIP), low intensity AT or combined training (CT). Before the interventions, all the volunteers went 8-weeks through a control period (without training). Measures are taken at baseline, 8-week (after control period) and 16-week (after the interventions). Primary outcomes were functional capacity (incremental shuttle walk test), MIP and lower limbs strength (Sit-to-Stand test of 30 seconds). Plasma levels of interleukin-6 (IL-6), soluble tumor necrosis factor receptor 1 (sTNFR1) and 2 (sTNFR2), adiponectin, resistin and leptin, redox status parameters and HRQoL (KDQOL-SF questionnaire) were the scondary outcomes. Data analyses were performed by two-way repeated measurements ANOVA.

Results

37 hemodialysis patients aged 48.2 years old (IC95% 43.2–54.7) were randomized. Increase of MIP, functional capacity, lower limbs strength and resistin levels, and reduction of sTNFR2 levels in 16-week, compared to baseline and 8-week, were observed in all the groups (p<0.001). IMT improved functional capacity, MIP and lower limbs strength in 96.7m (IC95% 5.6–189.9), 34.5cmH₂O (IC95% 22.4–46.7) and 2.2repetitions (IC95% 1.1–3.2) respectively. Increase in resistin leves and reduction in sTNFR2 leves after IMT was 0.8ng/dL (IC95% 0.5–1.1) and 0.8ng/dL (IC95% 0.3–1.3), respectively, without between-group differences. Compared to baseline and 8-week, adiponectin levels (p<0.001) and fatigue domain of the HRQoL (p<0.05) increased in 16-week only in CT.

Conclusion

IMT, AT and CT improved functional parameters and modulated inflammatory biomarkers, in addition, IMT provoked a similar response to low intensity AT in hemodialysis patients.

Trial registration

Registro Brasileiro de Ensaios clínicos RBR-4hv9rs.

The complex effects of adipokines in the patients with kidney disease

Kidney diseases are categorized as the highest prevalent ones with worldwide noticeable incidence. They cause accelerated cardiovascular diseases and noticeable mortalities. Adipose tissue and its messengers, adipokines, are reported to have the highest relationship with end-stage renal diseases or chronic kidney diseases. Over recent years, with shifting of scientists’ mindset from a simple overview of adipose tissue as a fat store to the complex paradigm of this issue as a multipotential secretory organ, the importance of studies on this tissue has emerged.

Prooxidant-antioxidant balance, hsTnI and hsCRP: mortality prediction in haemodialysis patients, two-year follow-up

Oxidative stress and inflammation are highly intertwined pathophysiological processes. We analyzed the markers of these processes and high-sensitive troponin I (hsTnI) for mortality prediction in patients on haemodialysis. This study enrolled a total of 62 patients on regular haemodialysis. The patients were monitored for two years, and the observed outcomes were all-cause and cardiovascular mortality. Blood samples were taken before one dialysis session for analysis of the baseline concentrations of prooxidant–antioxidant balance (PAB), total antioxidant status (TAS), total oxidative status (TOS), hsTnI, hsCRP and resistin. The overall all-cause mortality was 37.1% and CVD mortality 16.1%. By univariate and multivariate logistic regression, our findings suggest that good predictors of all-cause mortality include hsCRP and PAB (p < .05) and of CVD mortality hsCRP (p < .05) and hsTnI (p < .001). To evaluate the relationship between the combined parameter measurements and all-cause/CVD mortality risk, patients were divided into three groups according to their PAB, hsCRP and hsTnI concentrations. The cutoffs for hsCRP and hsTnI and the median for PAB were used. Kaplan–Meier survival curves pointed out that the highest mortality risk of all-cause mortality was in the group with hsCRP levels above the cutoff and PAB levels above the median (p < .001). The highest risk of CVD mortality was found in the group with hsCRP and hsTnI levels above the cutoff levels (p = .001). Our data suggest that hsCRP and PAB are very good predictors of all-cause mortality. For CVD complications and mortality prediction in HD patients, the most sensitive parameters appear to be hsTnI and hsCRP.

The Adiponectin Paradox for All-Cause and Cardiovascular Mortality

Basic science studies have shown beneficial effects of adiponectin on glucose homeostasis, chronic low-grade inflammation, apoptosis, oxidative stress, and atherosclerotic processes, so this molecule usually has been considered a salutary adipokine. It was therefore quite unexpected that large prospective human studies suggested that adiponectin is simply a marker of glucose homeostasis, with no direct favorable effect on the risk of type 2 diabetes and cardiovascular disease. But even more unforeseen were data addressing the role of adiponectin on the risk of death. In fact, a positive, rather than the expected negative, relationship was reported between adiponectin and mortality rate across many clinical conditions, comprising diabetes. The biology underlying this paradox is unknown. Several explanations have been proposed, including adiponectin resistance and the confounding role of natriuretic peptides. In addition, preliminary genetic evidence speaks in favor of a direct role of adiponectin in increasing the risk of death. However, none of these hypotheses are based on robust data, so further efforts are needed to unravel the elusive role of adiponectin on cardiometabolic health and, most important, its paradoxical association with mortality rate.

Aldosterone and Insulin Resistance: Vicious Combination in Patients on Maintenance Hemodialysis

Recently, we demonstrated that plasma aldosterone contributed to insulin resistance in chronic kidney disease. The aim of this study is the clinical impact of this relationship in hemodialysis patients. In a cross section study using a total of 128 hemodialysis patients, multiple regression analysis revealed that plasma aldosterone levels were independently associated with HOMA-IR, insulin resistance index. This association was found to be more stringent in diabetic patients than in non-diabetic patients. Aldosterone levels were associated with cardiac hypertrophy and carotid artery stenosis. HOMA-IR was associated with cardiac hypertrophy. The patients whose aldosterone and HOMA-IR were above the top tertile of each parameter in this cohort showed more severe cardiac hypertrophy and lower contractile function as compared with the patients whose aldosterone levels and HOMA-IR are below the lowest tertile of each parameter. In conclusion, in hemodialysis patients, aldosterone levels and insulin resistance are closely interrelated and the constellation of the two is related to severe cardiovascular tissue damages.

Association of adipokines with blood pressure, arterial elasticity and cardiac markers in dialysis patients: cross-sectional analysis of baseline data from a cohort study

Background

Adipokines are a set of cytokines secreted by white adipose tissue that have been suggested to be involved in the development of cardiovascular diseases. We aimed to evaluate the cross-sectional associations of a panel of representative adipokines with cardiovascular measures in a cohort of hemodialysis patients.

Methods

We measured plasma adiponectin, resistin, plasminogen activator inhibitor-1 (PAI-1), leptin, monocyte chemotactic protein 1 (MCP-1) and adipsin levels in 366 dialysis patients and 60 healthy controls. The associations of these adipokines with systolic blood pressure (assessed by ambulatory blood pressure monitoring), pulse wave velocity (PWV) and cardiac markers (BNP, NT-proBNP, Troponin I, Troponin T) in these patients were determined by general linear models with stepwise adjustment for covariates.

Results

In unadjusted comparison with controls, dialysis patients showed increased adiponectin, resistin, MCP-1 and adipsin levels, decreased PAI-1 concentrations (all p <0.001) and similar leptin levels (p = 0.82). On adjustment for body mass index and diabetes, however, the PAI-1 level was comparable between group (p = 0.06), whereas leptin levels became significantly higher in the patients(p <0.001). Higher adiponectin, lower PAI-1 and leptin levels were associated with higher systolic blood pressure, even after extensive adjustment (all p ≤ 0.01). Adiponectin was also consistently and inversely associated with PWV in fully adjusted models (p = 0.003). Resistin, PAI-1, leptin and adipsin showed negative associations with one or more circulating cardiac markers (all p ≤ 0.02).

Conclusions

We found significant associations between adipokines and cardiovascular measures. Our data suggest the possible involvement of adipokines in cardiovascular modulation in dialysis patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-017-0185-3) contains supplementary material, which is available to authorized users.

Inflammatory Cytokines as Uremic Toxins: "Ni Son Todos Los Que Estan, Ni Estan Todos Los Que Son"

Chronic kidney disease is among the fastest growing causes of death worldwide. An increased risk of all-cause and cardiovascular death is thought to depend on the accumulation of uremic toxins when glomerular filtration rate falls. In addition, the circulating levels of several markers of inflammation predict mortality in patients with chronic kidney disease. Indeed, a number of cytokines are listed in databases of uremic toxins and uremic retention solutes. They include inflammatory cytokines (IL-1β, IL-18, IL-6, TNFα), chemokines (IL-8), and adipokines (adiponectin, leptin and resistin), as well as anti-inflammatory cytokines (IL-10). We now critically review the cytokines that may be considered uremic toxins. We discuss the rationale to consider them uremic toxins (mechanisms underlying the increased serum levels and evidence supporting their contribution to CKD manifestations), identify gaps in knowledge, discuss potential therapeutic implications to be tested in clinical trials in order to make this knowledge useful for the practicing physician, and identify additional cytokines, cytokine receptors and chemokines that may fulfill the criteria to be considered uremic toxins, such as sIL-6R, sTNFR1, sTNFR2, IL-2, CXCL12, CX3CL1 and others. In addition, we suggest that IL-10, leptin, adiponectin and resistin should not be considered uremic toxins toxins based on insufficient or contradictory evidence of an association with adverse outcomes in humans or preclinical data not consistent with a causal association.

Serum resistin is causally related to mortality risk in patients with type 2 diabetes: preliminary evidences from genetic data

Resistin has been firmly associated with all-cause mortality. We investigated, whether, in patients with type 2 diabetes (T2D), this association is sustained by a cause-effect relationship. A genotype risk score (GRS), created by summing the number of resistin increasing alleles of two genome-wide association studies (GWAS)-derived single nucleotide polymorphisms (SNPs), serum resistin measurements and all-cause death records were obtained in 1,479 (403 events/12,454 person-years), patients with T2D from three cohorts, Gargano Heart Study-prospective design (n = 350), Gargano Mortality Study (n = 698) and Foggia Mortality Study (n = 431), from Italy. GRS was strongly associated with serum resistin in a non-linear fashion (overall p = 3.5 * 10^-7) with effect size modest for GRS = 1 and 2 and much higher for GRS >3, with respect to GRS = 0. A significant non-linear association was observed also between GRS and all-cause mortality (overall p = 3.3 * 10^-2), with a low effect size for GRS = 1 and 2, and nearly doubled for GRS ≥ 3, with respect to GRS = 0. Based on the above-reported associations, each genetic equivalent SD increase in log-resistin levels showed a causal hazard ratio of all-cause mortality equal to 2.17 (95%CI: 1.22-3.87), thus providing evidence for a causal role of resistin in shaping the risk of mortality in diabetic patients.

Adipocytokines in renal transplant recipients

In the last two decades, perceptions about the role of body fat have changed. Adipocytes modulate endocrine and immune homeostasis by synthesizing hundreds of hormones, known as adipocytokines. Many studies have been investigating the influences and effects of these adipocytokines and suggest that they are modulated by the nutritional and immunologic milieu. Kidney transplant recipients (KTRs) are a unique and relevant population in which the function of adipocytokines can be examined, given their altered nutritional and immune status and subsequent dysregulation of adipocytokine metabolism. In this review, we summarize the recent findings about four specific adipocytokines and their respective roles in KTRs. We decided to evaluate the most widely described adipocytokines, including leptin, adiponectin, visfatin and resistin. Increasing evidence suggests that these adipocytokines may lead to cardiovascular events and metabolic changes in the general population and may also increase mortality and graft loss rate in KTRs. In addition, we present findings on the interrelationship between serum adipocytokine levels and nutritional and immunologic status, and mechanisms by which adipocytokines modulate morbidity and outcomes in KTRs.

Association between serum resistin level and outcomes in kidney transplant recipients

Resistin is an adipocytokine that is associated with inflammation, coronary artery disease, and other types of cardiovascular disease among patients with normal kidney function. However, little is known about the association of resistin with outcomes in kidney transplant recipients. We collected socio-demographic and clinical parameters, medical and transplant history, and laboratory data from 988 prevalent kidney transplant recipients enrolled in the Malnutrition-Inflammation in Transplant-Hungary Study (MINIT-HU study). Serum resistin levels were measured at baseline. Associations between serum resistin level and death with a functioning graft over a 6-year follow-up period were examined in unadjusted and adjusted models. The mean±SD age of the study population was 51 ± 13 years, among whom 57% were men and 21% were diabetics. Median serum resistin concentrations were significantly higher in patients who died with a functioning graft as compared to those who did not die during the follow-up period (median [IQR]: 22[15-26] vs. 19[14-22] ng/ml, respectively; P < 0.001). Higher serum resistin level was associated with higher mortality risk in both unadjusted and fully adjusted models: HRs (95% CI): 1.33(1.16-1.54) and 1.21(1.01-1.46), respectively. In prevalent kidney transplant recipients, serum resistin was an independent predictor of death with a functioning graft.

Association between resistin levels and all-cause and cardiovascular mortality: a new study and a systematic review and meta-analysis

Context

Studies concerning the association between circulating resistin and mortality risk have reported, so far, conflicting results.

Objective

To investigate the association between resistin and both all-cause and cardiovascular (CV) mortality risk by 1) analyzing data from the Gargano Heart Study (GHS) prospective design (n=359 patients; 81 and 58 all-cause and CV deaths, respectively); 2) performing meta-analyses of all published studies addressing the above mentioned associations.

Data Source and Study Selection

MEDLINE and Web of Science search of studies reporting hazard ratios (HR) of circulating resistin for all-cause or CV mortality.

Data Extraction

Performed independently by two investigators, using a standardized data extraction sheet.

Data Synthesis

In GHS, adjusted HRs per one standard deviation (SD) increment in resistin concentration were 1.28 (95% CI: 1.07-1.54) and 1.32 (95% CI: 1.06-1.64) for all-cause and CV mortality, respectively. The meta-analyses included 7 studies (n=4016; 961 events) for all-cause mortality and 6 studies (n=4,187: 412 events) for CV mortality. Pooled HRs per one SD increment in resistin levels were 1.21 (95% CI: 1.03-1.42, Q-test p for heterogeneity<0.001) and 1.05 (95% CI: 1.01-1.10, Q-test p for heterogeneity=0.199) for all-cause and CV mortality, respectively. At meta-regression analyses, study mean age explained 9.9% of all-cause mortality studies heterogeneity. After adjusting for age, HR for all-cause mortality was 1.24 (95% CI: 1.06-1.45).

Conclusions

Our results provide evidence for an association between circulating resistin and mortality risk among high-risk patients as are those with diabetes and coronary artery disease.

Obesity, oxidative stress, and fibrosis in chronic kidney disease

Obesity in combination with diabetes and hypertension likely is contributing to the increasing incidence of chronic kidney disease (CKD) in the 21st century worldwide and requires novel insights and strategies for treatment. There is an increasing recognition that the kidney has an important role in the complex inter-organ communication that occurs with the development of inflammation and fibrosis with obesity. Inhibition of the adiponectin-AMPK pathway has now become established as a critical pathway regulating both inflammation and pro-fibrotic pathways for both obesity-related kidney disease and diabetic kidney disease. AMPK regulates NFκB activation and is a potent regulator of NADPH oxidases. Nox4 in particular has emerged as a key contribtor to the early inflammation of diabetic kidney disease. AMPK also regulates several transcription factors that contribute to stimulation of the transforming growth factor-beta (TGF-β) system. Another key aspect of AMPK regulation is its control of mammalian target of rapamycin (mTOR) and mitochondrial biogenesis. Inhibition of PGC-1α, the transcriptional co-activator of mitochondrial biogenesis is being recognized as a key pathway that is inhibited in diabetic kidney disease and may be linked to inhibition of mitochondrial function. Translation of this concept is emerging via the field of urine metabolomics, as several metabolites linked to mitochondria are consistently downregulated in human diabetic kidney disease. Further studies to explore the role of AMPK and related energy-sensing pathways will likely lead to a more comprehensive understanding of why the kidney is affected early on and in a progressive manner with obesity and diabetes.