Adiponectin is valuable in the diagnosis of acute heart failure with renal insufficiency

Acute heart failure (AHF) is a major public health issue due to its high incidence and poor prognosis; thus, efficient and timely diagnosis is critical for improving the prognosis and lowering the mortality rate. Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is widely used in the diagnosis of AHF; however, its efficacy is controversial in diagnosing AHF with renal insufficiency. There were numerous studies reporting the association of adiponectin (ADPN) and heart diseases. Therefore, the present study aimed to investigate whether ADPN is helpful in identifying AHF with renal insufficiency. A total of 407 participants (218 AHF patients and 189 controls) were enrolled into the current study. The plasma levels of ADPN and NT-proBNP were measured using a sandwich enzyme-linked immunosorbent assay and an electrochemiluminescence immunoassay, respectively. In addition, these levels were compared among the various New York Health Association classes, as well as the ischemic and non-ischemic AHF cases. The correlation between the two biomarkers and the renal function was analyzed by Spearman's correlation, while the diagnostic efficiency of ADPN and NT-proBNP was evaluated in AHF patients with and without renal insufficiency. The results revealed that NT-proBNP exhibited a higher diagnostic efficiency as compared with ADPN in patients without renal insufficiency [area under the receiver operating characteristic curve (AUC), 0.905 vs. 0.775]. By contrast, the ADPN presented a better diagnostic value in comparison with NT-proBNP in AHF with renal insufficiency (AUC, 0.872 vs. 0.828). Therefore, a combination of these two biomarkers may provide an excellent efficacy in the diagnosis of AHF with renal insufficiency (AUC, 0.904; sensitivity, 71.2%; specificity, 98.3%). In conclusion, ADPN is a valuable biomarker for diagnosing AHF, particularly in patients with impaired renal function.

Adiponectin, cardiovascular disease, chronic kidney disease: emerging data on complex interactions

Over the past decade, adiponectin has been a subject of interest in many fields of medicine. The effect of adiponectin in metabolism and inflammation has been described for cardiovascular disease (CVD) in animal studies and the general population, generally as a protective factor. Extensive literature pertaining to adult studies indicates that low adiponectin levels are associated with increased CVD morbidity and mortality in the general population and patients with obesity and type 2 diabetes. In chronic kidney disease (CKD), however, despite an increased risk of poor cardiovascular outcomes, blood levels of adiponectin are actually higher than typical physiological levels. These unusual relationships question the protective role of elevated adiponectin in the milieu of CKD. This review summarizes the studies of adiponectin in the general pediatric population and its association with CVD risks in children and adults with CKD. Specific adiponectin values are generally avoided in this review, as there are no standardized normative values at this time - different assays with different "normal" cutoffs have been used and hence comparisons between studies would be invalid.

High serum adiponectin concentration in children with chronic kidney disease

Adiponectin (ADPN) counteracts the inflammatory response of the endothelium, which plays an important role in the development of atherosclerosis in patients with chronic kidney disease (CKD). Data in children with CKD are scarce. We examined serum ADPN concentration in 90 children with various renal disorders: 28 with CKD on conservative treatment (CKD), 21 on regular dialysis treatment (D), and 41 after kidney transplantation (Tx); 27 age-matched healthy children served as controls (C). Body mass index (BMI), estimated glomerular filtration rate (eGFR), lipids, homocysteine, high sensitivity CRP (hsCRP), and systolic blood pressure (SBP) were also measured. Mean serum ADPN concentration was significantly higher in patients with CKD (27.3 μg/ml ±15.0), on D (34.2 μg/ml ±14.9), and after Tx (23.6 μg/ml ±9.5) compared with ADPN levels in C (13.5 μg/ml ±6.1) (p < 0.0001). Serum ADPN concentration was inversely related to BMI (p = 0.001) and SBP (p = 0.004). In the multiple linear regression analysis, only SBP remained independently associated with ADPN plasma levels. Data show that children with CKD have significantly higher serum ADPN, even after Tx. The protective antiarthrosclerotic effect of ADPN may be mediated by lower SBP, a finding that deserves further study.

Gender differences in the relationships among obesity, adiponectin and brachial artery distensibility in adolescents and young adults

BACKGROUND

Obesity-related cardiovascular diseases (CVDs) are a major cause of cardiovascular (CV) mortality. Obesity-related reduction in vascular protective adipose-derived proteins, such as adiponectin (APN), has an important role.

METHODS

We compared brachial artery distensibility (BrachD) with APN, the level of adiposity and other CV risk factors (CVRFs) in 431 post-pubertal subjects (mean 17.9 years). Gender differences in average values were examined by t-tests. Correlations among BrachD, obesity and other CVRFs were examined. Regression analysis was performed to determine whether APN provided an independent contribution to BrachD, while controlling for obesity and other CVRFs.

RESULTS

Male subjects had lower BrachD (5.72+/-1.37 vs 6.45+/-1.60% change per mm Hg, P<0.0001) and lower APN (10.50+/-4.65 vs 13.20+/-6.53; all P<0.04) than female subjects. BrachD correlated with APN (r=0.25, P< 0.0001). Both BrachD and APN correlated with measures of body size, including height, weight and body mass index (BMI). Both correlated with higher systolic blood pressure, glucose, insulin and lower high-density lipoprotein cholesterol (all P<0.01). In multivariate analysis, APN, gender, APN*gender and BMI z-score predicted BrachD (r(2)=0.305). On the basis of gender difference, only BMI z-score was significant for male subjects (r(2)=0.080), whereas APN and BMI z-score contributed for female subjects (r(2)=0.242, all P<0.0001).

CONCLUSIONS

BrachD is independently influenced by obesity in both male and female subjects. In female subjects, APN exerts an additional independent effect even after adjusting for blood pressure (BP), lipid levels and insulin. Differences in the effect of the APN-adiposity relationship on obesity-related vascular disease may be one reason for gender differences in the development and progression of atherosclerosis.

Lipoprotein metabolism in chronic renal insufficiency

Chronic renal insufficiency (CRI) is associated with a characteristic dyslipidemia. Findings in children with CRI largely parallel those in adults. Moderate hypertriglyceridemia, increased triglyceride-rich lipoproteins (TRL) and reduced high-density lipoproteins (HDL) are the most usual findings, whereas total and low-density lipoprotein cholesterol (LDL-C) remain normal or modestly increased. Qualitative abnormalities in lipoproteins are common, including small dense LDL, oxidized LDL, and cholesterol-enriched TRL. Measures of lipoprotein lipase and hepatic lipase activity are reduced, and concentrations of apolipoprotein C-III are markedly elevated. Still an active area of research, major pathophysiological mechanisms leading to the dyslipidemia of CRI include insulin resistance and nonnephrotic proteinuria. Sources of variability in the severity of this dyslipidemia include the degree of renal impairment and the modality of dialysis. The benefits of maintaining normal body weight and physical activity extend to those with CRI. In addition to multiple hypolipidemic pharmaceuticals, fish oils are also effective as a triglyceride-lowering agent, and the phosphorous binding agent sevelamer also lowers LDL-C. Emerging classes of hypolipidemic agents and drugs affecting sensitivity to insulin may impact future treatment. Unfortunately, cardiovascular benefit has not been convincingly demonstrated by any trial designed to study adults or children with renal disease. Therefore, it is not possible at this time to endorse general recommendations for the use of any agent to treat dyslipidemia in children with chronic kidney disease.

Serum adiponectin and renal dysfunction in men with type 2 diabetes

OBJECTIVE

Inflammation is associated with both chronic kidney dysfunction and type 2 diabetes. Adiponectin, a novel circulating anti-inflammatory protein made by adipocytes, has been reported to be lower in diabetic than nondiabetic subjects. In contrast, serum levels of adiponectin are elevated in end-stage renal disease. We sought to investigate the relation between adiponectin and mild to moderate renal dysfunction in men with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Multivariate logistic regression was used to evaluate the relation between serum adiponectin concentrations and the presence of renal dysfunction (estimated glomerular filtration rate [eGFR] <60 ml/min per 1.73 m(2) by the four-variable Modification of Diet in Renal Disease equation) in participants with type 2 diabetes in the Health Professionals' Follow-Up Study. A total of 733 men were included in this cross-sectional analysis.

RESULTS

Adiponectin was positively correlated with age (Spearman coefficient, r = 0.19, P < 0.001) and negatively correlated with weight (Spearman coefficient, r = -0.18, P < 0.001). Those with adiponectin in the second quartile or higher (>10 microg/ml) compared with those in the first quartile had a reduced odds for renal dysfunction (multivariate odds ratio 0.48 [95% CI 0.28-0.81]). These results were unchanged when serum lipids were included in the multivariate model.

CONCLUSIONS

We conclude that a higher serum adiponectin concentration is associated with reduced odds of moderate renal dysfunction in men with type 2 diabetes.

Adiponectin in children with chronic kidney disease: role of adiposity and kidney dysfunction

Low serum adiponectin is a known cardiovascular risk in adult chronic kidney disease (CKD). However, adiponectin concentrations and their relation with other cardiovascular risks have not been studied in children with preterminal CKD. Forty-four children and adolescents who were aged 6 to 21 yr and had stages 2 to 4 CKD had serum adipocytes, lipoproteins, markers of inflammation, homocysteine, and insulin levels determined cross-sectionally. There were 29 lean (body mass index [BMI] <85th percentile) and 15 nonlean (BMI > or =85th percentile) patients. Mean serum adiponectin level was 30.6 +/- 14.1 microg/ml (range 7.1 to 67.8 microg/ml). A total of 83% of patients had elevated adiponectin level. Despite similar kidney function, lean patients had significantly higher adiponectin levels than nonlean patients (34.1 +/- 13.4 microg/ml versus 23.6 +/- 13.3 microg/ml; P = 0.02). In univariate analysis, serum adiponectin negatively correlated with age (r = -0.34, P = 0.02), BMI (r = -0.47, P = 0.001), leptin (r = -0.41, P = 0.006), GFR (r = -0.39, P = 0.02), and insulin (r = -0.36, P = 0.01) and positively correlated with ApoA2 (r = 0.30, P = 0.04); no significant associations were found with markers of inflammation or homocysteine. Multivariate stepwise analysis showed that GFR (beta = -0.008, P = 0.001), BMI (beta = -0.16, P = 0.015), and age (beta = -0.04, P = 0.018) independently predicted serum adiponectin levels. Separate analysis of lean patients showed no significant relations with age or BMI; only GFR independently predicted serum adiponectin level (beta = -0.01, P = 0.0008). It is concluded that serum adiponectin is elevated in children and adolescents with stages 2 to 4 CKD and that decreased kidney function is a major determinant of elevated adiponectin concentrations. Despite overall elevated adiponectin, overweight patients display lower serum adiponectin levels and might be at risk for future cardiovascular complications.