Adipokines, endothelial dysfunction and nutritional status in peritoneal dialysis patients

Asymmetric dimethylarginine serum concentration in normal weight and obese CKD patients treated with hemodialysis

INTRODUCTION

Asymmetric dimethylarginine (ADMA), a cardiovascular risk factor, increases in renal failure. The aim of this study was to investigate ADMA levels in normal weight and obese patients on hemodialysis.

METHODS

In this cross-sectional study, 43 normal weight and 43 obese patients on regular hemodialysis were examined. Malnutrition-inflammation score (MIS), anthropometry, circulating ADMA, lipid profiles including triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and lipid ratios, glucose homeostasis parameters, blood pressure, and high-sensitivity C-reactive protein (hs-CRP) were assessed.

RESULTS

Serum levels of ADMA were significantly lower in the obese compared to the normal weight patients (10268.2 ± 10092.4 vs. 13765.2 ± 9951.3 ng/l, P = 0.03). At the same time MIS score (6.1 ± 2.4 vs. 10.7 ± 3.2, P < 0.001), systolic blood pressure (119 ± 26.8 vs. 134.2 ± 24.7 mmHg, P = 0.018) and mean arterial pressure (91.3 ± 18.6 vs. 100.9 ± 15.9 mmHg, P = 0.028) were significantly lower in the obese than the normal weight group. Fasting blood glucose (P = 0.045), TG/HDL (P = 0.03), TC/HDL (P = 0.019), and LDL/HDL (P = 0.005) ratios, and hs-CRP (P = 0.015) levels were significantly higher in the obese than in the normal weight group.

CONCLUSION

Circulating ADMA was significantly lower in obese than in normal weight patients on hemodialysis, which was concomitant with lower MIS, indicating a better nutritional inflammatory status, and lower blood pressure.

Association between Serum Adipocyte Fatty Acid Binding Protein Level and Endothelial Dysfunction in Chronic Hemodialysis Patients

Adipocyte fatty acid binding protein (A-FABP) is associated with atherosclerosis, and endothelial dysfunction is one of the reasons for adverse cardiovascular outcomes in patients undergoing hemodialysis (HD). This study investigated the correlation between serum A-FABP levels and endothelial function in HD patients. Fasting blood samples were collected from 90 HD patients. A-FABP levels were measured using a commercial enzyme immunoassay kit. Endothelial function was evaluated by a digital thermal monitoring test to measure vascular reactivity index (VRI). VRI < 1.0, 1.0 ≤ VRI < 2.0, and VRI ≥ 2.0 indicated poor, intermediate, and good vascular reactivity, respectively. In total, 14 (15.6%), 38 (42.2%), and 38 (42.2%) HD patients had poor, intermediate, and good VRI, respectively. Patients with poor VRI had lower pre-HD and post-HD body weight, body mass index, and serum creatinine level but higher serum A-FABP level (p = 0.001) than those with intermediate and good VRI. Log-transformed VRI (log-VRI) positively correlated with serum creatinine and negatively correlated with A-FABP by multivariate linear regression analysis. We concluded that A-FABP correlated with endothelial dysfunction in chronic HD patients.

Association between serum leptin levels and peritoneal dialysis: A meta-analysis

There is limited information available with regard to the association between serum leptin levels, or other adipokines, and serum lipid levels and insulin sensitivity in patients undergoing peritoneal dialysis (PD). Thus, the aim of the present study was to perform a meta-analysis investigating this association. Potential relevant studies were identified through searching the following databases: MEDLINE, Science Citation Index, Cochrane Library, PubMed, Embase, CINAHL, Chinese Biomedical, Chinese Journal Full-Text and Weipu Journal. Statistical analyses were calculated using version 12.0 STATA software. In total, 21 case-control studies comprising 1,187 subjects (574 patients and 613 controls) were collected for the meta-analysis. The results identified a statistically significant difference in the serum levels of leptin when comparing the PD patients with the healthy controls [controls vs. cases, standardized mean difference (SMD), 2.09; 95% confidence interval (CI), 1.58-2.59; P<0.001]. Furthermore, ethnicity-subgroup analysis indicated that the PD patients of Asian and Caucasian populations were associated with increased serum levels of leptin (Asian population, SMD, 2.05; 95% CI, 1.48-2.62; P<0.001; Caucasian population, SMD, 2.19; 95% CI, 1.19-3.18; P<0.001). Therefore, serum leptin levels may be used as a prognostic marker for PD.