The relationship of serum adipokines with malnutrition inflammation score in haemodialysis

Pro-Inflammatory Profile of Adipokines in Obesity Contributes to Pathogenesis, Nutritional Disorders, and Cardiovascular Risk in Chronic Kidney Disease

Obesity is a disease which leads to the development of many other disorders. Excessive accumulation of lipids in adipose tissue (AT) leads to metabolic changes, including hypertrophy of adipocytes, macrophage migration, changes in the composition of immune cells, and impaired secretion of adipokines. Adipokines are cytokines produced by AT and greatly influence human health. Obesity and the pro-inflammatory profile of adipokines lead to the development of chronic kidney disease (CKD) through different mechanisms. In obesity and adipokine profile, there are gender differences that characterize the male gender as more susceptible to metabolic disorders accompanying obesity, including impaired renal function. The relationship between impaired adipokine secretion and renal disease is two-sided. In the developed CKD, the concentration of adipokines in the serum is additionally disturbed due to their insufficient excretion by the excretory system caused by renal pathology. Increased levels of adipokines affect the nutritional status and cardiovascular risk (CVR) of patients with CKD. This article aims to systematize the current knowledge on the influence of obesity, AT, and adipokine secretion disorders on the pathogenesis of CKD and their influence on nutritional status and CVR in patients with CKD.

The relationship between serum adipokines and glucose homeostasis in normal-weight and obese patients on hemodialysis: a preliminary study

PURPOSE

Insulin resistance (IR) is a prevalent disorder in advanced renal failure irrespective of diabetes. Adipokines might play a role in IR, which has not been well-documented in uremic conditions. This study investigated the relationship of Zinc-α₂-glycoprotein (ZAG), adipose triglyceride lipase (ATGL), and adipolin with glucose-insulin homeostasis in normal weight (NW) and obese (OB) patients with hemodialysis.

METHODS

In this cross-sectional study, 59 patients (29 NW; 18.5 ≤ BMI < 25 kg/m², and 30 OB; BMI ≥ 30 kg/m²) were studied. Anthropometries, circulating ZAG, adipolin, ATGL, free fatty acids (FFAs), fasting blood glucose (FBG), insulin, and homeostasis model assessment of IR (HOMA)-IR were assessed.

RESULTS

There were no significant differences in age, gender, hemodialysis duration, dialysis adequacy and diabetes between the two groups. ZAG (100.9 ± 37.1 vs. 107.5 ± 30.5 ng/mL, P = 0.03) and adipolin (12.4 ± 1.6 vs. 13.2 ± 2.8 ng/mL, P = 0.002) concentrations were significantly lower, and FFAs (228.1 ± 112.6 vs. 185 ± 119 ng/mL, P = 0.014) were significantly higher in the OB than NW group. No significant differences were observed in ATGL, FBG, insulin and HOMA-IR between the two groups. Patients with lower IR had higher ZAG (112.9 ± 31.7 vs. 94.9 ± 34.5 ng/mL; P = 0.046), lower FFAs (167.8 ± 98.4 vs. 249.9 ± 120.8 ng/mL; P = 0.004), and marginally lower ATGL (9.1 ± 5.2 vs. 12.3 ± 9.6 mIU/mL; P = 0.079) concentrations than those with higher IR. ZAG was negatively (r =  - 0.323, P = 0.018 and r =  - 0.266, P = 0.054) and FFAs were positively (r = 0.321, P = 0.019 and r = 0.353, P = 0.009) correlated with insulin and HOMA-IR, respectively. ATGL was directly correlated with FFAs (r = 0.314, P = 0.018).

CONCLUSIONS

Novel adipokines, ZAG and ATGL, might contribute to glucose-insulin homeostasis in hemodialysis. Understanding potential causative, diagnostic or therapeutic roles of adipokines in IR require further studies.

Serum levels of the adipokine zinc-alpha2-glycoprotein (ZAG) predict mortality in hemodialysis patients

Wasting has been associated with increased cardiovascular and all-cause mortality in chronic kidney disease (CKD). We investigated whether serum zinc-alpha2-glycoprotein (ZAG), a potent cachectic and lipid-mobilizing factor that is increased in patients with CKD, predicts clinical outcomes in patients on chronic hemodialysis. We quantified serum ZAG at baseline in a prospective cohort of 252 patients undergoing maintenance hemodialysis. Serum ZAG concentrations were inversely associated with serum albumin, creatinine, and triglycerides and, conversely, positively associated with age. Although ZAG is strongly linked to protein energy wasting (PEW) in patients with cancer, higher ZAG concentrations were not associated with PEW in our cohort. During a mean study follow-up of 954 days, 49 patients died and 62 patients experienced a cardiovascular event. Kaplan-Meier analysis revealed a significant correlation between serum ZAG concentrations and all-cause mortality and cardiovascular events. In separate multivariable Cox regression models, serum ZAG concentrations remained significantly associated with all-cause mortality and cardiovascular events after adjustment for demographic factors (age, sex, and dialysis vintage), metabolic parameters (serum albumin, prealbumin, triglycerides, cholesterol, normalized protein catabolic rate, and body mass index), and cardiovascular risk factors (diabetes, dyslipidemia, history of cardiovascular disease, smoking, and diuretic use as a proxy of residual renal function). Thus, serum ZAG appears to be a strong and independent predictor of mortality and cardiovascular events in patients with end-stage renal disease. Further studies are necessary to confirm this association and to elucidate the underlying mechanisms.