Yesim Ozen Alahdab

Serum levels of omentin, chemerin and adipsin in patients with biopsy-proven nonalcoholic fatty liver disease

Abstract Objective. The novel adipokines omentin, chemerin, and adipsin are associated with insulin resistance and the components of the metabolic syndrome. We assayed circulating levels of these molecules and examined their association with clinical, biochemical, and histological phenotypes in patients with nonalcoholic fatty liver disease (NAFLD). Material and methods. Serum levels of omentin, chemerin, and adipsin were assayed by enzyme-linked immunosorbent assay in 99 patients with biopsy-proven NAFLD and 75 control subjects. We analyzed associations between adipokines and the characteristics of patients with NAFLD using multivariable linear regression models. Results. Adipsin levels did not differ between patients and controls, whereas both omentin and chemerin levels were significantly higher in patients with biopsy-proven NAFLD than in controls (both p values <0.001). Serum omentin levels were significantly associated with C-reactive protein (r = 0.29, p < 0.01) and the degree of hepatocyte ballooning (r = 0.27, p < 0.01), whereas chemerin showed a modest association with liver fibrosis (r = 0.22, p = 0.04). After stepwise linear regression analysis adjusting for potential confounders, serum omentin levels retained their independent significance as a predictor of hepatocyte ballooning in patients with NAFLD (β = 1.42; t = 2.79, p < 0.01). Conclusions. Our results suggest that serum omentin levels are raised in patients with NAFLD regardless of potential confounders and represent an independent predictor of hepatocyte ballooning.

Microalbuminuria in nondiabetic patients with nonalcoholic fatty liver disease: association with liver fibrosis.

Recent evidence has suggested an association between microalbuminuria and ultrasound-diagnosed nonalcoholic fatty liver disease (NAFLD) in patients with diabetes and prediabetes. However, few data are available on the occurrence of microalbuminuria in nondiabetic subjects with histologically proven NAFLD. We thus evaluated the relationships between microalbuminuria and liver histology in a hospital-based sample of 87 adults with biopsy-proven NAFLD from Turkey. An albumin excretion rate less than 30 mg/d was considered within the reference range, whereas an albumin excretion rate from 30 to 300 mg/d was considered to indicate microalbuminuria. Compared with those without microalbuminuria (n = 73), NAFLD patients with microalbuminuria (n = 14) had significantly higher homeostasis model assessment of insulin resistance values (3.9 +/- 1.3 vs 5.8 +/- 3.7, P < .001). There were no differences in the prevalence of microalbuminuria in patients with definite nonalcoholic steatohepatitis, borderline nonalcoholic steatohepatitis, and simple fatty liver. In the entire study cohort, mean fibrosis scores were significantly higher in patients with microalbuminuria than in those without (1.27 +/- 0.26 vs 0. 80 +/- 0.11, P < .05). This difference persisted after adjustment for potential confounders. These results indicate the presence of a significant association between the severity of insulin resistance and microalbuminuria in patients with NAFLD. In addition, microalbuminuria may identify NAFLD patients with higher fibrosis scores.

Serum levels of vaspin, obestatin, and apelin-36 in patients with nonalcoholic fatty liver disease.

The novel adipokines vaspin, obestatin, and apelin-36 are associated with insulin resistance and the components of the metabolic syndrome. We assayed circulating levels of these molecules and examined their association with clinical, biochemical, and histologic phenotypes in patients with nonalcoholic fatty liver disease (NAFLD). Serum levels of vaspin, obestatin, and apelin-36 were assayed by enzyme-linked immunosorbent assay in 91 patients with biopsy-proven NAFLD and 81 controls. We analyzed associations between adipokines and the characteristics of patients with NAFLD using multivariable linear regression models. Univariable analysis showed that concentrations of vaspin and apelin-36 were significantly higher in patients with NAFLD than in controls, whereas no differences in obestatin levels were found. Serum vaspin levels showed a statistically significant association with C-reactive protein (r = 0.378, P < .001) and liver fibrosis scores (r = 0.401, P < .001), whereas apelin-36 levels showed a modest association with homeostasis model assessment of insulin resistance (r = 0.204, P < .01). After stepwise linear regression analysis, serum vaspin levels were the only independent predictor of liver fibrosis scores in patients with NAFLD (β = 0.37, t = 3.99, P < .01). Serum vaspin levels are raised in patients with NAFLD regardless of potential confounders and represent an independent predictor of liver fibrosis scores. These findings support further investigation of this novel adipokine in metabolic liver diseases.

Circulating vaspin levels and epicardial adipose tissue thickness are associated with impaired coronary flow reserve in patients with nonalcoholic fatty liver disease

BACKGROUNDnPatients with nonalcoholic fatty liver disease (NAFLD) have a reduced coronary flow reserve (CFR) and an increased risk of cardiovascular disease. The fat cells that surround coronary arteries may play a central and underrecognized role in development of cardiovascular disease through the systemic secretion of adipokines. We therefore evaluated the relation of epicardial fat thickness, serum levels of epicardial fat-related adipokines (chemerin and vaspin), and CFR in patients with NAFLD.nnnMETHODSnWe investigated 54 patients with biopsy-proven NAFLD and 56 age- and sex-matched controls. CFR and epicardial fat thickness (EFT) were measured by transthoracic echocardiography. Serum levels of chemerin and vaspin were measured by ELISA.nnnRESULTSnEFT was significantly higher (0.64 ± 0.13 vs. 0.54 ± 0.10 cm, P<0.001) and CFR significantly lower (2.11 ± 0.45 vs. 2.52 ± 0.62, P < 0.001) in patients with NAFLD than in controls. Serum levels of vaspin and chemerin were both significantly increased in patients with NAFLD compared with controls. Stepwise regression analysis showed that EFT (β=-0.53, t=-3.7, P<0.001), serum vaspin levels (β=-0.30, t=-2.5, P=0.014), and liver fibrosis (β=-0.31, t=-2.11, P=0.041), in the order they entered into the model, were independent predictors of CFR in NAFLD patients.nnnCONCLUSIONnOur data suggest the presence of a complex interplay between EFT, serum vaspin, and liver histology in promoting an impaired hyperemic stimulation of coronary blood flow in patients with NAFLD.

Serum osteopontin levels as a predictor of portal inflammation in patients with nonalcoholic fatty liver disease

BACKGROUNDnOsteopontin is a secreted phosphorylated glycoprotein that is expressed by a variety of cell types and that mediates numerous and diverse biological functions. Osteopontin knockout mice are protected from obesity-induced hepatic steatosis. In the present study, we sought to investigate whether serum osteopontin concentrations are associated with liver histology in patients with nonalcoholic fatty liver disease.nnnMETHODSnSerum levels of osteopontin were measured by enzyme-linked immunosorbent assay in 179 well-characterized patients with nonalcoholic fatty liver referred for liver histology and 123 control subjects.nnnRESULTSnSerum osteopontin levels were markedly higher in patients with nonalcoholic fatty liver disease than in controls (p<0.001). Multivariable analysis showed that osteopontin levels were strongly and independently associated with both portal inflammation (β=0.294, p<0.01) and serum aminotransferase levels (aspartate aminotransferase: β=0.295, p<0.01; alanine aminotransferase; β=0.285, p<0.01).nnnCONCLUSIONnIn summary, these data demonstrate that serum levels of osteopontin are elevated in nonalcoholic fatty liver disease and are a significant independent predictor of portal inflammation in this clinical entity.

Circulating Levels of Vascular Endothelial Growth Factor A and Its Soluble Receptor in Patients with Biopsy-proven Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMSnVascular endothelial growth factor A (VEGF) is a multifunctional cytokine affecting angiogenesis and vascular function. The biological activity of VEGF is modulated by its soluble receptor VEGFR-1 (sVEGFR-1). We explored the associations of VEGF and sVEGFR-1 concentrations with liver histology in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD).nnnMETHODSnThe study was comprised of 99 patients with NAFLD and 75 healthy controls. Serum VEGF and sVEGFR-1 concentrations were measured using commercially available enzyme-linked immunosorbent assays.nnnRESULTSnSerum VEGF levels did not differ in patients with NAFLD (1882 ± 942 pg/mL) compared with healthy controls (1985 ± 945 pg/mL, p = 0.42). However, compared with healthy subjects, levels of sVEGFR-1 were significantly lower in patients with NAFLD (1.59 ± 0.58 ng/mL vs. 1.16 ± 0.34 ng/mL, respectively, p <0.001). After allowance for potential confounders, serum sVEGFR-1 levels retained their independent significance as a predictor of liver fibrosis in patients with NAFLD (β = -0.19; t = -1.81, p <0.05).nnnCONCLUSIONSnOur results show that patients with biopsy-proven NAFLD have a significant reduction in serum sVEGFR-1 concentrations that predict the degree of liver fibrosis, independent of potential confounders.

Helicobacter pylori: Management in 2013

Helicobacter pylori (H. pylori) is a prevalent, worldwide, chronic infection. Choice of treatment can be modified according to antibiotic-resistance rates of H. pylori. The ideal therapeutic regimen for H. pylori infection should achieve an eradication rate of ≥ 80%. In some countries, triple therapy with a proton-pump inhibitor (PPI), clarithromycin, and amoxicillin or metronidazole is still the best option. Bismuth-containing quadruple therapy consisting of bismuth salts, tetracycline, metronidazole and PPI, may be the preferred option in countries with clarithromycin resistance > 20%. Sequential therapy including a PPI and amoxicillin given for the first 5 d, followed by triple therapy including a PPI, clarithromycin, and nitroimidazole antimicrobial (all twice daily) for the remaining 5 d, can be another option for the first-line treatment of H. pylori. Recent data suggest that treatment with PPI, levofloxacin, and amoxicillin for 10 d is a good choice for second-line therapy. Concomitant therapy consisting of PPI, amoxicillin, clarithromycin and metronidazole is another option for second-line treatment. If second-line treatment also fails, it is recommended to culture H. pylori from biopsy specimens and perform antimicrobial susceptibility testing. Rescue treatment should be based on antimicrobial susceptibility.

Preliminary evidence of an association between the functional c-kit rs6554199 polymorphism and achalasia in a Turkish population

Backgroundu2002 C‐kit‐positive interstitial cells of Cajal (ICC) of the lower esophageal sphincter are reduced in achalasia. Two functional gene polymorphisms (rs2237025 and rs6554199) within the c‐kit gene may affect its transcriptional activity. In this pilot study, we hypothesized that these polymorphisms would be associated with achalasia.

Protective effect of the vasopressin agonist terlipressin in a rat model of contrast-induced nephropathy.

Background/Aims: Contrast-induced nephropathy (CIN) remains a leading cause of iatrogenic acute renal failure. Terlipressin, a long-acting analog of vasopressin, may improve renal function. This study aimed to investigate the possible protective effect of terlipressin against the development of experimental CIN in rats. Methods: Wistar albino rats (n = 32) were allocated randomly into four equal groups of 8 each, i.e. control, terlipressin, contrast media (CM), and terlipressin plus contrast media (TCM). CIN was induced by intravenous administration of indomethacin (10 mg/kg), N-nitro L-arginine methyl ester (L-NAME, 10 mg/kg, twice at 15 and 30 min), and high-osmolar contrast media meglumine amidotrizoate 60%. Renal function parameters, kidney histology, and tubular expression of vascular endothelial growth factor (VEGF) were determined. Results: Mean serum creatinine levels were decreased (p < 0.05) and creatinine clearance (p < 0.05) increased in the TCM group compared with the CM group. Notably, rats in the TCM group displayed less tubular necrosis (p < 0.05), medullary congestion (p < 0.05), and a reduced tubular expression of VEGF (p < 0.05) compared with the CM group. Conclusion: These results demonstrate that terlipressin can inhibit the development of CIN.

Effect of the Direct Renin Inhibitor Aliskiren in the Prevention of Experimental Contrast-Induced Nephropathy in the Rat

Background: Renal vasoconstriction, activated by the renin-angiotensin system, plays a pivotal role in the pathogenesis of contrast-induced nephropathy (CIN). The purpose of this study was to evaluate the effect of aliskiren, a direct renin inhibitor, for the prophylaxis of experimental CIN in the rat. Methods: Thirty-two Wistar albino rats were divided into four groups of 8 rats each, namely the control (C), aliskiren (A), contrast media (CM) and aliskiren plus contrast media (ACM) groups. Aliskiren was given orally at a dose of 50 mg/kg/day once daily for 5 consecutive days. CIN was induced by intravenous administration of indomethacin, N-nitro-L-arginine methyl ester and high-osmolar contrast medium meglumine amidotrizoate. Renal function parameters, kidney histology and tubular expression of vascular endothelial growth factor were determined. Results: Mean serum creatinine was significantly lower (p < 0.001) and mean creatinine clearance was higher (p < 0.001) in the ACM group compared with the CM group. However, there were no differences between the ACM and CM groups in terms of tubular necrosis, proteinaceous casts, medullary congestion and vascular endothelial growth factor expression. Conclusion: Our preliminary data seem to suggest a potential role of aliskiren for the prophylaxis of CIN in an experimental rat model.