Acute hyperbilirubinemia determines an early subclinical renal damage: Evaluation of tubular biomarkers in cholemic nephropathy.

BACKGROUND AND AIMS: Cholemic nephropathy is a cause of acute kidney injury occurring in patients with jaundice. The aim of this study was to evaluate early renal function impairment in patients with mild acute hyperbilirubinemia in the absence of alterations of the common parameters used in clinical practice (serum creatinine or urea) and with normal renal morphology. We studied urinary biomarkers of tubular damage urinary neutrophil gelatinase-associated lipocalin (u-NGAL), urinary beta-2-microglobulin (u-B2M), urinary osteopontin (u-OPN), urinary trefoil factor 3 (u-TFF3) and urinary Cystatin C (u-Cys). METHODS: This is a case-control study investigating the following urinary biomarkers of tubular damage: u-NGAL, u-B2M, u-OPN, u-TFF3 and u-Cys, in patients with mild acute hyperbilirubinemia. Seventy-four patients were included in this study: 36 patients with jaundice and 38 patients without jaundice. RESULTS: Subjects with jaundice (total bilirubin 12.4 ± 7.3 mg/dL) showed higher u-NGAL, u-B2M, u-OPN, u-TFF3 and u-Cys compared with controls. After logistic regression analyses, including the following independent variables: age, estimated Glomerular Filtration Rate (eGFR), haemoglobin, diabetes, hypertension and jaundice, we observed a higher risk of elevated u-NGAL values (OR = 3.8, 95% CI 1.07-13.5, p = .03) and u-B2M (OR = 9.4, 95% CI 2.3-38.9, p = .0018) in jaundiced subjects. Moreover, urinary biomarkers had a direct correlation with serum cholestasis indexes. CONCLUSIONS: This study demonstrated increased urinary biomarkers of tubular damage (u-NGAL, u-B2M, u-OPN, u-TFF3, and u-Cys) in patients with mild hyperbilirubinemia in comparison with a control group. These findings suggest early renal tubular damage in the absence of alterations of the normal parameters used in clinical practice (eGFR, serum urea and renal morphology).

Abnormalities of Lipoprotein Levels in Liver Cirrhosis: Clinical Relevance.

Progressive lipoprotein impairment occurs in liver cirrhosis and is associated with increased morbidity and mortality. The present review aims to summarize the current evidence regarding the prognostic value of lipoprotein abnormalities in liver cirrhosis and to address the need of a better prognostic stratification of patients, including lipoprotein profile assessment. Low levels of lipoproteins are usual in cirrhosis. Much evidence supports the prognostic role of hypolipidemia in cirrhotic patients. In particular, hypocholesterolemia represents an independent predictor of survival in cirrhosis. In cirrhotic patients, lipoprotein impairment is associated with several complications: infections, malnutrition, adrenal function, and spur cell anemia. Alterations of liver function are associated with modifications of circulating lipids. Decreased levels of lipoproteins significantly impact the survival of cirrhotic patients and play an important role in the pathogenesis of some cirrhosis-related complications.

Apolipoprotein AI and HDL are reduced in stable cirrhotic patients with adrenal insufficiency: a possible role in glucocorticoid deficiency.

BACKGROUNDS AND AIMS: Adrenal insufficiency (AI) has been reported in patients with stable cirrhosis. A lack of substrates has been suggested as a possible contributing pathogenic mechanism leading to glucocorticoid deficiency in these subjects. To better explore this hypothesis, we studied lipoproteins in cirrhotics with and without AI. METHODS: A total of 81 cirrhotic patients and 30 normal volunteers were enrolled. The severity of liver disease was graded by Child-Pugh score. Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG), and apolipoprotein AI (Apo-AI) levels were evaluated. HDL subfractions were measured by gradient gel electrophoresis. Adrenal function was assessed by the Low-Dose Short Synacthen Test. RESULTS: Cirrhotic patients showed a significant reduction of TC, HDL, LDL, TG, and Apo-AI levels compared with controls. HDL3 was significantly lower, while HDL2 was higher, in cirrhotics compared with the controls. AI was observed in 26 patients. TC, TG, HDL, and Apo-AI were significantly reduced in cirrhotics with AI compared with those with normal adrenal function. HDL2 and HDL3 did not differ between these two groups. Delta cortisol was related to TC (r = 0.30, p < 0.01), TG (r = 0.22, p = 0.05), and Apo-AI (r = 0.37, p < 0.001). Multivariate analysis revealed that Apo-AI and HDL were independently associated with AI. CONCLUSION: Our study shows that TC, TG, HDL, and Apo-AI are reduced in cirrhotics with AI. In particular, because both HDL and Apo-AI play a primary role in providing substrates for steroidogenesis to adrenal cells, this deficiency may contribute to the pathogenesis of AI in these patients.

Comparison of total cortisol, free cortisol, and surrogate markers of free cortisol in diagnosis of adrenal insufficiency in patients with stable cirrhosis.

BACKGROUND & AIMS: Measurements of serum levels of total cortisol can overestimate the prevalence of adrenal dysfunction in patients with cirrhosis because they have low concentrations of corticosteroid-binding globulin and albumin. We used measurements of serum total cortisol and serum free cortisol after the low-dose short Synacthen test (LDSST) to assess adrenal dysfunction. METHODS: We studied 79 patients with stable cirrhosis; adrenal dysfunction was defined by peak concentrations of total cortisol ≤494 mmol/L and/or peak concentrations of free cortisol ≤33 nmol/L after the LDSST. We determined free cortisol index (FCI) scores and calculated free cortisol levels by using Coolens' equation. The Cox regression model was used to assess the relationship between adrenal dysfunction and outcomes (death or liver transplant). RESULTS: On the basis of measurement of total cortisol, 34% of patients had adrenal dysfunction, and on the basis of measurement of free cortisol, 29% had adrenal dysfunction. There was agreement between total cortisol and free cortisol levels in 22% of patients; in 13%, adrenal dysfunction was diagnosed only on the basis of total cortisol and in 6% only on the basis of free cortisol (κ coefficient, 0.56; P < .01). Low concentrations of corticosteroid-binding globulin (21 vs 54 µg/mL, P < .01) led to an overestimation of adrenal dysfunction that was based on measurement of total cortisol. Measurements of calculated free cortisol constantly overestimated free cortisol concentrations, with variations as large as 87% for baseline values and up to 84% after stimulation. Adrenal insufficiency, defined by FCI scores <12, was detected in 30% of patients; among them, 23% also had subnormal peak levels of free cortisol (κ coefficient, 0.70; P < .001). Adrenal dysfunction was not significantly associated with patient outcomes, on the basis of Cox model analysis. CONCLUSIONS: Adrenal insufficiency, defined by LDSST, is frequent in patients with stable cirrhosis, on the basis of measurements of total and free cortisol. FCI scores are better than measurement of total cortisol in assessing adrenal function in patients with cirrhosis. We did not associate adrenal dysfunction with outcome, but further studies are needed.

Adrenocortical dysfunction in liver disease: a systematic review.

In patients with cirrhosis, adrenal insufficiency (AI) is reported during sepsis and septic shock and is associated with increased mortality. Consequently, the term "hepato-adrenal syndrome" was proposed. Some studies have shown that AI is frequent in stable cirrhosis as well as in cirrhosis associated with decompensation other than sepsis, such as bleeding and ascites. Moreover, other studies showed a high prevalence in liver transplant recipients immediately after, or some time after, liver transplantation. The effect of corticosteroid therapy in critically ill patients with liver disease has been evaluated in some studies, but the results remain controversial. The 250-µg adreno-cortico-tropic-hormone stimulation test to diagnose AI in critically ill adult patients is recommended by an international task force. However, in liver disease, there is no consensus on the appropriate tests and normal values to assess adrenal function; thus, standardization of normal ranges and methodology is needed. Serum total cortisol assays overestimate AI in patients with cirrhosis, so that direct free cortisol measurement or its surrogates may be useful measurements to define AI, but further studies are needed to clarify this. In addition, the mechanisms by which liver disease leads to adrenal dysfunction are not sufficiently documented. This review evaluates published data regarding adrenal function in patients with liver disease, with a particular focus on the potential limitations of these studies as well as suggestions for future studies.

Assessment of adrenocortical reserve in stable patients with cirrhosis.

BACKGROUND & AIMS: Adrenal insufficiency (AI) is reported in critically ill patients with cirrhosis and is associated with increased mortality. It is unclear if AI is an underlying condition or triggered by critical events (e.g. sepsis). We investigated AI in cirrhosis without infection or hemodynamic instability. METHODS: A total of 101 consecutive patients with cirrhosis were studied. AI was defined by a total serum cortisol (TC) <18 µg/dl at 20 or 30 min after injection of 1 µg of tetracosactrin. Transcortin, calculated free cortisol (cFC), and free cortisol index (FCI) were assessed in a subgroup of 41 patients, with FCI>12 representing normal adrenal function. RESULTS: AI was present in 38 patients (38%). Child score (median, 10 vs 7, p<0.0001), MELD score (median, 17 vs 12, p<0.0001), ascites (68% vs 37%, p<0.01), basal TC (median,7.6 vs 14.9 µg/dl, p<0.001), albumin (28 ± 0.8 vs 33 ± 0.7 g/L, p<0.0001), INR (median, 1.6 vs 1.2, p<0.0001), total bilirubin (median, 51 vs 31 µmol/L, p<0.05), total cholesterol (median, 120 vs 142, p<0.05), and LDL (median, 76 vs 81, p<0.05) were significantly different between those with and without AI. ROC curves showed a basal TC ≤ 12.8 µg/dl to be a cut-off value closely associated with AI. The cFC was significantly related to TC for baseline values (R=0.94, p<0.0001), peak values (R=0.90, p<0.0001), and delta values (R=0.95, p<0.0001), in patients with and without AI. However, no patient had a FCI<12. CONCLUSIONS: AI defined by an abnormal response to 1 µg tetracosactrin is frequent in stable patients with cirrhosis, in the absence of infections or hemodynamic instability and is related to the severity of liver disease. However, evaluation of the true incidence of AI should comprise direct assays of free cortisol. Clinical consequences of AI need to be explored.

Direct apoptotic effects of free fatty acids on human endothelial cells.

BACKGROUND AND AIM: Endothelial cell injury is a key event in the pathogenesis of diabetes-associated atherosclerosis and vascular complications. Increased apoptosis may contribute to the loss of endothelial integrity and leads to cardiovascular disease. This study was designed to elucidate whether high levels of free fatty acids (FFA) cause apoptosis and if so what is the possible role of insulin signaling alteration(s) in determining this effect. METHODS AND RESULTS: In human umbilical vein endothelial cells (HUVECs) cultured for 72h with high levels of FFA, apoptotic cells, detected by Annexin V-FITC and PI, were increased. Then we observed a decrease of Bcl-2/Bax ratio (pro-apoptotic condition), measured by RT-PCR and Western blot. As the Akt pathway is involved in insulin signaling and apoptosis, we investigated whether Akt mediated FFA apoptotic effects. HUVECs exposed to FFA showed an equal amount of total Akt protein content compared to controls. In HUVECs, FFA induced a significant decrease in phosphorylated active Akt. Furthermore, phosphorylated eNOS (active form) was decreased and cleaved caspase-9 (active form) was increased. These alterations were prevented when insulin at 10(-8)M was added in culture medium containing FFA. The insulin anti-apoptotic effect was prevented by Ly29400, a PI3K/Akt inhibitor. CONCLUSION: High levels of FFA cause HUVECs apoptosis through Akt inhibition; insulin can prevent these effects. Inappropriate FFA elevation may affect vascular endothelium by impairing cell survival via activation of apoptosis, thus contributing to the development of cardiovascular disease in type 2 diabetic patients.

Emerging hepatic syndromes: pathophysiology, diagnosis and treatment.

Liver cirrhosis is a major cause of morbidity and mortality worldwide, mainly due to complications of portal hypertension. In this article, we review the current understanding on the pathophysiology, the diagnostic criteria and the available therapeutic options for patients with emerging hepatic syndromes in cirrhosis, namely the hepatorenal, hepato-adrenal and hepatopulmonary syndrome. The hepatorenal syndrome is a well-recognized complication of advanced cirrhosis and is usually associated with an accelerated course to death unless liver transplantation is performed. The hepatopulmonary syndrome is often missed in the evaluation of patients with cirrhosis; however, early recognition is essential for the efficient management of individual patients. The hepato-adrenal syndrome, although not fully characterized, offers an exciting field for research and potential therapeutic interventions.

Hepatic insulin resistance in NAFLD: relationship with markers of atherosclerosis and metabolic syndrome components.

AIMS: Fat accumulation in the liver and in the muscle results in hepatic and muscle insulin resistance and has been associated with increased cardiovascular risk. It is unclear whether the individual role of hepatic and muscle insulin resistance in the onset of dyslipidaemia is observed in nonalcoholic fatty liver disease (NAFLD) patients and whether this association is mediated through traditional risk factors. The aim of this study was to assess hepatic and muscle insulin resistance in NAFLD and its relationship with carotid artery intima-media thickness (IMT) and the apoB/apoAI ratio as markers of atherosclerosis. METHODS: We studied 132 patients with a non-invasive diagnosis of NAFLD stratified into two groups according to the severity of steatosis at ultrasound scan. In all subjects, we measured hepatic insulin resistance (H-IR) and muscle insulin sensitivity index (MISI) by oral glucose tolerance test as proposed by DeFronzo, IMT, apoB/apoAI and the components of the metabolic syndrome (MS) as defined by ATP III. RESULTS: H-IR was significantly higher in moderate/severe steatosis than in the mild steatosis group (p < 0.0001). By contrast, MISI did not differ between the two groups. There was a significant correlation between H-IR, MISI and all of the components of MS. H-IR was significantly correlated with carotid IMT (r = 0.35; p < 0.0001) and the apoB/apoAI ratio (r = 0.43; p < 0.0001). Otherwise, a significant correlation was observed only between MISI and apoB/apoAI ratio. Multivariate analysis revealed that H-IR is related to early markers of atherosclerosis independent of MS components. CONCLUSIONS: In our study population, NAFLD was positively associated with carotid IMT, and this association is independent of MS components, but strictly related to H-IR that might contribute to the development of atherosclerosis through an impairment of the lipid profile in terms of the apoB/apoAI ratio. By contrast, no significant relation was observed between MISI and carotid IMT.

Cardiovascular dysfunction in patients with liver cirrhosis.

Hyperdynamic syndrome is a well-known clinical condition found in patients with cirrhosis and portal hypertension, characterized by increased heart rate and cardiac output, and reduced systemic vascular resistance and arterial blood pressure. The leading cause of hyperdynamic circulation in cirrhotic patients is peripheral and splanchnic vasodilatation, due to an increased production/activity of vasodilator factors and decreased vascular reactivity to vasoconstrictors. The term "cirrhotic cardiomyopathy" describes impaired contractile responsiveness to stress, diastolic dysfunction and electrophysiological abnormalities in patients with cirrhosis without known cardiac disease. Underlying circulatory and cardiac dysfunctions are the main determinant in the development of hepatorenal syndrome in advanced cirrhosis. Moreover, the clinical consequences of cirrhosis-related cardiovascular dysfunction are evident during and after liver transplantation, and after transjugular intrahepatic portosystemic shunt insertion. Cardiovascular complications following these procedures are common, with pulmonary edema being the most common complication. Other complications include overt heart failure, arrhythmia, pulmonary hypertension, pericardial effusion, and cardiac thrombus formation. This review discusses the circulatory and cardiovascular dysfunctions in cirrhosis, examining the pathophysiologic and clinical implications in light of the most recent published literature.

Hypothalamus-pituitary dysfunction is common in patients with stable cirrhosis and abnormal low dose synacthen test.

BACKGROUND: Adrenal insufficiency is often present in cirrhosis. We hypothesize that a prolonged adrenocorticotropic hormone (ACTH) stimulus can restore cellular capacity of adrenal glands to secrete cortisol. Aim of our study was to assess adrenal responsiveness to prolonged ACTH stimulation in cirrhotics. METHODS: Prospective observational study in 121 consecutively admitted cirrhotic patients undergoing a low dose short synacthen test and plasma ACTH measurement using a chemiluminescence immunoassay. Long synacthen test was performed if the low dose was abnormal. RESULTS: 46 patients had abnormal low dose short test (38%), and 29 underwent the long test: 41% showed normal response (Group 1), 55% showed delayed response (Group 2) and 1 had abnormal response (4%). Baseline ACTH levels did not significantly differ between the two groups. Median basal cortisol was higher in Group 1 (296 vs. 198 nmol/L; p=0.02). Using ROC curve basal cortisol <254 nmol/L was associated with a delayed long synacthen test response (AUC 0.78, p=0.001) with good accuracy (sensitivity 67%, specificity 81%). CONCLUSION: A delayed cortisol response after a prolonged ACTH stimulation is found in over fifty percent of cirrhotics with abnormal low dose short synacthen test, confirming that the mechanism of hypoadrenalism in these patients could be related both to adrenal cellular dysfunction and hypothalamus-pituitary adrenal axis impairment.

Diabetes increases renovascular impedance in patients with liver cirrhosis.

Renal failure is a common complication of cirrhosis and is associated with poor prognosis. Several reports have demonstrated the clinical utility of renal resistive indices in the assessment of renal function in cirrhosis patients. It is unknown whether the occurrence of diabetes affects renal haemodynamic indices in patients with cirrhosis. Therefore, the aim of our study was to compare renal Doppler indices in cirrhotic patients with and without type 2 diabetes mellitus (T2DM) and in diabetics without cirrhosis, and to relate the Doppler parameters to albuminuria. We evaluated 89 consecutive patients with normal renal functioning, including 37 with cirrhosis and T2DM (CD-Group), 41 with cirrhosis without diabetes (C-Group) and 11 with diabetes without cirrhosis (D-Group). The kidney pulsatility index (PI) and resistance index (RI) were measured by Doppler ultrasound. Renal function was expressed as the estimated glomerular filtration rate (eGFR) using the modification of diet in renal disease (MDRD) formula. Microalbuminuria (µAlb) was also evaluated. No significant differences were observed with respect to age, the Child-Pugh class or the serum creatinine level. The eGFR was mildly reduced in the CD-Group compared with the C-Group and D-Group, and µAlb was present in 24.4 % of the patients in the CD-Group and in 9 % of those in the D-Group. The PI and RI were significantly increased in the CD-Group and D-Group compared with the C-Group. Both the PI and RI were significantly associated with µAlb independent of age and Child-Pugh class. The novel finding of this study was that T2DM potentially impairs renal haemodynamics in patients with cirrhosis.

Alterations in thyroid Doppler arterial resistance indices, volume and hormones in cirrhosis: relationships with splanchnic haemodynamics.

The hypothesis of thyroid involvement in the haemodynamic alterations of cirrhosis was evaluated. We measured thyroid volume (thrV), free triiodiothyronine (FT3), free thyroxin (FT4), thyroid stimulating hormone (TSH), resistance index (thrRI) and pulsatility index (thrPI) in the inferior thyroid artery in 45 cirrhotic patients of different aetiologies and Child class, and in 13 healthy subjects. Portal vein velocity, flow, diameter and hepatic, splenic, and renal arterial resistance indices were also evaluated. ThrV was increased in Child-C patients (p < 0.05). FT3 was decreased in cirrhotic patients (p < 0.05), TSH and FT4 were not different. ThrPI and thrRI were increased in cirrhotic patients (thrPI: 1.01 +/- 0.15 vs. 0.81 +/- 0.11; thrRI: 0.62 +/- 0.05 vs. 0.53 +/- 0.04; p < 0.01) and were inversely correlated with FT3 (p < 0.05), and directly correlated with hepatic, splenic and renal resistance indices (p < 0.01). In conclusion, thyroid is involved, primarily and secondarily, in the haemodynamic alterations of cirrhosis; a reduction in vasodilator FT3 may play a role in the pathophysiology.

Corticosteroid replacement therapy in hepatoadrenal syndrome: case report with a review of the literature.

In liver cirrhosis, hepatoadrenal syndrome has been described recently as a progressive impairment in the adrenocortical reserve, with deficient production or action of glucocorticoids resulting in adrenal insufficiency. Data on the treatment of this syndrome are scarce. We report a case of a 60-year-old male patient referred to our hospital because of rectal bleeding and bilateral leg swelling. He complained of marked weakness, bilateral leg swelling, and shortness of breath with exertion for the last 2 months. Biochemistry and imaging indicated liver cirrhosis. Because of the weakness and persistent hypotension, we performed a low-dose synacthen test, which indicated adrenal insufficiency (baseline cortisol level 1.8 µg/dl, increasing to 3.5 and 3.7 µg/dl at 20 and 30 min, respectively). The patient's general condition improved promptly after corticosteroid supplementation.

Elevated plasma glucose-dependent insulinotropic polypeptide associates with hyperinsulinemia in metabolic syndrome.

BACKGROUND AND AIMS: Metabolic syndrome (MS) is a high-risk condition for type 2 diabetes, a disease characterized by insulin resistance and insulin secretion abnormalities. Insulin resistance has been widely characterized in MS subjects while insulin secretion has been poorly investigated. The present study was hence undertaken to further investigate the α and ß cell function and entero-insular axis in this pre-diabetic condition. MATERIALS AND METHODS: Using 120' oral glucose tolerance test (OGTT, 75  g) and 60' intravenous glucose tolerance test (IVGTT, 0.3  g/kg), we studied α and ß cell function, insulin resistance, and incretin levels in 96 subjects with normal fasting glucose and normal glucose tolerance to OGTT, with (MS+, n=29) and without MS (MS-, n=67). RESULTS: MS+ individuals showed in comparison with MS-: higher insulinogenic index (IG30) and higher area under the curve (AUC) (0-120) for glucose and insulin during the OGTT, P<0.05; higher AUC (0-10) for glucose (P<0.05) but similar first phase insulin secretion (P=NS) as measured by ΔAIRG and AUC (0-10) for insulin during the IVGTT; increased AUC (0-60) for insulin during the IVGTT (P=0.04); higher GIP levels at 30' (P=0.03), 60' (P=0.01), 90' (P=0.003), and 120' (P=0.004); higher AUC (0-120) for GIP (P=0.007); similar AUC (0-120) for GLP-1 during the OGTT; and delayed glucagon suppression after the OGTT. CONCLUSION: NGT subjects with MS showed increased GIP secretion that could be responsible for the delayed glucagon suppression during the OGTT, thereby suggesting a role for incretins in regulating glucose homeostasis in this condition.