Hepatic steatosis, low-grade chronic inflammation and hormone/growth factor/adipokine imbalance

Non-alcoholic fatty liver disease (NAFLD), a further expression of metabolic syndrome, strictly linked to obesity and diabetes mellitus, is characterized by insulin resistance (IR), elevated serum levels of free fatty acids and fatty infiltration of the liver, which is known as hepatic steatosis. Hepatocyte apoptosis is a key feature of this disease and correlates with its severity. Free-fatty-acid-induced toxicity represents one of mechanisms for the pathogenesis of NAFLD and hormones, growth factors and adipokines influence also play a key role. This review highlights the various pathways that contribute to the development of hepatic steatosis. Circulating concentrations of inflammatory cytokines are reckoned to be the most important factor in causing and maintaining IR. Low-grade chronic inflammation is fundamental in the progression of NAFLD toward higher risk cirrhotic states.

What about non-alcoholic fatty liver disease as a new criterion to define metabolic syndrome?

Non-alcoholic fatty liver disease (NAFLD) is currently not a component of the diagnostic criteria for metabolic syndrome (MetS); however, the development of NAFLD has some common mechanisms with the development of MetS, as they share the pathophysiologic basis of insulin resistance. It is also recognized that NAFLD is the hepatic manifestation of MetS. To define MetS, the presence of at least three of the proposed criteria is required, and sometimes it is sufficient to have only one laboratory value, modified by diet or drugs, for the classification of MetS. Ultrasonographically-detected NAFLD (US-NAFLD) is more stable, only changing during the middle- to long-term. Although controversies over MetS continue, and considering that abdominal ultrasonography for diagnosing NAFLD has high specificity and guidelines to modify the natural course of NAFLD by diet composition or lifestyle have not yet been established, why should we not introduce US-NAFLD as a new criterion to define MetS?

Could inflammatory markers help diagnose nonalcoholic steatohepatitis?

BACKGROUND

Nonalcoholic fatty liver disease describes a set of conditions that range from fatty liver to nonalcoholic steatohepatitis (NASH), and is considered the hepatic manifestation of metabolic syndrome. Obesity and insulin resistance are strongly associated with systemic markers of inflammation.

OBJECTIVE

Focusing on this aspect, we have attempted to find a noninvasive method that could likely assess the presence of NASH and help to decide the liver biopsy performance.

METHODS

Using histology as a gold standard to diagnose nonalcoholic fatty liver disease, we consecutively studied 43 patients with NASH and 40 with fatty liver, comparing their data with those of 48 healthy control participants. The outcomes evaluated were ultrasonographic spleen longitudinal diameter coupled with the splenic artery resistive index, serum IL-6 and vascular endothelial growth factor concentrations.

RESULTS

The NASH group had higher spleen longitudinal diameter values (P=0.0001) as well as significantly higher IL-6 and vascular endothelial growth factor concentrations than the other groups (P=0.0001). The optimal cut-off value for spleen longitudinal diameter that best discriminated NASH from fatty liver patients was 116 mm (specificity 95% and sensitivity 88%); the sensitivity and specificity of this parameter was better than both IL-6 and vascular endothelial growth factor in the same setting (area under the receiver operating characteristic curve 0.920 vs. 0.817 and 0.678). Splenic artery resistive index was similar between patients with NASH and those with fatty liver, but differed when compared with controls, P=0.0001.

CONCLUSIONS

IL-6 was highly specific in confirming the absence of NASH at normal values. In our series, normal values of spleen longitudinal diameter and IL-6 were strongly associated with fatty liver.

Non-alcoholic fatty liver disease: further expression of the metabolic syndrome

Non-alcoholic fatty liver disease has been associated with metabolic disorders, including central obesity, dyslipidemia, hypertension and hyperglycemia. Metabolic syndrome, obesity, and insulin resistance are major risk factors in the pathogenesis of non-alcoholic fatty liver disease. Non-alcoholic fatty liver disease refers to a wide spectrum of liver damage, ranging from simple steatosis to non-alcoholic steatohepatitis, advanced fibrosis and cirrhosis.

A prospective study of acute drug-induced liver injury in patients suffering from non-alcoholic fatty liver disease

AIM

Liver damage due to facultative hepatotoxins is scarcely foreseeable. We evaluated the prevalence of acute drug-induced liver injury (DILI) in a specific setting, assessing eventual interactions with pre-existing hepatic illnesses.

METHODS

The research was carried out in an Italian tertiary care hospital, by analyzing 248 patients with non-advanced liver disease, divided into two well-matched groups: 174 patients (median age 53, 94 females) with hepatitis C virus-related chronic hepatitis; and 74 (median age 55, 39 females) with non-alcoholic fatty liver disease (NAFLD).

RESULTS

Six patients (2.4% of the whole population) belonging to the NAFLD group (chi(2)-test, P = 0.004) suffered from acute hepatoxicity related to the following drugs, that is antihypertensive, acting on platelet aggregation, antimicrobial, non-steroidal anti-inflammatory and proton pump inhibitor. The NAFLD presence was an independent risk factor in determining drug-related acute hepatitis, with an odds ratio of 3.95 (95% confidence intervals: 11.48-1.35). Central obesity was relevant in every patient with acute toxicity. Alcohol consumption and drug association did not influence the acute drug-induced liver damage.

CONCLUSION

NAFLD conveys a nearly fourfold increase of DILI risk in obese middle-aged patients. NAFLD, characterized by mitochondrial dysfunction, could predispose to drug-induced hepatotoxicity that probably shares the same pathophysiological mechanism.

JNKs, insulin resistance and inflammation: A possible link between NAFLD and coronary artery disease

The incidence of obesity has dramatically increased in recent years. Consequently, obesity and associated disorders such as nonalcoholic fatty liver disease constitute a serious problem. Therefore, the contribution of adipose tissue to metabolic homeostasis has become a focus of interest. In this review, we discuss the latest discoveries that support the role of lipids in nonalcoholic fatty liver disease. We describe the common mechanisms (c-Jun amino-terminal kinases, endoplasmic reticulum stress, unfolded protein response, ceramide, low-grade chronic inflammation) by which lipids and their derivatives impair insulin responsiveness and contribute to inflammatory liver and promote plaque instability in the arterial wall. Presenting the molecular mechanism of lipid activation of pro-inflammatory pathways, we attempt to find a link between nonalcoholic fatty liver disease, metabolic syndrome and cardiovascular diseases. Describing the common mechanisms by which lipid derivatives, through modulation of macrophage function, promote plaque instability in the arterial wall, impair insulin responsiveness and contribute to inflammatory liver and discussing the molecular mechanism of lipid activation of pro-inflammatory pathways, the key roles played by the proliferator-activated receptor and liver X receptor α, nuclear receptors-lipid sensors that link lipid metabolism and inflammation, should be emphasized. Further studies are warranted of anti-inflammatory drugs such as aspirin, anti-interleukin-6 receptors, immune-modulators (calcineurin inhibitors), substances enhancing the expression of heat shock proteins (which protect cells from endoplasmic reticulum stress-induced apoptosis), and anti- c-Jun amino-terminal kinases in well-designed trials to try to minimize the high impact of these illnesses, and the different expressions of the diseases, on the whole population.

Nonalcoholic Fatty Liver Disease: A Challenge from Mechanisms to Therapy

Focusing on previously published mechanisms of non-alcoholic fatty liver disease (NAFLD), their uncertainty does not always permit a clear elucidation of the grassroot alterations that are at the basis of the wide-spread illness, and thus curing it is still a challenge. There is somehow exceptional progress, but many controversies persist in NAFLD research and clinical investigation. It is likely that hidden mechanisms will be brought to light in the near future. Hereby, the authors present, with some criticism, classical mechanisms that stand at the basis of NAFLD, and consider contextually different emerging processes. Without ascertaining these complex interactions, investigators have a long way left ahead before finding an effective therapy for NAFLD beyond diet and exercise.

Systematic review on intervention with prebiotics/probiotics in patients with obesity-related nonalcoholic fatty liver disease

BACKGROUND

The gut microbiota is modulated by metabolic derangements, such as nutrition overload and obesity.

AIM

The aim of this systematic review is to summarize the role of these gut modifiers in nonalcoholic fatty liver disease (NAFLD) and obesity.

METHODS

A systematic search of MEDLINE (from 1946), PubMed (from 1946) and EMBASE (from 1949) databases through May 2014 was carried out to identify relevant articles. The search terms were 'probiotic' AND 'NAFLD', 'prebiotic' AND 'NAFLD', 'antibiotic' AND 'NAFLD', 'probiotics' AND 'obesity', 'prebiotic' AND 'obesity' or 'antibiotic' AND 'obesity'; these terms were searched as text word in 'clinical trials' and as exploded medical subject headings where possible.

RESULTS

The evidence in the literature is scant, due to the scarcity of appropriately powered, randomized, controlled clinical trials, involving various centers and population of different origin.

CONCLUSION

Although probiotics and prebiotics have been proposed in the treatment and prevention of patients with obesity-related NAFLD, their therapeutic use is not supported by high-quality clinical studies.

Association of NAFLD and Insulin Resistance with Non Metastatic Bladder Cancer Patients: A Cross-Sectional Retrospective Study

Among risk factors (apart from smoking) likely involved in bladder cancer (BCa), metabolic syndrome (MS), obesity and type 2 diabetes mellitus (T2DM) have been explored with contrasting results. In spite of these studies, there is little data on the association between nonalcoholic fatty liver disease (NAFLD), its main driver, i.e., insulin resistance (IR), and BCa. Implanting a cross-sectional retrospective study we tried to investigate both NAFLD and IR prevalence in a hospital based population of BCa patients. We studied laboratory data from 204 patients with histologically confirmed non metastatic BCa and 50 subjects with no BCa, but with bladder diseases (no Ca BD). We evaluated the presence of NAFLD by the triglycerides/glucose Index (TyG Index), using a cut-off of 0.59 and by the Aspartate Aminotransferase/Alanine Aminotransferase AST/ALT ratio. IR was assessed by the same TyG Index (cut-off 4.68) and the triglycerides/High-Density Lipoprotein HDL ratio (cut-off 2.197). The diagnosis of impaired fasting glucose (IFG), condition of prediabetes, as well as that of T2DM was assessed according to canonical guidelines. The TyG Index predicted NAFLD presence in both groups (p = 0.000), but the BCa group showed a major percentage of NAFLD cases with respect to no Ca BD group (59% versus 40%). A greater proportion of IR (47%) in BCa group than in no Ca BD one (37%) was evidenced by the TyG Index with its median value significantly different (p = 0.0092). This high rate of IR in the BCa group was confirmed by the triglycerides/HDL ratio (p = 0.02). Prediabetes and T2DM were more prevalent in the BCa group than no Ca BD group (p = 0.024). In this study a consistent NAFLD presence was found in BCa patients. This is an important comorbidity factor that deserves further consideration in prospective studies. The higher prevalence of NAFLD, IR, prediabetes and T2DM in the BCa group evidences the need that these disorders should be reckoned as adjunct factors that could impact on this cancerous disease.

Liver-spleen axis: intersection between immunity, infections and metabolism

Spleen has been considered a neglected organ so far, even though is strictly linked to liver. The spleen plays an important role in the modulation of the immune system and in the maintenance of peripheral tolerance via the clearance of circulating apoptotic cells, the differentiation and activation of T and B cells and production of antibodies in the white pulp. Moreover, splenic macrophages are able to remove bacteria from the blood and protect from sepsis during systemic infections. We review the spleen function and its assessment in humans starting from the description of spleen diseases, ranging from the congenital asplenia to secondary hyposplenism. From the literature data it is clear that obesity in humans affects different compartments of immune system, even thought there are still few data available on the implicated mechamisms. The intent is to enable clinicians to evaluate the newly recognized role of metabolic and endocrine functions of the spleen with special emphasis to obesity and nonalcoholic fatty liver disease in the context of the available literature. Moreover, understanding the spleen function could be important to develop appropriate prevention strategies in order to counteract the pandemia of obesity. In this direction, we suggest spleen longitudinal diameter at ultrasonography, as simple, cheap and largely available tool, be used as new marker for assessing splenic function, in the context of the so-called liver-spleen axis.

Spleen: A new role for an old player?

The spleen could be considered a neglected organ. To date, it has been deemed an ancillary organ in portal hypertension or an organ localization in lymphoproliferative diseases, even though it has had significant attention in infectious diseases for some time. Now, it is thought to be central in regulating the immune system, a metabolic asset and involved in endocrine function with regard to nonalcoholic fatty liver disease. The main mechanisms involved in this complex network will be critically discussed in this article.

Drug-induced liver injury: is it somehow foreseeable?

The classic view on the pathogenesis of drug-induced liver injury is that the so-called parent compounds are made hepatotoxic by metabolism (formation of neo-substances that react abnormally), mainly by cytochromes P-450 (CYP), with further pathways, such as mitochondrial dysfunction and apoptosis, also playing a role. Risk factors for drug-induced liver injury include concomitant hepatic diseases, age and genetic polymorphisms of CYP. However, some susceptibility can today be predicted before drug administration, working on the common substrate, by phenotyping and genotyping studies and by taking in consideration patients' health status. Physicians should always think of this adverse effect in the absence of other clear hepatic disease. Ethical and legal problems towards operators in the health care system are always matters to consider.

Inhibition of the mTOR pathway: a possible protective role in coronary artery disease

The main approach to obesity and type-II diabetes is to unravel the mechanisms involved in nutrient absorption and fuel allocation. In conditions of over-nutrition, cells must cope with a multitude of extracellular signals generated by changes in nutrient load, hormonal milieu, adverse cytokine/adipokine profile, and apoptosis/anti-apoptosis processes. To date studies have demonstrate that among all nutrients, lipids and carbohydrates play a major regulatory role in the gene transcription of glycolytic and lipogenic enzymes, insulin, and adipokines. These nutrients mainly exert their effects through the gene expression of sterol responsive binding protein 1 and 2 (SREBP) and the mammalian target of rapamycin (mTOR). Excess of adipose tissue is known to confer a significantly higher risk of coronary artery disease. Administration of rapamycin effectively attenuated inflammation, inhibited progression, and enhanced stability of atherosclerotic plaques in animal models. Herein we discuss the mTOR pathway and the molecular mechanisms of mTOR inhibitors, hypothesizing a possible protective role in atherosclerosis, taking into account also previous clinical studies emphasizing their opposite role.

What are the implications of the spontaneous spleno-renal shunts in liver cirrhosis?

BACKGROUND

Although significant advances are expected to be made in the assessment of the portal hypertension-related complications, the prognostic role of spleno-renal shunts has not been fully explored so far. Clarifying this aspect could help tackle the life-treating events occurring in patients suffering from liver cirrhosis. The aim of the study was to analyze the relationships between the spleno-renal shunts presence at doppler ultrasound and the liver cirrhosis complications.

DESIGN

eighty one patients out of 129 formed the study population (35 females). Chronic liver damage in these patients was caused by HCV (66), HBV (2), alcohol abuse (2) or unknown etiology, likely non-alcoholic steatohepatitis (11).

SETTING

two Liver Units of university/primary hospitals in Southern Italy.

MAIN OUTCOME MEASURES

grading of esofageal varices; detection of ascites: assessment of hepatic encephalopathy; evaluation of liver cirrhosis severity; tracking hepatocellular carcinoma; doppler features of spleno-renal shunts and splenic flow velocity; spleen longitudinal diameter at sonography.

RESULTS

The prevalence of spleno-renal shunts was 18.5%, without no difference concerning the etiology (HCV versus non-HCV, p = 0.870); the prevalence of hepatocellular carcinoma in patients with spleno-renal shunts was superior to that of patients without them (Pearson Chi-square, p = 0.006, power of sample size 74%), also after adjustment for liver decompensation (p = 0.024). The median score of hepatic encephalopathy in patients with and without spleno-renal shunts was similar, i.e., 0 (range, 0-2) versus 0 (0 - 3), p = 0.67. The median splenic vein flow velocity in patients with spleno-renal shunts was significantly inferior to that of patients without them, i.e., 13 cm/sec (95% confidence intervals, 6-18) versus 21 cm/sec (17-24), p < 0.0001. By far the largest percentage of large esophageal varices was in patients without spleno-renal shunts (p = 0.005). In contrast, the frequency of ascites and hepatic encephalopathy severity was overlapping in the two groups. BMI values but not Child-Pugh's classification predicted spleno-renal shunts (Ors = 1.84, 95% confidence intervals = 1.28-2.64, p = 0.001 and 1.145, 95% confidence intervals = 0.77-1.51, p = 0.66).

CONCLUSION

Taking into consideration the relatively small sample size, patients with spleno-renal shunts are burdened by an increased incidence of hepatocellular carcinoma. BMI predicted the spleno-renal shunts presence.

Is serum Interleukin-17 associated with early atherosclerosis in obese patients?

Atherosclerosis is a chronic inflammatory process of the vessel walls, and CD4+ T-cells are peculiar to both human and murine atherosclerotic lesions. There is a recent line of research favoring hypothetic allergic mechanisms in the genesis of atherosclerosis and, consequently, coronary artery disease (CAD), among which Interleukin (IL)-17 appears to be a key cytokine regulating local tissue inflammation. The objective was to add a piece of information on the role of IL-17 in the genesis of atherosclerosis. Eighty obese patients with normal liver enzyme levels but presenting with ultrasonographic evidence of NAFLD formed the population of this cross-sectional study. Anthropometric measures, data on excess adiposity, metabolic profile, serum concentrations of IL-17, eotaxin-3, IL-8, and CCL4/MIP1β, C-reactive protein, fibrinogen, ferritin, TNF-α, as well carotid intima-media thickness (IMT), a marker of atherosclerosis, and the main risk factors for CAD, such as blood pressure and smoking status, but also less determinant ones such as degree of NAFLD severity, Intramuscular Triglyceride storage and Resting Metabolic Rate were evaluated. Serum concentrations of Il-17 were detected as related to those of inflammatory cytokines, IL-6, IFN-γ and TNF-α. Furthermore, circulating levels of IL-17 were linked to those mirroring allergic process, IL-8, CCL4/MIP1β and eotaxin. Early atherosclerosis, evidenced as increased IMT, was not associated with circulating IL-17 levels. At multiple regression,IMT was predicted, other than by age, by the amount of the visceral adiposity, expressed as visceral adipose tissue at ultrasonography, and by serum eotaxin. In conclusion, a strong relationship was found between the IL-17-related chemokine eotaxin and IMT. The association found between the amount of visceral fat and circulating levels of eotaxin on the one hand, and IMT on the other, could reinforce the hypothesis that IL-17, released by the visceral adipose tissue, induces eotaxin secretion via the smooth muscle cells present in the atheromatosus vessels.

Sarcopenia, a condition shared by various diseases: can we alleviate or delay the progression?

Sarcopenia is a severe condition common to various chronic diseases and it is reckoned as a major health problem. It encompasses many different molecular mechanisms that have been for a while discovered but not definitely clarified. Although sarcopenia is a disability status that leads to serious health consequences, the scarcity of suitable animal models has curtailed research addressing this disorder. Another limitation in the field of clinical investigation of sarcopenic patients is the lack of a generally accepted definition coupled with the difficulty of adopting common diagnostic criteria. In fact, both do not permit to clarify the exact prevalence rate and consequently limit physicians to establish any kind of therapeutical approach or, when possible, to adopt preventive measures. Unfortunately, there is no standardized cure, apart from doing more physical activity and embracing a balanced diet, but newly discovered substances start being considered. In this review, authors try to give an overview addressing principal pathways of sarcopenia and offer critical features of various possible interventions.

Blood ammonia levels in liver cirrhosis: a clue for the presence of portosystemic collateral veins

BACKGROUND

Portal hypertension leads to the formation of portosystemic collateral veins in liver cirrhosis. The resulting shunting is responsible for the development of portosystemic encephalopathy. Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity. So, it has become partially obsolete. Realizing the need for non-invasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, we came back to determine whether there was a correlation between blood ammonia concentrations and the detection of portosystemic collateral veins, also evaluating splenomegaly, hypersplenism (thrombocytopenia) and the severity of liver cirrhosis.

METHODS

One hundred and fifty three consecutive patients with hepatic cirrhosis of various etiologies were recruited to participate in endoscopic and ultrasonography screening for the presence of portosystemic collaterals mostly esophageal varices, but also portal hypertensive gastropathy and large spontaneous shunts.

RESULTS

Based on Child-Pugh classification, the median level of blood ammonia was 45 mcM/L in 64 patients belonging to class A, 66 mcM/L in 66 patients of class B and 108 mcM/L in 23 patients of class C respectively (p < 0.001).The grade of esophageal varices was concordant with venous ammonia levels (rho 0.43, p < 0.001). The best area under the curve was given by ammonia concentrations, i, e., 0.78, when comparing areas of ammonia levels, platelet count and spleen longitudinal diameter at ultrasonography. Ammonia levels predicted hepatic decompensation and ascites presence (Odds Ratio 1.018, p < 0.001).

CONCLUSION

Identifying cirrhotic patients with high blood ammonia concentrations could be clinically useful, as high levels would lead to suspicion of being in presence of collaterals, in clinical practice of esophageal varices, and pinpoint those patients requiring closer follow-up and endoscopic screening.

It Is High Time Physicians Thought of Natural Products for Alleviating NAFLD. Is There Sufficient Evidence to Use Them?

Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease all over the world due to the obesity pandemic; currently, therapeutic options for NAFLD are scarce, except for diet recommendations and physical activity. NAFLD is characterized by excessive accumulation of fat deposits (>5%) in the liver with subsequent inflammation and fibrosis. Studies in the literature show that insulin resistance (IR) may be considered as the key mechanism in the onset and progression of NAFLD. Recently, using natural products as an alternative approach in the treatment of NAFLD has drawn growing attention among physicians. In this review, the authors present the most recent randomized controlled trials (RCTs) and lines of evidence from animal models about the efficacy of nutraceutics in alleviating NAFLD. Among the most studied substances in the literature, the following molecules were chosen because of their presence in the literature of both clinical and preclinical studies: spirulina, oleuropein, garlic, berberine, resveratrol, curcumin, ginseng, glycyrrhizin, coffee, cocoa powder, epigallocatechin-3-gallate, and bromelain.

Enhanced serum concentrations of transforming growth factor-beta1 in simple fatty liver: is it really benign?

BACKGROUND

Inside the spectrum of non-alcoholic fatty liver disease, simple fatty liver is generally thought of as being "non progressive", differently from non-alcoholic steatohepatitis, which increases in severity due to the presence of apoptosis/inflammation and fibrosis. The "benignity" of fatty liver is widely accepted but conceptually difficult to maintain because the mechanisms underlying this entity are the same ones that determine the more severe form.Findings provide evidence that iron overload is associated with increased liver damage and collagen deposition. Transforming growth factor-beta1 released by hepatic stellate cells during chronic liver injury plays a critical role in liver apoptosis and fibrogenesis.

OBJECTIVE

To verify whether both the forms of non-alcoholic fatty liver disease were really dissimilar, evaluating the serum profile of two key parameters, indexes of severity.

METHODS

A total of 123 patients (57 females) participated, forming three groups: forty five patients with fatty liver, 42 patients with non-alcoholic steatohepatitis and 36 with chronic hepatitis C. All had a biopsy-proven diagnosis.

MEASUREMENTS

Serum concentrations of transforming growth factor-beta1 and ferritin.

RESULTS

High concentrations of transforming growth factor-beta1 were noticed in patients suffering from both fatty liver and non-alcoholic steatohepatitis, 129.1 (45.4) versus 116.8 (42.2) ng/mL, P = 0.2; they were significantly superior to those of chronic hepatitis C patients 87.5 (39.5) ng/mL, P < 0.001. Ferritin levels were on average above normal values and similar in the three groups (P = 0.9), also when adjusted for gender (P = 0.5) and age (P = 0.3).

CONCLUSION

No difference between serum concentrations of transforming growth factor-beta1 and ferritin in fatty liver and non-alcoholic steatohepatitis suggests that these forms share more common aspects, regarding their progression, than previously thought.

Bisphenol A in polycystic ovary syndrome and its association with liver-spleen axis

CONTEXT

Bisphenol A, one of the highest-volume chemicals currently available, is known to act as endocrine disruptor and alters several metabolic functions, including inflammatory pathways. Elevated serum levels of bisphenol A have been found in women with polycystic ovary syndrome (PCOS) and a role of low-grade chronic inflammation has been recently reported in the pathogenesis of this syndrome. Increased spleen volume, a reliable and stable index of chronic inflammation, was strictly associated with the severity of hepatic steatosis (HS) in obese subjects, determining the so-called liver-spleen axis.

OBJECTIVE

To evaluate the contribution of increased serum bisphenol A levels to low-grade chronic inflammation, HS and hyperandrogenism in women with PCOS.

DESIGN, SETTING AND PARTICIPANTS

Forty lean and overweight/obese premenopausal women with PCOS and 20 healthy age-matched women were consecutively enrolled in a cross-sectional study from 2009 to 2011 at the Federico II University Hospital in Naples.

MEASUREMENTS

Bisphenol A, homoeostasis model assessment of insulin resistance (HoMA-IR), laboratory liver tests, testosterone, sex hormone-binding globulin, free androgen index (FAI), C-reactive protein, interleukin-6, and the ultrasound quantification of HS and spleen longitudinal diameter.

RESULTS

Independently of body weight, higher bisphenol A levels in PCOS women were associated with higher grades of insulin resistance, HS, FAI and inflammation, spleen size showing the best correlation. At multivariate analysis, spleen size and FAI were the best predictors of bisphenol A (β coefficients 0.379, P = 0.007 and 0.343, P = 0.014, respectively).

CONCLUSIONS

In premenopausal women with PCOS, we evidenced an association of serum bisphenol A levels with HS and markers of low-grade inflammation, in particular with spleen size, unravelling the presence of the liver-spleen axis in this syndrome.

Serum Bcl-2 concentrations in overweight-obese subjects with nonalcoholic fatty liver disease

AIM

To shed some light on the relationship between anti-apoptotic serum Bcl-2 concentrations and metabolic status, anthropometric parameters, inflammation indices, and non-alcoholic fatty liver disease severity were investigated in 43 young individuals with fatty liver (FL) and 41 with nonalcoholic steatohepatitis (NASH).

METHODS

Circulating levels of Bcl-2 were detected in 84 patients with ultrasonographic findings of "bright liver" and/or hyper-transaminasemia of unknown origin and/or increase in γ-glutamyl-transpeptidase (γ-GT) strictly in the absence of other acute or chronic liver disease, whose age was not advanced, who gave consent to liver biopsy and were then divided on the basis of the histological results into two groups (43 with FL and 41 with NASH). Twenty lean subjects, apparently healthy and young, were chosen as controls.

RESULTS

Serum Bcl-2 concentrations were significantly higher in the FL group than in the NASH group. Insulin resistance and γ-GT activity were significantly higher in NASH subjects. Apoptotic hepatocytes were significantly more numerous in NASH patients. NASH patients presented with larger spleens and augmented C-reactive protein (CRP) concentrations than healthy subjects. Steatosis grade at histology was similar in both NASH and FL populations. The number of apoptotic cells was significantly related to anti-apoptotic Bcl-2 protein values in FL patients. Bcl-2 serum levels positively correlated to body mass index (BMI) values (P ≤ 0.0001) but not to age of the population. Triglycerides/HDL ratio correlated well to waist circumference in males (P = 0.0008). γ-GT activity was associated with homeostatic metabolic assessment (HOMA) (P = 0.0003) and with serum ferritin (P = 0.02). Bcl-2 concentrations were not related to either spleen size or CRP values. NASH patients presented a weak negative correlation between lobular inflammation and Bcl-2 levels. A prediction by low values of serum Bcl-2 towards a greater presence of metabolically unhealthy overweight/obese patients (MUOs) was evidenced. HOMA, BMI and uric acid, in that sequence, best predicted serum Bcl-2 concentrations.

CONCLUSION

MUOs could be detected by Bcl-2 levels. By favoring the life span of hepatocytes, and enhancing triglyceride formation, the anti-apoptotic process inhibits free fatty acids toxicity in FL.

Circulating levels of sirtuin 4, a potential marker of oxidative metabolism, related to coronary artery disease in obese patients suffering from NAFLD, with normal or slightly increased liver enzymes

The present study shows low circulating levels of SIRT4 in obese patients with nonalcoholic fatty liver disease mirroring its reduced mitochondrial expression in an attempt to increase the fat oxidative capacity and then the mitochondrial function in liver and in muscle. SIRT4 modulates the metabolism of free fatty acids reducing their high circulating levels but, unfortunately, increasing ROS production. Great concentration of free fatty acids, released by adipose tissue, coupled with oxidative stress, directly results in endothelial dysfunction, early atherosclerosis, and coronary artery disease risk factor.

Could SCGF-Beta Levels Be Associated with Inflammation Markers and Insulin Resistance in Male Patients Suffering from Obesity-Related NAFLD?

One of the pathologic hallmarks of obesity is macrophage infiltration of adipose tissue that has been confirmed as source of multipotent adult stem cells. Stem cell growth factor-beta (SCGF-β) shows activity on granulocyte/macrophage progenitor cells in combination with granulocyte macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF). Obesity-associated inflammation induces insulin resistance (IR), which is central to nonalcoholic fatty liver disease (NAFLD) or hepatic steatosis (HS). We searched for relationship between levels of SCGF-β and those of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-β (TNF-β), interleukin-12p40 (IL-12p40), interleukin-10 (IL-10), ferritin, GM-CSF and M-CSF and between SCGF-β concentrations and IR in obese patients with HS. Eighty obese patients were retrospectively studied. Serum cytokines levels were appreciated by magnetic bead-based multiplex immunoassays. IR was evaluated by homeostatic model assessment (HOMA), HOMA-derived β-cell function (HOMA-B%), quantitative insulin sensitivity check Index (QUICKI) and single point insulin sensitivity estimator (SPISE). HS and spleen volume were assessed by ultrasonography (US). SCGF-β and IL-6 levels predicted HOMA values (p = 0.032 and 0.041, respectively) only in males. In male patients, CRP and IL-6 levels (p = 0.007) predicted SCGF-β concentrations (p = 0.03 and 0.007, respectively), which in turn predicted HS at US, p = 0.037. SCGF-β levels were linked to IR and HS severity with the mediation role of CRP. IL-10 levels negatively predicted SCGF-β concentrations (p = 0.033). M-CSF levels predicted serum concentration of both TNF-β and IL-12p40 (p = 0.00), but did not predict serum IL-10 (p = 0.30). Prediction of HOMA values by SCGF-β levels, likely mediated by markers of inflammation, characterizes this study, shedding some light on mechanisms inducing/worsening IR of male patients with obesity-related NAFLD.

Pathogenesis of hepatic steatosis: the link between hypercortisolism and non-alcoholic fatty liver disease

Based on the available literature, non alcoholic fatty liver disease or generally speaking, hepatic steatosis, is more frequent among people with diabetes and obesity, and is almost universally present amongst morbidly obese diabetic patients. Non alcoholic fatty liver disease is being increasingly recognized as a common liver condition in the developed world, with non alcoholic steatohepatitis projected to be the leading cause of liver transplantation. Previous data report that only 20% of patients with Cushing's syndrome have hepatic steatosis. Aiming at clarifying the reasons whereby patients suffering from Cushing's syndrome - a condition characterized by profound metabolic changes - present low prevalence of hepatic steatosis, the Authors reviewed the current concepts on the link between hypercortisolism and obesity/metabolic syndrome. They hypothesize that this low prevalence of fat accumulation in the liver of patients with Cushing's syndrome could result from the inhibition of the so-called low-grade chronic-inflammation, mainly mediated by Interleukin 6, due to an excess of cortisol, a hormone characterized by an anti-inflammatory effect. The Cushing's syndrome, speculatively considered as an in vivo model of the hepatic steatosis, could also help clarify the mechanisms of non alcoholic fatty liver disease.

Young adult obese subjects with and without insulin resistance: what is the role of chronic inflammation and how to weigh it non-invasively?

BACKGROUND

Obesity is a leading risk factor for metabolic syndrome whose further expression is non-alcoholic fatty liver disease. Metabolic syndrome is associated with a proinflammatory state that contributes to insulin resistance. Finally, a "metabolically benign obesity" that is not accompanied by insulin resistance has recently been postulated to exist.

AIM

To find whether any inflammation markers were independently associated with the presence of insulin resistance, evaluating specific anthropometric, ultrasonographic and laboratory parameters in a population of young adult obese subjects.

METHODS

Of forty two young individuals, divided into two groups (with or without insulin resistance), were studied serum C-reactive protein and fibrinogen as indexes of chronic pro-inflammatory status. Body mass index, waist circumference and metabolic syndrome presence were assessed as part of the metabolic evaluation. Ultrasonography weighted visceral and subcutaneous abdominal fat thickness, spleen size as longitudinal diameter and liver hyperechogenicity.

RESULTS AND DISCUSSION

Serum C-reactive protein and fibrinogen as well as spleen longitudinal diameter were significantly increased in the obese young with insulin resistance compared to non-insulin resistance group. Insulin resistance was significantly associated with hepatic steatosis score at sonography (r = 0.33, P = 0.03), spleen longitudinal diameter (r = 0.35, P = 0.02) and C-reactive protein (r = 0.38, P = 0.01), but not with body mass index, visceral or subcutaneous abdominal adipose tissue, waist circumference and fibrinogen (P = 0.18, 0.46, 0.33, 0.37 and 0.4, respectively). Steatosis score at sonography was well associated with spleen volume (rho = 0.40, P = 0.01) and C-reactive protein levels (rho = 0.49, P = 0.002). Metabolic syndrome was much more frequent in obese patients with insulin resistance. These findings show that in young adults the only abdominal adiposity without insulin resistance, plays a scarce role in determining hepatic steatosis as well as metabolic syndrome.

CONCLUSION

Increases in spleen size and CRP levels represent a reliable tool in diagnosing insulin resistance.