Fatty liver: How frequent is it and why?

There is increasing evidence that fatty liver may be the most frequent liver disorder in Western countries. However, the epidemiology of fatty liver is still not fully understood and there is a clear need of better assessing and defining the potential role of the risk factors identified by clinical series in the general population. This article reviews the available data on the epidemiology of fatty liver and addresses some important questions that should be answered in much needed future research

Hepatology highlights

n/

qeios in a nutshell

Qeios gives researchers the power to produce and share with everyone the best possible knowledge

Qeios

n/

Estimation of percentage body fat in 6- to 13-year-old children by skinfold thickness, body mass index and waist circumference

We evaluated the accuracy of skinfold thicknesses, BMI and waist circumference for the prediction of percentage body fat (PBF) in a representative sample of 372 Swiss children aged 6-13 years. PBF was measured using dual-energy X-ray absorptiometry. On the basis of a preliminary bootstrap selection of predictors, seven regression models were evaluated. All models included sex, age and pubertal stage plus one of the following predictors: (1) log-transformed triceps skinfold (logTSF); (2) logTSF and waist circumference; (3) log-transformed sum of triceps and subscapular skinfolds (logSF2); (4) log-transformed sum of triceps, biceps, subscapular and supra-iliac skinfolds (logSF4); (5) BMI; (6) waist circumference; (7) BMI and waist circumference. The adjusted determination coefficient (R _{adj}^{2} ) and the root mean squared error (RMSE; kg) were calculated for each model. LogSF4 (R _{adj}^{2} 0·85; RMSE 2·35) and logSF2 (R _{adj}^{2} 0·82; RMSE 2·54) were similarly accurate at predicting PBF and superior to logTSF (R _{adj}^{2} 0·75; RMSE 3·02), logTSF combined with waist circumference (R _{adj}^{2} 0·78; RMSE 2·85), BMI (R _{adj}^{2} 0·62; RMSE 3·73), waist circumference (R _{adj}^{2} 0·58; RMSE 3·89), and BMI combined with waist circumference (R _{adj}^{2} 0·63; RMSE 3·66) (P<0·001 for all values of R _{adj}^{2} ). The finding that logSF4 was only modestly superior to logSF2 and that logTSF was better than BMI and waist circumference at predicting PBF has important implications for paediatric epidemiological studies aimed at disentangling the effect of body fat on health outcome

On the operational definition of fatty liver

n/

exposure to antiresorptive therapy with bisphosphonates does not induce histological changes in human alveolar jawbone

Aim: The identification of specific alterations in the alveolar jawbone of patients treated with nitrogen-containing bisphosphonates (NBP) but without bisphosphonate-related osteonecrosis of the jaw (BRONJ) may help to identify the early steps of BRONJ and to select patients at risk for it. Materials and Methods: We performed a case-control study. Cases were 60 individuals treated with NBP without clinical and radiological signs of BRONJ and requiring surgical tooth extraction. Controls were 60 individuals never treated with NBP and requiring tooth extraction. Cases and controls were matched by sex (same) and age (within 5 years). 18 categorical (basophile reversal lines, osteoblasts, osteoblastic lines, osteocytes, empty osteocytic lacunae, osteoclasts, Howship's lacunae, vessel dilatation, vascular congestion, arteriolar thickening, intravascular fat globules, calcific fat necrosis, fatty bone marrow, ruptured adipocytes, granular cytoplasm of adipocytes, oil cysts, perivascular fibrosis, diffuse fibrous metaplasia) and 2 ordinal histopathological variables (inflammation and bone maturation) were investigated. Exact univariable and multivariable (correction for gender and age) logistic regression was used to test the association between NBP use and the histopathological variables. Because of multiple comparisons, the critical p-value was set to 0.0025 (0.05/20). Results: Cases and controls did not differ for any study variable except for vascular congestion that was significantly associated with NBP use (multivariable OR = 0.24, exact 95% CI 0.10 to 0.57 for cases vs. controls, p = 0.0006). Conclusions: Use of NBP does not produce specific histological alveolar bone alterations in the absence of overt BRONJ disease

Chronic treatment with fluoxetine up-regulates cellular BDNF mRNA expression in rat dopaminergic regions.

During the last few years several studies have highlighted the possibility that major depression can be characterized by a general reduction in brain plasticity and an increased vulnerability under challenging situations. Such dysfunction may be the consequence of reduced expression and function of proteins important for neuroplasticity such as brain-derived neurotrophic factor (BDNF). On this basis, by using a sensitive non-radioactive in-situ hybridization, we evaluated the effects of a chronic treatment with fluoxetine on BDNF expression within rat dopaminergic regions. In fact, besides the well-established role of the hippocampus, increasing evidence indicates that other brain regions may be involved in the pathophysiology of depression and consequently be relevant for the therapeutic action of antidepressant drugs. Our results indicate that 3 wk of fluoxetine administration up-regulates BDNF mRNA levels selectively within structures belonging to the meso-cortico-limbic pathway. The expression of the neurotrophin is significantly increased in the ventral tegmental area, prefrontal cortex, and shell region of the nucleus accumbens, whereas no changes were detected in the substantia nigra and striatum. Moreover, in agreement with previous studies, fluoxetine increased BDNF mRNA levels in the hippocampus, an effect that was limited to the cell bodies without any change in its dendritic targeting. These data show that chronic treatment with fluoxetine increases BDNF gene expression not only in limbic areas but also in dopaminergic regions, suggesting that such an effect may contribute to improve the function of the dopaminergic system in depressed subjects

Metabolic correlates of subcutaneous and visceral abdominal fat measured by ultrasonography: a comparison with waist circumference

Background: The relative contribution of visceral (VAT) and subcutaneous (SAT) adipose tissue to cardiometabolic disease is controversial. The aim of this study was to evaluate whether dissecting abdominal fat in VAT and SAT using US may detect stronger and more specific association with MS, MS components, hyperuricemia and altered liver enzymes compared to waist circumference. Methods: We performed a cross-sectional study on 2414 subjects aged 18 to 66 years (71 % women) followed at the International Center for the Assessment of Nutritional Status (ICANS, Milan, Italy). VAT and SAT were measured using ultrasonography. Multivariable logistic regression controlling for age and gender was used to evaluate the association of the parameters of interest (waist circumference (WC), VAT, SAT and VAT + SAT) with the MS (international harmonized definition), its components (high triglycerides, low HDL, high blood pressure, high glucose), high uric acid (>= 7 mg/dl), high alanine transaminase (ALT, >= 30 U/l) and high gamma-glutamyl-transferase (GGT, >= 30 U/l). Results: VAT was independently associated with all the outcomes of interest, while SAT was independently associated with MS and only with high blood pressure and high ALT when we considered the single parameters of MS and NAFLD. VAT had the strongest association with high triglycerides, high ALT and high GGT. The VAT + SAT association had the strongest association with MS. WC had the strongest association with low HDL and high blood pressure. VAT and WC were similarly associated to high glucose and high uric acid. Conclusion: US-determined VAT and SAT are both independently associated with MS. Moreover, to our knowledge, we are the first to show that VAT, being associated to all of the MS components in addition to hyperuricemia and altered liver enzymes, performs equally or better than WC except for high blood pressure and low HDL

Systematic review and meta-analysis on the adverse events of rimonabant treatment: Considerations for its potential use in hepatology

<p>Abstract</p> <p>Background</p> <p>The cannabinoid-1 receptor blockers have been proposed in the management of obesity and obesity-related liver diseases (fatty liver as NAFLD or NASH). Due to increasing number of patients to be potentially treated and the need to assess the advantage of this treatment in terms of risk/benefit, we analyze the side events reported during the treatment with rimonabant by a systematic review and meta-analysis of all randomized controlled studies.</p> <p>Methods</p> <p>All published randomized controlled trials using rimonabant <it>versus </it>placebo in adult subjects were retrieved. Relative risks (RR) with 95% confidence interval for relevant adverse events and number needed to harm was calculated.</p> <p>Results</p> <p>Nine trials (n = 9635) were considered. Rimonabant 20 mg was associated with an increased risk of adverse event (RR 1.35; 95%CI 1.17-1.56), increased discontinuation rate (RR 1.79; 95%CI 1.35-2.38), psychiatric (RR 2.35; 95%CI 1.66-3.34), and nervous system adverse events (RR 2.35; 95%CI 1.49-3.70). The number needed to harm for psychiatric adverse events is 30.</p> <p>Conclusion</p> <p>Rimonabant is associated with an increased risk of adverse events. Despite of an increasing interest for its use on fatty liver, the security profile and efficacy it is needs to be carefully assessed before its recommendation. At present the use of rimonabant on fatty liver cannot be recommended.</p