NAFLD is one of the most important causes of liver disease worldwide and will probably emerge as the leading cause of end-stage liver disease in the coming decades, with the disease affecting both adults and children. The epidemiology and demographic characteristics of NAFLD vary worldwide, usually parallel to the prevalence of obesity, but a substantial proportion of patients are lean. The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy. Furthermore, individuals with NAFLD have a high frequency of metabolic comorbidities and could place a growing strain on health-care systems from their need for management. While awaiting the development effective therapies, this disease warrants the attention of primary care physicians, specialists and health policy makers.

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Global burden of NAFLD and NASH: trends, predictions, risk factors and prevention

SUMMARY Background Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease, and its worldwide prevalence continues to increase with the growing obesity epidemic. This study assesses the epidemiology of NAFLD in adults based on clinical literature published over the past 30 years. Aim To review epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults based on clinical literature published over the past 30 years. Methods An in-depth search of PubMed (1980–2010) was based on five search terms: ‘nonalcoholic fatty liver disease’ OR ‘non-alcoholic steatohepatitis’ OR ‘fatty liver’ OR ‘steatosis’ AND ‘incidence’ [MeSH Terms] OR ‘prevalence’ [MeSH Terms] OR ‘natural history’. Studies of paediatric cohorts were excluded. Articles were categorised by topic and summarised, noting generalisations concerning their content.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2036.2011.04724.x

Systematic review: the epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults.

https://aasldpubs.onlinelibrary.wiley.com/doi/epdf/10.1002/hep.21496

The NAFLD fibrosis score: A noninvasive system that identifies liver fibrosis in patients with NAFLD

Fatty liver (FL) is the most frequent liver disease in Western countries. We used data from the Dionysos Nutrition & Liver Study to develop a simple algorithm for the prediction of FL in the general population. 216 subjects with and 280 without suspected liver disease were studied. FL was diagnosed by ultrasonography and alcohol intake was assessed using a 7-day diary. Bootstrapped stepwise logistic regression was used to identify potential predictors of FL among 13 variables of interest [gender, age, ethanol intake, alanine transaminase, aspartate transaminase, gamma-glutamyl-transferase (GGT), body mass index (BMI), waist circumference, sum of 4 skinfolds, glucose, insulin, triglycerides, and cholesterol]. Potential predictors were entered into stepwise logistic regression models with the aim of obtaining the most simple and accurate algorithm for the prediction of FL. An algorithm based on BMI, waist circumference, triglycerides and GGT had an accuracy of 0.84 (95%CI 0.81–0.87) in detecting FL. We used this algorithm to develop the "fatty liver index" (FLI), which varies between 0 and 100. A FLI < 30 (negative likelihood ratio = 0.2) rules out and a FLI ≥ 60 (positive likelihood ratio = 4.3) rules in fatty liver. FLI is simple to obtain and may help physicians select subjects for liver ultrasonography and intensified lifestyle counseling, and researchers to select patients for epidemiologic studies. Validation of FLI in external populations is needed before it can be employed for these purposes.

/pdf/the-fatty-liver-index-a-simple-and-accurate-predictor-of-1rxiltoz3l.pdf

The Fatty Liver Index: a simple and accurate predictor of hepatic steatosis in the general population

The metabolic syndrome is a multiplex risk factor that consists of several risk correlates of metabolic origin. In addition, to dyslipidemia, hypertension, and hyperglycermia, the syndrome carries a prothrombotic state and a proinflammatory state. Persons with the metabolic syndrome are at essentially twice the risk for cardiovascular disease compared with those without the syndrome. It further raises the risk for type 2 diabetes by about 5-fold. Although some investigators favor keeping risk factors separate for purposes of clinical management, others believe that identifying individuals with an aggregation of risk factors provides additional useful information to guide clinical management. In particular it focuses attention on obesity and sedentary life habits that are the root of the syndrome. This review addresses the prevalence of this clustering phenomenon throughout the world. Such seems appropriate because of the increasing prevalence of obesity in almost all countries. The available evidence indicates that in most countries between 20% and 30% of the adult population can be characterized as having the metabolic syndrome. In some populations or segments of the population, the prevalence is even higher. On the other hand, in parts of developing world in which young adults predominate, the prevalence is lower; but with increasing affluence and aging of the population, the prevalence undoubtedly with rise.

Metabolic Syndrome Pandemic

https://www.journal-of-hepatology.eu/article/S0168-8278(05)00279-5/pdf

Prevalence of and risk factors for fatty liver in a general population of Shanghai, China.

Background and Aim:  To explore the relationship between fatty liver and the metabolic syndrome in the adults of Shanghai and evaluate the value of fatty liver as a marker for risk factor clustering.

Methods:  Questionnaires, physical examinations, laboratory tests (blood lipid and glucose) and real-time liver ultrasonographies were performed in Shanghai adults and analyzed using randomized, multistage, stratified cluster sampling. Prevalence of the metabolic syndrome was defined by the National Cholesterol Education Program–Adult Treatment Panel III (NCEP-ATPIII) criteria with the exception of abdominal obesity (waist circumference > 90 cm in men and > 80 cm in women); fatty liver was diagnosed in accordance with the presence of an ultrasonographic pattern consistent with ‘bright’ liver (brightness and posterior attenuation of liver).

Results:  The study population consisted of 3175 subjects (1218 men) with a mean (± SD) age of 52.4 ± 15.1 years. Metabolic syndrome and fatty liver were found in 726 (22.87%) and 661 (20.82%) of sampled cases, respectively. After adjustment by age and sex, the prevalence of the metabolic syndrome and fatty liver in the general population of Shanghai were 15.30 and 17.29%, respectively. The risk for fatty liver in subjects with abdominal obesity, diabetes, dyslipidemia and hypertension increased 32.78-fold (95% confidence interval (CI) 14.85–72.35), 31.58-fold (95% CI 14.18–70.35), 22.64-fold (95% CI 10.26–49.99) and 23.25-fold (95% CI 10.54–51.30), respectively, compared with controls, whereas the risk for fatty liver in subjects with metabolic syndrome was increased by 39.33-fold (95% CI 17.77–87.05). After the 661 patients with fatty liver had been stratified by body mass index (BMI), the prevalence of abdominal obesity, hypertension and the metabolic syndrome were increased from 25.0, 47.2 and 36.1%, respectively, in people with normal BMI to 81.0, 73.8 and 55.4%, respectively, in obese persons. However, the prevalence of hypertriglyceridemia, high fasting glucose and low high-density lipoprotein–cholesterol showed no significant changes with increased BMI. Moreover, among fatty liver patients with normal BMI, the detection rate for one or more features of metabolic disorders was as high as 83.3% and that for five features was 2.8%. Compared with obesity (BMI ≥ 25 kg/m2) and abdominal obesity, fatty liver had the highest clustering rate, specificity, positive predictive value and attributable risk percentage in detecting risk factor clustering in both sexes.

Conclusions:  There is a high prevalence of metabolic syndrome and fatty liver among Shanghai adults. Metabolic disorders are closely related to fatty liver; moreover, fatty liver appears to be a good predictor for the clustering of risk factors for metabolic syndrome.

Fatty liver and the metabolic syndrome among Shanghai adults.

Objective To investigate the prevalence and major risk factors of fatty liver among adult residents in Shanghai Methods A cross-sectional survey with multiple-stage stratified cluster and random sampling was performed All residents aged 16 and above were invited to participate in the survey; they came from four communities of Yangpu District and Pudong New District Questionnaire, physical examination, serum lipid-profile, and 75 gram oral glucose tolerance test and ultrasonographic examination of liver were undertaken Analysis of data was performed through SPSS 110 for Windows statistical package Results A total of 3175 residents took part in the survey, which was 75% of adult residents of the investigated communities and 226/10 000 of Shanghai municipal residents Of the 3175, 1218 were males and 1957 were females The mean age of the participants was 524±151 years and ranged from 16~88 years Fatty liver was detected with ultrasound examination in 661 participants (2082%), among which 348% had alcoholic fatty liver, 4 08% had suspected alcoholic fatty liver, and 9243% had nonalcoholic fatty liver The age-adjusted, sex-adjusted prevalence of fatty liver in Shanghai adult residents was 1729%, the prevalence of alcoholic fatty liver, suspicious alcoholic fatty liver, and nonalcoholic fatty liver in Shanghai adult residents were 079%, 115%, and 1535%, respectively The prevalence of fatty liver was increased with aging in males and in females Among participants younger than 50 years old,the prevalence of fatty liver in males was significantly higher than that in females (x2 =13934, P 001), but in participants older than 50 years the case was just the opposite, higher in females (x2 = 4146, P 005) The mean age (years), body mass index (BMI), waist circumference, blood pressure, fasting and two hour serum glucose level, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and the presence of obesity, diabetes mellitus, hypertension, dyslipidemia, and gallstones in the fatty liver group was significantly higher than those in the group without fatty liver (all P 0001), but the high-density lipoprotein cholesterol (HDL-C) level and the educational level were both lower in the fatty liver group (P 0001 and 005, respectively) Logistic regression analysis demonstrated that the prevalence of fatty liver was only positively correlated to nine risk factors, including male sex, educational level, waist circumference, BMI, fasting glucose level, HDL-C, TG, hypertension and diabetes mellitus In heavy drinkers, obesity increased the risk for fatty liver by 48-fold (95% CI 14-166, P = 00141), but heavy drinking only increased the risk for fatty liver 15-fold (95% CI 09-26, P = 01685) Conclusions There is a high prevalence of fatty liver among adult residents in Shanghai, and nonalcoholic fatty liver is the major type Metabolic disorders such as obesity and diabetes mellitus, hypertension and hyperlipidemia are more closely associated with fatty liver than heavy drinking in Shanghai

Feng Li

Papers

Prevalence of and risk factors for fatty liver in a general population of Shanghai, China.

Fatty liver and the metabolic syndrome among Shanghai adults.

Epidemiological survey of prevalence of fatty liver and its risk factors in a general adult population of Shanghai