A new definition for metabolic dysfunction-associated fatty liver disease: An international expert consensus statement
The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) is increasing. The exclusion of other chronic liver diseases including “excess” alcohol intake has until now been important to establish a diagnosis of (MAFLD). There is a need for “positive diagnosis” criteria to understand the pathogenesis of this liver disease. Eslam and colleagues proposed a new definition for the diagnosis of MAFLD, published in The Journal of Hepatology under the title “A new definition for metabolic dysfunction-associated fatty liver disease: An international expert consensus statement”. The summary of the definitions can be studied below:
Objective:
To propose a comprehensive and simple set of diagnostic criteria for MAFLD, independent of the amount of alcohol consumed and can be applied to patients in any clinical setting.
To provide clarity in diagnostic criteria and help clinicians in routine clinical care.
To provide comparative data for different studies and clinical trials.
Method:
With the help of their expertise, recent researches, and clinical knowledge, a panel of international experts from 22 countries proposed this new definition and criteria for the diagnosis of MAFLD.
Diagnostic Criteria:
The basis of proposed criteria for a positive diagnosis of MAFLD is hepatic steatosis in adults detected either by imaging techniques, blood biomarkers/ scores or by liver histology in addition to one of the following three criteria-
1) Overweight or obesity: defined as BMI ≥25 kg/m2 in Caucasians or BMI ≥23 kg/m2 in Asians
2) Lean/normal weight: defined as BMI <25 kg/m2 in Caucasians or BMI <23 kg/m2 in Asians
In these individuals, MAFLD is diagnosed if at least two metabolic risk abnormalities from the following are present:
• Waist circumference ≥102/88 cm in Caucasian men and women (or ≥90/80 cm in Asian men and women)
• Blood pressure ≥130/85 mmHg or specific drug treatment
• Plasma triglycerides ≥150 mg/dl (≥1.70 mmol/L) or specific drug treatment
• Plasma HDL-cholesterol <40 mg/dl (<1.0 mmol/L) for men and <50 mg/dl (<1.3 mmol/L) for women or specific drug treatment • Prediabetes (i.e., fasting glucose levels 100 to 125 mg/dl [5.6 to 6.9 mmol/L], or 2-hour post-load glucose levels 140 to 199 mg/dl [7.8 to 11.0 mmol] or HbA1c 5.7% to 6.4% [39 to 47 mmol/mol]) • Homeostasis model assessment of insulin resistance score ≥2.5 • Plasma high-sensitivity C-reactive protein level >2 mg/L
3) Type 2 diabetes mellitus: According to widely accepted international criteria
MAFLD: a single overarching term
MAFLD should be the single term used to describe the disease broadly rather than a dichotomous classification (steatosis vs. steatohepatitis). The progression of MAFLD is best described by the grade of activity and the stage of fibrosis.
MAFLD cirrhosis—no longer cryptogenic cirrhosis
Patient with cirrhosis should be considered under ‘MAFLD-related cirrhosis’ if they meet the proposed diagnostic criteria for MAFLD and at least one of the following:
• Documentation of MAFLD on a previous liver biopsy
• Historical documentation of steatosis by hepatic imaging
Dual aetiology: concomitant MAFLD with other liver diseases
The criteria for a diagnosis of MAFLD are:
. other cause of liver disease eg. an alcohol-use disorder defined as consumption of >3 drinks per day in men and >2 drinks per day in women, or binge drinking (defined as >5 drinks in males and >4 drinks in females, consumed over 2 hours), as defined by the National Institute of Alcoholism and Alcohol Abuse,
. viral infection (HIV, HBV, and HCV),
. autoimmune hepatitis,
. inherited liver disorders,
. drug-induced liver injury or other known liver diseases.
Alternative causes of fatty liver disease
Instead of terms like ‘primary’ and ‘secondary’ cause, it is suggested to use “alternative cause” of fatty liver disease to describe the conditions such as medications, coeliac disease, starvation, total parenteral nutrition, severe surgical weight loss, or disorders of lipid metabolism. These might be associated with MAFLD or be present with other triggers of less frequent forms of fatty liver disease.
The distinction between diagnostic criteria and inclusion criteria for clinical trials
There is a difference between diagnostic criteria for any disease or syndrome and inclusion criteria for any clinical trial or study. Diagnostic criteria generally are a set of symptoms, signs, and tests used routinely in clinical care to better understand the disease to guide its management. On the other hand, inclusion criteria for clinical trials are the main features s of a study target population that would be investigated to address the research question. Hence, setting a definition for MAFLD trials will increase the likelihood of detecting a significant impact of clinical approaches targeting MAFLD by excluding patients with fatty liver unrelated to metabolic dysfunction.
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