Clinical characteristics of lean metabolic-associated fatty liver disease and the impact of concurrent diabetes mellitus

ABSTRACT Metabolic-associated fatty liver disease (MAFLD) was proposed in 2020 to replace the original term nonalcoholic fatty liver disease (NAFLD) with new diagnostic criteria. The disease risks of lean and overweight/obese MAFLD patients remain controversial. The participants from the Taiwan biobank cohort were included. Advanced liver fibrosis is defined as NAFLD fibrosis score (NFS) >0.675. We use carotid plaques of duplex ultrasounds to diagnose atherosclerosis. A total of 20,058 participants (age 55.67 ± 10.32; males 37.6%) were included in the final analysis. Seven thousand eight hundred and forty-three (39.1%) participants were diagnosed with MAFLD. Of them, 965 (12.3%) were lean MAFLD patients. Among lean MAFLD patients, 25.6% were comorbid with diabetes mellitus (DM). Lean MAFLD patients were older and had higher percentages of females and DM than overweight/obese MAFLD patients. After propensity score matching for age and sex, they had lower levels of NFS but a higher percentage of carotid plaques. Among four subtypes of MAFLD including “lean with DM,” “lean without DM,” “overweight/obese with DM,” and “overweight/obese without DM,” logistic regression showed that “lean with DM” subjects had the highest risk of atherosclerosis and “overweight/obese with DM” subjects had the highest risk of advanced liver fibrosis in MAFLD patients. The population-based study revealed that lean MAFLD patients make up 12.3% of all MAFLD patients, and they have a higher proportion of coexisting diabetes. Among lean MAFLD patients concurrent with diabetes, they have the highest risk of atherosclerosis and should receive special attention clinically.