Improving muscle mass protects against severe NAFLD

People with lower muscle mass and grip strength are at increased risk of developing severe nonalcoholic fatty liver disease (NAFLD), reveals a study.

“Interventions to improve physical capability may be protective, but this needs to be investigated in appropriately designed trials,” the investigators said.

Using data from the UK Biobank study, the investigators examined a total of 333,295 participants in this prospective study. They used a Jamar J00105 hydraulic hand dynamometer to measure grip strength and the Janssen equation to estimate skeletal muscle mass by bioelectrical impedance. Muscle mass was adjusted for body weight, and all exposures were standardized by sex.

Using Cox proportional hazard models, the investigators examined the associations of muscle mass and strength with severe NAFLD, defined as hospital admission or death, by tertile. They also investigated nonlinear associations using penalized cubic splines fitted in the Cox proportional hazard models.

Of the participants, 3,311 had severe NAFLD (3,277 hospitalizations and 34 deaths) after a median follow-up of 10 years. Severe NAFLD risk was lower in the middle (hazard ratio [HR], 0.76, 95 percent confidence interval [CI], 0.70‒0.83) and the highest tertiles of muscle mass (HR, 0.46, 95 percent CI, 0.40‒0.52) than in the lowest tertile. A similar pattern was seen in tertiles of grip strength.

Notably, only muscle mass showed nonlinearity. Being on the lower tertile of grip strength and muscle mass accounted for 17.7 percent and 33.1 percent of severe NAFLD cases, respectively.

“Lower muscle mass [was] associated with a higher risk of severe NAFLD. Therefore, improving muscle mass might be a protective factor against this increasing public health problem,” the investigators said.