Metabolic-associated fatty liver disease is associated with low muscle mass and strength in patients with chronic hepatitis B

BACKGROUND

Although the prognostic relevance of sarcopenia has been increasingly recognised in the context of liver disease, there is a paucity of data evaluating body composition in patients with chronic hepatitis B (CHB). Beyond virus-related factors, nutritional and metabolic aspects can be associated with skeletal muscle abnormalities in these patients and should not be disregarded.

AIM

To evaluate the association between components of sarcopenia and demographic, clinical, lifestyle, nutritional, and biochemical variables in CHB patients.

METHODS

Dual-energy X-ray absorptiometry (DXA) was used to assess muscle mass by quantifying appendicular lean mass (ALM) adjusted for body mass index (ALM_BMI). Muscle function was evaluated by hand grip strength (HGS) and the timed up and go test. Metabolic-associated fatty liver disease (MAFLD) was defined according to the criteria proposed by an international expert panel. A body shape index and the International Physical Activity Questionnaire were used to assess central obesity and physical activity level, respectively.

RESULTS

This cross-sectional study included 105 CHB outpatients followed at the tertiary care ambulatory centre (mean age, 48.5 ± 12.0 years; 58.1% males; 76.2% without cirrhosis; 23.8% with compensated cirrhosis). The DXA-derived fat mass percentage was inversely correlated with the ALM_BMI (r = - 0.87) and HGS (r = - 0.63). In the multivariable analysis, MAFLD, sedentarism and central obesity were positively and independently associated with low ALM_BMI. MAFLD and central obesity were independently associated with low HGS.

CONCLUSION

MAFLD and central obesity were associated with low muscle mass and strength in patients with chronic hepatitis B, independent of the liver disease stage.

A role for the MAPK/ERK pathway in oligodendroglial differentiation in vitro: stage specific effects on cell branching

The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway is important for both long-term survival and timing of the progression of oligodendrocyte differentiation. Oligodendroglial cells treated with MEK inhibitor were distinguished by using stage specific markers: NG2 proteoglycan, A2B5, 2'3'nucleotide-cyclic 3'phosphodiesterase (CNPase) and myelin basic protein (MBP), and classified according to their morphology into different developmental stages. Treatment significantly increased the number of cells with more immature morphologies and decreased the number of mature cells. Furthermore, it increased the number of rounded cells that could not be classified into any of the oligodendroglial developmental stages. The strongest effects were usually observed shortly after treatment. Rounded cells were CNPase/MBP positive and they were not stained by anti-NG2 or A2B5, indicating that they were mature cells unable either to extend and/or to maintain their processes. These data showed an effect of the MAPK/ERK pathway on oligodendroglial branching, with possible consequences for the formation of the myelin sheath.