ИСТИНА

Background and aims. A chronic alcoholic myopathy is the common form of skeletal muscle destruction in alcoholism. What is important in the development of the disease: the duration of alcohol abuse or the dose of the ethanol consumed? Methods. The time course of chronic alcoholic myopathy was examined in 23 male patients (46.9±1.5 years). The control group consisted of 7 healthy men. All patients were divided into 3 groups for the duration of alcohol consumption: 7.7+0.6 (group 1, n=9); 18.1+1.2 (group 2, n=7) and 31.3+1.0 years (group 3, n=7). A biopsy from m. vastus lateralis was taken. The average daily dose of alcohol was 16.11.4 units of ethanol (1 unit = 10ml of pure ethanol). Results. The clinical symptoms of myopathy, atrophy or transformation of muscle fibers (MF) were not observed in group 1, however, the level of p-p70S6k and p-p90 RSK was reduced (p<0.05) vs Control. The second group demonstrated the clinical symptoms of myopathy, the atrophy of type II MF (p<0.05), the shift of MF to a fast type (p<0.05) and the reduced activity of p-p70S6k and p-p90 RSK (p<0.05). In the third group we observed the clinical symptoms of myopathy syndrome, the atrophy of both types of MF (p<0.05), the shift of MF to a fast (p<0.05) and reduced activity of p-p70S6k and p-p90 RSK, (p<0.05). IGF-I level in plasma was significantly lower in the groups ,2,3 vs group without atrophy. Conclusions: the duration of alcohol consumption is more important factor than the dosage to develop the myopathy symptoms. The involvement of different types of MF in the process of atrophy and the shift of fibers to the fast type depend on the alcohol abuse duration. The anabolic signaling pathways markers and IGF-1 reduced before noticed symptoms of myopathy. Supported by Russian Science Foundation № 14-15-00392