The aim was to determine the body composition of rats with experimental type 1 diabetes mellitus and its correction with amino acids using bioimpedance analysis.

Material and methods. Diabetes mellitus was modeled by the injection of streptozotocin. On the 6th week the rats were divided into 3 subgroups: DM1-1 – without correction, DM1-2 – correction with L-arginine and DM1-3 – correction with N-acetyl-L-cysteine for 2 weeks. Body composition was determined by the Vet BIS1 impedance analyzer with a study of total water volume in the body, extracellular and intracellular fluid, fat and fat-free body mass.

Results. Weight of rats in DM1 group at the 6th week was 40 % less than in control, with a 63 % reduction in fat and 22 % decrease of fat-free body mass. The development of hyperglycemia in week 6 caused general dehydration, with a decrease in absolute values of both fluid volumes. On the 7th and 8th weeks, body weight, fat and fat-free body mass in the subgroups DM1-1, DM1-2, and DM1-3 did not differ statistically. Both amino acids caused a decrease in glucose concentration, but this did not affect existing total dehydration with a decrease of both fluid volumes.

Conclusions. The development of streptozotocin-induced type 1 diabetes mellitus in rats in 6 weeks resulted in a statistically significant loss of body weight, mostly due to fat mass decrease with a violation of its ratio to fat-free mass. Persistent hyperglycemia already in the 6th week of experimental diabetes mellitus causes general dehydration due to loss of extracellular and intracellular water, with a predominance of intracellular dehydration. Two-week correction of diabetes with L-arginine and N-acetyl-L-cysteine at 8th week significantly reduces glucose concentration in subgroups, but does not affect the progressive reduction of body weight, fat and free-fat mass, and fluid volumes.