[Glucosamine concentration in serum of old persons with hyperinsulinemia and normal insulin levels].

Increased glucose metabolism through the hexosamine biosynthesis pathway has been shown to mediate many of adverse effects i.e. desensitisation of glucose transport in tissues, an inhibition of glycolysis and glycogen synthesis in skeletal muscles, an impairment of insulin secretion in pancreatic islet cells, arteriosclerosis and nephropathy by stimulation of growth factor TGF-alpha and TGF-beta 1 promoters expression. The aim of the presented study was to compare of glucosamine concentrations in the blood serum between elderly human subjects (women and men) with hyperinsulinaemia and normoinsulinaemia. Subjects were divided into two groups: a group of 16 subjects with hyperinsulinaemia (concentration of fasting insulin is higher than 15 mU/l) and a group of 19 subjects with normoinsulinaemia (concentration of insulin was less or equal 15 mU/l). In the venous blood serum concentrations of insulin, C-peptide, glucose and glucosamine were determined. The Caltrac accelerometer was used to estimate energy expenditure in subgroup of 20 subjects: 10 subjects with hyperinsulinaemia and 10 with normoinsulinaemia. Significant differences were found between glucosamine and insulin concentrations (p < 0.01) and between C-peptide concentrations (p < 0.05) in both groups investigated. The mean value of the glucosamine concentration in the group with hyperinsulinaemia was higher by 22.6 mg/dl in comparison to mean value established in the group with normoinsulinaemia. Mean values of total and related to physical activity energy expenditure per day per 1 kg of body mass in the group with hyperinsulinaemia were less (p < 0.05) compared to the group with normoinsulinaemia. The presented results show that hyperinsulinaemia may contribute to the hyperactivity of hexosamine biosynthesis pathway.