RESUMO
The organic bone matrix contains glycosaminoglycans (GAG) of which the precise function and importance in bone mineralisation are still unclear. We examined 85 persons--35 healthy women (25 premenopausal [preMP] mean aged 40.7 years; 10 menopausal [MP] mean aged 59.3 years) and 50 patients with postmenopausal osteoporosis [PMOP] at a mean age 60.4 years. The dynamic of urinary excretion of GAG was measured in 24-hour collected urine by precipitation with cetylpyridinum chloride and spectrophotometry at 560 nm, corrected for the level of excretion of creatinine. There was a significant increase in GAG excretion in patients with PMOP compared with healthy persons (8.25 mg/g and 9.53 mg/g vs 24.11 mg/g; p < 0.0001). A significant positive correlation was established between GAG and calcium urinary excretion and a negative one between GAG and serum estradiol levels. During the treatment with calcitonin the excretion of GAG was decreased which can be used for monitoring the changes of bone metabolism.