Effect of estrogen (Premarin) replacement therapy on serum level of total estrogen and urinary excretion of calcium and hydroxyproline in postmenopausal Chinese women.

The study subjects included a total of 30 postmenopausal Chinese women, including 14 natural menopausal women, 13 castrated menopausal women and 3 post-irradiated menopausal women. Premarin 1.25 mg/day was given orally for 3 weeks and off one week, repeated for 6 cycles. Fasting morning urine and blood samples were collected before hormone treatment and at the end of 3 weeks, 11 weeks, and 23 weeks of Premarin therapy. Serum total estrogen level was measured by radioimmunoassay. Urinary calcium and creatinine were measured by atomic absorption and Jeffe's reaction, respectively. The concentration of urinary hydroxyproline was determined by Kivirikko's method. After Premarin therapy, the mean concentration of serum total estrogen increased 3 to 4 times from the pretreatment level of 71.7 pg/ml. On the other hand, the mean value of calcium/creatinine (Ca/Cr) molar ratio dropped down from 0.249 to 0.098. The mean value of hydroxyproline/creatinine (HOPr/Cr) molar ratio was reduced from 0.028 to 0.012. In view of the hormonal and biochemical changes after Premarin therapy, it is concluded that estrogen (Premarin) replacement should be effective in the treatment of enhanced bone loss or osteoporosis in postmenopausal women. The relationship of estrogen and calcitonin in the regulation of bone metabolism is also discussed.