Serum total estrogen levels and urinary excretion of calcium and hydroxyproline in premenopausal and postmenopausal Chinese women.

Abstract

Ruey-Jian Chen, MD1 Abstract The study subjects included 26 normal young women with regular menstruation cycles and 30 postmenopausal women. The blood and fasting morning urine samples of premenopausal women were taken between the 4th to 11th day of menstrual cycle. In postmenopausal women the blood and urine specimens were taken at least one year after natural menopause, two months after surgical castration, and two months after completion of radiation therapy for cervical cancer. Serum total estrogen level was measured by radioimmunoassay. The urine hydroxyproline concentration was determined by Kivirikko's method. The mean concentrations of serum total estrogens levels were 185.5 pg/ml and 71.7 pg/ml in premenopausal and postmenopausal women respectively. The mean values of urinary calcium/creatinine (Ca/Cr) molar ratio in premenopausal and postmenopausal women were 0.139 and 0.249 respectively. The mean value of hydroxyproline/creatinine (HOPr/Cr) molar ratio was 0.012 in premenopausal women and 0.028 in postmenopausal women. The parameters of bone loss, such as Ca/Cr ratio and HOPr/Cr ratio, are inversely related with the circulating total estrogen concentration. Therefore, decreased endogenous estrogen production seems to be the major pathophysiologic basis for the enhanced rate of urinary calcium and hydroxyproline excretion in Chinese postmenopausal women.