SERUM BETA CROSSLAPS AS A PREDICTOR FOR OSTEOPOROSIS IN POSTMENOPAUSAL WOMEN

Objective: to evaluate bone turnover by an early marker, crosslaps (beta-ctx), in postmenopausal women receiving hormone replacement therapy (hrt) or bisphosphonates (bp) to reduce bone loss.materials and methods: thirty patients with no menstruation for at least one year, fsh>40 iu/l, estrogen <20ng/ml at the time of presenting to zeynep kamil women and children’s training and research hospital were included in this study. the patients were divided into two groups, the hrt group and the bp group. in the hrt group (n=12), patients were prescribed 1mg estradiol, 0.5mg norethisterone acetate and 1000mg calcium (ca) daily for 6 months. in the bp group (n=18), patients were given 70mg alendronate weekly for 6 months. bone density was evaluated using dual-energy x-ray absorptiometry at the beginning of the study and after six months. t-scores were used for the quantitative evaluation of bone loss. at the beginning and at the end of the six months, serum beta-ctx levels were measured. differences in the t-scores and serum beta-ctx levels of the study groups were compared.results: the t-scores of patients who received bp were significantly higher compared with those of patients on hrt at the beginning of the study (p<0.01). the t-scores of patients who received bp were significantly higher than those on hrt at the end of six months (p<0.05). within either group, the t-scores at the beginning and at the end of six months were not statistically significantly different (p>0.05). the serum beta-ctx levels of patients who received bp were significantly higher compared with those on hrt at the beginning of the study (p<0.01). beta-ctx levels were also higher compared with patients receiving hrt after the six-month period (p<0.05). the serum beta-ctx levels were significantly lower at the end of the six months in patients who received bp compared with the levels at the beginning (p<0.05).conclusion: changes in serum beta-ctx measurements are detectable earlier than warning signs in bone mineral densitometry and may be a better guide to follow the effectiveness of treatment, especially in patients with high bone turnover; however, long-term studies are required for standard clinical use