Aim: N-Telopeptides (NTX), which are known as bone turnover markers are being increasingly used in early diagnosis of osteoporosis, determining the fracture risk and following up of the treatment outcome. Material and Method: In this study serum and urine NTX levels of postmenapousal patients [ages 60-83 (mean 69.45), n: 11] with no previous treatment of osteoporosis are compared with the levels after 6-months of risedronate treatment and serum and urine NTX levels of the control group [ages 57-73 (mean 64.64), n: 11]. Results: Consequently serum NTX (sNTX) levels of postmenapousal patients before risedronate therapy were significantly higher then the sNTX levels of the control group. After risedronate therapy sNTX levels were significantly higher and urine (uNTX) levels were lower when compared with the NTX levels before treatment. Also either sNTX or uNTX levels before and after the treatment were positively and strongly correlated. Discussion and Conclusion: Eventually bone turnover markers carry much importance in diagnosis and follow-up the treatment. Also the strong correlation between levels of NTX before and after the treatment shows that the sensitivity and specifity of these methods are high. Therefore they can be used as an alternative and adjunct method to bone densitometry to assess the response to treatment, especially to demonstrate the early changes. (Osteoporoz Dünyasindan 2006;12:55-9)Key words: Bone markers, Serum N-telopeptide, ürine N-telopeptide, risedronate, postmenopausal osteoporosis
