Patients and methods: Serum levels of carboxyterminal telopeptide of collagen I of organic bone matrix (CTx) were determined in each examined patient (63 women at the age of 42 to 60 years and 45 men at the age of 46 to 69 years) with established diagnosis of osteopenia or osteoporosis in the area of proximal femur. Methods: Dual-energy X-ray absorptiometry (DEXA), Hologic, QRD-4000 (U.S.A.). CTx: NORDIC Bioscience Diagnostics (DK). Objective: 1. To determine statistical significance in bone material density (BMD) measured in four standard sites of proximal femur (Ward’s neck, trochanter major, total). 2. To determine relationship between CTx values and BMD values in individual sites of measurement (BMD ward’s, BMD neck, BMD trochanter, BMD total). Statistical analysis: Paired Wilcoxon test, linear regression analysis. Results: 1. There were statistically significant differences between BMD values determined at individual measured sites. 2. a statistically significant relation was found only between pathologically increased values of CTx and BMD in the area of Ward’s triangle in the group of men and women (r2M = 0.54, r2W = 0.55). The correlation between CTx and the site of measurement approached, but did not reach significance (r2M = 0.43, r2W = 0.40). Other positions of measurement in the area of proximal femur (trochanter, total) did not significantly correlate with the CTx values in either sex. Conclusion: The investigation compared the CTx levels with densitometric sites of measurement divided according to the speed of bone matter loss. In view of the fact that there were statistically significant differences between the BMD values at four measurement sites, it appears to be necessary to compare parameters of bone turnover selectively for each measurement site. The results indicate that even a single observation of increased serum CTx levels suggest pathologically decreased BMD levels in the Ward’s triangle area or in the neck area. CTx correlates only with the site hodnotaof rapid decrease of bone matter and therefore represents a sensitive parameter of bone resorption.

        Key words: bone resorption – CTx – DEXA – collum femoris – neck of femur – BMD