Age- and BMD-related differences in biochemical markers of bone metabolism in rural and urban women from Lublin Region, Poland.

The utility of biochemical markers of bone metabolism has not been proven in the diagnosis of metabolic diseases of the bone tissue; however they are widely used as a tools for treatment monitoring. Their serum concentrations are influenced by a number of factors, like gender, health status, anthropometric and environmental factors. All the factors listed above should be taken into consideration during clinical use. The aim of the study was to determine the reference values and evaluate the influence of environmental and anthropometric variables on biochemical markers of bone turnover for women from Lublin Region (Poland). Subjects of the study were 188 normal women aged 30-79, all residents of Lublin Region. Analysed markers of bone turnover were: osteocalcin (OC) and C-terminal cross-linking telopeptide of type I collagen (CTX-I), both assessed using ELISA method. All blood samples were taken and analyzed at the Clinical Chem. Laboratory and Patho-morphology Department at the Institute of Agricultural Medicine in Lublin. The lumbar spine (L2-L4) of all subjects was examined in a-p position using the dual X-ray absorptiometry-DXA (DPX-A LUNAR Corp.) at the Department of Metabolic and Degenerative Diseases of Bone Tissue of Institute of Agricultural Medicine in Lublin. Data pertaining to factors affecting bone tissue were collected using a specially prepared questionnaire. Serum levels of OC and CTX-I in women in every age range were different, generally increasing with age. Serum levels of OC and CTX-I in the analysed population strongly depended of both menopausal status and bone mineral density. In conclusion, this study demonstrates that age and menopausal status variations need to be considered when interpreting laboratory measurements of biochemical markers of bone metabolism.