Bone turnover markers in postmenopausal osteoporosis and their correlation with bone mineral density and menopause duration

Background: Biochemical bone turnover markers (BTMs) estimates the bone remodeling process, being valuable in the personalized approach of osteoporotic patients. Aim: The aim of the study was to evaluate the correlation between biochemical BTMs and bone mineral density (BMD), depending on menopause period, in postmenopausal osteoporotic women, compared to postmenopausal women without osteoporosis. Patients, Materials and Methods: The study included 149 untreated postmenopausal women, divided into three groups: group 1 (65 osteoporotic women with less than 10 years of menopause), group 2 (44 osteoporotic patients, with over 10 years of menopause), and the control group with 40 postmenopausal women without osteoporosis. Results: All BTMs levels were higher in the groups with osteoporosis, than in the control group. Lumbar BMD values correlated positively with deoxypyridinoline (DPD) and negatively with bone-specific isoform of alkaline phosphatase (BAP), tartrate-resistant acid phosphatase band 5b (TRAP 5b), osteocalcin (OC) and cross-linked N-telopeptides of type I collagen (NTX). Serum estradiol levels correlated positively with spine BMD in the whole study group (r=0.508, p=0.001). BTMs correlated positively with each other. Osteoporotic women with longer period of menopause presented significantly higher values of resorption markers (NTX and TRAP 5b), compared to the group with menopause duration less than 10 years. At a cutoff value of 12 mu g/L, BAP presented 82.4% sensitivity and 62.5% specificity. Conclusions: Our study showed that BTMs correlated negatively with lumbar BMD and positively with each other. Resorption markers levels increase with duration of estradiol deprivation period.