When women in their 40s or 50s had above-normal levels of the N-telopeptide bone turnover marker detected in a simple urine test, they had a 59% greater chance of developing bone fractures as they aged, according to epidemiologists at the University of Pittsburgh Graduate School of Public Health.
When the elevated N-telopeptide (NTX) levels were found in combination with low bone mineral density (BMD) measurements in their spines, the women had nearly a three-fold greater fracture risk.
This research analyzed the signs of bone breakdown in younger, premenopausal women to determine if the population will experience fractures as they age. The study was published in the online edition of Menopause.
“Bone fractures – particularly in the hip, wrist and back – have serious consequences, including disability and death, Jane Cauley, DrPH, stated in a University of Pittsburgh news release. “Knowing a woman’s risk of fracture can help doctors determine the best course of action to protect her bones as she enters menopause, a time when estrogen deficiency negatively affects skeletal health.”
Cauley and colleagues studied data for 2,305 premenopausal or perimenopausal women aged 42 years to 52 years collected during 7.6 years as part of the multicenter Study of Women’s Health Across the Nation (SWAN).
The women enrolled in the SWAN study, who were premenopausal or early perimenopausal at the outset of the investigation, reported for nine clinic visits and self-reported fractures during the study period. Investigators measured serum osteocalcin at baseline and urinary NTX at baseline and 1 year clinic visits. They then calculated any changes in bone turnover markers and NTX and quantified hazard and odds ratios, according to the study abstract.
Cauley and colleagues found 10% higher baseline NTX levels, but no difference in osteocalcin levels in the 184 women with fractures that occurred during the study. Furthermore, a 1-SD BMD measurement taken premenopausally was associated with an increased fracture risk during menopause.
Cauley JA, Danielson ME, Greendale GA, et al. Bone resorption and fracture across the menopausal transition: the Study of Women's Health Across the Nation. Menopause. Published online ahead of print Aug. 1, 2012. doi: 10.1097/gme.0b013e31825ae17e.
Disclosure: The study was supported by the National Institutes of Health (NIH), Department of Health and Human Services through the National Institute on Aging, the National Institute of Nursing Research and the NIH Office of Research on Women’s Health and other grants.