US researchers have developed an index that could help predict which women may experience faster bone loss during the menopause.
The Bone Balance Index takes into account total bone breakdown and bone formation in order to gauge net bone balance across the skeleton.
“Researchers have previously shown that it is difficult to predict an individual´s bone loss by testing the blood or urine for proteins that reflect either bone breakdown or bone formation alone,” explained one of the study´s authors, Dr Albert Shieh, from the University of California, Los Angeles. “Since both bone breakdown and bone formation occur at the same time in the body, we created an index that accounts for both processes, and tested whether this new index can help predict bone loss.”
The researchers found that the index was most useful for predicting bone loss in the bones of the spine.
Data from 685 women aged between 42 and 52 was used to create the index. Participants were either premenopausal or in early perimenopause when they enrolled, and all of the women had their final menstrual period during the follow-up part of the study.
Urine and blood samples from the women were tested to measure bone turnover markers — proteins that reflect bone breakdown and bone formation. The women also had their bone mineral density measured every year during the course of the study.
The researchers combined measurements of bone breakdown and bone formation to determine each individual´s net bone balance before the final menstrual period. According to the Endocrine Society, they found that this index was a stronger predictor of bone loss from two years before the final menstrual period to three to four years later — a time when bone density typically declines — than a measurement of bone breakdown alone.
“This novel approach to assessing an individual´s bone health may help identify which women are at risk of losing vertebral bone mineral density across the menopause transition,” said Dr Shieh. “More studies are needed to test whether this index is useful for predicting bone loss after the menopause transition, and if it is useful for predicting fractures.”
He concluded: “Since markers of bone breakdown alone have limited utility in predicting bone loss at an individual level, better approaches are needed to ensure individuals at highest risk of rapid bone loss are identified as quickly as possible.”
The team´s findings have been published in the Endocrine Society´s Journal of Clinical Endocrinology & Metabolism.