A pilot study of the feasibility of long-term human bone balance during perimenopause using a ⁴¹Ca tracer

The mechanisms governing calcium fluxes during bone remodeling processes in perimenopausal women are poorly known. Despite higher, albeit erratic, estradiol levels in perimenopause, spine bone loss is greater than during the first five years past the final menstrual flow when estradiol becomes low. Understanding changes during this dynamic transition are important to prevent fragility fractures in midlife and older women. The exploration of long-lived ⁴¹Ca (T_1/2 = 1.04 × 10⁵ yrs) tracer measurements using accelerator mass spectrometry (AMS) leads to the possibility of monitoring bone remodeling balance. With this new technology, we explored a pilot long-term feasibility study of bone health by measuring the ⁴¹Ca trace element in urine for six years from premenopausal to later perimenopausal phases in one midlife woman. We measured bone mineral density in parallel.