Bone mass and biomarkers in young women with anorexia nervosa: a prospective 3-year follow-up study

Abstract

Anorexia nervosa (AN) increases the risk of impaired bone health, low areal bone mineral density (aBMD), and subsequent fractures. This prospective study investigated the long-term effects of bone and mineral metabolism on bone and biomarkers in 22 women with AN. Body composition and aBMD were measured by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography. Total and free 25-hydroxyvitamin D (25OHD), C-terminal collagen cross-links (CTX), osteocalcin, bone-specific alkaline phosphatase (BALP), leptin, sclerostin, and oxidized/non-oxidized parathyroid hormone (PTH) were analyzed before and after 12weeks of intensive nutrition therapy and again 3years later. An age-matched comparison group of 17 healthy women was recruited for the 3-year follow-up. Body mass index (BMI) and fat mass increased from baseline to 3years in women with AN. Sclerostin decreased during nutrition therapy and further over 3years, indicating reduced bone loss. CTX was elevated at baseline and after 12weeks but decreased over 3years. BALP increased during nutrition therapy and stabilized over 3years. Free 25OHD was stable during treatment but decreased over 3years. Non-oxidized PTH was stable during treatment but increased over 3years. Trabecular volumetric BMD in AN patients decreased during the first 12weeks and over 3years despite stable BMI and bone biomarkers implying increased BMD. Our findings highlight the importance of early detection and organized long-term follow-up of bone health in young women with a history of AN.