Anorexia Nervosa and Osteoporosis: A Possible Complication to Remember

Anorexia nervosa (AN) belongs to the spectrum of food disorders and affects approximately 2.9 million people worldwide. It is responsible for numerous and serious medical complications. Osteoporosis is a common complication, and the decrease in bone mineral density (BMD) is one of the few potentially irreversible consequences of AN. When associated with AN, it can manifest at a very young age, possibly leading to irreparable damage. We describe the case of a 30-year-old woman with a one-year evolution diagnosis of AN, complaining of back pain. Physical examination revealed a slight elevation of the right shoulder and pain at compression of paravertebral right dorsal musculature with a palpable strained muscle. Full-length X-ray imaging of the dorsal spine revealed a slight dextroconvex dorsolumbar scoliosis. A dorsal spine computerized tomography (CT) was performed, confirming a fracture of the upper platform of the sixth dorsal vertebrae. Osteodensitometry showed lumbar spine osteoporosis and femoral osteopenia. The decrease in BMD and, later on, the development of osteoporosis can occur in both types of AN. It is a severe complication that affects up to 50% of these patients. It can be irreversible and increase the lifetime risk of bone fractures and, therefore, morbimortality. Low body weight and body mass index (BMI) strongly correlate with the decrease in BMD. Treatment of osteoporosis associated with AN is not standardized and clearly labeled. Weight gain is described as the strategy with the most impact in reversing the loss of bone mass and increasing the BMD. The regularization of gonadal function also seems to independently potentiate the increase of BMD. The occurrence of long bone and vertebrae fractures frequently results in a decrease in height and chronic back pain, culminating in greater morbimortality and healthcare costs. This clinical case aims to show theclose relationship between restrictive food disorders and the decrease of BMD and the subsequent development of osteoporosis and its complications. Although rare in young and healthy people, when associated with restrictive food disorders, it should raise a red flag in its clinical evaluation. Preventing osteoporosis development and reduction of fracture risk in this population is essential. The current absence of consistent evidence regarding screening of osteoporosis in this particular group should raise awareness and promote further larger-scale studies to establish standardized recommendations concerning not only screening but also pharmacological treatment of osteoporosis in patients with AN.