Bone Metabolism       

Fractures are increased in older patients with TS, but these patients may not have received optimal estrogen treatment in the past. Most studies using dual-energy x-ray absorptiometry find decreased bone mineral density (BMD) (149,  153), but small size may lead to underestimation of BMD by dual-energy x-ray absorptiometry (154). When adjusted for size, women that have received appropriate estrogen treatment usually have normal BMD in trabecular bone, e.g. the spine (149, 154). However, there seems to be an intrinsic, estrogen-independent deficit in cortical bone in TS (149, 155, 156). A baseline BMD should be obtained at the initial visit in the adult clinic, with follow-up depending on the initial result. If the BMD is normal (adjusting for size), additional evaluation need not take place until age 40–50 yr or when the patient plans to discontinue estrogen treatment. If BMD is low in a young woman with TS, one needs to investigate and treat possible contributory factors such estrogen replacement noncompliance, tobacco use, excessive alcohol use, possible celiac disease, or vitamin deficiency. Proper estrogen treatment improves BMD and is the mainstay of bone protection. Adequate calcium and vitamin D intake is essential, because many women have low levels of vitamin D. Weight-bearing exercise is very important in achieving and maintaining BMD and should be encouraged. Bisphosphonates or other antiosteoporotic pharmaceuticals are not recommended for treating osteopenia in young women with TS, because reduced cortical BMD in TS is not proven to lead to increased fractures and bisphosphonates have not been shown to be effective in enhancing cortical BMD in TS. Furthermore, these agents may blunt treatment with newer modalities in the future and are contraindicated in women who might attempt pregnancy. For women with confirmed osteoporosis, especially those at risk for fracture, or who have already sustained a low-impact fracture, the usual medical treatment for osteoporosis is indicated.

This information is an excerpt from: CLINICAL PRACTICE GUIDELINE Care of Girls and Women with Turner Syndrome: A Guideline of the Turner Syndrome Study Group  Carolyn A. Bondy for the The Turner Syndrome Consensus Study Group* National Institutes of Health, National Institute of Child Health and Human Development, Bethesda, Maryland 20892 The Journal of Clinical Endocrinology & Metabolism 92(1):10–25 Printed in U.S.A. Copyright © 2007 by The Endocrine Society doi: 10.1210/jc.2006-1374

The Clinical Practice Guidelines is the most current standard of care for Turner syndrome in the US.  For the full document, go to:  http://press.endocrine.org/doi/pdf/10.1210/jc.2006-1374