Importance of Estrogen on Bone Health in Turner Syndrome: A Cross-Sectional and Longitudinal Study Using Dual-Energy X-Ray Absorptiometry

• Published in: The journal of clinical endocrinology and metabolism Vol. 89; no. 1; pp. 193 - 199
• Main Authors: Högler, Wolfgang, Briody, Julie, Moore, Bin, Garnett, Sarah, Lu, Pei Wen, Cowell, Christopher T.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Endocrine Society 01-01-2004; Copyright by The Endocrine Society
• Subjects: Absorptiometry, Photon; Adolescent; Adult; Aging; Biological and medical sciences; Body Height; Bone Density - physiology; Bone Diseases, Metabolic - epidemiology; Bone Diseases, Metabolic - etiology; Child; Child, Preschool; Cross-Sectional Studies; Estrogens - physiology; Female; Female genital diseases; Femur Neck; Gynecology. Andrology. Obstetrics; Humans; Longitudinal Studies; Lumbar Vertebrae; Medical sciences; Non tumoral diseases; Puberty; Turner Syndrome - complications; Turner Syndrome - physiopathology; Chromosomal aberration; Human; Puberty; Dysgenesia; Genital system; Estrogen; Sexual differentiation disorder; X ray; Turner syndrome; Ovarian hormone; Female genital diseases; Osteoarticular system; Bone mass; Malformation; Gonad; Cross sectional study; Dual energy absorptiometry; Bone; Sex steroid hormone; Osseous tissue; Muscle mass
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2003-030799

Osteoporosis and fractures are features in adults with Turner syndrome (TS). Using dual-energy x-ray absorptiometry, correcting bone mineral content (BMC) for height and lean mass (LTM) avoids misclassification of short children as osteopenic. Total body (TB), lumbar spine (LS), and femoral neck (FN) dual-energy x-ray absorptiometry scans were performed on 83 patients with TS (aged 4–24 yr). A prepubertal subgroup (n = 17) receiving GH was followed for 24 months.
Age z-scores for height, TB BMC, LTM, the BMC/LTM ratio, and LS volumetric bone mineral density (vBMD) decreased significantly (P < 0.001) with age in prepubertal subjects (n = 51) but were constant in the combined pubertal and postmenarchal group (n = 32). Osteopenia was found in 14.5% (TB), 15.8% (LS), and 28.4% (FN) of patients. In the longitudinal subgroup, TB BMC z-scores decreased by −0.28 (0.31) in subjects remaining prepubertal (n = 11) but increased by 0.71 (0.56) in subjects entering puberty (n = 6; P = 0.007). The z-scores for height and LTM increased in both groups.
Our results show a height-independent prepubertal decrease in bone mass accrual, which ceased with puberty. Optimizing bone mass in TS may require earlier induction of puberty than currently recommended. However, reduced FN volumetric bone mineral density and a dissociation of bone and muscle measures were age independent, suggesting an additional intrinsic bone defect.