Osteoporosis and fractures in Turner syndrome-importance of growth promoting and oestrogen therapy.

Abstract

Turner syndrome (TS) is a chromosomal aberration (45,X) characterized by endogenous oestrogen deficiency and short stature. The aim was to study body composition, bone mineral density, fracture frequency, social and life style factors and biochemical bone markers, as well as hormones, in adults with TS in comparison with a female random population sample. Seventy women with TS responded to questionnaires. They underwent physical examination, bone mineral density measurement with Dual Energy X-ray Absorptiometry (DEXA) and blood sampling. Mean age was 31 +/- 12 (range 16-71) years. A random population sample of women from the WHO MONICA Project, Göteborg (25-64 years) served as controls (n = 740). Women with TS were shorter than the controls and had lower body weight and lean body mass (P < 0.0001). Body mass index and waist/hip circumference ratio were higher in TS (P < 0.0001). Osteoporosis was present in seven TS women, six above 45 years of age. None of these had received oestrogen substitution continuously. Fractures (all types) were reported by 11 (16%) TS women (six (50%) above 45 years) compared with 5% in the population sample (P < 0. 001). Four TS women with fractures had osteoporosis, all above 45 years of age. Osteoporosis and fractures did not differ between women with the 45,X karyotype and those with mosaicism. Impaired hearing was reported by 40%, and 73% wore glasses. Six percent among TS were smokers compared with 25% in the population (P < 0.001). TS women reported a lower degree of leisure time physical activity than controls (P < 0.001). Parathyroid hormone and osteocalcin were higher among TS (P < 0.02 and 0.001). Insulin-like growth factor-I was similar. Ninety-one percent of all TS had oestrogen substitution and 96% of TS below 25 years of age had received growth hormone treatment. Osteoporosis and fractures were common above, but not below, 45 years of age in Turner syndrome. It is probable that modern therapy, including growth promoting and continuous oestrogen therapy, will prevent osteoporotic fractures in the future.