Coeliac disease-specific tissue transglutaminase autoantibodies are associated with osteoporosis and related fractures in middle-aged women

Objective. To investigate whether the serological marker for coeliac disease, tissue transglutaminase autoantibody (tTGAb), is associated with decreased bone mass density (BMD) and increased frequency of fractures in middle-aged women screened for osteoporosis. Material and methods. The study comprised 6480 women (mean age 56 years, range 50-64) who answered a number of questionnaires and who underwent dual X-ray absorptiometry of the wrist bone. Serum samples were analysed for tTGAb using radioligand binding assays. A tTGAb level of 4 U/ml was used to determine a positive value and a level of 17 U/ml was used as an alternative discrimination of high levels. Results. A tTGAb level 4 U/ml was found among 90/6480 (1.4%) women and correlated with lower BMD (multiple linear regression coefficient -382.1; 95% CI = - 673.6-90.7, p=0.011) and with fracture frequency (r=0.18, p=0.023). The 59 women with tTGAb levels 17 U/ml had a lower BMD (0.410.08 g/cm2 versus 0.440.08 g/cm2, p=0.001) and a lower T-score (-1.401.28 versus -0.901.40, p=0.003) as well as a higher prevalence of osteoporosis (13.4% versus 6.5%, p=0.008) compared with the remaining 6421 women with tTGAb levels 17 U/ml. Furthermore, fracture frequency was more pronounced in women with tTGAb levels 17 U/ml, among whom 19/59 (32.2%) had fractures during the study period compared with 1204/6421 (18.8%) among women with tTGAb levels 17 U/ml (p=0.009). Conclusions. High levels of tTGAb indicating coeliac disease are associated with lower BMD and higher fracture frequency in women between 50 and 64 years of age. Osteometry is therefore warranted in middle-aged women detected with tTGAb.