Prevalence of undiagnosed coeliac syndrome in osteoporotic women

Objectives. The aims of the study were to quantify the prevalence of asymptomatic coeliac disease (CD) in a cohort of osteoporotic females, and to investigate the features of bone loss. Design and subjects. We studied 255 women (mean age 66.6 +/-8.5 SD) with primary osteoporosis (WHO diagnostic criteria). After the first CD screening with the measure of serum IgG antigliadin antibodies (IgG-AGA), 53 women showed a positive test: antibodies to tissue transglutaminase (TG-ab) were subsequently determined to confirm the diagnosis of CD. Bone metabolism was evaluated by: serum and urinary calcium, serum and urinary phosphate, serum alkaline phosphatase, urinary crosslaps, serum 25(OH)D and serum parathyroid hormone. Results. High levels of IgG-AGA and TG-ab were observed in 24 patients with a prevalence of serological disease of 9.4%. These women were characterized, in comparison with the other patients, by a statistically significant reduction in serum 25(OH)D (17.8 +/-7.2 vs. 55.1 +/- 20.3 nmol L-1, P<0.01) together with a significant increase of iPTH (65.1<plus/minus>29.7 vs. 35.1 +/- 20.0 pg mL(-1); P<0.01). Patients with high TG-ab levels showed also slightly raised values of urinary crosslaps (288<plus/minus>88 vs. 270 +/- 90 pm mol(-1) Cr). In IgG-AG positive patients a statistically significant inverse correlation was found between 25(OH)D serum levels and log-transformed TG-ab values (r: -0.95, P<0.001). Intestinal biopsies were obtained in 10 TG-ab positive women and verified CD in six patients. Conclusions. These data support the hypothesis that patients with undiagnosed celiac disease develop high remodelling processes related to calcium malabsorption, secondary hyperparathyroidism and unavailability of vitamin D with a consequent more marked bone loss.