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 +/- 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 +/- 88 vs. 270 +/- 90 microm 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.