Bone Structural Parameters in Adults with Cystic Fibrosis: Contribution of Adherence to the Mediterranean Diet

Background: Cystic fibrosis-related bone disease (CFBD) is a comorbidity whose prevalence is increasing. Conventional areal DXA (aDXA) only assesses part of bone strength, whereas new techniques provide a more comprehensive assessment of bone structure. However, these tools are rarely implemented systematically. Furthermore, the contribution of clinical factors to bone structural parameters remains insufficiently characterized. Therefore, this study aimed to comprehensively assess cortical and trabecular bone alterations in adults with CF, and to explore clinical and lifestyle factors associated with bone health. Methods: A case–control study was conducted including 32 adults with CF and 70 healthy controls matched by age, sex, and BMI. Bone status was assessed using aDXA, trabecular bone score (TBS), and three-dimensional DXA (3D-DXA). Clinical data, body composition, lifestyle variables, and biochemical markers were collected. Multivariate linear regression models were applied to explore factors associated with bone parameters. Results: Twenty-two percent of CF people had prevalent fragility fractures and the percentage with low bone mass was significantly higher (28.1% vs. 5.7%; p < 0.001). TBS categories indicated more degraded microarchitecture in CF (p = 0.002). Cortical and trabecular 3D-DXA values were also significantly lower (p < 0.001). Adherence to the Mediterranean diet (MedDiet) was significantly associated with most of the bone parameters evaluated. Other variables associated with bone parameters included sex, fat-free and fat mass, prolonged corticosteroid use, intake of oral nutritional supplements, FEV1, disease duration and P1NP-values. Conclusions: Adults with CF revealed significant cortical and trabecular structural deficits. Among the evaluated factors, adherence to MedDiet was associated with several bone parameters, suggesting a potential role of dietary patterns in CF bone health. Further studies are needed to confirm these preliminary results.