Phosphate Overload

Studies in mice demonstrated that dietary phosphate (Pi) loading that mimic the level of US adult consumption leads to reduced spontaneous locomotor activity, exercise capacity, and reduced resting metabolic rate when in normal mice by impairing skeletal muscle mitochondrial function and fat oxidation. However, relevance of this findings in humans remains unknown.

The goal of this observational study is to create, manage and analyze a multicenter national database of patients affected by diseases of phosphate metabolism, aimed at collecting and studying anamnestic, diagnostic, genetic, clinical, and therapeutic data in a relatively wide number of patients with these rare inherited metabolic disorders in Italy. The study will include 28 specialist clinical centers of endocrinology, pediatric endocrinology, and pediatrics, located throughout the Italian territory, and to which patients refer from all the 20 regions of Italy. Data will be collected over time, both in retrospective and prospective manners, during the 10-year duration of the study, starting from the recruiting visit (basal visit) and then during each follow-up visits patients will undergo for the control of disease at the recruiting clinical centers. Collected data will include both the most classic traits of each disease and the less common ones, with the final goal of refining and deepening medical knowledge in the field of these rare inherited metabolic disorders, and, thus, to be able to define optimal tailored diagnostic, clinical, and therapeutic management of patients, improving their quality of life. The main aspects this observational study aims to assess and clarify are: 1. Evaluation of prevalence and incidence of diseases of phosphate metabolism in Italy, globally and for single different disorders 2. Clinical and biochemical characterization of different diseases of phosphate metabolism (according to single disorders and different genetic base), through both cross-sectional and longitudinal analyses of collected data 3. Evaluation of skeletal health and bone fragility in patients with diseases of phosphate metabolism, globally and based on single phosphate metabolism disorder, gender, and age 4. Self-evaluation of health-related quality of life in patients with a disease of phosphate metabolism 5. Over time evaluation of responses to therapies in patients with diseases of phosphate metabolism. The study will include a single cohort of female and male patients of any age, affected by a disease of phosphate metabolism. The study does not include either any control group/comparison group or healthy volunteers. The study itself does not involve any medical intervention or drug administration. Therapies for which response outcomes will be collected in the database, are those commonly employed for the treatment of diseases of phosphate metabolism, regardless of patients' inclusion in this observational study.