Paget’s disease in Portugal

The Rheumatology Department of Unidade Local de Saúde Santa Maria (ULSSM) in Lisbon has roots dating back to 1977 and has long had a particular focus on metabolic bone diseases. In this study, the Metabolic Bone Diseases clinical team of this Department reviewed more than 40 years of experience caring for people with Paget’s Disease of Bone (PDB). The team analysed 80 patients diagnosed between 1974 and 2021, focusing on where they were born and lived, possible environmental exposures, the pattern of bone involvement, symptoms, complications and response to treatment.

The majority of patients were female and the age at diagnosis was around 63 years. Of note, many patients came from rural backgrounds, with a particularly high proportion born in Alentejo, a region in southern Portugal where PDB has previously been reported as more frequent. However, only a small proportion of patients had a family history of PDB. Many had also had long-term contact with domestic animals or livestock. These findings do not prove that rural living or animal contact causes the disease, but they support the idea that geography, environment and genetic susceptibility may interact in its development.

The most common symptom was bone pain. Around half of the patients had disease affecting more than one bone, known as polyostotic disease. This form was associated with greater bone turnover activity on blood tests and with involvement of particular skeletal sites, including the pelvis, spine, femur, sacrum and skull.

Most patients were treated with zoledronate, a bisphosphonate given by infusion. Treatment was followed by an improvement in bone remodelling markers in the blood and the majority of patients did not need retreatment. Notably, patients initially treated with zoledronate tended to remain well controlled for longer than those treated with other medicines.

This Portuguese cohort highlights the importance of geographic patterns in PDB and reinforces the role of zoledronate as an effective treatment associated with long periods of remission. In the future, we intend to perform genetic studies of this group of patients, which may help to clarify why some people are more susceptible to the condition, why it appears to cluster in particular regions and why bone involvement differs between patients.

• Roberto Pereira da Costa and José Carlos Romeu on behalf of the authors.

Reference

Lopes, A.R., Matos, C.O., da Costa, R.P., Travessa, A., Dias, P., Martins, P., Tenazinha, C., Fernandes, S., Barros, R., Cruz-Machado, A.R. and Romeu, J.C., 2026. Paget's disease of bone: Clinical and epidemiological characterisation of the population of a Portuguese tertiary centre. Bone, 208, p.117857.