Overall and by subtype epidemiology of idiopathic inflammatory myopathies among African descent patients with free access to high standard healthcare
Authors' conclusion
There is a high incidence and prevalence of IIM in the Caribbean Island of Martinique, and a pulmonary and cardiac threat at IIM diagnosis in African descent population.
Study context
- Population
- African descent patients with adult-onset IIM, University Hospital of Martinique, January 1, 2000 to June 2023
- Participants
- 174 patients
- Exposure
- Anti-synthetase syndrome (ASyS) vs overlap myositis (OM) vs dermatomyositis (DM) vs polymyositis (PM) vs immune-mediated necrotizing myositis (IMNM) vs IBM
- ASySn = 55
- OMn = 44
- DMn = 44
- PMn = 16
- IMNMn = 14
- IBMn = 1
- Outcome
- Epidemiology (incidence and prevalence) of IIM
Methodological detailssingle-centre (island's only tertiary care center)
- Single-centre (island's only tertiary care center)
Main finding
As reported in the abstract
IIM epidemiology
Mean IIM incidence
2.34/100,000
2022 prevalence of IIM (per 100,000 inhabitants)
32.2/100,000
Observational data: associations, not effects.
Further findings
Time from first symptoms to diagnosis
- Median time from first symptoms to diagnosis, months [2.0 to 12.3]
- 4.2
Most frequent manifestations
%
- Arthralgia
- 65
- Muscle weakness
- 61
- Skin DM lesions
- 53
Interstitial lung disease (ILD) and cardiac involvement at diagnosis
%
- ILD, 77 patients
- 52
- Cardiac involvement, 28 patients
- 16
ASyS vs other subtypes
- ASyS more frequently clinically amyopathic
- P < 0.05
- ASyS more frequently ILD
- P < 0.05
Relapse after treatment
- Relapsed, 69 patients
- 40 %
- Median time to relapse, years [1.1 to 7.2]
- 2.8
Original publication
Overall and by subtype epidemiology of idiopathic inflammatory myopathies among African descent patients with free access to high standard healthcare. Semin Arthritis Rheum. Published 8 November 2025. doi:10.
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