Obstructive Sleep Apnea in Inflammatory Arthritis: Disease-Specific Evidence and Clinical Implications

Background/Objectives: Obstructive sleep apnea (OSA) may complicate fatigue and cardiovascular risk assessment in rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (axSpA). We evaluate the strength and clinical applicability of disease-specific evidence. Methods: This expert narrative review uses a documented PubMed/MEDLINE update through 28 October 2026, supplemented by reference-list checking, general OSA trials, and professional guidance. Evidence is appraised qualitatively by ascertainment, selection, adjustment, and directness. Results: RA has the largest but most heterogeneous evidence base: pooled OSA prevalence was 29.8% (95% confidence interval [CI], 15.2–46.7%; I2 = 99.6%), with mixed definitions. In PsA, 21/42 polysomnography (PSG)-tested volunteers had OSA (50%; descriptive 95% CI, 35.5–64.5%), whereas 22/247 clinic patients had a recorded diagnosis (8.9%; 95% CI, 6.0–13.1%). These estimates are not interchangeable. Ankylosing spondylitis (AS) findings differ between matched objective testing and administrative cohorts. Adiposity, demographics, medication, and surveillance constrain interpretation. Positive airway pressure has established sleep-related indications; improvements in arthritis activity or arthritis-specific cardiovascular events remain unproven. Tirzepatide evidence concerns adults with obesity and moderate-to-severe OSA. Conclusions: PsA and axSpA evidence remains limited. Shared biology supports a conceptual hypothesis rather than a demonstrated causal axis. Targeted case finding should lead to guideline-concordant objective diagnosis; universal asymptomatic rheumatology screening and disease-modifying effects of OSA treatment are not established.