Object: Inflammation may provoke cerebral arteriolar ectasia, inducing microaneurysm formation and further promoting intracerebral hemorrhage (ICH). Chronic osteomyelitis (COM) is an inflammatory disorder for which study of its role in ICH is lacking. This study explored whether COM increases the risk of ICH.
Methods: From Taiwan national insurance inpatient claims, 22,052 patients who were newly diagnosed with COM between 1997 and 2010 were identified; 88, 207 age and sex frequency-matched subjects without COM were selected at random for comparison. Risks of ICH associated with COM and comorbidities, including hypertension, diabetes, hyperlipidemia, chronic kidney disease, and drug abuse, were assessed by the end of 2010.
Results: The incidence of ICH was 1.68 times higher in the COM cohort than in the comparison cohort, with an adjusted hazard ratio (HR) of 1.50 (95% CI 1.29-1.74) estimated in the multivariable Cox model. Age-specific analysis showed that the HR of ICH for COM patients decreased with age, with an adjusted HR of 3.28 (95% CI 1.88-5.75) in the < 40-year age group, which declined to 1.11 (95% CI 0.88-1.40) in the elderly. The incidence of ICH increased with the severity of COM; for those with severe COM the adjusted HR was 4.42 (95% CI 3.31-5.89). For subjects without comorbidities, the incidence of ICH was 1.20-fold (95% CI 1.00-1.45) higher in the COM cohort than in the comparison cohort.
Conclusions: This study suggests for the first time that COM is an inflammatory factor associated with increased risk of ICH, especially in younger patients.
Keywords: CKD = chronic kidney disease; COM = chronic osteomyelitis; HR = hazard ratio; ICH = intracerebral hemorrhage; IR = incidence rate; IRR = incidence rate ratio; NHI = National Health Insurance; RA= rheumatoid arthritis; SLE = systemic lupus erythematosus; VZV = varicella-zoster virus; chronic infection; chronic osteomyelitis; inflammatory disease; intracerebral hemorrhage; vascular disorders.