Objectives Chronic inflammatory disease may trigger vascular atherosclerosis. This study aimed to determine whether chronic osteomyelitis (COM) is linked to an increased risk of coronary heart disease (CHD).

Methods A national insurance claim dataset of more than 23 million enrolees was used to identify 15 054 patients with newly diagnosed COM and 60 216 randomly selected age-matched and gender-matched controls between 2001 and 2009 for comparing the risk and incidence of CHD. The study period was from the entry date to the first date of the following events: the diagnosis of CHD, death, withdrawal from the Taiwan National Health Insurance programme or the end of 2010. The analysis of the CHD risk was performed using Cox proportional hazards regression model.

Results During a follow-up period of 67 927 person-years, the overall incidence rate of CHD in COM cohort was 1.95 times higher than non-COM cohort (16.66 vs 8.52 per 1000 person-years). After controlling age, gender and four comorbidities (hypertension, diabetes, hyperlipidaemia and stroke), the risk remained significantly higher in the COM cohort than the control group (adjusted HR=1.65, 95% CI 1.54 to 1.78, p<0.001). In age-stratified analysis, the younger population had a stronger association between COM and CHD risk than the elderly (from HR=3.42, 95% CI 1.60 to 7.32 in age <35 to HR  1.39, 95% CI 1.15 to 1.68 in age ≥80).

Conclusions This study demonstrates that COM is an independent risk factor for CHD, particularly in the younger population. Further studies are necessary to explore the underlying mechanisms linking COM and CHD.