Constipation and risk of cardiovascular diseases: a Danish population-based matched cohort study

Objectives To assess the risks of myocardial infarction, stroke, peripheral artery disease, venous thromboembolism, atrial fibrillation or atrial flutter and heart failure in patients with constipation compared with a general population cohort. Design Population-based matched cohort study. Setting All Danish hospitals and hospital outpatient clinics from 2004 to 2013. Participants Patients with a constipation diagnosis matched on age, sex and calendar year to 10 individuals without constipation from the general population. Main outcomes measures Comorbidity-adjusted and medication-adjusted hazard ratios (aHRs) for cardiovascular outcomes based on Cox regression analysis. Results 83 239 patients with constipation were matched to 832 384 individuals without constipation. The median age at constipation diagnosis was 46.5% and 41% were men. Constipation was strongly associated with venous thromboembolism (aHR 2.04, 95% CI 1.89 to 2.20), especially splanchnic venous thrombosis (4.23, 95% CI 2.45 to 7.31). Constipation was also associated with arterial events, including myocardial infarction (1.24, 95% CI 1.14 to 1.35), ischaemic stroke (1.50, 95% CI 1.41 to 1.60), haemorrhagic stroke (1.46, 95% CI 1.26 to 1.69), peripheral artery disease (1.34, 95% CI 1.20 to 1.50), atrial fibrillation or atrial flutter (1.27, 95% CI 1.20 to 1.34) and heart failure (1.52, 95% CI 1.42 to 1.62). The associations were strongest during the first year after the constipation diagnosis and strengthened with an increased number of laxative prescriptions. Conclusions Constipation was associated with an increased risk of several cardiovascular diseases, in particular venous thromboembolism.