The bidirectional association between hemorrhoidal disease and varicose veins: a nationwide population-based cohort study.

Objective: Hemorrhoidal disease (HD) and varicose veins (VV) are both common diseases. The aim was to investigate the association between them.

Methods: A nationwide cohort study was conducted using the Taiwan National Health Insurance Research Database (NHIRD) from 2005 to 2021, which included information of over 31 million beneficiaries. To assess the risk of developing VV among HD patients, records of 832,310 patients with HD diagnoses (the HD cohort) and those of propensity score-matched patients without HD diagnoses (the non-HD cohort) were identified and compared. Hazard ratios (HRs) and 95% confidence intervals (CIs) derived from the Cox proportional hazards model were used to estimate the association risks. Similarly, an opposite direction was approached using records of 112,027 patients with VV diagnoses (the VV cohort) to assess the risk of developing HD among VV patients.

Results: HD was associated with an increased risk of VV (adjusted HR, 1.52; 95% CI: 1.47-1.57). Similarly, VV were associated with an increased risk of HD (adjusted HR, 1.50; 95% CI: 1.45-1.55). The associations between the two diseases were evident in both sexes and all age groups. Patients with comorbid HD and VV had higher incidences of mitral valve regurgitation (P < 0.001), hernia (P < 0.001), varicocele (P = 0.008), and mortality (P = 0.006).

Conclusions: This study revealed a significant bidirectional association between HD and VV. It is recommended that physicians be mindful of either condition in patients already diagnosed with the other, as their coexistence could imply the potential for additional associated connective tissue diseases and adverse long-term outcomes.