Importance: Hidradenitis suppurativa (HS) is a common inflammatory skin disease. The disease has been associated with cardiovascular (CV) risk factors, but the risk of CV disease in patients with HS is unknown.
Objective: To investigate CV risk in patients with HS.
Design, setting, and participants: A population-based cohort study was conducted from January 1, 1997, to December 31, 2011, using individual-level linkage of nationwide administrative registers. In a study population of 35 368 Danish individuals, 5964 patients aged 18 years or older with a hospital-based diagnosis of HS (cases) were matched 1:5 on age, sex, and calendar time with 29 404 individuals serving as controls.
Main outcomes and measures: Outcomes were myocardial infarction (MI), stroke, CV-associated death, major adverse CV events (MACEs), and all-cause mortality. Incidence rate ratios (IRRs) were estimated by Poisson regression.
Results: The 5964 patients with HS had a mean (SD) age of 37.7 (11.7) years; 4346 (72.9%) were women. In this sample, a total of 62 (42 749.0 person-years) MIs, 74 (42 647.8 person-years) ischemic strokes, 63 (42 941.7 person-years) CV-associated deaths, 169 (42 463.5 person-years) MACEs, and 231 (42 941.7 person-years) all-cause deaths occurred during follow-up. Adjusted (age, sex, socioeconomic status, smoking, comorbidity, and medication) IRRs (95% CIs) were 1.57 (1.14-2.17) for MI, 1.33 (1.01-1.76) for ischemic stroke, 1.95 (1.42-2.67) for CV-associated death, 1.53 (1.27-1.86) for MACEs, and 1.35 (1.15-1.59) for all-cause mortality. When patients with severe psoriasis were used as controls, the adjusted IRRs in patients with HS were 1.00 (0.74-1.35) for MI, 0.93 (0.71-1.22) for ischemic stroke, 1.58 (1.17-2.12) for CV-associated death, 1.08 (0.90-1.29) for MACEs, and 1.09 (0.94-1.28) for all-cause mortality.
Conclusions and relevance: Hidradenitis suppurativa was associated with a significantly increased risk of adverse CV outcomes and all-cause mortality independent of measured confounders. The risk of CV-associated death was higher in patients with HS compared with the risk in those with severe psoriasis. The results call for increased awareness of this association and for studies of its clinical consequences.