Cardiovascular disease risk factors in patients with hidradenitis suppurativa: a systematic review and meta-analysis of observational studies

Hidradenitis suppurativa (HS) is a chronic, inflammatory, debilitating skin disease. The aim of the study was to systematically review the literature and critically answer the question: In patients with HS, do cardiovascular risk factors appear at a significantly higher rate compared with controls? The main search was conducted in Medline, Embase and the Cochrane Central Register. Studies eligible for inclusion were of case-control, cross-sectional and cohort design, and included comparison of any cardiovascular risk factor(s) in patients with HS with those of control groups. An I-2 value > 50% was considered to show substantial heterogeneity. In this case, DerSimonian and Laird random-effect models were considered to compute pooled odds ratios (OR). Otherwise, a fixed-effects model was suitable. Nine studies, with 6174 patients with HS and 24 993 controls, were included. Significant association of HS with obesity [OR 3.45, 95% confidence interval (CI) 2.20-5.38, P < 0.001], central obesity (OR 2.97, 95% CI 1.41-6.25, P = 0.004), active smoking (OR 4.34, 95% CI 2.48-7.60, P < 0.001), history of smoking (OR 6.34, 95% CI 2.41-16.68, P < 0.001), hypertriglyceridemia (OR 1.67, 95% CI 1.14-2.47, P = 0.009), low high-density lipoprotein (HDL) (OR 2.48, 95% CI 1.49-4.16, P < 0.001), diabetes (OR 2.85, 95% CI 1.34-6.08, P = 0.007) and metabolic syndrome (OR 2.22, 95% CI 1.62-3.06, P < 0.001) was detected. Associations were significant both in population and hospital patients with HS, with hospital HS groups having uniformly higher ORs than the population HS groups. Causality could not be assessed. Heterogeneity was substantial in all analyses. This systematic review indicated that cardiovascular risk factors appear at a significantly higher rate in patients with HS compared with controls. The need for screening of patients with HS for modifiable cardiovascular risks is emphasized.