Risk factors for cardiovascular diseases in patients with vitiligo: an analysis of current evidence

Objective The relationship between vitiligo and cardiovascular diseases remains controversial. This study aimed to systematically review the evidence comparing cardiovascular disease risk factors between patients with vitiligo and controls and to perform a meta-analysis of the results.Data sources A comprehensive database search was performed for all studies in PubMed, EMBASE, and Cochrane Central Register databases from inception to November, 2023. The main keywords used were vitiligo, hypertension, diabetes, hyperlipidemia, metabolic syndrome, obesity, smoking, alcohol consumption, C-reactive protein, and homocysteine.Study selection Only observational studies and no randomized controlled trials were included. Of the 1269 studies initially selected, the full texts of 108 were assessed for eligibility, and 74 were ultimately included in the analysis.Data extraction and synthesis Three reviewers independently extracted the following data: study design, number and characteristics of participants, inclusion indicators, and disease duration. A meta-analysis of the single-group rates was performed for the diabetes, hypertension, hyperlipidemia, and obesity groups. Random-effects or fixed-effects models were used to calculate the sample-size weighted averages for the indicators included in the studies.Main outcomes and measures The primary outcomes were co-morbidity analysis and co-morbidity rates of vitiligo with metabolic syndrome, obesity, hyperlipidemia, hypertension, and diabetes mellitus. Secondary outcomes were factors associated with vitiligo and cardiovascular disease.Results This meta-analysis concluded that comorbidities in patients with vitiligo included metabolic syndrome, diabetes, obesity, hyperlipidemia, and hypertension, with comorbidity rates of 28.3%, 6.0%, 38.5%, 43.0%, and 15.8%, respectively. Simultaneously, we showed that the vitiligo group differed significantly from the control group in the following aspects: fasting blood glucose, insulin, systolic and diastolic blood pressure, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, homocysteine, C-reactive protein, smoking, and alcohol consumption. However, no significant differences were observed between the vitiligo and control groups in terms of waist circumference, body mass index, or phospholipid levels.Limitations The vast majority of the studies were from Eastern countries; therefore, extrapolation of these results to Western populations is questionable. The significant heterogeneity may be due to different protocols, doses, durations, center settings, population registries, etc., which severely compromise the validity of the results.Conclusion This study summarized not only the factors associated with, but also those not associated with, cardiovascular disease in patients with vitiligo. This study provides a foundation for the prevention and treatment of cardiovascular disease in patients with vitiligo.