Long-term narrowband ultraviolet B (NB-UVB) therapy may decrease risk for cardiovascular and cerebrovascular events in patients with vitiligo, according to study data published in the Journal of the European Academy of Dermatology and Venereology.
Investigators extracted data from the Korean National Health Insurance claims database for the years 2007 through 2017. Patients aged ≥40 years with a clinical diagnosis of vitiligo were eligible for study inclusion. NB-UVB exposure was dichotomized as “no exposure” (<3 sessions) or “long-term exposure” (≥100 sessions). Patients with long-term exposure were propensity score matched by age, sex, insurance type, and medical comorbidities to patients with <3 sessions of exposure. Matched medical comorbidities included diabetes, hypertension, and hyperlipidemia. The primary outcome was incidence of cardiovascular or cerebrovascular events, including ischemic heart disease, myocardial infarction, cerebrovascular infarction, and cerebrovascular hemorrhage. Cox proportional hazards models were used to assess the impact of NB-UVB phototherapy on cardiovascular and cerebrovascular outcomes.
A total of 3229 patients with ≥100 phototherapy sessions were propensity score matched to 9687 patients with <3 phototherapy sessions. In the long-term phototherapy group, the incidence rate of all cardiovascular and cerebrovascular events was 60.0 per 10,000 person-years. In patients with no phototherapy exposure, the incidence rate increased to 95.6 per 10,000 person-years. The risk for all events was significantly lower in the phototherapy group (hazard ratio [HR], 0.637; 95% confidence interval [CI], 0.523-0.776). Patients with long-term phototherapy exposure were also less likely to experience cardiovascular events (HR, 0.682; 95% CI, 0.495-0.940), particularly ischemic heart disease (HR, 0.700; 95% CI, 0.498-0.984). The risk for any cerebrovascular event was similarly reduced in the long-term phototherapy group (HR, 0.601; 95% CI, 0.470-0.769). Specifically, phototherapy was associated with lower risk for cerebrovascular infarction and hemorrhage, although the latter association was not statistically significant.
In a large cohort of patients with vitiligo, long-term NB-UVB exposure appeared to reduce the incidence of cardiovascular and cerebrovascular events. However, investigators noted that no data were available on body mass index, family history, smoking history, or lifestyle. These major confounding factors should be assessed in future studies. “Our findings provide clinicians and researchers with insights into the beneficial effects of UV radiation on the cardiovascular system,” investigators wrote. “[O]ur findings may [also] be useful for patients with vitiligo who are concerned about the systemic adverse effects of long-term NB-UVB phototherapy.”
Bae JM, Kim YS, Choo EH, et al. Both cardiovascular and cerebrovascular events are decreased following long-term NB-UVB phototherapy in patients with vitiligo: a propensity-score matching analysis [published online July 23, 2020]. J Eur Acad Dermatol Venereol. doi: 10.1111/jdv.16830