Ultraviolet Radiation Exposure and the Risk of Herpes Zoster in Three Prospective Cohort Studies.

Abstract

To examine the association between ultraviolet radiation (UVR) exposure and the risk of herpes zoster (HZ) in 3 prospective cohorts. We included 205,756 participants from the Health Professionals Follow-up Study (HPFS; 1986-2008), Nurses' Health Study (NHS; 1996-2012), and Nurses' Health Study II (NHS II; 1991-2013). Ambient UVR exposure was based on updated geocoded address histories linked with a high-resolution spatiotemporal ultraviolet model. Incident HZ cases were identified by self-reported clinician diagnosis. Sunburn history and medical, lifestyle, and dietary factors were assessed using biennial questionnaires. Multivariable Cox proportional hazards models were used. A total of 24,201 cases of HZ occurred during 3,626,131 person-years. Ambient UVR exposure was associated with a higher risk of HZ in men (HPFS: multivariable-adjusted hazard ratio [MVHR] comparing highest vs lowest quintiles, 1.14; 95% CI, 1.02-1.29; P=.03 for trend) but not in women (NHS: MVHR, 0.99; 95% CI, 0.93-1.05; NHS II: MVHR, 0.96; 95% CI, 0.90-1.03). A higher lifetime number of severe sunburns was associated with a higher risk of HZ in all cohorts (HPFS: MVHR for ≥10 sunburns vs none, 1.08; 95% CI, 0.96-1.20; P=.02 for trend; NHS: MVHR, 1.14; 95% CI, 1.05-1.22; P=.01 for trend; NHS II: MVHR, 1.13; 95% CI, 1.00-1.28; P<.001 for trend). Ambient UVR exposure was associated with a higher risk of HZ in men but not in women. A history of severe sunburn was associated with a modest increased risk of HZ in men and women, possibly because of immunosuppression from overexposure to the sun.