Increased risk of herpes zoster in patients with peptic ulcers: A longitudinal follow-up study using a national sample cohort.

The purpose of this study was to investigate the association of herpes zoster infection with peptic ulcer disease in a Korean population. The Korean National Health Insurance Service selects samples directly from the entire Korean population database, and 1,125.691 participants with 114,369,638 medical claim codes were selected from the entire Korean population (50 million). A total of 127,802 peptic ulcer disease participants were matched with 127,802 control participants at a ratio of 1:1, considering age group, sex, income group, region of residence, hypertension, diabetes, and dyslipidemia. We analyzed stratified Cox proportional hazard models to calculate the hazard ratios of peptic ulcer with respect to herpes zoster. For subgroup analyses, we divided the participants by age, sex. and time periods after the index date. The rate of herpes zoster was higher in the peptic ulcer group (9.1% [11,669/127,802]) than in the control group (7.4% [9,397/127,802], P < .001). The adjusted hazard ratio of herpes zoster was 1.24 (95% CI = 1.21-1.28. P < .001). In subgroup analyses performed according to age and sex, all crude and adjusted hazard ratios of herpes zoster were higher in the peptic ulcer disease group than in the control group (each P < .05). In another subgroup analysis according to follow-up periods, the crude and adjusted hazard ratios of herpes zoster were higher in the peptic ulcer disease group than in the control group except for < 1 year periods after the index dates (each P < .001). The hazard ratios of herpes zoster were significantly increased in the peptic ulcer group compared with those in the control group in all age and sex groups.