The risk of herpes zoster is positively associated with obesity, especially morbid obesity.

This study aimed to investigate the association between obesity and herpes zoster (HZ) occurrence. This study used data covering 2 million people in Taiwan in 2000, which were obtained from the National Health Insurance Research Database. The cohort study observed aged 20-100 years with obesity from 2000 to 2017 (tracking to 2018). Obesity was indicated by the presence of two or more outpatient diagnoses or at least one admission record. And, obesity was categorized into non-morbid obesity and morbid obesity. Patients with HZ before the index date were excluded. The obesity cohort and control cohort were matched 1:1 according to age, sex, comorbidities, and index year. There were 18,855 patients in both the obesity and control cohorts. The obesity cohort [adjusted hazard ratio (aHR) 1.09] had a higher risk of HZ than the control cohort. Further analysis, the morbid obesity group (aHR 1.47), had a significantly higher risk of HZ than the non-morbid obesity group. Among the patients without any comorbidities, the patients with obesity had a significantly higher risk of developing HZ than the patients without obesity (aHR 1.18). Obese patients are at a higher risk of HZ development, especially in the patients with morbid obesity. Weight reduction is critical for preventing the onset of chronic diseases and decreasing the risk of HZ in patients with obesity.