Herpes zoster and the risks of osteoporosis and fracture: a nationwide cohort study

This study aimed to investigate the association between herpes zoster (HZ) and the risks of osteoporosis and fracture. We conducted a nationwide retrospective cohort study using the National Health Insurance Research Database of Taiwan. The study enrolled 63,786 patients: 31,893 diagnosed with HZ between 2000 and 2012 were included in the HZ cohort, and 31,893 matched controls without HZ were included in the non-HZ cohort, with 1:1 exact matching for age, sex, and index year. Hazard ratios (HRs) were calculated for the risks of osteoporosis and fracture according to the HZ status using the Cox proportional hazards regression models. During a mean follow-up period of 6.0years, 5597 and 4639 patients in the HZ and non-HZ cohorts, respectively, developed osteoporosis or fractures (incidence rate: 29.8 vs. 23.8 per 1000 person-years). HZ diagnosis was significantly associated with an elevated risk of developing osteoporosis or fracture (adjusted HR [aHR]=1.20, p<0.001). On analyses for each individual event, the HZ cohort had significantly increased risks for all events, including osteoporosis (aHR=1.32, p<0.001), hip fracture (aHR=1.34, p<0.001), vertebral fracture (aHR=1.38, p<0.001), and other fractures (aHR=1.10, p<0.001) compared with the non-HZ cohort. Patients with postherpetic neuralgia had especially higher risks of osteoporosis and fracture. Age- and sex-stratified analyses also revealed similar patterns. In conclusion, HZ was independently associated with an increased risk of osteoporosis and fracture. Further studies are required to investigate its underlying mechanisms.