The impact of evacuation on the incidence of chronic kidney disease after the Great East Japan Earthquake: The Fukushima Health Management Survey

Background: About 146,000 people were forced into long-term evacuation due to the nuclear power plant accident caused by the Great East Japan Earthquake in 2011. Disaster is known to induce hypertension in survivors for a certain period, but it is unclear whether prolonged disaster stress influences chronic kidney disease (CKD). We conducted an observational cohort study to elucidate the effects of evacuation stress on CKD incidence. Methods: Participants were individuals living in communities near the Fukushima nuclear power plant, aged 40–74 years without CKD as of their 2011 general health checkup (non-evacuees: n = 9780, evacuees: n = 4712). We followed new-onset CKD [estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² or proteinuria] using general annual health checkup data from 2012 to 2014. Association between evacuation and CKD incidence was analyzed using the Cox proportional hazard model. Results: Mean age of the participants at baseline was 65 years, 46.7% were men, and baseline eGFR was 75.7 ml/min/1.73 m². During the mean follow-up period of 2.46 years, CKD incidence rate was 80.8/1000 and 100.2/1000 person-years in non-evacuees and evacuees, respectively. Evacuation was a significant risk factor of CKD incidence after adjusting for age, gender, obesity, hypertension, diabetes, dyslipidemia, smoking, and baseline eGFR [hazard ratio (HR): 1.45; 95% confidence interval (CI) 1.35–1.56]. Evacuation was significantly associated with the incidence of eGFR <60 ml/min/1.73 m² (HR: 1.48; 95% CI 1.37–1.60), but not with the incidence of proteinuria (HR: 1.21; 95% CI 0.93–1.56). Conclusion: Evacuation was a risk factor associated with CKD incidence after the disaster.