Prevalence, incidence, and recovery of metabolic syndrome after the fukushima nuclear power plant disaster: A 10-year longitudinal study

After the 2011 Fukushima nuclear power plant accident, the prevalence of metabolic syndrome sharply increased in municipalities near the nuclear power plant, where a massive evacuation of community residents occurred (the evacuation area). However, after the initial increase, the rate of increase in metabolic syndrome in the evacuation area was slower than that in the surrounding area (non-evacuation area). In this study, we compared the incidence of and recovery from metabolic syndrome as well as its prevalence between evacuation and non-evacuation areas during the 10 years after the accident to explore whether the slower increase in metabolic syndrome after the initial increase in the evacuation area stemmed from suppressed incidence or from fast recovery. We analyzed specific health check-up data of community residents aged 40-74 in Fukushima Prefecture from fiscal year (FY) 2012 to FY 2021 (N = 710,201). To explore the prevalence of metabolic syndrome, we examined the associations of time, residential area, and their interaction with metabolic syndrome using mixed-model repeated measures. We used data from those without metabolic syndrome in FY 2012 to investigate the incidence. We similarly examined the associations of time, residential area, and their interaction with metabolic syndrome using FY 2013 to FY 2021 data. To explore recovery, we used the data of those with metabolic syndrome in FY 2012 and repeated the same procedure. The rate of increase in the prevalence and incidence of metabolic syndrome was slower in the evacuation area than in the non-evacuation area. On the other hand, as for the recovery, the time trend of metabolic syndrome did not differ between the two areas. The slower increase in metabolic syndrome in the evacuation area was partly explained by the slower incidence in the evacuation area but not by recovery.