Changes in metabolic profiles after the Great East Japan Earthquake: a retrospective observational study

Abstract

Background: A magnitude 9.0 earthquake struck off eastern Japan in March 2011. Many survivors have been living in temporary houses provided by the local government since they lost their houses as a result of the great tsunami (tsunami group) or the expected high-dose radiation resulting from the nuclear accident at the Fukushima Daiichi Nuclear Power Plant (radiation group). The tsunami was more than 9 m high in Soma, Fukushima, which is located 30 km north of the Fukushima Daiichi Nuclear Power Plant and adjacent to the mandatory evacuation area. A health screening program was held for the evacuees in Soma in September 2011. The aim of this study was to compare the metabolic profiles of the evacuees before and after the disaster. We hypothesized that the evacuees would experience deteriorated metabolic status based on previous reports of natural disasters.

Methods: Data on 200 subjects who attended a health screening program in September or October of 2010 (pre-quake) and 2011 (post-quake) were retrospectively reviewed and included in this study. Pre-quake and post-quake results of physical examinations and laboratory tests were compared in the tsunami and radiation groups. A multivariate regression model was used to determine pre-quake predictive factors for elevation of hemoglobin A1c (HbA1c) in the tsunami group.

Results: Significantly higher values of body weight, body mass index, waist circumference, and HbA1c and lower high-density lipoprotein cholesterol levels were found at the post-quake screening when compared with the pre-quake levels (p = 0.004, p = 0.03, p = 0.008, p < 0.001, and p = 0.03, respectively). A significantly higher proportion of subjects in the tsunami group with high HbA1c, defined as ≥ 5.7%, was observed after the quake (34.3%) than before the quake (14.8%) (p < 0.001). Regional factors, periodic clinic visits, and waist circumference before the quake were identified as predictive factors on multivariate analysis for the deterioration of HbA1c.

Conclusions: Post-quake metabolic variables were impaired compared with pre-quake baseline levels in survivors who were living in temporary houses. A natural disaster could affect metabolic profiles, and careful follow-up for survivors should be planned.

Figure 1

Geographic details of Soma and Iitate. Fukushima prefecture (dark area in maps A and B, where the scale bars indicate 500 km and concentric circles show 100-km intervals) is located southwest of the center of the 2011 Great East Japan Earthquake. Soma City (“S” on the enlarged map C, where the scale bar indicates 25 km) is located approximately 170 km from the center of the earthquake (the dotted circle indicates 200 km from the center of the earthquake) and 30 km from the Fukushima Daiichi Nuclear Power Plant (“N” on map C, where solid concentric circles indicate 25-km intervals). Soma City experienced an earthquake expressed as a “level 6-low” on the 7-point Japanese seismic intensity scale, indicating that it is difficult for people to remain standing. The tsunami was more than 9.3 m in height in the city. The village of Iitate is on the mountainous side of Soma and in a northwestern direction from the Fukushima Daiichi Nuclear Power Plant (“I” on map C). Evacuees are living in temporary prefabricated houses on hills (D). The sizes of houses range between approximately 20 m² for 1 to 3 people and 40 m² for 4 or 5 people. Evacuees are allowed to live in these houses for up to 3 years after they move in.

Figure 2

Flow diagram of subjects. Data collected at the post-quake health screening were retrospectively analyzed after matching those with pre-quake data.

Figure 3

Scatter plots of differences in the screening variables before and after the earthquake. Scatter plots of body weight (A), BMI (B), waist circumference (C), systolic blood pressure (D), diastolic blood pressure (E), HbA1c (F), HDL cholesterol (G), LDL cholesterol (H), and triglyceride (I) are shown. Red bars indicate the median and interquartile range.