Aims/introduction: We investigated impacts of the Great East Japan Earthquake on diabetic patients and characterized those with disaster-susceptible diabetes.
Materials and methods: We enrolled 497 diabetic patients who had been followed at hospitals in devastated areas. We collected metabolic parameters prospectively, 1 and 3 months after the earthquake, and retrospectively for pre-earthquake time-points. Questionnaire surveys were carried out regarding earthquake-related damage and post-earthquake lifestyle alterations. Available data were analyzed to examine associations with post-earthquake glycosylated hemoglobin alterations.
Results: The mean glycosylated hemoglobin level of the participants was not elevated at 1 month, and was significantly decreased at 3 months as compared with the pre-earthquake glycosylated hemoglobin. There were no significant differences in earthquake-related damage or lifestyle alterations between the improved and worsened glycemic control groups according to the data obtained from the questionnaire survey. As reported, fasting serum C-peptide levels were significantly lower in the worsened glycemic control group (P < 0.05). Notably, plasma noradrenaline levels were significantly higher in the worsened glycemic control group (P < 0.05). Furthermore, at 1 month after the earthquake, the plasma noradrenaline level was significantly higher in the low C-peptide group (fasting serum C-peptide <1.0 ng/mL) than in the high C-peptide group (fasting serum C-peptide ≥1.0 ng/mL), but this difference had disappeared by 3 months after the earthquake. These findings show that post-earthquake plasma noradrenaline levels were temporarily increased in the low C-peptide group.
Conclusions: Sympathetic nerve activation might be elicited more easily in subjects with lower endogenous insulin secretory capacity, and could be involved in the mechanism underlying post-earthquake worsening of glycemic control.
Keywords: Glycemic control; Natural disaster; Sympathetic activation.