The Great East Japan Earthquake: Blood Pressure Control in Patients With Chronic Kidney Disease

BACKGROUND: At 1446 on 11 March 2011, northeastern Japan was struck by a major earthquake measuring 9.0 on the Richter scale. There have been several reports of transient blood pressure increases after a major earthquake, but the impact of a major earthquake on blood pressure in chronic kidney disease (CKD) patients has not been fully investigated. METHODS: Changes in clinic blood pressure following the earthquake were investigated in 132 hypertensive patients with stage 3 and 4 CKD who were residents of Fukushima City. RESULTS: Both systolic and diastolic blood pressures were significantly elevated 1-3 weeks after the earthquake compared with before the earthquake (134 ± 19 mm Hg vs. 138 ± 20 mm Hg, P = 0.02 for systolic; 76 ± 13 mm Hg vs. 79 ± 12 mm Hg, P = 0.01 for diastolic), and these values returned to baseline by 5-7 weeks after the earthquake. Multiple logistic regression analysis identified male sex (odds ratio (OR), 0.35; 95% confidence interval (CI), 0.14-0.86; P = 0.02), mean blood pressure at baseline (OR, 0.92; 95% CI, 0.86-0.96; P < 0.01), and sympatholytic medications, such as α-blockers, β-blockers, or central sympatholytics (OR, 0.23; 95% CI, 0.07-0.76; P = 0.01), as independent factors related to elevation of mean blood pressure 1-3 weeks after the earthquake in CKD patients. CONCLUSIONS: Blood pressure was significantly increased after a major earthquake in hypertensive patients with stage 3 and 4 CKD. During the first 3 weeks after the earthquake, blood pressure control was associated with the use of sympatholytic medications.