Association between the prevalence of hypertension and dairy consumption by housing type among survivors of the Great East Japan Earthquake

Abstract

Survivors of the Great East Japan Earthquake in 2011 had higher risks of cardiovascular diseases and hypertension, particularly residents of heavy flooding areas and evacuees. Thus far, the association between the prevalence of hypertension and dairy consumption remains unknown among these evacuees. We investigated this association by housing type after the Great East Japan Earthquake. In this cross-sectional study, we conducted a baseline survey among 9569 survivors of the earthquake, aged ≥18 years, between September 2011 and February 2012. Hypertension was defined as a systolic/diastolic blood pressure ≥140/90 mmHg or as persons undergoing treatment for high blood pressure. The frequency of dairy consumption was determined using a questionnaire. Participants living in prefabricated housing and emergency shelters were regarded as residents of temporary housing. Hypertension was prevalent among 43.8% and 44.7% of the participants in temporary and non-temporary housing, respectively. A logistic regression analysis of the prevalence of hypertension by daily dairy consumption showed that the magnitude of multivariable-adjusted odds ratios differed according to housing type (odds ratio, 0.64; 95% confidence interval, 0.51-0.80 in temporary housing; odds ratio, 0.85; 95% confidence interval, 0.73-0.995 in non-temporary housing; P for interaction = 0.0501). These associations were consistent across subgroups according to sex, age, behavioral factors, obesity, disorders of lipid metabolism, and economic status. A higher frequency of dairy consumption was associated with a lower prevalence of hypertension among community-dwelling survivors of earthquakes and tsunamis, particularly those living in temporary housing. Therefore, dietary therapy involving dairy consumption could help prevent hypertension among evacuees.