Incidence of Hypertension in Individuals with Abdominal Obesity in a Rural Japanese Population: The Tanno and Sobetsu Study

Although abdominal obesity (AO) assessed by waist circumference (WC) is an important component of the metabolic syndrome (MetS), the usefulness of AO as a predictor of hypertension (HT) is not known. In this study, we investigated the incidence of HT in residents of two rural communities in Japan. The subjects were 187 men and 209 women selected from 712 residents who had undergone medical examinations in the towns of Tanno and Sobetsu, Hokkaido, in 1994 and 2002. Participants with HT in 1994 were excluded. Participants with AO were determined according to the WC criteria in the Japanese definition of MetS ( 85 cm for men, >= 90 cm for women). The participants were divided into two groups: a non-AO group and an AO group. We compared the incidence of HT between the two groups and found a significantly higher incidence in the AO group. The results of logistic regression analysis showed that the relative risk of developing HT in individuals with AO was 2.33 (p=0.017; 95% confidence interval [CI], 1.17-4.63) and that the risk per 1-cm increase in WC from 1994 to 2002 was 1.06 (p=0.003; 95% Cl, 1.02-1.10), both adjusted for several confounding factors. The results of this study suggest that, to prevent HT in Japanese, it is important to manage abdominal obesity and to monitor WC in individuals with or without abdominal obesity. (Hypertens Res 2008; 31: 1385-1390)