Impaired fasting glucose and the risk of hypertension in Japanese men between the 1980s and the 1990s. The Osaka Health Survey.

OBJECTIVE: To determine whether impaired fasting glucose (IFG) increased the risk for hypertension in two large Japanese cohorts during the different time periods. RESEARCH DESIGN AND METHODS: We prospectively investigated two Japanese cohorts: a 1980s population, comprising 4,130 normotensive and nondiabetic men aged 35-60 years entered between 1981 and 1983, and a 1990s population, comprising 4,319 normotensive and nondiabetic men aged 35-60 years entered between 1991 and 1992. Data on lifestyle factors were obtained from questionnaires. IFG was defined as a fasting plasma glucose level > or = 110 and < 126 mg/dl. RESULTS: During the 4-year observation period, 708 cases of hypertension were confirmed in the 1980s and 848 cases were confirmed in the 1990s. In both the 1980s and 1990s populations, IFG was associated with the risk of hypertension. The frequency of IFG in men in the 1990s group was twice as high as that in the 1980s group. The multivariate-adjusted odds ratio (OR) of hypertension was 1.54 (95% CI, 1.01-2.34) for men with IFG in the 1980s population and 1.73 (1.31-2.29) in the 1990s population, compared with those without IFG in the two populations. In the 1990s population, among lean men with a BMI < or = 23 kg/m2, men with IFG had a multivariate-adjusted OR of hypertension of 2.31 (1.46-3.65) compared with those without IFG. CONCLUSIONS: This study demonstrated direct correlation between IFG and hypertension and greater incidence of this hypertension in the 1990s group than in the 1980s group.