Body weight, blood pressure, and mortality in a cohort of obese patients

The associations between body weight, raised blood pressure, and mortality remain controversial. The authors examined these relations by considering all degrees of obesity in the Dusseldorf Obesity Mortality Study (1961-1994). Among 6,193 obese German patients aged 18-75 years and having a body mass index (BMI) of greater than or equal to25 kg/m(2), 1,059 deaths were observed after a median follow-up of 14.8 years. The entire cohort was grouped into quartiles according to BMI (25-<32, 32-<36, 36-<40, greater than or equal to40 kg/m(2)) and systolic blood pressure (SBP) (<140, 140-<160, 160-<180, greater than or equal to180 mmHg). Cox proportional hazards analyses were performed to adjust for age. For women, the mortality risk curves for the four BMI groups in relation to SBP were flat without crossing, whereas the risk curve for moderately obese men (BMI 25-<32 kg/m(2)) crossed the risk curves for the higher BMI groups. In the group of patients with very high blood pressure (SBP greater than or equal to 180 mmHg), moderately obese subjects (BMI 25-<32 kg/m(2)) had a higher mortality risk for men when compared with the BMI group 32-<36 kg/m(2) (hazard ratio =1.62, 95% confidence interval: 1.0, 2.7) but not for women (hazard ratio = 0.71, 95% confidence interval: 0.4, 1.2). These findings support previous observations that the risk of death is lower for hypertensive men in high compared with low BMI groups.