Increased risk of coronary heart disease in Japanese blue-collar workers.

The purpose of this study was to test the hypothesis that blue-collar workers have an increased risk of coronary heart disease. Subjects were 653 male (mean age, 32.6 years) and 492 female (mean age, 26.3 years) workers employed during 1993 at a computer manufacturing company. The measurements determined were body mass index (BMI), waist to hip ratio (WHR), skinfold thickness, blood pressure, grip strength, back strength, vertical jump and trunk flexion. Male blue-collar workers had significantly higher WHR (P < 0.001), systolic blood pressure (P = 0.031), grip strength (P = 0.030), and standing flexion (P = 0.038) than do white-collar workers. Female blue-collar workers had significantly higher BMI (P = 0.018), WHR (P < 0.001), and grip strength (P = 0.007). Blue-collar workers took significantly less exercise, and habitually snacked (females only), smoked and drank more alcohol (males only) than white-collar workers. In conclusion, blue-collar workers have more intra-abdominal fat than white-collar workers of either sex. The difference may be due to factors contributing to the less healthy lifestyles of blue-collar workers.