Changes in body mass index and its relationships to other cardiovascular risk factors among Japanese population: results from the 1980 and 1990 national cardiovascular surveys in Japan.

Few studies have attempted to investigate the changes in body mass index (BMI) and its relationship to other cardiovascular factors in Asian populations, including Japanese. Data from two national cross-sectional surveys on circulatory disorders in 1980 and 1990 in Japan were used in this study. The sample consisted of 10,556 participants in the 1980 survey and 8,385 in the 1990 survey, aged > or = 30 years. The results show that after adjusting for age, smoking, alcohol consumption (ALC) and daily life physical activity (PA), mean BMI increased 0.49 kg/m2 (95% confidence interval: 0.34-0.65) in men aged 30-59 and 0.61 kg/m2 (0.37-0.86) in those aged > or = 60 from 1980 to 1990. In women, however, mean BMI decreased 0.24 kg/m2 (-0.39 0.09) in those aged 30-59 and increased 0.38 kg/m2 (0.12-0.64) in those aged > or = 60. BMI was significantly associated with hypertension, diabetes and hypercholesterolaemia. In both genders, cu-smokers had lower mean BMI than never smokers, while among the cu-smokers, mean BMI was positively associated with the number of cigarettes smoked per day. In men, BMI was positively associated with ALC and negatively associated with PA, while in women, BMI was negatively associated with ALC and positively associated with PA. The results suggest that BMI has significantly increased in men and in elderly women. BMI, even in the Japanese population who are characterized by relative low BMI, is significantly associated with several cardiovascular risk factors.