DIFFERENT TRENDS IN SERUM-CHOLESTEROL LEVELS AMONG RURAL AND URBAN POPULATIONS AGED 40-59 IN JAPAN FROM 1960 TO 1990

In Japan, coronary heart disease mortality is low and has been declining since 1970, despite recent increases in serum cholesterol levels which have been reported in nationwide surveys. Longitudinal and cross-sectional surveys of serum cholesterol levels in rural and urban populations from 1960 to 1990 were reviewed. In the surveys in the 1960s, serum cholesterol levels in urban populations were higher than those in rural populations. An increase in serum cholesterol levels for men and women was observed in all longitudinal studies among rural populations; mean increases in serum cholesterol levels per year were 0.034 mmol/l (p < 0.001) and 0.033 mmol/l (p < 0.001), respectively. These trends were still observed after combining the data from the longitudinal and cross-sectional studies in both men and women (0.027 and 0.028 mmol/l per year, respectively), while there was no significant increase among urban populations. The results of National Nutrition Surveys are consistent with these findings and show that meat consumption per day per capita increased from 23.9 to 66.2 g in rural populations and 51.2 to 77.6 g in urban populations in the 1966 and 1990 surveys. It is suggested that different trends in coronary heart disease mortality should also be apparent in rural and urban populations over this period.