Explaining the increase in coronary heart disease mortality in Beijing between 1984 and 1999.

BACKGROUND: Coronary heart disease (CHD) mortality is rising in many developing countries. We examined how much of the increase in CHD mortality in Beijing, China, between 1984 and 1999 could be attributed to changes in major cardiovascular risk factors and assessed the impact of medical and surgical treatments.

METHODS AND RESULTS: A validated, cell-based mortality model synthesized data on (1) patient numbers, (2) uptake of specific medical and surgical treatments, (3) treatment effectiveness, and (4) population trends in major cardiovascular risk factors (smoking, total cholesterol, blood pressure, obesity, and diabetes). Main data sources were the WHO MONICA and Sino-MONICA studies, the Chinese Multi-provincial Cohort Study, routine hospital statistics, and published meta-analyses. Age-adjusted CHD mortality rates increased by approximately 50% in men and 27% in women (1608 more deaths in 1999 than expected by application of 1984 rates). Most of this increase ( approximately 77%, or 1397 additional deaths) was attributable to substantial rises in total cholesterol levels (more than 1 mmol/L), plus increases in diabetes and obesity. Blood pressure decreased slightly, whereas smoking prevalence increased in men but decreased substantially in women. In 1999, medical and surgical treatments in patients together prevented or postponed approximately 642 deaths, mainly from initial treatments for acute myocardial infarction ( approximately 41%), hypertension (24%), angina (15%), secondary prevention (11%), and heart failure (10%). Multiway sensitivity analyses did not greatly influence the results.

CONCLUSIONS: Much of the dramatic CHD mortality increases in Beijing can be explained by rises in total cholesterol, reflecting an increasingly "Western" diet. Without cardiological treatments, increases would have been even greater.