Unmet Potential for Cardiovascular Disease Prevention in the United States

R. M. van Dam, W. C. Willett
2009 Circulation  
I n this issue of Circulation, Ford et al 1 report trends in the prevalence of a low-cardiovascular-risk profile in US adults over Ϸ30 years based on data from the National Health and Nutrition Examination Surveys. Low risk was defined as the absence of cigarette smoking, hypertension, hypercholesterolemia, overweight, and diabetes mellitus. These authors show that the prevalence of a low-risk profile increased in the 1970s and 1980s (reflecting decreases in smoking, hypercholesterolemia, and
more » ... lesterolemia, and hypertension) but decreased between 1988 to 1994 and 1999 to 2004 because of a greater prevalence of overweight, hypertension, and diabetes mellitus. The authors previously described reasons for the large decline in cardiovascular mortality between 1980 and 2000, including improvements in medical treatment and reductions in the population prevalence of cardiovascular risk factors. 2 They estimated that the decline in coronary heart disease mortality between 1980 and 2000 resulting from reductions in risk factors was 24% for total cholesterol, 20% for systolic blood pressure, and 12% for smoking. In contrast, greater prevalences of adiposity and diabetes mellitus increased cardiovascular mortality by an estimated 8% and 10%, respectively. The new data showing a reversal of the trend for the prevalence of the low-risk factor profile suggest that the decline in cardiovascular mortality may end, raising important questions about the future health and longevity of Americans. Article see p 1181 More detailed analyses heighten concerns about trends in cardiovascular health within the United States. Using vital statistics data, Ford and Capewell 3 previously described that the age-adjusted coronary heart disease mortality declined from 1980 to 2002 by 52% in men and 49% in women. When distinguishing by age group, however, we see a continuous decline in older men and women (Ն55 years of age) up to 2002, whereas for younger men and women (35 to 55 years of age), a steep decline in the 1980s was followed by a more gradual decline in the 1990s and no decline between 2000 and 2002. In women 35 to 44 years of age, coronary heart disease mortality increased between 1997 and 2002. These disturbing trends among younger age groups have occurred in the presence of unprecedented availability of evidence-based medical therapies for coronary heart disease. However, the increasing prevalence of overweight, high blood pressure, and diabetes mellitus in US adults is consistent with a stagnation or reversal of the decline in cardiovascular mortality. Even more worrisome, these trends do not yet reflect the effects of the current epidemic of childhood obesity, 4 which causes an early onset of type 2 diabetes, hypertension, and dyslipidemia. 5,6 Because the complications of diabetes mellitus increase strongly with duration, by 40 years of age, the affected children will have accrued several decades of exposure that will greatly elevate risks of not just coronary heart disease and stroke but also microvascular complications that can eventually lead to amputations, blindness, and kidney failure. Studies of body mass index at the end of childhood in relation to mortality provide insight into future premature mortality. We evaluated body mass index at 18 years of age in relation to mortality during 12 years of follow-up in US women 24 to 44 years of age at baseline. Compared with a body mass index of 18.5 to 21.9 kg/m 2 , the hazard ratio for premature death was 1.66 (95% confidence interval, 1.31 to 2.10) for a body mass index of 25.0 to 29.9 kg/m 2 and 2.79 (95% confidence interval, 2.04 to 3.81) for a body mass index of Ն30 kg/m 2 . 7 Similar results were obtained in a study of Swedish men who were on average 19 years of age at baseline and were followed up for 38 years. 8 These results suggest that the current epidemic of obesity in children will have a substantial impact on life expectancy in the coming decades. 9 In recent years, life expectancy already declined in many US counties, even though the national average is still increasing. Ezzati et al 10 described that between 1961 and 1983, no US county had a significant decrease in life expectancy, whereas between 1983 and 1999, life expectancy decreased significantly in 11 counties for men and 180 counties for women. These counties are clustered in low-income areas of the south and southeast United States and overlap with regions with high rates of obesity. Thus, national averages can be misleading because they can hide widening gaps in health among parts of the US population. Although cardiovascular disease has long been and remains the major cause of death in the United States, massive evidence documents that the age-specific rates could be reduced dramatically to those of low-risk areas such as the Mediterranean region. For example, Stamler et al 11 studied the relation between low-risk status, defined as the absence of current cigarette smoking, hypertension, and hypercholesterolemia, and cardiovascular mortality in large US cohorts. The relative risks of cardiovascular mortality for low-risk persons
doi:10.1161/circulationaha.109.891507 pmid:19752318 fatcat:egui2hhtjvafhhkf5jjjdttdju