After two decades of improvement, the percentage of Americans without major heart disease risk factors is dropping, according to a review in the September issue of Circulation.
“From a preventive health point of view, it’s important that individuals achieve as many of these goals as possible, and it’s disappointing that less than 10 percent of Americans are meeting them all,” said lead author Earl S. Ford, MD, medical officer of the U.S. Public Health Services at the Centers for Disease Control and Prevention in Atlanta.
Ford and colleagues said that cohorts consistently show that individuals with low levels of cardiovascular risk factors experience low rates of subsequent cardiovascular events. They said their study’s objective was to examine the prevalence and trends in low-risk factor burden for cardiovascular disease among adults in the U.S. population.
Researchers used data from adults 25 to 74 years of age who participated in four national surveys. They created an index of low risk from the following variables: not currently smoking, total cholesterol less than 5.17 mmol/L (less than 200 mg/dL) and not using cholesterol-lowering medications, systolic blood pressure less than 120 mm Hg and diastolic blood pressure less than 80 mm Hg and not using antihypertensive medications, body mass index less than 25 kg/m2 and not having been previously diagnosed with diabetes mellitus.
“Our analysis suggests that achieving low risk status for most U.S. adults remains a distant and challenging goal,” said Ford. “Unfortunately, the limited strides that were made towards this goal during the 1970s and 1980s were eroded by the increases in excess weight, diabetes and hypertension during more recent decades.
“Until the early 90s, we were moving in a positive direction, but then it took a turn and we’re headed in a negative direction,” Ford said. “When you look at the individual factors, tobacco use is still headed in the right direction and so are cholesterol levels, although that has leveled off. The problem is that blood pressure, BMI and diabetes are all headed in the wrong direction.”
The age-adjusted prevalence of low-risk factor burden increased from 4.4 percent during 1971 to 1975 to 10.5 percent during 1988 to 1994 before decreasing to 7.5 percent during 1999 to 2004, according to the authors. The patterns were similar for men and women, although the prevalence among women exceeded that among men in each survey.
In addition, Ford and colleagues reported that whites had a significantly higher prevalence of low-risk factor burden than blacks during each survey except during 1976 to 1980. Furthermore, a larger percentage of whites had a low-risk factor burden than Mexican Americans during 1988 to 1994 and 1999 to 2004.
In an accompanying editorial, Rob M. van Dam, PhD, and Walter C. Willett, MD, PhD, of Harvard Medical School and Brigham and Women’s Hospital in Boston, said the findings are disturbing because the trends among younger age groups have occurred in the presence of unprecedented availability of evidence-based heart disease treatment and even more worrisome because the trends do not yet reflect the effects of the current epidemic of childhood obesity.
The findings provide an important signal that the health of Americans is at a crossroad, they noted.
“Much potential exists to reverse ominous trends in cardiovascular risk factors and mortality in the United States, but this is unlikely to occur without making prevention of overweight and obesity a clear national priority,” the editorial authors wrote.