Slightly High Cholesterol Can Increase Later Heart Risk

New findings from researchers at the Duke Clinical Research Institute suggest that even slightly high cholesterol levels in otherwise healthy adults between the ages of 35 and 55 can have long-term affects on their heart health, with every decade of high cholesterol increasing their chances of heart disease by 39%.

Lead author Ann Marie Navar-Boggan, MD, PhD, likens the cumulative effects of elevated cholesterol to the long-term effects of smoking. The findings from Duke Clinical Research Institute are published in the American Heart Association journal Circulation.

“The number of years with elevated cholesterol, or ‘lipid years,’ can affect patients in a similar way as the number of ‘pack years’ affect smokers,” Navar-Boggan says. “What we’re doing to our blood vessels in our 20s, 30s, and 40s is laying the foundation for disease that will present itself later in our lives.”

For the study, Navar-Boggan and colleagues at Duke, Boston University, and McGill University examined data on 1,478 adults who were part of the Framingham Heart Study that began in 1948 and free of heart disease at age 55.

“Few, if any, studies have gathered the quality of cardiovascular data that the Framingham study has," says biostatistician Michael Pencina, PhD, a senior author of the paper. "That wealth of data collected over time made it possible to analyze the long-term effects of cholesterol in young people—a topic on which not enough is known because it requires decades of tracking.”

Researchers calculated the length of time each participant had been living with high cholesterol by the time they reached age 55, and patients were followed for up to 20 years to see how cholesterol levels affected their risk of heart disease.

Elevated cholesterol for this study was defined as non-HDL cholesterol of 160 mg/dL or higher. Researchers found similar results for patients with LDL cholesterol of 130 mg/dL or higher.

At age 55, nearly 40% of participants had at least 10 years of exposure to high cholesterol. Over the next 15 years, their risk of heart disease was 16.5%, nearly 4 times the risk of those without high cholesterol (4.4%).

What was surprising, Navar-Boggan says, is that “the effect is perhaps even stronger among adults who are otherwise healthy.”

The first step for young adults—a demographic known for missing regular check-ups—is to be tested.

“It’s never too soon for young adults to talk with their doctors about a comprehensive strategy for heart health, first and foremost focusing on diet and exercise," Navar-Boggan says.