By Frederik Joelving
NEW YORK (Reuters Health) - Teens and young adults may want to pay attention to their cholesterol levels instead of waiting until later, when there is less room for improvement, according to a new study.
There is no ironclad proof that doing so would actually benefit anyone, and the idea that people under 35 should be screened for high cholesterol is controversial. But some doctors now believe the circumstantial evidence is strong enough to warrant earlier interventions.
In the latest study, published in the Journal of the American College of Cardiology, researchers found that people with natural mutations associated with lower cholesterol throughout life had a consistently lower risk of heart disease.
And that risk reduction was three times bigger than what can be achieved with cholesterol-lowering medications when people are in their 60s, according to the report.
"The study doesn't suggest giving statins earlier would be beneficial, but it suggests lowering cholesterol earlier would be," said Dr. Brian Ference, who heads the Cardiovascular Genomic Research Center at Wayne State University School of Medicine in Detroit.
"It is really important to emphasize a healthy diet and exercise to keep LDL cholesterol low early in life," Ference, who led the new work, told Reuters Health.
Heart disease is the leading killer worldwide and accounts for more than a third of deaths in the U.S., according to the American Heart Association. Every year, heart attacks alone kill some 400,000 Americans.
Today, doctors typically prescribe statins to people whose ten-year cardiovascular risk is high based on age, gender, cholesterol levels, smoking and blood pressure.
Statins lower LDL cholesterol, which contributes to the buildup of plaque in the heart's arteries that can snag blood flow and trigger heart attacks.
Ference and his colleagues figured that if cholesterol levels could be kept in check throughout life, maybe it would be possible to prevent the plaque from forming in the first place.
Instead of conducting a long and expensive experiment to test their idea directly, they resorted to genetic mutations as a proxy for lower LDL cholesterol.
These so-called SNPs (pronounced snips) are natural variations in a single building block of DNA that can be inherited randomly at the time of conception.
Based on previous studies involving nine different SNPs and more than 300,000 people, they found each mutation was tied to a considerable reduction in heart disease risk. What's more, the risk reduction was similar across the board - at about 55 percent - when analyzed per unit of cholesterol.
That suggests the drop in heart disease is caused by the lower cholesterol, and not some other factor linked to the mutations, said Ference.
By comparison, treating people in their 60s with a statin cuts their risk by some 20 percent, the researchers estimated based on two dozen earlier trials.
"Long-term exposure to lower LDL is three times more effective than starting later in life," Ference said. "The key is to keep your LDL cholesterol low starting as early as possible."
For people who can't get their cholesterol down by lifestyle changes, he added, "it may be reasonable to begin statin therapy in early adulthood."
But he acknowledged that only a gold-standard experiment can prove it's helpful to start early on the drugs, which may cause muscle and joint pain in the short run and whose long-term side effects are unknown.
Dr. Michael L. LeFevre of the government-backed U.S. Preventive Services Task Force said the idea of starting on cholesterol medicine earlier in life was likely to meet resistance in the medical community.
"One assumption underlying the conclusion recommendation is that it doesn't matter how one lowers cholesterol, it only matters how much. And with this study, for how long," he told Reuters Health by email.
"Studies of cholesterol medications have not uniformly supported the 'lower is better' assumption," LeFevre added. "A good example is that we know adding ezetimibe (a drug that lowers cholesterol absorption in the intestine) to a statin further lowers cholesterol, but it has not been demonstrated to further lower the risk of heart disease."
SOURCE: http://bit.ly/PtHhuR Journal of the American College of Cardiology, online October 17, 2012.