Nearly 1 in 13 young adults had heart plaque in new study. What does this mean?

A study published in The New England Journal of Medicine late August has begun attracting fresh attention after its most striking finding was recast for a general audience. Apparently, silent atherosclerosis or plaque build-up in the arteries was detectable in about one in 13 adults aged 18 to 29. Spanish researchers have put the findings back in the spotlight, now emphasising their implications for early prevention.

The study examined 16,808 adults aged 18 to 70 in Denmark and Spain who had no known cardiovascular disease. Researchers used detailed imaging to look for disease in several arterial regions. Overall, 57.1% had detectable plaque. Among those aged 18 to 29, the figure was 8.7% among men and 6.7% among women. Finding plaque means that a young person is headed for a heart attack in his later years. But it also shows how the underlying process of cardiovascular disease can become visible for corrective action.

“The real opportunity is, therefore, not to wait for a scan to reveal disease. It is to identify and control important risk factors while there is still time to change the lifetime trajectory. Checking cholesterol, blood pressure, blood sugar and family history from young adulthood, preferably age 18 onwards, can help identify risks before symptoms appear,” says Dr Ranjan Shetty, lead cardiologist and medical director, Sparsh Hospital, Bengaluru.

Plaque is a process, not a sudden event

Atherosclerosis develops gradually. Cholesterol-containing particles, particularly LDL (low density lipoprotein or bad cholesterol) particles, can be retained within the artery wall. The body responds with inflammation, and over time fatty deposits can develop into more complex plaques containing cholesterol, inflammatory cells, fibrous tissue and calcium.

For years, these changes may produce no symptoms. The arteries can accommodate gradual disease without an obvious reduction in blood flow. The danger can arise later if a plaque becomes unstable, ruptures or erodes and triggers a blood clot. A clot that blocks a coronary artery can cause a heart attack; one that interrupts blood flow to the brain can cause an ischaemic stroke.

That long silent phase is what makes the new findings important. The event may be sudden, but the biological process behind it often has been developing for years.

Does it really begin in childhood?

In many people, the earliest stages of atherosclerosis can begin during childhood and adolescence. This does not mean that children normally have the mature, obstructive plaques seen in older adults. Rather, microscopic and early arterial changes can develop long before cardiovascular disease becomes clinically apparent. “The process is cumulative. A teenager with persistently high LDL cholesterol, for example, is being exposed to an important driver of atherosclerosis years before the usual age at which heart disease is diagnosed. High blood pressure, abnormal blood sugar, smoking and excess body fat can add to that burden in later years,” says Dr Shetty.

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This is why researchers increasingly think about cardiovascular risk not only in terms of a person’s measurements today, but also in terms of cumulative exposure over a lifetime.

“Genetics can make that exposure particularly important. Familial hypercholesterolaemia (excess cholesterol because of family history), for instance, can produce very high LDL cholesterol from childhood. Such a person may accumulate a much greater lifetime cholesterol burden than someone whose cholesterol rises only later in adulthood,” explains Dr Shetty.

Why Indian teenagers deserve particular attention

The question is especially relevant in India because South Asians have a recognised predisposition to earlier cardiometabolic disease. Research reviews have found that South Asians can develop Type 2 diabetes and cardiovascular disease at younger ages and at lower levels of body mass index (BMI) than many other populations. The reasons are complex, involving genetics, body composition, insulin resistance, diet, physical activity and early-life influences.

South Asians tend to develop more abdominal or visceral fat even with normal BMI, and this can be associated with insulin resistance and metabolic abnormalities. “A teenager who does not appear markedly overweight can therefore still have an unfavourable metabolic profile. There is also a characteristic lipid pattern described in South Asian populations: relatively high triglycerides, low HDL cholesterol and more cholesterol-carrying particles, sometimes even when conventional LDL cholesterol does not appear dramatically elevated. Lipoprotein(a), an inherited cholesterol-carrying particle associated with cardiovascular risk, may also be elevated in some South Asians,” says Dr Shetty.

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The changing teenage environment

Indian studies have documented cardiometabolic risk factors among adolescents, particularly those who are overweight or obese. In one study of urban Indian adolescents, central obesity was accompanied by high triglycerides, low HDL cholesterol, hypertension and abnormal glucose regulation among those with metabolic syndrome.

A systematic review of 16 Indian studies involving more than 19,000 adolescents estimated that metabolic syndrome affected roughly 3.4% to 5%, depending on the diagnostic criteria used. The authors also noted substantial variation between studies, so these figures should not be treated as a national prevalence estimate.

The concern is not simply “junk food”. A broader shift towards calorie-dense foods, refined carbohydrates, sugary drinks and frequent snacking, combined with less physical activity, can promote excess body fat and insulin resistance. In some Indian children, genetic susceptibility and family history may amplify these effects.

Does every teenager need a test?

The study does not justify routine artery imaging for healthy teenagers. Detecting plaque is not the same as proving that screening everyone will prevent heart attacks, and advanced imaging can bring costs, incidental findings and, for CT-based tests, radiation exposure.

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The more immediate lesson is simpler: cardiovascular prevention cannot begin only when a person reaches middle age. “Children and adolescents with obesity, hypertension, diabetes, a strong family history of premature cardiovascular disease or suspected inherited cholesterol disorders may need assessment by a clinician. For the wider population, healthy diet, regular physical activity, avoidance of tobacco and attention to blood pressure, cholesterol and metabolic health remain the foundations of prevention,” says Dr Shetty.