PARIS – Arguably one of the most important and far-reaching studies presented at the annual congress of the European Society of Cardiology didn’t take place in the massive main ballroom with dazzling lights and sound and thousands of cardiologists in attendance, but in a tiny, makeshift, open-sided venue slapped together of cardboard and fiberboard and plunked down in the noisy poster hall.
It was there that Terence Dwyer, MBBS, MD, began by observing, “We know quite a bit about the relationship of cardiovascular risk factors in adults to cardiovascular disease; we know virtually nothing about the relationship of those risk factors in childhood because – until now – there has been no direct evidence relating to this. What I’m going to present to you is some direct evidence.”
The data come from the International Childhood Cardiovascular Cohort (i3C) Consortium, which includes investigators from seven pioneering prospective child cohort studies, which collectively measured major cardiovascular risk factors in more than 42,000 children beginning back in the 1970s.
Some of these studies will be familiar names to many American physicians and epidemiologists. They include the Bogolusa Heart Study, the Muscatine Study, the Princeton Lipid Research Clinic Study, and the Minneapolis Childhood Cohort Studies. Similar studies were launched decades ago in Australia and Finland. The oldest of these cohorts are now in their 50s, and they are developing cardiovascular disease. The new i3C findings based on pooled data from these studies provides the first direct evidence that high serum cholesterol, blood pressure, body mass index, and smoking in childhood are linked to increased risk of hospitalization for acute MI, stroke, and peripheral artery disease in early middle age, said Dr. Dwyer, emeritus professor of epidemiology at the University of Oxford (England).
The analysis showed that each 10% increase above average in serum cholesterol in childhood was associated with a 16% increased risk of hospitalization for a cardiovascular event at a mean age of 49 years. A 2-point rise in BMI was associated with a 20% higher risk. A 10% increase above average in systolic blood pressure in childhood was linked to a 40% increase in risk of a cardiovascular event in later life. And smoking in childhood or adolescence was associated with a 77% higher risk of a cardiovascular event.
The i3C analysis also demonstrated thatFor example, individuals who both as adults and children had two or more of the four major cardiovascular risk factors studied had a sixfold greater risk of a major cardiovascular event in early middle age than if they had two or more risk factors as adults but none as children. If they had two or more risk factors as adults and one risk factor in childhood, their risk of a cardiovascular event was roughly twice as great as if they had no risk factors as a child. And if they had two or more risk factors present in childhood but none in adulthood, their risk of an event was threefold higher than if none of the four major cardiovascular risk factors were present during both periods of life, he continued.
The investigators consider their findings preliminary because most participants in the cohort studies are just reaching age 50 years.
“As we follow them for another 5 years, because of their age, the number of cardiovascular events will increase dramatically,” Dr. Dwyer explained. “One of the reasons we’re presenting this data now in preliminary form is these cohort studies will be the only data of this kind for about another 20 years. We want it out there when it can be most useful. It’s not like the situation with RCTs [randomized, controlled trials] where you’re able to wait 2 years for the next RCT.”