Two-thirds of children who smoked tobacco from age 10 through their mid-20s had a significantly increased risk of early heart damage, according to a large population study published yesterday [Dec. 11, 2024] in the Journal of the American College of Cardiology (JACC).
Persistent tobacco smoking at those ages was associated over time with a 33% to 52% odds of premature and potentially irreversible injury to both the structure of the heart muscle (myocardium), and how it works, the study shows.
It was also linked to an excessive increase in heart size and weight (mass), even after controlling for competing risk factors—an important finding given the potential relationship between an increase in heart thickness and the higher risk of cardiovascular mortality.
“This study shows that teen smoking doesn’t just increase the risk of heart disease later in life – it causes early and lasting damage to heart muscle and function,” said Emily Bucholz, assistant professor of pediatrics at the University of Colorado School of Medicine and associate editor of JACC, in a news release. “It’s a wake-up call for prevention efforts to protect young hearts early.”
Early damage to the heart can greatly increase the chance of injury to blood vessels in adolescence and future cardiovascular mortality in midlife, other studies have shown. Research into heart damage and smoking among healthy children is scarce, the researchers say, since cardiac injury in childhood is usually due to rare medical events.
Early smoking harms how heart pumps blood
The researchers specifically report impacts to the left ventricle of the heart, the chamber that sends blood to the rest of the body. In pediatrics, the left ventricle often serves as a marker of cardiac injury. They found the prevalence of:
- Left ventricular (LV) hypertrophy (thickened muscle wall, which can impact how well the heart pumps blood) increased from 2.8% at age 17 to 7.5% at age 24
- Left ventricular diastolic (LVD) dysfunction (difficulty relaxing and filling with blood after contracting) increased from 10.4% to 16.9%
Persistent smoking from ages 10 through 24 was significantly associated with higher left ventricular size and thickness (mass index, or LVMI) at 24 years. It was also linked to an increase in LVMI from ages 17 to 24 years, the study shows.
“The increase of cardiac mass structure in just a few years of smoking should convey how dangerous the consequences are for people who continue to smoke from a young age,” says Andrew Agbaje, lead author of the study and an associate professor of Clinical Epidemiology and Child Health at the University of Eastern Finland, Kuopio, Finland, in a news release.
Higher rates of smoking with age
Researchers from the University of Eastern Finland collaborating with the University of Bristol in England used the Avon Longitudinal Study of Parents and Children (ALSPAC, or “Children of the 90s”) birth cohort data to examine the impact of tobacco smoking during growth from childhood to young adulthood and its association with structural and functional cardiac injury.
ALSPAC is a long-term health research project that originally enrolled 14,901 children. Roughly 4,000 (27%) attended the clinic visit at 24 years of age, and 1,958 (49%) of those had echocardiograms performed.
This study’s analysis included 1,931 children—including 1,211 females—who had complete smoking and echocardiographic measures at 24 years. Nearly 900 had echocardiograms at both the 17- and 24-year visit.
The proportion of those who smoked tobacco was:
- 0.3% at age 10
- 1.6% at age 13
- 13.6% at age 15
- 24% at age 17
- 26.4% at age 24
The years between 13 and 17 years old are the single most critical period for what Agbaje calls the “jet-speed” adoption of a tobacco smoking habit. Sixty percent of those who initiated smoking at age 17 or younger continued smoking at 24 years old, highlighting the addictive nature of tobacco products, the data shows.
“It is extremely frightening and sobering to observe that smoking prevalence increased from 1.6% to 24% (15 times increase) within four years of growth,” Agbaje says. “It is also the basis for the tobacco company’s profit, since 6 out of every 10 new users of tobacco/nicotine are likely to be hooked for several decades.”
Smoke and nicotine-free path to prevent heart disease risk
The study’s results could be similar for vaping and e-cigarette users, who might unknowingly be at risk of significant, irreversible heart damage, the researchers say. About one out of every seven 18- to 24-year-olds in the U.K. who never regularly smoked now use e-cigarettes, one study shows. In the U.S., youth use e-cigarettes, or vapes, more than any other tobacco product, according to the CDC.
“The recent upsurge in vaping among teenagers is a serious health [concern],” Agbaje says. “We now know that vaping and e-cigarette products contain substances that can damage the lungs, in addition to the abnormal heart rhythm that nicotine causes to the heart.”
In related developments, a study earlier this year also associated cannabis use in adults 18 to 74 with adverse cardiovascular health. It linked heavier use (more days per month) to higher odds of negative heart health outcomes.
Limitations of this latest study include insufficient data on socio-environmental influences, including parental smoking, friends and peer smoking, or consuming alcohol.
In addition, levels of cotinine (a product of tobacco metabolism in the body that helps measure true nicotine exposure) were unavailable to analyze, the researchers say. Also, study participants were Caucasian, which may make findings ungeneralizable to other racial groups, they say.
“Our goal is to provide data for policymakers, clinicians, and public health practitioners on crucial timing for preventing smoking and its early consequences in youth,” says Agbaje.
“Parents and caregivers must lead by example and government agencies should be bold to address the preventable heart disease risk by creating a smoke and nicotine-free country. Raising tobacco taxes is insufficient because the cost of health care due to smoking-related diseases twice exceeds tobacco tax profits. Why should we pay for what is killing our teenagers softly?”
Reference
Agbaje AO. Incidental and Progressive Tobacco Smoking in Childhood and Subsequent Risk of Premature Cardiac Damage. Journal of the American College of Cardiology (JACC). Published online December 2024. doi.org/10.1016/j.jacc.2024.09.1229
Related
- Agbaje AO. Elevated blood pressure and worsening cardiac damage during adolescence. The Journal of Pediatrics. 2023;257:113374. doi:10.1016/j.jpeds.2023.02.018
- Jacobs DR, Woo JG, Sinaiko AR, et al. Childhood cardiovascular risk factors and adult cardiovascular events. New England Journal of Medicine. 2022;386(20):1877-1888. doi:10.1056/nejmoa2109191
- World Health Organization. “Ban smoking and vaping in school to protect young people.” Accessed Dec. 12, 2024.