Even slightly elevated blood pressure in the teen years may silently harden arteries for decades, with new CCTA imaging revealing early clues to who will develop dangerous coronary plaque in midlife.
Study: Blood Pressure in Adolescence and Atherosclerosis in Middle Age. Image credit: New Africa/Shutterstock.com
A recent study in JAMA Cardiology investigated the association between blood pressure (BP) in adolescence and incidence of atherosclerosis in middle age.
The study is the first to use coronary computed tomography angiography (CCTA) to directly assess coronary atherosclerosis in relation to adolescent BP, offering a more comprehensive view than previous surrogate-marker studies.
Consequences of high blood pressure
High BP is one of the most common risk factors that causes premature death, accounting for approximately 10.8 million deaths in 2021. Although mostly hypertension management is focused on adulthood, many cases of hypertension have been recorded in children and adolescents. Such increases have been attributed to higher obesity rates in this population.
Many studies have associated early-life BP with adult cardiovascular disease (CVD) risk and mortality. These studies have indicated that adolescent BP is a marker of vascular damage in adulthood, including increased pulse wave velocity, increased carotid intima-media thickness, and impaired endothelial function. Scientists believe that understanding the etiological mechanism underlying most CVD could shed light on the lasting consequences of early BP increase.
Currently, no studies have used an imaging modality, particularly CCTA, to visualize the coronary arteries, assess stenosis, and detect calcified, noncalcified, and mixed plaques. These noncalcified and mixed lesions increase the risks of cardiovascular events. Existing studies have also not examined the association between BP thresholds in adolescence and atherosclerosis in middle age using CCTA.
Measuring long-term artery health
The current study linked conscription data of adolescents enrolled in the Swedish Military Conscription Register with the Swedish Cardiopulmonary Bioimage Study (SCAPIS) using personal identification numbers. Men younger than 20 years of age at conscription, with complete data on BP, atherosclerotic outcomes, and covariates available at follow-up in SCAPIS, were included.
Of 10,802 eligible participants who matched conscription data, 9,110, 8,925, and 10,205 participants were included in CCTA stenosis, CAC score, and carotid plaque analysis, respectively. Based on systolic blood pressure (SBP) and diastolic blood pressure (DBP), BP was classified into four groups: normal BP (SBP <120 mm Hg and DBP <80 mm Hg), elevated BP (SBP = 120-129 mm Hg and DBP <80 mm Hg), hypertension stage 1 (SBP = 130-139 mm Hg or DBP = 80-89 mm Hg), and hypertension stage 2 (SBP ≥140 mm Hg or DBP ≥90 mm Hg).
Atherosclerosis in middle age was assessed using advanced imaging. Researchers also collected information on smoking duration at conscription and participants’ education levels. Because BP was measured in a potentially stressful conscription setting, a mild white-coat effect may have occurred, possibly weakening the observed associations.
Strong risks emerge early
A total of 10,222 men, with a mean age at conscription of 18.3 years, were included in the analysis. At conscription, their mean (standard deviation) SBP and DBP values were 127.6 (10.7) mm Hg and 68.3 (9.5) mm Hg, respectively. Approximately 16.9 % of participants were assigned to stage 2 hypertension.
The median follow-up period at SCAPIS was 39.5 years. The median SBP and mean DBP were estimated to be 128.0 mm Hg and 78.7 mm Hg, respectively. Approximately 24 % of the participants had a hypertension diagnosis. In middle age, 54.3 % of the participants had any coronary stenosis. In addition, 52.0 % of the cohort had a CAC score greater than 0, and 60.6 % had carotid plaque(s).
The current study identified a strong dose-response association between BP categories and coronary stenosis on CCTA, particularly for severe stenosis. A dose-response association was found between BP categories and all coronary plaque types, i.e., mixed, calcified, and noncalcified plaques. Adolescents with stage 2 hypertension exhibited a greater tendency to develop severe stenosis, compared to those with normal BP.
Notably, the study also found that even adolescents in the “elevated BP” range, below hypertensive thresholds, showed increased risk of severe coronary atherosclerosis compared with those with normal BP, underscoring the clinical relevance of modest BP elevations.
Spline models showed a steady increase in coronary and carotid atherosclerosis as adolescent SBP rose. SBP levels below 120 mm Hg were linked to lower coronary risk, while adolescents with stage 2 SBP had a substantially higher likelihood of severe stenosis than those with normal SBP.
A positive association was also observed between adolescent DBP and coronary atherosclerosis. Participants with DBP values less than 80 mm Hg were found to be at lower odds of severe coronary stenosis and CAC. However, DBP categories, unlike SBP categories, were not significantly associated with severe stenosis when analyzed as categorical variables, indicating a weaker and statistically nonsignificant relationship for DBP.
Spline models also indicated a positive association between mean arterial pressure and atherosclerosis. However, splines for pulse pressure revealed a very weak link with atherosclerosis indicators.
Sensitivity analyses using different definitions of coronary stenosis produced similar results. Including only participants with data from all eleven coronary segments weakened the association for stenosis of 50 % or greater. Additional adjustments had little impact, but not adjusting for body mass index (BMI) at conscription moderately strengthened the association. Excluding those with CVD slightly weakened the findings.
Results were consistent among participants not taking antihypertensive medication, but the association disappeared in those receiving treatment, suggesting that treatment may slow atherosclerosis progression and mask the link with adolescent BP.
Rethinking teen heart risk
Higher adolescent blood pressure was found to be associated with a greater risk of coronary atherosclerosis in adulthood, especially severe stenosis with higher systolic blood pressure. Elevated blood pressure in adolescence, per current guidelines, is a strong predictor of atherosclerosis later in life.
Given sex differences in atherosclerosis burden, and the fact that the current study included only men, future studies should focus on women to evaluate the association between adolescent BP and atherosclerosis.
The authors also emphasize that their estimates may underestimate the true associations because early-life hypertension increases the likelihood of later antihypertensive treatment, which can slow atherosclerosis progression.
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