Arterial intima-media thickness, endothelial function, and apolipoproteins in adolescents frequently exposed to tobacco smoke.
BACKGROUND
Exposure to tobacco smoke is associated with markers of preclinical atherosclerosis in adults, but its effect on arterial structure in adolescents is unknown.


RESULTS
Healthy 13-year-old adolescents from the atherosclerosis prevention trial STRIP were studied. Maximum carotid and aortic intima-media thickness and brachial artery flow-mediated dilation were measured in 494 adolescents using high-resolution ultrasound. Serum lipid, lipoprotein, and apolipoprotein (Apo) A-I and B concentrations were determined using standard methods. Exposure to tobacco smoke was measured annually between ages 8 and 13 years using serum cotinine concentrations, analyzed with gas chromatography. To define longitudinal exposure, cotinine values of children having serum cotinine measured 2 to 6 times during follow-up were averaged and divided into tertiles (exposure groups): low (n=160), intermediate (n=171), and high (n=163). Adolescents with higher longitudinal exposure to tobacco smoke had increased carotid intima-media thickness (exposure groups [mean+/-SD]: low, 0.502+/-0.079 mm; intermediate, 0.525+/-0.070 mm; high, 0.535+/-0.066 mm; P<0.001) and increased aortic intima-media thickness (exposure groups: low, 0.527+/-0.113 mm; intermediate, 0.563+/-0.139 mm; high, 0.567+/-0.126 mm; P=0.008). The flow-mediated dilation decreased when cotinine level increased (exposure groups: low, 10.43+/-4.34%; intermediate, 9.78+/-4.38%; high, 8.82+/-4.14%; P=0.004). Moreover, ApoB (P=0.014) and ApoB/ApoA-I ratio (P=0.045) increased with increase in cotinine level. The associations between tobacco smoke exposure and ultrasound variables were unchanged after adjusting for traditional atherosclerosis risk factors and for ApoB.


CONCLUSIONS
Frequent exposure to tobacco smoke is independently associated with arterial changes of preclinical atherosclerosis and increased ApoB levels among healthy adolescents. Clinical Trial Registration- clinicaltrials.gov. Identifier: NCT00223600.
Kallio
Katariina
K
Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland. katariina.kallio@utu.fi
Jokinen
Eero
E
Saarinen
Maiju
M
Hämäläinen
Mauri
M
Volanen
Iina
I
Kaitosaari
Tuuli
T
Rönnemaa
Tapani
T
Viikari
Jorma
J
Raitakari
Olli T
OT
Simell
Olli
O
D000293:Adolescent; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000187:drug effects*; D016632:Apolipoprotein A-I / Q000097:blood*; D001055:Apolipoproteins B / Q000097:blood*; D050197:Atherosclerosis / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D015415:Biomarkers / Q000097:blood; D001916:Brachial Artery / Q000187:drug effects / Q000503:physiopathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000187:drug effects*; D002648:Child; D002849:Chromatography, Gas; D003367:Cotinine / Q000097:blood; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D005387:Finland; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016540:Smoking Cessation; D013997:Time Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000187:drug effects*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000187:drug effects*; D018608:Ultrasonography, Doppler; D014664:Vasodilation / Q000187:drug effects
C505693:APOA1 protein, human; D016632:Apolipoprotein A-I; D001055:Apolipoproteins B; D015415:Biomarkers; D014028:Tobacco Smoke Pollution; D003367:Cotinine