Long-term reprogramming of cardiovascular function in infants of active smokers.
Newborn infants of smokers show symptoms of cardiovascular stress hyperreactivity. Persistent hyperreactivity could increase the risk of short- and/or long-term complications, such as hypertension. Here we determined whether incipient dysfunction in a smoker's infant persists or worsens with age, by comparing cardiovascular reflex function of control and tobacco-exposed infants longitudinally from birth to 1 year. We compared infants born at term to nonsmoking couples (controls; n=19) and mothers who smoked moderately (average consumption=15 cigarettes per day; n=17). All were tested at 1 to 3 weeks, 3 months, and 1 year during sleep. We recorded blood pressure and heart rate noninvasively during passive repositioning (60 degrees head-up tilt). Tilting control infants raised blood pressure slightly above baseline at 1 week (+2%) and much more at 1 year (+10%). This trend was reversed in the tobacco-exposed cohort (+10% at 1 week but only +4% at 1 year). At 3 months and 1 year, the heart rate response of tobacco-exposed infants to tilt was also abnormal (highly exaggerated). Our study reveals that maternal smoking leads to long-lasting "reprogramming" of infant blood pressure control mechanisms. The underlying dysfunction in a smoker's infant could plausibly be a precursor or early marker of long-term susceptibility to complications, such as raised blood pressure.
Cohen
Gary
G
Department of Women and Child Health, Neonatal Unit, Karolinska Institute, Elevhemmet H1-02, S-171 76 Stockholm, Sweden. Gary.Cohen@ki.se
Jeffery
Heather
H
Lagercrantz
Hugo
H
Katz-Salamon
Miriam
M
D001794:Blood Pressure / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000503:physiopathology*; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D010290:Parents; D011187:Posture / Q000502:physiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology* / Q000503:physiopathology*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology* / Q000503:physiopathology*; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data; D014630:Vagus Nerve / Q000502:physiology; D014661:Vasoconstriction / Q000502:physiology; D014680:Veins / Q000502:physiology
D014028:Tobacco Smoke Pollution