Preschoolers exposed to passive cigarette smoke have higher blood pressure

Second-hand smoke in the home increases arterial hypertension in children as young as 4 and 5 years, according to new evidence from a screening project of preschool children in Germany. Results of the study appeared online in the journal Circulation.

The population-based study of 4,200 kindergarteners showed that both systolic and diastolic blood pressure (BP) were higher in children living with 1 (33% of participants) or both (12% of participants) smoking parents, even after correction for risk factors such as body mass index (BMI), parental hypertension, or birth weight. According to the researchers, parental smoking increased the likelihood of a child having systolic blood pressure in the top 15% of the population by 21%.

Data showed a linear correlation between BP and children’s height and BMI, with obese children (BMI>95th percentile) displaying significantly higher systolic and diastolic BP values than children with a leaner BMI (<85th percentile). Other risk factors for higher BP values in preschoolers included children born preterm or with low birth weight, children exposed to maternal smoking and maternal hypertension during pregnancy, children of hypertensive and/or obese parents, and lower levels of parental education. Systolic and diastolic BP values were shown to progressively increase with the number of parent-related risk factors. The mean difference between children without any risk factors and children with 3 cumulative risk factors was 3.2 mm Hg (P=.003) for systolic and 2.9 mm Hg for diastolic BP (P=.001).

The study provides evidence that environmental nicotine exposure causes an increase in BP in children as young as preschool age, said the researchers, and because childhood BP tracks into adult life, implementing smoke-free environments at home and in public places could significantly reduce the risk of hypertension and cardiovascular and pulmonary disease not only in adults but in the pediatric population as well.

Simonetti GD, Schwertz R, Klett M, Hoffmann GF, Schaefer F, Wuhl E. Determinants of blood pressure in preschool children: the role of parental smoking. Circulation. 2011. Epub ahead of print.