COLORADO SPRINGS, March 17 (UPI) -- Secondhand smoke in the home appears to induce markers for heart disease as early as the toddler years, a U.S. study found.

Lead author Dr. Judith Groner of Nationwide Children's Hospital and Research Institute, in Columbus, Ohio, said many forms of cardiovascular disease in adults are initiated and progress silently during childhood.

The study involved 128 children, ages 2 to 5 and adolescents ages 9 to 14. The study found hair samples of children ages 2 to 5 had average nicotine levels of 12.68 nanograms per milligram of hair compared to the 9 to 14 year age group, which had 2.57 nanograms per milligram of hair.

The exposure resulted in a dramatic increase of markers of inflammation and vascular injury signaling damage to the endothelium, the inner lining of the vessel walls.

"Toddlers in the homes of smokers not only had higher levels of nicotine but also had higher levels of markers for cardiovascular disease in the blood," senior author John Bauer said in a statement.

The findings were presented at the American Heart Association's 48th Annual Conference on Cardiovascular Disease Epidemiology and Prevention in Colorado Springs, Colo.