Asthma and hay fever have been linked to hypertension and high cholesterol and may as much as double the risk of heart disease, according to a new Northwestern University study of children.

The findings, published in the Journal of Allergy & Clinical Immunology, indicate children with allergic disease — particularly asthma and hay fever — have about twice the rate of high blood pressure and high cholesterol, setting them on a course for heart disease at a surprisingly early age.

Even when researchers took obesity into account, children with allergies and asthma were much more likely to have hypertension or high levels of “bad” cholesterol.

"This study shows that cardiovascular risk starts far earlier in life than we ever realized," said lead researcher Dr. Jonathan Silverberg, an associate professor of dermatology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine dermatologist.

"Given how common these allergic diseases are in childhood, it suggests we need to screen these children more aggressively to make sure we are not missing high cholesterol and high blood pressure. There may be an opportunity to modify their lifestyles and turn this risk around."

Asthma, hay fever, and eczema are associated with chronic inflammation, impaired physical activity, sleep disturbance, and great risk of premature death.

To gauge the potential for cardiovascular risks, Dr. Silverberg tracked the association of asthma, hay fever, and eczema in the U.S. with cardiovascular risk factors among 13,275 children. Asthma occurred in 14 percent of children, eczema in 12 percent, and hay fever in 16.6 percent. All three were also associated with higher rates of overweight or obesity, but the links between these conditions and cardiovascular problems were distinct and pronounced, he concluded.

Dr. Silverberg noted inflammation from asthma and hay fever might contribute to the higher rates of cardiovascular disease. In addition, children with profound asthma are typically more sedentary, which also may have a harmful effect and drive up blood pressure and cholesterol, he said.