April 10 (HealthDay News) -- Low birth weight followed by excessive weight gain during childhood and young adulthood may lead to the low-grade inflammation that can raise the risk of heart disease later, a new report says.

Researchers noted the findings in a study of 5,840 people from birth to the age of 31; however, few heart-related problems have appeared among the participants, probably because they are still relatively young. The researchers intend to follow them for at least another 20 years.

The Finnish study, expected to be published in the April 10 issue of the European Heart Journal, may highlight the role that starting healthy lifestyles at birth could play in preventing heart problems.

The researchers looked at the participant's levels of C-reactive protein (CRP) in their blood. The liver secrets CRP, and slightly elevated levels can indicate a chronic, low-grade inflammation. The study, done on Finnish participants, found that those who were amongst the smallest at birth, but who then put on the most weight by age 31, had the highest average CRP levels.

"Low-grade inflammation is important, because it has been associated with future cardiovascular events in many population studies over the past few years, and it may play a role in the development of cardiovascular disease," study co-author Paul Elliott, head of the Department of Epidemiology and Public Health at Imperial College London, said in a prepared statement.

CRP levels were 16 percent higher per 1 kilogram lower birth weight, 21 percent higher per 10 centimeters shorter length at birth, and 24 percent higher per 1 kg/m3 lower at birth (kg/m3 is known as ponderal index), after adjusting for potential confounding factors. Every extra kg/m2 (body-mass index) gained from the age of 14 to 31 was associated with a 16 percent rise in CRP levels; this association was greatest for people who had the highest BMI at age 14.

In their report, the authors said: "The finding that weight gain from adolescence to young adulthood appears to play a greater role in low grade inflammation than weight in adolescence per se, could have important implications for the primordial prevention of cardiovascular disease. Promoting healthier lifestyle in childhood and adolescence, leading to weight stabilization, might be a crucial step in establishing a low cardiovascular risk profile in young adults."

SOURCE: European Society of Cardiology, news release, April 9, 2008