A new study has found two more indicators for future heart disease risk - low birth weight and excessive weight gain during adolescence and young adulthood.
At the same time, the study also highlights the vital role of healthy lifestyles, from the foetal period, through childhood, adolescence and young adulthood, in preventing heart problems.
In the study, the researchers followed 5,840 people from before birth to the age of 31 to find a link between low birth weight, excessive weight gain and heart problems in later life.
For determining the cause behind this mechanism, the researchers used a protein called C-reactive protein (CRP) as a marker for general inflammation. CRP is secreted from the liver, is present in blood, and slightly elevated levels can indicate a chronic inflammatory state (low grade inflammation, as opposed to acute inflammation).
"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," explained Paul Elliott, one of the authors of the study.
The researches found that when the Finnish participants in the study reached the age of 31, those who were amongst the smallest at birth, but who then put on the most weight up to the age of 31, had the highest average CRP levels.
Dr Ioanna Tzoulaki, the first author of the study and Lecturer in Epidemiology at the Department of Epidemiology and Public Health, Imperial College London, said: "We compared birth weight of children participating in the Finland 1966 Birth Cohort study with their CRP levels at age 31, and we found that those who had lower birth weight, have higher CRP levels when they are adults, and also the other way round - people who had higher birth weight had lower CRP levels as adults. The 'lower' and 'higher' CRP levels are relative to measurements in other participants in the study."
"These findings lead us to conclude that small size at birth and excessive weight gain during adolescence and young adulthood may predispose to low grade inflammation, which, in turn, is associated with increased risk of developing cardiovascular disease," she added.
After discussing a number of possible mechanisms, the authors concluded that low birth weight, followed by a greater than average increase in BMI, may trigger the production of the low grade inflammatory response.
"Low birth weight has been associated with future cardiovascular diseases and type II diabetes in many studies. This study adds to them and provides a possible explanation for their findings: that this association might be mediated through the effects of birth size on low grade inflammation, as measured by CRP levels," explained Prof Elliott.
The study is published in Europe's leading cardiology journal, the European Heart Journal.