The results of a new study have shown that a person's risk of developing heart-related health problems are greater if they had a low-income childhood.
The study - led by the University of Turku in Finland and published in the journal JAMA Pediatrics - supports the idea that efforts to improve heart health should address the family environment of growing children.
In the United States, there are around 5.7 million people living with heart failure, a progressive condition in which the heart become less and less able to pump enough blood for what the body needs.
The most common symptoms of heart failure are shortness of breath, fatigue, and swelling in various parts of the body such as the abdomen, legs, feet, and ankles. As the symptoms progress, they make it harder and harder to lead a normal life and do everyday things.
The leading causes of heart failure are disorders that alter and damage the heart. These include diabetes, high blood pressure, and coronary artery disease, a condition in which the main vessels that supply blood to the heart stiffen and narrow.
Increased left ventricular (LV) mass and LV diastolic dysfunction are signs of abnormality in the lower left chamber of the heart. The former means that the chamber is enlarged and the latter means that the chamber is not relaxing properly during pumping.
Low family income an independent factor
In their study paper, the authors note that both increased LV mass and LV diastolic dysfunction are linked to heart failure, and that studies show that they are more common in middle-aged and older adults of lower education.
Citing other research that also looked at the link between occupation and these conditions later in life, the authors note that their study is the first to look at how the conditions might link to socioeconomic status in the early years.
For their investigation, the team used data from 1,871 participants collected between 1980 and 2011 in the Cardiovascular Risk in Young Finns Study, a large follow-up study of heart health from childhood into adulthood.
The extent of the data allowed the researchers to examine the link between childhood family income status (which they classed as low, middle, or high income) when the participants were aged between 3 and 18 years, and LV mass and LV diastolic function measured more than 30 years later, when they were aged between 34 and 49 years.
The analysis found that low family income in childhood was linked to increased LV mass and poorer LV diastolic performance during adulthood, 31 years later.
The link was still there when the researchers took into account other factors that might have an effect, including age, sex, socioeconomic status in adulthood, and other cardiovascular risk factors in childhood and adulthood.
The authors acknowledge that a weakness of the study is the fact that it only included white people and that no measures of LV mass and diastolic performance were taken in childhood, making it difficult to determine when the effects of low income in childhood may have started to influence heart function. Nevertheless, they conclude that:
"These findings emphasize that approaches of CVD [cardiovascular disease] prevention must be directed also to the family environment of the developing child."