The risk of heart disease and premature death may be higher for people who experience sudden, unpredictable income drops in early adulthood, a new study suggests.
Young adults with two or more significant drops in income over a 15-year period had more than twice the risk of developing heart disease and nearly twice the risk of dying early, compared to those with a more stable income, according to the study published in Circulation.
"Typically studies that assess the association between income and death use older populations," said lead author Tali Elfassy of the University of Miami, Florida. "We looked at adults who were aged 23 to 35 at the beginning of our study."
A drop in income can be very stressful, Elfassy said. "Think about the average American family," she explained. "A $5,000 to $10,000 decrease in income can be really devastating."
Elfassy and her colleagues analysed data from the ongoing Coronary Artery Risk Development in Young Adults (CARDIA) study, which is tracking 3,937 people from four American cities: Birmingham, Alabama; Minneapolis, Minnesota; Chicago, Illinois; and Oakland, California.
The study volunteers were all aged 23 to 35 in 1990 when CARDIA started. Their health status was checked every six months, and they were queried about their income five times between 1990 and 2005.
Between 2005 and 2015, people with multiple drops in income had more than a two and a half times higher risk of developing cardiovascular disease and a 92 per cent higher likelihood of dying prematurely compared with those who had stable paychecks.
The researchers also focused in on the impact a bigger economic hit - a loss of more than $20,000 - would have on cardiovascular events. Compared to individuals without any large changes in income, those with at least one big decrease were nearly four times more likely to develop cardiovascular disease and nearly two and a half times more likely to die prematurely.
Tiffany Gary-Webb, an associate professor of epidemiology and behavioural health at the University of Pittsburgh Graduate School of Public Health, welcomed the findings. "I think we need more studies like this to try to understand some of the things happening in the world today - all this economic instability and how it impacts health outcomes," said Gary-Webb. "We talk a lot about other outcomes, like employment, but we don't always take the next step and link to health outcomes."
Unpredictable income drops may force people to make hard choices and forgo healthcare, Gary-Webb said. "If you have an unstable income you may have to make tradeoffs of things like rent or food for medicine," she added. "A lot of those tradeoffs may not be amenable to good health behaviours."
The link between income drops and heart disease may be through stress, said Dr. James Glazier, a cardiologist with the Detroit Medical Center's Harper University Hospital. It's not the first time a connection has been made between income and health, Glazier said. He points to the Whitehall Studies that several decades ago found that heart disease was more prevalent in lower income British civil servants than those with higher incomes.
Moreover, Glazier said, there have been recent studies in stock brokers showing that when there was market volatility, blood pressure shot up.
"Chronic stress can hurt your heart," Glazier said. "And we know that emotional stress, like the loss of a spouse, can lead to heart problems. That effect has actually been given a name, broken-heart syndrome or Takatsubo cardiomyopathy."
Even without the science, we recognise the deadly impact of stress, Glazier said. "It's in the vernacular: 'If you don't stop worrying, you'll have a stroke.' 'Stop worrying or you'll kill yourself.'"