"While this study is observational in nature and certainly not an evaluation of such programmes, our results do highlight that large negative changes in income may be detrimental to heart health and may contribute to premature death", Elfassy said.
Elfassy noted the largest income shifts were associated with almost double the risk of death and more than double the risk for heart disease.
The study found a significant association with the biggest fluctuations in personal income and more than double the risk for cardiovascular diseases, such as heart attacks, strokes, heart failure or death during the following 10 years.
The study was not able to determine the cause of the association between income volatility and health because it was observational and not created to prove cause and effect.
However, unstable income can affect a person's health in a number of ways, said Donna Arnett, past president of the American Heart Association and dean of the University of Kentucky College of Public Health. High blood pressure, high cholesterol and smoking all contribute to the condition.
"Could it be you can't take your medications because you can't afford them, you can't afford to see a physician, you can't afford the right diet?"
Elfassy pointed out that previous studies have linked income to a person's risk of heart disease, but those studies tend to focus on income at one single point in time.
"Fluctuations in income are actually very common", Elfassy said.
Overall, about one in four deaths in the United States results from heart disease, according to the Centers for Disease Control and Prevention.
High income volatility (defined by an individual's standard deviation of change from 1990-2005) was associated with a higher risk of death (HR 1.78, 95% CI 1.03-3.09) and of cardiovascular disease (HR 2.07, 95% CI 1.10-3.90) than low volatility, reported Adina Zeki Al Hazzouri, PhD, of the University of Miami, and colleagues in Circulation. The researchers assessed income volatility based on large swings in income.
Prof Elfassy said: "Income volatility is generally considered to be a sudden and unpredictable change in income over time, and most often it consists of declines in income".
The study noted while from young adulthood through midlife, most individuals experience at least some increases in income. The research also found high income volatility and income drops were experienced more by women and African-Americans than white men. "They also had less years of education than those who did not have income fluctuation".