Employees with the lowest wages have a higher risk of hypertension than those with top wages, according to University of California-Davis researchers. The correlation between lower socioeconomic status and hypertension was unexpectedly strong with women and individuals in the 25-to-44 age range, investigators found.

“We were surprised that low wages were such a strong risk factor for two populations not typically associated with hypertension, which is more often linked with being older and male,” said senior study author J. Paul Leigh, a professor of public health sciences at UC-Davis.

The findings, published in the December issue of the European Journal of Public Health, are believed to be the first regarding the role of income in hypertension. Annual all-source income was divided by work hours and ranged from $2.38 to $77 per hour in 1999 dollars. Respondents reported hypertension based on a physician’s diagnosis.

The team found that doubling the wage was associated with a 16% decrease in the risk of a hypertension diagnosis. Doubling the wage reduced the risk of a hypertension diagnosis by 1.2% over two years and 0.6% for one year.

Doubling the wages of younger workers was associated with a 25% to 30% decrease in the risk of a hypertension diagnosis; doubling the wages of women was associated with a 30% to 35% decrease in the risk of a hypertension diagnosis.

The study information came from the Panel Study of Income Dynamics database. A total of 5,651 household heads and their spouses between the ages of 25 and 65 were followed during 1999-2001, 2001-03 and 2003-05.