Salary, Schooling, Inflammation Linked
Lower Income and Less Education Tied to Higher Blood Levels of Inflammatory Chemicals
Nov. 19, 2007 -- The blood may hold chemical clues about the relationship
between income and health.
A new study shows that people with lower incomes and fewer years of formal
education tend to have higher blood levels of two inflammatory chemicals.
High levels of those chemicals -- interleukin-6 (IL-6) and C-reactive
protein (CRP) -- have been linked to heart
It's not that a person's salary or schooling determines their health. But
education and income often sync up with a person's opportunities, access to
medical care, and other factors.
In the new study, the University of Michigan's Nalini Ranjit, PhD, and
colleagues measured IL-6 and CRP levels in some 6,800 U.S. men and women aged
Data included participants' education, income, BMI (body
mass index, which relates height to weight), waist circumference, smoking, drinking, physical activity, diabetes, and medications.
Participants also rated their depression, hostility, and chronic stress.
In all of the groups studied -- white, African-American, Chinese, and
Hispanic -- lower incomes were linked to higher levels of IL-6.
In whites and African-Americans, lower levels of education were linked to
higher levels of IL-6.
The patterns were similar for CRP, Ranjit's team reports.
Being overweight was the most common link between education, income, and
higher levels of IL-6 and CRP.
But it wasn't just about weight. Hostility and smoking also mattered. There
may be multiple factors that connect increased inflammation and lower income,
according to the study.
The study doesn't show how participants' inflammation and health fared over
The results appear in tomorrow's edition of Circulation.