Teenagers who experience a lot of daily interpersonal stress have increased blood levels of a protein linked to chronic inflammation — which in turn might indicate a greater risk of heart disease later in life — according to findings from a small study.

Dr. Andrew J. Fuligni, at the University of California, Los Angeles, and colleagues had 69 high school seniors keep daily records for two weeks of negative interpersonal interactions, such as conflict with family, harassment by peers, or reprimands from teachers.

The researchers then measured the teens' blood levels of C-reactive protein about 8 months later.

Previous research has linked higher blood levels of C-reactive protein, a marker for body-wide inflammation, with increased risk for cardiovascular disease in adults.

The researchers found that C-reactive protein levels increased with the frequency of daily stressful episodes involving other people, even after accounting for such factors as differing individual sensitivity to rejection, stressful life events, and substance use.

"Daily hassles and difficulties, such as arguing with family members or friends, can have health consequences if they occur frequently over a period of time," Fuligni told Reuters Health.

In their report in the journal Psychosomatic Medicine, Fuligni and colleagues describe these results as "consistent with the emerging body of evidence pointing to the link between stress and increased inflammation." This, in turn, places individuals at risk for later development of cardiovascular disease, they report.

Fuligni suggests similar studies looking at younger adolescents and children, as well as research to see whether different coping skills mitigate markers of inflammation in young people.