According to research published in the August, 2003 issue of Brain, Behavior and Immunity, obesity and depression can increase inflammation that can lead to heart disease. C-reactive protein (CRP) is a chemical that indicates the presence of inflammation, specifically inflammation that can irritate the lining of the arteries and lead to heart disease. A high level of CRP is considered to be a risk factor for heart disease. The study involved 3,205 German men between the ages of 45 and 74. About 23% of the subjects were obese. The men who were obese had higher level of CRP than men who are not obese. In obese men who are depressed, the CRP level is even higher. Depression did not affect CRP levels among non-obese men, however, suggesting that a combination of obesity and depression may be more risky for some men. Overall, the percentage of men deemed to be depressed was the same in the obese group as in the non-obese group. There was no correlation between depression and obesity.