FRIDAY, Sept. 8, 2023 (HealthDay News) -- For individuals with obesity undergoing bariatric surgery, depression is associated with higher inflammation before and after surgery, according to a study published online Aug. 31 in Psychological Medicine.

Anna P. McLaughlin, Ph.D., from King's College London, and colleagues examined longitudinal associations between depression and inflammatory markers and their effect on weight loss and clinical outcomes in an observational study of 85 patients with obesity (41 with depression and 44 controls). Depression was assessed by clinical interview before and six months after surgery.

The researchers found that after controlling for confounders, depression diagnosis before surgery was associated with significantly higher serum high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, and IL-6/10 ratio levels. Patients with preexisting depression had significantly higher inflammation at six months after surgery despite having similar weight loss to controls. Higher baseline hsCRP levels predicted poorer weight loss in hierarchical regression but did not affect depression severity at follow-up. Greater depression severity after surgery was predicted by more severe baseline depressive symptoms and childhood emotional abuse.

"Our data showing that increased inflammation predicts lower weight-loss after bariatric surgery suggests that personalized treatments involving approaches that lower inflammation could enable better outcomes after surgery," coauthor Valeria Mondelli, M.D., Ph.D., also from King's College London, said in a statement.