Hyperleptinaemia and chronic inflammation after peritonitis predicts poor nutritional status and mortality in patients on peritoneal dialysis.

BACKGROUND The serum leptin level is elevated in patients undergoing peritoneal dialysis (PD) and associated with a loss of lean body mass. The nutritional status of PD patients may further be worsened following peritonitis. We investigated the association between hyperleptinaemia, inflammation and malnourishment in PD-related peritonitis. METHODS We conducted a prospective study on PD patients who developed peritonitis. Blood samples were obtained as baseline (D0) before the onset of peritonitis, and once peritonitis developed, leptin, adiponectin (ADPN) and other inflammatory markers were collected, on day 1 (D1), day 7 (D7) and day 42 (D42) of peritonitis. Patients were followed-up for any censor event or 1 year after peritonitis. RESULTS Forty-two patients with a mean age of 62.9+/-13.2 years were recruited. Fourteen (33.3%) were diabetic. The serum leptin levels increased significantly from baseline to day 1 and 7, but fell back to the premorbid state at day 42. In contrast, the ADPN level decreased from a baseline value of 15.60+/-10.4 microg/ml to 13.01+/-8.1 microg/ml on day 1 (P=0.01) but rose to 14.39+/-8.9 microg/ml on day 7 (P=0.28) and 13.87+/-7.9 microg/ml on day 42 (P=0.21). High-sensitivity C-reactive protein (hs-CRP) increased significantly from baseline to day 1, 7 and even at day 42. The lean body mass (LBM) and nutritional markers decreased significantly after peritonitis. For patients with high hs-CRP (>3.0 mg/l) at day 42, there was a higher mortality rate than for those with lower hs-CRP (<3.0 mg/l, P=0.02), even if they were in clinical remission of peritonitis. CONCLUSIONS Our study confirmed an increase in serum leptin during acute peritonitis and a prolonged course of systemic inflammation after apparent clinical remission of peritonitis. These factors related to the persistent chronic inflammation may contribute to the development of malnourishment and poor survival rate.