Interaction effect between fasting plasma glucose and lipid profiles on mortality of peritoneal dialysis patients

Background Peritoneal dialysis (PD) patients have a high risk of abnormal glucose and lipids metabolism. Objective We investigated the effects of baseline fasting plasma glucose (FPG) as well as its interaction with lipid profiles on all-cause and cardiovascular disease (CVD) cause-specific mortality in PD patients. Methods A total of 1995 PD patients were enrolled. Kaplan-Meier survival curves and Cox regression models were performed to assess the association of FPG levels with mortality in PD patients. Results During a median (25th-75th quartile) follow-up period of 48.1 (21.8-77.9) months, 567 (28.4%) patients died, including 282 (14.1%) CVD deaths. Kaplan-Meier survival curves showed that all-cause and CVD cause-specific mortality increased significantly with elevated baseline FPG levels (Log-rank tests: both P-values <.001). However, with adjustment for potential confounding factors, baseline FPG levels were not significantly associated with all-cause and CVD cause-specific mortality. Nevertheless, a significant interaction between baseline FPG and low-density lipoprotein cholesterol (LDL-C) on all-cause mortality was found (P for interaction test: .013), and subgroup analyses further showed that all-cause mortality was significantly increased for baseline FPG >= 7.0 mmol/L compared with the normal reference (FPG <5.6 mmol/L) (hazard ratio 1.89, 95% confidence interval 1.11-3.23, P-value = .020) for patients with LDL-C >= 3.37 mmol/L only, but not for those with lower LDL-C levels (<3.37 mmol/L). Conclusion The significant interaction effect between baseline FPG and LDL-C on all-cause mortality showed that, for PD patients with LDL-C >= 3.37 mmol/L, higher FPG levels (>= 7.0 mmol/L) were significantly associated with an increased risk of all-cause mortality and need more intensive management of their FPG by clinicians in the future.