Leptin-adiponectin ratio and the extent of CAD in pre-diabetic patients undergoing PCI

Background: The obesity-related hormones leptin and adiponectin are independently and oppositely associated with insulin resistance, an important risk factor for coronary artery disease and restenosis after coronary intervention. In this report, we set out to determine the role of the leptin-adiponectin ratio (LAR) in non-diabetic patients with or without impaired glucose tolerance (IGT) undergoing a percutaneous coronary intervention (PCI). Methods: After obtaining informed consent, three hundred unselected PCI patients were enrolled in this prospective single center study. In both stable and acute subjects, assessment was done on the day of discharge and included a fasting glucose and insulin, leptin, adiponectin, and an oral glucose tolerance test (OGTT) in the non-diabetic patients. IGT, or "prediabetes", was defined as 2h-glycemia between 140 and 200 mg/dL during an OGTT. For this analysis, known diabetic patients (n=50) and newly diagnosed diabetic patients (2h OGTT>200 mg/dL, n=25) were excluded. Results: Of the 225 PCI patients without a history of diabetes or newly diagnosed diabetes, 141 had a normal OGTT, while 81 were diagnosed with pre-diabetes (IGT). Pre-diabetic patients were older (67±1 vs 63±1, p=0.002) and had a higher BMI (28.0±.5 vs 26.8±.4, p=0.023) and HbA1c (5.89±.04 vs 5.67±.02, p<0.001). LAR was significantly higher in prediabetic patients (4.57±0.48) vs normoglycemic patients (3.45±0.33, p=0.050). LAR was found to be numerically higher in prediabetic vs normoglycemic patients with two and three vessel disease (VD), but not among patients with single vessel disease (VD) (figure 1). In prediabetic patients, LAR was found to be significantly increased with more advanced CAD (p=0.021), independently of stable vs unstable presentation. We did not observe a significant correlation between LAR and the Duke CAD index (p=0.108). More extensive CAD resulted in worse outcome including revascularization rates during a median follow-up of 2.1y in pre-diabetic but not in normoglycemic patients (Log-rank p=0.004). Conclusion: The leptin-adiponectin ratio is related to the extent of CAD in pre-diabetic patients but not in normoglycemic patients. This finding might in part explain the poorer outcome in revascularized patients with impaired glucose tolerance.