Plasma adiponectin is related to other cardiovascular risk factors in nondiabetic Korean men with CAD, independent of adiposity and cigarette smoking: Cross-sectional analysis

Background: Circulating adiponectins have multiple protective roles as anti-diabetic, anti-atherosclerotic, and anti-inflammatory factors. We examined the relationship between plasma adiponectin concentration and other cardiovascular risk in nondiabetic coronary artery disease (CAD) men and the relationship can be maintained even after adjusted for major environmental factors that contribute to adiponectin concentrations. Methods: Nondiabetic CAD men (n = 613) were 31-70 y and had body mass index (BMI) of 18.5-29.9 kg/m². Results: Circulating adiponectins positively correlated with age and negatively with BMI, waist circumference and % body fat (p-values of all < 0.001). Plasma adiponectin concentrations were higher in never-smokers (5.07 ± 0.30 μg/ml) than current (4.15 ± 0.12 μg/ml) and ex-smokers (3.75 ± 0.20 μg/ml) both before and after adjusted for age and adiposity (p = 0.002 and p = 0.008, respectively), however they were not significantly different according to alcohol drinking status. After adjusted for age, adiposity and cigarette smoking, plasma adiponectin still have positive correlations with HDL cholesterol, apolipoprotein AI and LDL particle size, and inversely with fasting triglyceride, atherogenic index, insulin resistance and C-reactive protein (CRP). However there was no significant relationships between adiponectin and apolipoprotein B, total cholesterol or LDL cholesterol. In subset analysis by tertile adiponectin concentrations (lowest: < 2.92, moderate: 2.92 ≤ adiponectin < 4.75, highest: ≥ 4.75 μg/ml), 'moderate' and 'highest' adiponectin groups had lower triglyceride (p < 0.001), lower atherogenic index (p = 0.001), lower fasting insulin (p = 0.004), lower insulin resistance (p = 0.001), lower CRP (p = 0.001), higher HDL cholesterol (p < 0.001), higher apolipoprotein AI (p = 0.005) and higher LDL particle size (p < 0.001) as compared with 'lowest' adiponectin group when adjusted for age, adiposity and cigarette smoking. Platelets were lower in 'highest' adiponectin groups as compared with 'lowest' and 'moderate' adiponectin group after the adjustment. However, there was no significant difference in total cholesterol (p = 0.145), LDL cholesterol (p = 0.145), apolipoprotein B (p = 0.222) and fasting glucose (p = 0.157). Conclusion: An increase of adiponectin concentrations or the maintenance of higher concentration may be negatively associated with cardiovascular risk factors in nondiabetic CAD male patients, independent of adiposity and smoking status.