BACKGROUND: Metabolic syndrome and inflammation are interlinked in patients with moderate chronic kidney disease (CKD). METHODS: We examined whether these 2 conditions exert additive or multiplicative joint effects on subsequent coronary events and death in 710 Atherosclerosis Risk in Communities Study participants with a glomerular filtration rate less than 60 mL/min/1.73 m(2) (<1.0 mL/s). RESULTS: From the lowest to the highest quartile of level of plasma fibrinogen (an inflammation marker), the prevalence of metabolic syndrome (39%, 46%, 47%, and 64%; P < 0.001) increased. In multivariate Cox regression models, each 100-mg/dL increase in plasma fibrinogen level was associated with a significantly increased hazard of fatal/nonfatal coronary events (hazard ratio [HR], 1.62; 95% confidence interval [CI], 1.33 to 1.98) and death (HR, 1.49; 95% CI, 1.28 to 1.74). In the same models, metabolic syndrome also was associated with coronary events (HR, 1.49; 95% CI, 1.01 to 2.20) and death (HR, 1.40; 95% CI, 1.01 to 1.94). There was no significant interaction of plasma fibrinogen and metabolic syndrome with respect to risk of both fatal/nonfatal coronary events (P = 0.79) and death (P = 0.29). However, patients without metabolic syndrome and in the lowest quartile of plasma fibrinogen levels had the lowest incidence of fatal/nonfatal coronary events or death, whereas those with metabolic syndrome and in the highest quartile of plasma fibrinogen levels had the highest incidence of these events. CONCLUSION: Inflammation is associated strongly with metabolic syndrome in patients with moderate CKD. Inflammation and metabolic syndrome have additive and not multiplicative joint effects on coronary events and death.