['The aim of this study was to investigate the role of inflammatory markers as potential predictors of cardiovascular events in subjects with and without the metabolic syndrome.', 'This was a post hoc analysis from the Diet and Omega-3 Intervention Trial (DOIT), comprising 563 elderly men with (n = 221) and without (n = 342) metabolic syndrome. Circulating inflammatory markers were measured.', 'During 3 years, 68 cardiovascular events were recorded. In the total population, C-reactive protein (CRP) (P < 0.001), interleukin-18 (IL-18) (P = 0.008), and IL-6 (P = 0.003) were elevated in subjects with events. In subjects with metabolic syndrome, IL-18 was the strongest predictor (adjusted odds ratio 2.9 [95% CI 1.1-7.8]). In subjects without metabolic syndrome, only CRP seemed to be an independent predictor (3.3 [1.5-7.3]). There was a significant interaction between fasting glucose and IL-18 (P = 0.008) and IL-6 (P = 0.024) but not CRP. Elevated fasting glucose (>6.2 mmol/l) markedly increased the predictive power of inflammatory markers (IL-18: 5.5 [1.4-21.1], IL-6: 3.5 [1.0-11.8], and CRP: 3.5 [1.0-11.9]). For IL-18, there was a stepwise increase in event rate by quartiles of fasting glucose.'] Is interleukin-18 a strong predictor of cardiovascular events in elderly men with the metabolic syndrome : synergistic effect of inflammation and hyperglycemia?