Insulin resistance increases cardiovascular risk of obese patients. Triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL) >or=3.0 (in mg/dl) is a marker of insulin resistance in overweight persons. We aimed at assessing cardiovascular risk profile in 301 overweight elderly Neapolitan outpatients, according to TG/HDL ratio and metabolic syndrome (MS), diagnosed by National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF) criteria. TG/HDL ratio was >or=3.0 in 97 patients (group A) and <3.0 in 204 (group B). Overall, 93-97% of group A patients and 38-51% of group B patients had MS, depending on the diagnostic criterion. Group A patients with MS had significantly higher waist-to-hip ratio, total and non-HDL cholesterol than group B patients with MS. In group B, MS and non-MS patients had similar waist-to-hip ratio, blood pressure, total and non-HDL cholesterol. Ten year coronary risk, calculated by the Framingham equations (n = 243), was 10.3 +/- 5% in group B, non-MS patients; 13.1 +/- 6% in group B, MS patients; 19.9 +/- 8% in group A (F = 32.8; P < 0.001). At the multiple regression analysis, TG/HDL ratio was associated with coronary risk (r(2) = 0.227) more closely than gender, blood pressure, waist-to-hip ratio, non HDL cholesterol, and MS considered as a whole. A separate regression analysis showed that the logarithmically transformed TG/HDL ratio, an index of the HDL cholesterol esterification rate, is also associated with coronary risk (r(2) = 0.252). Thus, TG/HDL ratio could help to characterize high-risk overweight patients deserving a special therapeutic effort. Cardiovascular risk profile of insulin-sensitive patients, identified by lower values of this parameter, is only moderately affected by MS.