readings to be the measured blood pressure. We took venous blood in the fasting state or at least five hours after a light, fat free breakfast, before a two hour 75 g oral glucose tolerance test was done. Serum for lipid analyses was refrigerated at −4°C and assayed within 72 hours. We used a Cobas Fara centrifugal analyser (Roche Diagnostics System, Nutley, NJ) to measure cholesterol and triglyceride concentrations. We measured high density lipoprotein cholesterol by precipitating non-high density lipoprotein cholesterol with dextran sulfate-magnesium chloride with the use of a centrifuge and measuring cholesterol in the supernatant fluid. We used the Friedewald formula to calculate low density lipoprotein cholesterol concentration. We measured C reactive protein in serum stored at −70°C with a high sensitivity immunonephelometric assay in a BN ProSpec nephelometer (Dade Behring, Milton Keynes). We measured fibrinogen by an automated Clauss assay in an MDA-180 coagulator (Organon Teknika, Cambridge), using the manufacturer’s reagents and the international fibrinogen standard. We measured blood glucose by the glucose oxidase method on a YSI Model 23A glucose analyser,22 23 and serum insulin with an in-house human insulin radioimmunoassay.24 We defined prevalent coronary heart disease as meeting MONICA criteria,25 giving positive responses to questions
