Risk factors associated with acute myocardial infarction in Kuwait, 1978.

Two hundred and ninety-nine of 428 patients diagnosed with acute myocardial infarction (AMI) in Kuwait during 1978 were matched with hospitalized controls by sex, nationality, and same year of age. Patients were almost six times as likely as controls to be smokers (odds ratio [OR] = 5.6; 95% confidence limits [CL] = 2.8-12.3; P less than 0.0001) and 50% more likely to be diabetic (OR = 1.49; 95% CL = 0.96-2.32; P = 0.06). Patients were less likely than controls to be currently married (OR = 0.23; 95% CL = 0.04-0.84; P = 0.02) or to have a personal history of hypertension (OR = 0.60; 95% CL = 0.39-0.92; P = 0.01). Each of these four exposures affected AMI risk more strongly when considered together with the other three than when considered separately. Although in this study personal history of hypertension appears to reduce AMI risk, selection bias from using a hospital source of controls does not fully account for this reduction. Neither occupation nor socioeconomic status affected AMI risk.