Risk factors for syncope in a community-based sample (The Framingham HeartStudy)

The epidemiology of syncope has not been well described. Prior studies have examined risk factors for syncope in hospital-based or other acute or long -term core settings. To determine risk factors for syncope in a community-b ased sample, we performed a nested case-control study. We examined reports of syncope in Framingham Heart Study participants who underwent routine cli nic visits from 1971 to 1990. For each syncope case (n = 543) 2 controls we re matched for age, sex, and examination period. Mean age of subjects was 6 7 years (range 25 to 95); 59% were women. History of stroke or transient is chemic attack, history of myocardial infarction, high blood pressure, use o f antihypertensive medication, use of other cardiac medication, smoking, al cohol intake, body moss index, systolic blood pressure, diastolic blood pre ssure, heart rate, atrial fibrillation, PR interval prolongation, intervent ricular block, and diabetes or elevated glucose level were examined as pote ntial predictors. Using conditional logistic regression analysis, the predi ctors of syncope included a history of stroke or transient ischemic attack (odds ratio [OR] 2.56, 95% confidence interval [CI] 1.62 to 4.04), use of c ardiac medication (OR 1.67, 95% CI 1.21 to 2.30), and high blood pressure ( OR 1.46, 95% CI 1.14 to 1.88). Lower body mass index was marginally associa ted with syncope (OR per 4 kg/m(2) decrement 1.10, 95% CI 0.99 to 1.22), as were increased alcohol intake (OR per 5 oz/week 1.11, 95% CI 0.99 to 1.26) , and diabetes or on elevated glucose level (OR 1.29, 95% CI 0.96 to 1.75). To our knowledge, this study represents the first community-based study of risk factors for syncope. (C) 2000 by Excerpta Medica, Inc.