Newer risk factors for stroke.

Stroke places a tremendous burden on health resources throughout the world. Improved detection and modification of risk factors could reduce the impact of this disease. Important non-modifiable risk factors for ischemic stroke include age, gender, ethnicity, and heredity. Modifiable risk factors include hypertension, cardiovascular disease, diabetes, hyperlipidemia, asymptomatic carotid stenosis, cigarette smoking, and alcohol abuse. Data from the Northern Manhattan Stroke Study provide new insights into these stroke risk factors. In this study, African-Americans and Hispanics had a greater incidence of stroke, with almost a twofold increase compared with Caucasians. The protective effect of physical activity and moderate alcohol consumption was confirmed and further established as modifiable risk factors. The independent effects of lipids, apolipoproteins, and lipoprotein were also clarified. High-density lipoprotein was shown to be protective against ischemic stroke (particularly atherosclerotic stroke subtypes). Conversely, lipoprotein-a increased the risk for stroke. The ratio of apolipoprotein b to apolipoprotein a-1 was shown to be associated with carotid atheroma. In addition, newer risk factors, including homocysteine and chronic infection (Chlamydia pneumoniae and periodontal disease), are being studied as predictors of ischemic stroke. With these recent advances in the understanding of risk factors, the ability to detect or modify the risk for ischemic stroke should lead to a substantial reduction in the number of people killed or disabled by stroke each year.