To the Editor:
Despite a number case-control studies in the literature suggesting that lipoprotein(a) is a risk factor for cerebrovascular disease, both the recent article by Glader et al1 and the report from the Physicians Health Study by Ridker et al2 failed to demonstrate an association of lipoprotein(a) and the future risk of stroke. One possible explanation discussed by Glader et al is the paucity of young stroke patients in their study population. Nagayama et al3 had previously reported significantly higher lipoprotein(a) levels in patients under age 45 years with atherosclerotic stroke. In the Stroke Prevention in Young Women Study, we4 examined the role of lipoprotein(a) in a population-based study of women under the age of 45 years with ischemic stroke. In both univariate and multivariate analyses, we found no significant difference in lipoprotein(a) levels between cases and age-matched controls. Even among the subset of patients with atherosclerotic stroke, we could not demonstrate an association with elevated lipoprotein(a) levels. The number of patients in our study with atherosclerotic stroke was small (n=15), however, but comparable to that of Nagayama et al (n=11).
The structure of lipoprotein(a) and its potential link to both atherosclerosis and hypercoagulability is an intriguing hypothesis, but at this time the epidemiologic basis for a relationship of lipoprotein(a) and stroke remains uncertain.
- Copyright © 2000 by American Heart Association
Glader CA, Stegmayr B, Boman J, Stenlund H, Weinehall L, Hallmans G, Dahlen GH. Chlamydia pneumoniae antibodies and high lipoprotein(a) levels do not predict ischemic cerebral infarctions. Stroke.. 1999;30:2013–2018.
Nagayama M, Shinohara Y, Nagayama T. Lipoprotein(a) and ischemic cerebrovascular disease in young adults. Stroke.. 1994;25:74–78.
Wityk RJ, Kittner SJ, Jenner JL, Hebel JR, Epstein A, Wozniak AM, Stolley PD, Stern BJ, Sloan MA, Price TR, McCarter RJ, Macko RF, Johnson CJ, Earley CJ, Buchholz D, Schaefer EJ. Lipoprotein(a) and the risk of ischemic stroke in young women. Atherosclerosis. In press.