Published online before print December 22, 2005, doi: 10.1161/01.STR.0000199631.09861.29
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(Stroke. 2006;37:343-a.)
© 2006 American Heart Association, Inc.
Letters to the Editor |
Relation of Parity With Common Carotid Intima-Media Thickness Among Women of the Study of Health in Pomerania
Walsall Manor Hospital, Walsall, United Kingdom
To the Editor:
Wolff et al1 report that both multiparity and nulliparity are associated with increased carotid artery intima-media thickening. I propose that folate deficiency may account, in part, for this result.
Folate deficiency is linked with hyperhomocystinemia,2 which, in turn, is associated with accelerated progression of atherosclerosis3 and, thereby, carotid artery intima-media thickening. Pregnancy is potentially a cause of folate deficiency.4 Consequently, it is possible that multiparous women are at risk of prolonged folate deficiency; this may explain their susceptibility to the development of carotid artery intima-media thickening.
There may also be a link between folate deficiency and nulliparity. Folate is necessary for DNA and RNA synthesis, and folate deficiency may therefore theoretically lead to infertility. Moreover, there is an association between folate deficiency and spontaneous miscarriage.5 It is therefore possible that a high proportion of childless women may be folate deficient. If this assumption is correct, these women are also at risk of increased carotid artery intima-media thickening.
Wolff et al used a multivariate analysis to assess the significance of confounding variables. The causes of folate deficiency include chronic disease, such as Celiac or Crohn disease and poor diet, and these variables were not included as confounders. The possibility that a higher proportion of childless women included in this study suffer from an affliction leading to folate deficiency, compared with women with one or two children, cannot be ruled out.
If folate deficiency partially accounts for the results reported by Wolff et al then this may prompt further research into the benefits of folate supplementation to certain subgroups of patients to prevent progression of atherosclerosis.
References
1. Wolff B, Volzke H, Robinson D, Schwahn C, Ludemann J, Kessler C, John U, Felix SB. Relation of parity with common carotid intima-media thickness among women of the Study of Health in Pomerania. Stroke. 2005; 36: 938–943.
2. Boushey CJ, Beresford SA, Omenn GS, Motulsky AG. A quantitative assessment of plasma homocysteine as a risk factor for vascular disease. Probable benefits of increasing folic acid intakes. JAMA. 1995; 274: 1049–1057.
3. Selhub J, Jacques PF, Bostom AG, D’Agostino RB, Wilson PW, Belanger AJ, O’Leary DH, Wolf PA, Schaefer EJ, Rosenberg IH. Association between plasma homocysteine concentrations and extracranial carotid-artery stenosis. N Engl J Med. 1995; 332: 286–291.
4. McPartlin J, Halligan A, Scott JM, Darling M, Weir DG. Accelerated folate breakdown in pregnancy. Lancet. 1993; 341: 148–149.[CrossRef][Medline] [Order article via Infotrieve]
5. George L, Mills JL, Johansson ALV, Nordmark A, Olander B, Granath F, Cnattingius S. Plasma Folate Levels and Risk of Spontaneous Abortion. JAMA. 2002; 288: 1867–1873.
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