Serum Vitamin E and Lipid-adjusted Vitamin E Assess- Ment in Friedreich Ataxia Phenotype Patients and Un- Affected Family Members, Moncef Feki

cant. To the best of our knowledge, the present study is the first to systematically investigate interindividual seasonal variations of CRP in several large populations. In two studies, seasonal variation of CRP was investigated on an intraindividual basis. Woodhouse et al. (2 ) reported higher CRP concentrations in winter with a peak in March, and Crawford et al. (13 ) found a significant seasonal variation of CRP with a peak in late February. The lack of seasonal variability of CRP in the present study may be somewhat contradictory to a previous report from our group (8 ) and to others (2, 13), in which seasonal variations of a variety of acute-phase proteins, such as fibrinogen, PAI-1, plasminogen, and 1-glycoprotein, have been observed. However, in contrast to the major acute-phase reactant CRP, these coagulation proteins are not exclusively related to the acute-phase response. The predictive value of CRP for cardiovascular events has been consistently established in a variety of prospective studies (3, 4), and highly sensitive assays for CRP are now widely available with low analytical variability. In a recently published study (14 ), Meier-Ewert et al. demonstrated that baseline CRP concentrations are not subject to time-of-day variation. In the present study, we found no convincing evidence for seasonal variation of CRP; thus there should be no concern about misclassification of participants in population studies and in clinical practice measured during various seasons.