@article {1522,
	title = {Analytical and biologic variability in measures of hemostasis, fibrinolysis, and inflammation: assessment and implications for epidemiology.},
	journal = {Am J Epidemiol},
	volume = {149},
	year = {1999},
	month = {1999 Feb 01},
	pages = {261-7},
	abstract = {<p>An increasing number of cardiovascular epidemiologic studies are measuring non-traditional risk markers of disease, most of which do not have established biovariability characteristics. When biovariability data have been reported, they usually represent a short time period, and, in any case, there is little consensus on how the information should be used. The authors performed a long-term (6-month) repeated measures study on 26 healthy individuals, and, using a nested analysis of variance (ANOVA) approach, report on the analytical (CVA), intraindividual (CVI), and between individual (CVG) variability of 12 procoagulant, fibrinolysis, and inflammation assays, including total cholesterol for comparison. The results suggest acceptable analytical variability (CVA < or = 1/2 CVI) for all assays. However, there was a large range of intraindividual variation as a proportion of total variance (2-78\%), and adjusting for intraindividual and between individual variation in bivariate correlations increased the observed correlation by more than 30 percent for three of these assays. Overall, the assays showed a significant increase in intraindividual variation over 6 months (p < 0.05). While these findings suggest that most of these assays have biovariability characteristics similar to cholesterol, there is variation among assays. Some assays may be better suited to epidemiologic studies, and knowledge of an assay{\textquoteright}s biovariability data may be useful in interpreting simple statistics, and in designing multivariate models.</p>},
	keywords = {Adult, Aged, Analysis of Variance, Cardiovascular Diseases, Cholesterol, Epidemiology, Female, Fibrinolysis, Hemostasis, Humans, Inflammation, Male, Middle Aged, Models, Statistical, Multivariate Analysis, Risk Factors},
	issn = {0002-9262},
	author = {Sakkinen, P A and Macy, E M and Callas, P W and Cornell, E S and Hayes, T E and Kuller, L H and Tracy, R P}
}
@article {628,
	title = {Association between physical activity and markers of inflammation in a healthy elderly population.},
	journal = {Am J Epidemiol},
	volume = {153},
	year = {2001},
	month = {2001 Feb 01},
	pages = {242-50},
	abstract = {<p>Higher levels of physical activity are associated with lower risk of cardiovascular disease. There is growing evidence that the development of the atherosclerotic plaque is associated with inflammation. In this study, the authors investigated the cross-sectional association between physical activity and markers of inflammation in a healthy elderly population. Data obtained in 1989-1990 and 1992-1993 from the Cardiovascular Health Study, a cohort of 5,888 men and women aged >/=65 years, were analyzed. Concentrations of the inflammation markers-C-reactive protein, fibrinogen, Factor VIII activity, white blood cells, and albumin-were compared cross-sectionally by quartile of self-reported physical activity. Compared with persons in the lowest quartile, those in the highest quartile of physical activity had 19\%, 6\%, 4\%, and 3\% lower concentrations of C-reactive protein, white blood cells, fibrinogen, and Factor VIII activity, respectively, after adjustment for gender, the presence of cardiovascular disease, age, race, smoking, body mass index, diabetes, and hypertension. Multivariate regression models suggested that the association of higher levels of physical activity with lower levels of inflammation markers may be mediated by body mass index and glucose. There was no association between physical activity and albumin. Higher levels of physical activity were associated with lower concentrations of four out of five inflammation markers in this elderly cohort. These data suggest that increased exercise is associated with reduced inflammation. Prospective studies will be required for verification of these findings.</p>},
	keywords = {Aged, Analysis of Variance, Biomarkers, C-Reactive Protein, Cardiovascular Diseases, Factor VIII, Female, Fibrinogen, Humans, Inflammation, Leukocyte Count, Male, Physical Exertion, Sex Factors, Smoking},
	issn = {0002-9262},
	doi = {10.1093/aje/153.3.242},
	author = {Geffken, D F and Cushman, M and Burke, G L and Polak, J F and Sakkinen, P A and Tracy, R P}
}
