@article {659, title = {Post-menopausal hormone therapy and concentrations of protein C and antithrombin in elderly women.}, journal = {Br J Haematol}, volume = {114}, year = {2001}, month = {2001 Jul}, pages = {162-8}, abstract = {

The effects of post-menopausal hormone therapy (HRT) on blood coagulation in elderly women are not well defined. We studied associations of HRT use with levels of natural anticoagulant proteins in a cross-sectional study of 3393 women > or = 65 years of age participating in the Cardiovascular Health Study. Protein C antigen and antithrombin were measured in all users (n = 230 unopposed oestrogen; 60 oestrogen/progestin) and a comparison group of 196 age- and race-matched non-users. Compared with non-users, oestrogen use was associated with higher protein C (4.80 vs. 4.30 microg/ml, P < 0.01). Results were similar for oestrogen/progestin (P > 0.05). In both user groups, antithrombin was lower than in non-users (109\% for each vs. 115\% in non-users, P < 0.001). Adjustment for factors related to prescription of HRT and to anticoagulant protein levels had little impact on the results. For antithrombin, associations with HRT were larger for thinner Caucasian women and black women. Venous thrombosis from HRT may be mediated partly by alterations in antithrombin, but not protein C concentrations. This study extends previous observations to older women, the group at highest risk of venous thromboembolism. Studies of HRT-induced alterations in anticoagulant function in relation to the occurrence of thrombosis with HRT are required.

}, keywords = {Aged, Antithrombins, Black People, Body Mass Index, Cross-Sectional Studies, Estrogen Replacement Therapy, Female, Humans, Logistic Models, Postmenopause, Progestins, Protein C, Risk Factors, Venous Thrombosis, White People}, issn = {0007-1048}, doi = {10.1046/j.1365-2141.2001.02911.x}, author = {Cushman, M and Psaty, B M and Meilahn, E N and Dobs, A S and Kuller, L H} } @article {742, title = {Prospective study of the A455V polymorphism in the thrombomodulin gene, plasma thrombomodulin, and incidence of venous thromboembolism: the LITE Study.}, journal = {J Thromb Haemost}, volume = {1}, year = {2003}, month = {2003 Jan}, pages = {88-94}, abstract = {

Plasma thrombomodulin (soluble TM; sTM) is considered to be a marker of endothelial injury, but a recent report indicated that the relationship of sTM with thrombosis is complex. Venous thromboembolic events were identified in adults in two longitudinal cohort studies, the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study, totaling 21 690 participants. After 8 years of follow-up, sTM was measured in baseline plasma of 305 participants who developed venous thrombosis and 607 who did not. Thrombomodulin A455V genotype was determined in 302 cases and 626 controls. There was no difference in the prevalence of the three TM genotypes between cases and controls and no difference in age-adjusted mean values of sTM by genotype. There were no associations of age-adjusted sTM or TMA455V genotype with overall venous thromboembolism or with thrombosis in any subtype of venous thromboembolism.

}, keywords = {Age Factors, Aged, Amino Acid Substitution, Case-Control Studies, Female, Genotype, Humans, Incidence, Male, Polymorphism, Genetic, Prevalence, Prospective Studies, Risk Factors, Thromboembolism, Thrombomodulin, Venous Thrombosis}, issn = {1538-7933}, doi = {10.1046/j.1538-7836.2003.00029.x}, author = {Aleksic, N and Folsom, A R and Cushman, M and Heckbert, S R and Tsai, M Y and Wu, K K} } @article {1047, title = {PROC, PROCR and PROS1 polymorphisms, plasma anticoagulant phenotypes, and risk of cardiovascular disease and mortality in older adults: the Cardiovascular Health Study.}, journal = {J Thromb Haemost}, volume = {6}, year = {2008}, month = {2008 Oct}, pages = {1625-32}, abstract = {

BACKGROUND AND OBJECTIVES: Genes encoding protein C anticoagulant pathways are candidates for atherothrombotic and other aging-related disorders.

METHODS: Using a tagSNP approach, and data from the Cardiovascular Health Study (CHS), we assessed associations of common polymorphisms of PROC, PROS1 and PROCR with: (i) plasma protein C, soluble protein C endothelial receptor (sEPCR) and protein S levels measured in a subsample of 336 participants at study entry; and (ii) risk of incident clinical outcomes [coronary heart disease (CHD), stroke, and mortality] in 4547 participants during follow-up. Secondarily, we explored associations between plasma protein C, protein S and sEPCR levels and other candidate genes involved in thrombosis, inflammation, and aging.

RESULTS: The PROCR Ser219Gly polymorphism (rs867186) was strongly associated with higher sEPCR levels, explaining 75\% of the phenotypic variation. The PROCR Ser219Gly variant was also associated with higher levels of circulating protein C antigen. An IL10 polymorphism was associated with higher free protein S levels. The minor alleles of PROC rs2069901 and PROS1 rs4857343 were weakly associated with lower protein C and free protein S levels, respectively. There was no association between PROCR Ser219Gly and risk of CHD, stroke, or mortality. The minor allele of another common PROCR tagSNP, rs2069948, was associated with lymphoid PROCR mRNA expression and with increased risk of incident stroke and all-cause mortality, and decreased healthy survival during follow-up.

CONCLUSIONS: A common PROCR variant may be associated with decreased healthy survival in older adults. Additional studies are warranted to establish the role of PROCR variants in ischemic and aging-related disorders.

}, keywords = {Aged, Aged, 80 and over, Aging, Antigens, CD, Blood Coagulation Factor Inhibitors, Cardiovascular Diseases, Coronary Disease, Endothelial Protein C Receptor, Female, Humans, Inflammation, Male, Middle Aged, Mortality, Polymorphism, Genetic, Protein C, Protein S, Receptors, Cell Surface, Risk, Stroke, Thrombosis}, issn = {1538-7836}, doi = {10.1111/j.1538-7836.2008.03118.x}, author = {Reiner, A P and Carty, C L and Jenny, N S and Nievergelt, C and Cushman, M and Stearns-Kurosawa, D J and Kurosawa, S and Kuller, L H and Lange, L A} } @article {1119, title = {Peak thrombin generation and subsequent venous thromboembolism: the Longitudinal Investigation of Thromboembolism Etiology (LITE) study.}, journal = {J Thromb Haemost}, volume = {7}, year = {2009}, month = {2009 Oct}, pages = {1639-48}, abstract = {

BACKGROUND: Thrombin is an enzyme that is essential for the acceleration of the coagulation cascade and the conversion of fibrinogen to clottable fibrin.

OBJECTIVES: We evaluated the relationship of basal peak thrombin generation with the risk of future venous thromboembolism (VTE), and determined whether associations were independent of other coagulation markers.

METHODS: The Longitudinal Investigation of Thromboembolism Etiology (LITE) study investigated VTE in two prospective population-based cohorts: the Atherosclerosis Risk in Communities (ARIC) study and the Cardiovascular Health Study (CHS). Peak thrombin generation was measured on stored plasma in a nested case-control sample (434 cases and 1004 controls). Logistic regression was used to estimate the relationship of peak thrombin generation with VTE, adjusted for age, sex, race, center, and body mass index. Mediation was evaluated by additionally adjusting for factor VIII and D-dimer.

RESULTS: Relative to the first quartile of peak thrombin generation, the odds ratio (OR) of VTE for those above the median was 1.74 [95\% confidence interval (CI) 1.28-2.37]. The association was modestly attenuated by adjustment for FVIII and D-dimer (OR 1.47, 95\% CI 1.05-2.05). Associations appeared to be stronger for idiopathic than for secondary VTE. Elevated peak thrombin generation more than added to the VTE risk associated with FV Leiden or low activated partial thromboplastin time.

CONCLUSIONS: In this prospective study of two independent cohorts, elevated basal peak thrombin generation was associated with subsequent risk of VTE, independently of established VTE risk factors.

}, keywords = {Adult, Aged, Biomarkers, Blood Coagulation Factors, Case-Control Studies, Ethnic Groups, Factor VIII, Female, Fibrin Fibrinogen Degradation Products, Humans, Male, Middle Aged, Partial Thromboplastin Time, Prospective Studies, Risk Factors, Thrombin, United States, Venous Thromboembolism}, issn = {1538-7836}, doi = {10.1111/j.1538-7836.2009.03561.x}, author = {Lutsey, P L and Folsom, A R and Heckbert, S R and Cushman, M} } @article {1068, title = {Platelet count and the risk for thrombosis and death in the elderly.}, journal = {J Thromb Haemost}, volume = {7}, year = {2009}, month = {2009 Mar}, pages = {399-405}, abstract = {

AIM: Our aim was to examine the association between platelet count and the incidence of myocardial infarction, ischemic stroke, hemorrhagic stroke, venous thrombosis, and mortality.

METHODS AND RESULTS: Platelet count was measured at baseline in 1989-1990 and at 3 years follow-up, or at baseline (for a newly recruited group) in 1992-1993 in 5766 community-dwelling individuals aged 65 years and older (mean age at baseline, 73 years). During 12-15 years of follow-up, there were 821 incident myocardial infarctions, 807 ischemic strokes, 161 hemorrhagic strokes, 159 venous thrombotic events, and 3413 participants died. Platelet count was not associated with the occurrence of myocardial infarction, ischemic or hemorrhagic stroke, venous thrombosis, or cardiovascular mortality. Non-cardiovascular mortality was higher among both participants with low and with high platelet count. Adjusted non-cardiovascular mortality rates for platelet counts below 100, 100-199, 300-399, and above 400 x 10(9) L(-1) relative to the reference mortality rate in participants with platelet count values between 200 and 299 x 10(9) L(-1) were 1.89 (1.21-2.96), 1.08 (0.98-1.20), 1.20 (1.06-1.37), and 1.47 (1.14-1.90), respectively.

CONCLUSION: Platelet counts were not associated with vascular outcomes but low and high platelet counts were associated with non-cardiovascular mortality, including cancer mortality.

}, keywords = {Aged, Aged, 80 and over, Cause of Death, Cerebral Hemorrhage, Female, Humans, Male, Myocardial Infarction, Platelet Count, Risk, Stroke, Survival Analysis, Thrombosis, Venous Thrombosis}, issn = {1538-7836}, doi = {10.1111/j.1538-7836.2008.03267.x}, author = {van der Bom, J G and Heckbert, S R and Lumley, T and Holmes, C E and Cushman, M and Folsom, A R and Rosendaal, F R and Psaty, B M} }