@article {684, title = {A prospective study of venous thromboembolism in relation to factor V Leiden and related factors.}, journal = {Blood}, volume = {99}, year = {2002}, month = {2002 Apr 15}, pages = {2720-5}, abstract = {

The aim of this study was to examine the occurrence of venous thromboembolism (VTE) in relation to factor V-related risk factors. Using a nested case-control design combining 2 population-based prospective studies, we measured factor V Leiden, HR2 haplotype, activated protein C (APC) resistance, and plasma factor V antigen in 335 participants who developed VTE during 8 years of follow-up and 688 controls. The overall odds ratio (OR) of VTE was 3.67 (95\% CI, 2.20-6.12) in participants carrying factor V Leiden compared with noncarriers. APC resistance measured after predilution with factor V-deficient plasma conferred an OR of 2.58 (95\% CI, 1.62-4.10). All 3 participants homozygous for the HR2 haplotype had a VTE, and the OR of VTE for homozygosity was estimated to be 5.5 (95\% CI, 2.45-12.5). Carriers of the HR2 haplotype otherwise were not at increased risk of VTE overall (OR = 1.05; 95\% CI, 0.64-1.72), but double heterozygotes for HR2 and factor V Leiden carried an OR of idiopathic VTE of 16.3 (95\% CI, 1.7-159) compared with noncarriers. Factor V antigen also was not associated with VTE overall, but for participants with the combination of high factor V antigen plus factor V Leiden the OR of idiopathic VTE was 11.5 (95\% CI, 4.2-31.4). In the general population, APC resistance and factor V Leiden were important VTE risk factors; homozygosity for the HR2 haplotype may be a risk factor but was rare; otherwise, HR2 haplotype and factor V antigen were not risk factors except in carriers of factor V Leiden.

}, keywords = {Activated Protein C Resistance, Aged, Cohort Studies, Continental Population Groups, Factor V, Genotype, Haplotypes, Humans, Incidence, Longitudinal Studies, Middle Aged, Odds Ratio, Prospective Studies, Risk Factors, Thromboembolism, Venous Thrombosis}, issn = {0006-4971}, doi = {10.1182/blood.v99.8.2720}, author = {Folsom, Aaron R and Cushman, Mary and Tsai, Michael Y and Aleksic, Nena and Heckbert, Susan R and Boland, Lori L and Tsai, Albert W and Yanez, N David and Rosamond, Wayne D} } @article {942, title = {Frailty and risk of venous thromboembolism in older adults.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {62}, year = {2007}, month = {2007 Jan}, pages = {79-82}, abstract = {

BACKGROUND: Frailty is a common risk factor for morbidity and mortality in elderly persons. Recent evidence links frailty to activation of coagulation and inflammatory pathways. We aimed to determine whether frailty in community-dwelling older adults is a risk factor for venous thromboembolism (VTE).

METHODS: We conducted a prospective cohort study in four U.S. communities involving 4859 participants 65 years old and older. At baseline, in 1989-1993, we assessed frailty based on weight loss, grip strength, feelings of exhaustion, walk time, and physical activity. Incident VTE (deep vein thrombosis or pulmonary embolus) through 2002 was identified by review of hospital records.

RESULTS: Fifty-two percent of the sample was classified as having intermediate or definite frailty. After adjustment for age, race, sex, body mass index, and diabetes, the relative risk of total VTE (n = 150) for people who were frail compared with no frailty was 1.31 (95\% confidence interval [CI], 0.93-1.84). The comparably adjusted relative risk for idiopathic VTE (n = 58) was 1.79 (95\% CI, 1.02-3.13).

CONCLUSIONS: The incidence rates of idiopathic VTE was higher in community-dwelling older adults with baseline frailty compared with no frailty. Further studies of the clotting process in frailty may allow the development of an improved strategy to determine VTE risk in this vulnerable subset of older adults.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Female, Follow-Up Studies, Frail Elderly, Humans, Male, Morbidity, Motor Activity, Prospective Studies, Risk Factors, Thromboembolism, United States, Venous Thrombosis}, issn = {1079-5006}, doi = {10.1093/gerona/62.1.79}, author = {Folsom, Aaron R and Boland, Lori L and Cushman, Mary and Heckbert, Susan R and Rosamond, Wayne D and Walston, Jeremy D} }