Importance of Family History as a Risk Factor for Venous Thromboembolism

Abstract

V enous thromboembolism (VTE) is a multifactorial disease with many known genetic and acquired risk factors. 1 A positive family history is an independent risk factor for VTE that may reflect the presence of a hereditary thrombophilic disorder. However, the predictive value of a positive family history for detection of known heritable causes of VTE is low, 2,3 suggesting that there are as-yet undiscovered genetic or environmental risk factors that account for the familial clustering of this disorder. Article see p 1012In the current edition of Circulation, Zöller and colleagues 4 present the results of their database linkage study that explored the role of family history as a risk factor for VTE. Using unique individual national identifiers to link data from the national Swedish Multigenerational Registry (a family data set that links second-generation Swedes born since 1932 with their siblings) with information from the Swedish Hospital Discharge Register (which contains complete data on all hospital discharge diagnoses since 1986), they identified 45 362 patients hospitalized for deep vein thrombosis, pulmonary embolism, thrombophlebitis (including superficial phlebitis), or thrombosis in unusual sites over a 21-year period. On the basis of results from other population-based epidemiological studies, the reported VTE incidence rates of 32.5 per 100 000 in male and 36.2 per 100 000 in female individuals are somewhat lower than expected, 5,6 likely reflecting the high rate of out-of-hospital VTE management in Sweden. 7 However, the exponential rise in incidence rates with increasing age is consistent with prior work. As previously reported, 5 there is a spike in incidence rates among female individuals 10 to 40 years of age, reflecting the reproductive period; a male predominance then emerges after 50 years of age.The most striking findings of the study by Zöller and colleagues were the increased incidence rates and standardized incidence ratios for VTE in patients with a history of VTE in Ն1 siblings and the effect of age on the standardized incidence ratios. The overall standardized incidence ratios ranged from 2 to 3, which is consistent with prior reports, 3 but the ratios were Ͼ20-fold higher among those with Ն2 affected proband siblings than those with a single affected proband sibling, making this one of the strongest risk factors for VTE identified to date (the Table). 8 The highest incidence rates among patients with a familial sibling history were observed in those Ն70 years of age (386.5 per 100 000 in male and 374.3 per 100 000 in female individuals), whereas the highest familial standardized incidence ratios occurred at much younger ages (ratio of 4.34 among male individuals 20 to 29 years of age and 5.49 among female individuals 10 to 19 years of age). Familial standardized incidence ratios declined with increasing age, reflecting the diminishing impact of family history as a risk factor for VTE at older ages. Environmental sharing appeared to have little effect on the risk of VTE, a finding that s...

Risk factors in venous thromboembolism in hospitalized patients

“…Smoking may represent a weak risk factor for DVT, especially in studies considering VTE events as the only outcome [19]; we found smoking to be relatively frequent in VTE (32.9%), but not enough to be independently associated with thrombotic risk. Family history is an independent risk factor for VTE, reflecting a hereditary thrombophilia [20]. However, our study indicated no association with VTE, which may be due to an underestimation of the frequency, since we considered only confirmed VTE of the siblings.…”

The effects of obesity on venous thromboembolism: A review

“…Although obesity appears to be a moderate risk factor for VTE [32,49], it can interact with other risk factors in VTE development and recurrence. Here, we have summarized the relationship of obesity with some common weak-to-moderate risk factors for VTE, including genetic factors, use of sex steroid hormones, inflammation, and insulin resistance [50,51].…”

Awareness and Knowledge of Venous Thromboembolism Among Saudi Adults in the Dawadmi Province: A Cross-Sectional Study

“…The annual incidence of VTE is one to two per 1,000 adults worldwide [1,3]. Several risk factors are associated with thrombosis, including older age, obesity, smoking, history of thrombosis, surgery, hospitalization, varicose veins, thrombophilia, oral contraceptives, and pregnancy [4][5][6][7]. Worldwide, PE, especially in postpartum and pregnant women, is the cause of maternal death [8].…”