Diet, physical activity and venous thromboembolism

Abstract

Summary There is substantial evidence for the influence of life-style factors on the incidence of arterial thromboembolic diseases such as myocardial infarction and stroke. However, limited knowledge exists on the relation between life-style factors and venous thromboembolism (VTE). VTE, a collective term for deep vein thrombosis and pulmonary embolism, is a common disease with serious short- and long-term complications including death. The aims of this thesis were to investigate whether life-style factors such as alcohol (type, amount, and drinking pattern), dietary pattern, fish consumption, and physical activity would influence the risk of VTE. We performed a population-based cohort study with participants from the Tromsø IV study. In the Tromsø IV study conducted in 1994-95, all inhabitants in the municipality of Tromsø aged 25 years or older were invited to participate and more than 27 000 attended (77% of the eligible population). Information was collected through questionnaires, blood samples and physical examinations. Incident VTE events were registered from inclusion (1994-95) until the end of follow-up, December 31 2010. Total alcohol consumption was not associated with risk of VTE. However, intake of ≥ 3 units of wine per week lowered the risk of VTE by 22%, whereas intake of similar amount of liquor increased the risk of VTE by 50%. The beneficial effect of wine drinking was further strengthened (50% risk reduction) by adjustments for other types of alcohol (beer and liquor). Frequent binge drinking was also found to increase the risk of VTE. A heart-healthy diet was, as expected, associated with a lowered risk of myocardial infarction, but was not related to risk of VTE. Fish consumption was only associated with a non-significant, moderately reduced risk of VTE. However, the addition of fish oil supplements was associated with a 48% reduced risk. Immobility is a strong risk factor for VTE. Thus, we anticipated that regular physical exercise would protect against VTE. However, we found no association between the amount of regular physical activity at moderate intensity and the risk of VTE in the general population. However, high amounts of physical activity was associated with an increased risk in elderly and obese, whereas subjects younger than 60 years old and those normal-weighted (BMI≤25) had lower risk of VTE by increasing amounts of physical activity. Our findings imply that life-style factors have differential impact on arterial and venous thromboembolic diseases.