Cardiovascular fitness in young males and risk of unprovoked venous thromboembolism in adulthood

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d14948795e135">Background</h5> <p id="P1">Whether high cardiovascular fitness is associated with reduced risk of venous thromboembolism (VTE) is unknown. The present study aims to determine whether high cardiovascular fitness reduces the risk of VTE. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d14948795e140">Methods</h5> <p id="P2">A Swedish cohort of male conscripts (n=773925) born in 1954–1970 with no history of previous VTE were followed from enlistment (1972–1990) until 2010. Data on cardiovascular fitness using a cycle ergonometric test (maximal aerobic workload in Watt [Wmax]) at conscription were linked with national hospital register data and the Multi-Generation Register. We identified all full-siblings and first-cousin pairs discordant for maximal aerobic workload. This co-relative design allows for adjustment for familial resemblance. </p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d14948795e145">Results</h5> <p id="P3">In total, 3005 (0.39%) males were affected by VTE. Cardiovascular fitness estimated with Wmax was not associated with VTE risk when adjusted for body mass index (BMI). However, cardiovascular fitness estimated with Wmax/kg and adjusted for BMI was associated with reduced risk for VTE (Hazard ratio 0.81, 95% confidence interval 0.78–0.85 per standard deviation compared to mean Wmax/kg). The association was weaker over time and also when examining discordant first cousins and full-sibling pairs. </p> </div><div class="section"> <a class="named-anchor" id="S4"> <!-- named anchor --> </a> <h5 class="section-title" id="d14948795e150">Conclusions</h5> <p id="P4">These results suggest that there is a relationship between cardiovascular fitness and weight that is important for future VTE risk. </p> </div>