Body height, mobility, and risk of first and recurrent venous thrombosis

BackgroundTall people have an increased risk of a first venous thrombosis. Sedentary lifestyle has been shown to act synergistically with body height, especially during long-haul flights. ObjectiveTo estimate the relation between height and risk of a first and recurrent venous thrombosis and a possible additional association with a mobile or an immobile lifestyle. MethodsPatients with a first venous thrombosis and control subjects were included between 1999 and 2004 (MEGA case-control study). Patients were followed for recurrence for an average time of 5.1years (MEGA follow-up study). Odds ratios and hazard ratios (HRs) per increase of 5cm were calculated compared with a height of 165-170cm, separately and in combination with (im)mobility. ResultsIn 4464 patients who reported their height, we found an increasing risk of a first and recurrent event with height. For men, a 2.9-fold (95% confidence interval [CI] 1.9-4.4) increased risk for first venous thrombosis was found for those between 195 and 200cm and a 3.8-fold (95% CI 1.5-9.8) higher risk for those >200cm compared with the reference category. For recurrence risk, the HRs were 1.7 (95% CI 0.8-3.3) and 3.7 (95% CI 1.4-10.0), respectively. For women, a 1.5-fold (95% CI 0.7-3.4) and 3-fold (95% CI 0.9-9.4) increased risk was found for those >185cm for first and recurrent venous thrombosis, respectively. For the tallest men and women, a slight additionally increased risk was observed for sedentary lifestyle. ConclusionsTall men and women have an increased risk of first and recurrent venous thrombosis, possibly higher in combination with a sedentary lifestyle.