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

Background Tall 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. Objective To 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. Methods Patients 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 5.1 years (MEGA follow‐up study). Odds ratios and hazard ratios (HRs) per increase of 5 cm were calculated compared with a height of 165–170 cm, separately and in combination with (im)mobility. Results In 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 200 cm and a 3.8‐fold (95% CI 1.5–9.8) higher risk for those > 200 cm 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 > 185 cm for first and recurrent venous thrombosis, respectively. For the tallest men and women, a slight additionally increased risk was observed for sedentary lifestyle. Conclusions Tall men and women have an increased risk of first and recurrent venous thrombosis, possibly higher in combination with a sedentary lifestyle.