Inflammatory markers, D-dimer, pro-thrombotic factors, and physical activity levels in patients with peripheral arterial disease

Men and women with lower extremity peripheral arterial disease (PAD) have reduced physical activity levels compared with persons without PAD. We describe associations between physical activity levels with D-dimer, pro-coagulant factors, and inflammatory markers in patients with PAD. Participants were 188 patients with PAD identified from non-invasive vascular laboratories. Physical activty was measured over 7 days with a vertical accelerometer. We measured the ankle-brachial index (ABI) and levels of D-dimer, C-reactive protein (CRP), fibrinogen, serum amyloid A (SAA), prothrombin 1.2, t-PA antigen, PAI-1, and the t-PA antigen/PAI-1 ratio. Adjusting for age, sex, race, body mass index, ABI, comorbidities, smoking, total cholesterol/HDL ratio and statin use (for CRP only), we found significant inverse linear associations between physical activity levels and log D-dimer (p = 0.002), log CRP (p < 0.001), fibrinogen (p = 0.014), and log SAA (p = 0.012). There were no significant associations between physical activity levels and other blood factors. In an analysis adjusting for all blood factors simultaneously along with known and potential confounders, log D-dimer was the only blood factor associated significantly with physical activity levels (p = 0.036). Based on these findings, future studies should assess whether interventions to increase physical activity in patients with PAD reduce levels of D-dimer and inflammatory markers.