Effect of strenuous arm crank exercise on platelet function in patients with spinal cord injury.

Abstract

To investigate the effects of arm crank exercise on various platelet functions and prostacyclin in individuals with spinal cord injury (SCI). Case-control study. Research project at a hospital-based exercise physiology laboratory. Seven men (with lesions at levels T11, n = 1; T12, n = 2; L1, n = 2; L2, n = 2) and 3 women (T12, n = 1; L1, n = 2) in the SCI group had SCI for at least 6 weeks. Ten age- and gender-matched healthy people who had not engaged in any regular physical activity for at least 1 year were selected as the control group. All subjects exercised strenuously by using an arm crank engometer. Platelet adhesiveness on fibrinogen-coated surface and epinephrine-induced aggregation in vitro, plasma soluble P-selectin (sP-selectin), and urinary 6-keto-prostaglandin F(1alpha) (6-keto PGF(1alpha)) levels. The SCI group had higher platelet adhesiveness and aggregability and plasma sP-selectin level, but lower urinary 6-keto PGF(1alpha) level than the control group. Platelet adhesiveness and aggregability were enhanced by strenuous arm exercise in all subjects, but only in the SCI group was sP-selectin level increased by exercise. Strenuous exercise raised the levels of 6-keto PGF(1alpha) in control group subjects, but not in subjects with SCI. Individuals with SCI had more extensive basal and exercise-induced platelet activation and sP-selectin release than people without SCI. Moreover, strenuous arm exercise, which enhanced the release of prostacyclin in healthy subjects, failed to do so in those with SCI.