Platelet hemostasis capacity in smokers. In vitro function analyses with 3.2% citrated whole blood.

Introduction: Platelet function may be influenced by cigarette smoking. We therefore examined the effect of smoking on platelet hemostasis capacity (PHC) with an in vitro analyzer (PFA-100).

Methods And Results: Healthy blood donors (n=54) were included in the study and divided into four groups: nonsmoking males (n=14), nonsmoking females (n=14), smoking males (n=12) and smoking females (n=14). For in vitro analyses, in each participant citrated blood (3.2% buffered) was tested for PHC by two cartridges coated with collagen, and additionally with epinephrine (Col/Epi) or ADP (Col/ADP). Analyses were performed within 4 h after sample taking. PHC was expressed as the time in seconds to occlude the cartridge (closure time, CT). The average CT was significantly prolonged in female smokers compared to the female nonsmoking group for both types of cartridges (Col/Epi: P=.02; Col/ADP: P=.03). No significant differences were detected comparing the CT of smoking and nonsmoking males. After pooling male and female smokers and nonsmokers, no significant differences could be found, neither for the Col/Epi cartridges nor the Col/ADP cartridges. Plaletet aggregation assays performed in parallel showed no significant differences, except a reduced aggregability in male smokers compared to male nonsmokers using epinephrine 8.0 microM/ml as activating agent (P=.01). Furthermore, smoking volunteers presented with a significantly increased fibrinogen level compared to nonsmoking volunteers (P<.01).

Conclusions: The results of our study show that in habitual smokers PHC (PFA-100) and the capability of platelets to react upon agonist stimulation in aggregation assays is not significantly influenced or increased compared to healthy nonsmokers. However, an immediate effect of cigarette smoking cannot be excluded.