Reports showed that use of combined oral contraceptive (OC) induces hypertension and has been linked with hypertensive complications. Tobacco smoking has also been shown to cause increased risk of developing cardiovascular diseases (CVD) in premenopausal women. Studies also suggest that nicotine, a major tobacco alkaloid may worsen or improve atherothrombotic CVD. Altered hemorheology, prothrombotic and proinflammatory markers, have been implicated in the development of atherothrombotic CVD. However, the effect of nicotine exposure on hemorheological, prothrombotic and proinflammatory markers during OC treatment is not yet established. We therefore sought to determine the effects of nicotine exposure during OC treatment on hemorheological, prothrombotic and proinflammatory markers.Design and method:
Female Wistar rats aged 6 weeks were given (p.o.) vehicle, low-dose nicotine (0.1 mg/kg) or high-dose nicotine (1.0 mg/kg) with or without OC containing 5.0 μg levonorgestrel and 1.0 μg ethinylestradiol daily for 8 weeks.Results:
Results demonstrated that OC treatment or nicotine exposure led to increased hemorheological (blood viscosity, hematocrit and plasma viscosity), prothrombotic (plasminogen activator inhibitor-1), proinflammatory (C-reactive protein, uric acid, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio) and anti-inflammatory (corticosterone) markers. However, these effects except that on corticosterone were normalized by concomitant OC and nicotine exposure.Conclusions:
These results indicate that nicotine exposure ameliorates abnormal blood rheology, prothrombotic and proinflammatory changes during OC use. The results imply that nicotine exposure could impact negatively on atherothrombotic markers in OC non-users, whereas the impact in OC users could be positive.