ACUTE EFFECTS OF LOW-DOSE NICOTINE GUM ON PLATELET-FUNCTION IN NONSMOKING HYPERTENSIVE AND NORMOTENSIVE MEN

Twenty non-smoking middle-aged men with mild untreated essential hypertension were compared to age-matched controls (n = 22) in a double-blind placebo controlled study. Plasma and urinary concentrations of the platelet-specific protein beta-thromboglobulin (beta-TG), platelet count and mean platelet volume were measured before and after chewing 2 mg nicotine gum. The mean plasma nicotine concentration increased to 4.3 ng/ml in the hypertensive group and to 3.9 ng/ml in the normotensive group after 30 minutes of chewing the nicotine gum. Blood pressure and heart rate increased significantly, but there was no difference between the groups. Venous plasma catecholamine concentrations were unchanged. beta-TG concentrations in plasma and urine were similar in the two groups, and plasma beta-TG levels did not change after nicotine gum in either group. Urinary high molecular weight beta-TG decreased after nicotine compared to placebo. Platelet count and volume increased significantly in the hypertensive group, but not in the normotensive group. The response in platelet count was significantly higher in the hypertensive group. Thus, small amounts of nicotine increase platelet counts more in hypertensive than in normotensive nonsmoking men, without inducing the platelet release reaction.