80
Journal of the Royal Society of Medicine Volume 85 February 1992
Acute changes in haematological parameters
on
cessation of smoking
B J Bain FRACP MRCPath' M Rothwell BSc MB BS2 M D Feher MB BS MRCP2 R Robinson BSc MB BW2 J Brown BSc MB BS2 P S Sever PhD FRCP2 Departments of 'Haematology and 2Clinical Pharmacology, St Mary's Hospital Medical School, Praed Street, London W2 1PG Keywords: smoking; haemoglobin concentration; packed cell volume; white cell count
Summary Cigarette smoking is known to affect many haematological parameters but little is known of their rate of return to normal on withdrawal of cigarettes. Two groups of chronic smokers were studied whilst smoking and in the 2 weeks after cessation. A rapid return towards normal was found in the elevated haemoglobm concentration, packed cell volume, red cell count, white cell count, neutrophil count, lymphocyte count and platelet count, indicating that at least some of the abnormalities in these parameters are an acute, reversible effect of cigarette smoking rather than being a response to tissue damage. Introduction Alterations in haematological parameters may be important pathophysiological determinants of the high risk of vascular disease in smokers. Smokers, in comparison with non-smokers, show increases in many haematological variables, including haemoglobin concentration (Hb), haematocrit (Hct), red cell count (RBC), mean corpuscular volume (MCV), white cell count (WBC) and neutrophil, lymphocyte, eosinophil and monocyte counts1-4. Few studies have assessed the acute effects of cessation of smoking on the blood count5 6. We therefore studied haematological parameters in two groups of chronic smokers, whilst smoking and in the first 2 weeks of tobacco withdrawal in order to ascertain the effect of cessation of smoking on these variables.
Subjects and methods Two groups of chronic smokers were studied. The first group (n=30), comprising 12 males and 18 females, were part of a study of smoking withdrawal and atherogenic risk factors7. The subjects were aged 20-68 years (median 38) and smoked between 7 and 53 (median 20) cigarettes a day. They were studied 2 weeks before and 2 weeks after stopping smoking. A one-month interval between tests was chosen to eliminate any confounding effects of the cyclical changes in haematological parameters which occur in women during the menstrual cycle. The second group comprised 11 male smokers aged 22-26 years (median 23) who were studied three times while smoking and on nine further occasions after cessation of smoking; one subject who recommenced smoking was studied a second time when he again stopped. These subjects smoked 10-35 (median 20) cigarettes a day and had smoked for 1-8 (median 4) years. In both groups cessation of smoking was confirmed by measurement of urinary nicotine and cotinine concentrations. Venous blood samples were obtained with minimal haemostasis and with the subject sitting. In the first
Table 1. Mean values for haematological parameters in 30 chronic smokers while smoking and 2 weeks after cessation. The significance of the change has been assessed by a paired t-test
Before
After
Significance
RBC (x10-'2) 4.66 Hb (g/dl) 14.50 Hct 0.43 MCV (fl) 91.6 WBC (xlO-9/l) 8.4 4.3 Neutrophils (x 10-9/1) 3.2 Lymphocytes (xlO-9/l) 0.55 Monocytes (x10-9/l) 0.17 Eosinophils (x 10-9A1) 0.03 Basophils (x10-9/1) Platelet count (xlO-9/l) 289
4.51 14.22 0.41 91.8 7.4 3.75 2.75 0.51 0.14 0.04 275
Journal of the Royal Society of Medicine Volume 85 February 1992
Acute changes in haematological parameters
on
cessation of smoking
B J Bain FRACP MRCPath' M Rothwell BSc MB BS2 M D Feher MB BS MRCP2 R Robinson BSc MB BW2 J Brown BSc MB BS2 P S Sever PhD FRCP2 Departments of 'Haematology and 2Clinical Pharmacology, St Mary's Hospital Medical School, Praed Street, London W2 1PG Keywords: smoking; haemoglobin concentration; packed cell volume; white cell count
Summary Cigarette smoking is known to affect many haematological parameters but little is known of their rate of return to normal on withdrawal of cigarettes. Two groups of chronic smokers were studied whilst smoking and in the 2 weeks after cessation. A rapid return towards normal was found in the elevated haemoglobm concentration, packed cell volume, red cell count, white cell count, neutrophil count, lymphocyte count and platelet count, indicating that at least some of the abnormalities in these parameters are an acute, reversible effect of cigarette smoking rather than being a response to tissue damage. Introduction Alterations in haematological parameters may be important pathophysiological determinants of the high risk of vascular disease in smokers. Smokers, in comparison with non-smokers, show increases in many haematological variables, including haemoglobin concentration (Hb), haematocrit (Hct), red cell count (RBC), mean corpuscular volume (MCV), white cell count (WBC) and neutrophil, lymphocyte, eosinophil and monocyte counts1-4. Few studies have assessed the acute effects of cessation of smoking on the blood count5 6. We therefore studied haematological parameters in two groups of chronic smokers, whilst smoking and in the first 2 weeks of tobacco withdrawal in order to ascertain the effect of cessation of smoking on these variables.
Subjects and methods Two groups of chronic smokers were studied. The first group (n=30), comprising 12 males and 18 females, were part of a study of smoking withdrawal and atherogenic risk factors7. The subjects were aged 20-68 years (median 38) and smoked between 7 and 53 (median 20) cigarettes a day. They were studied 2 weeks before and 2 weeks after stopping smoking. A one-month interval between tests was chosen to eliminate any confounding effects of the cyclical changes in haematological parameters which occur in women during the menstrual cycle. The second group comprised 11 male smokers aged 22-26 years (median 23) who were studied three times while smoking and on nine further occasions after cessation of smoking; one subject who recommenced smoking was studied a second time when he again stopped. These subjects smoked 10-35 (median 20) cigarettes a day and had smoked for 1-8 (median 4) years. In both groups cessation of smoking was confirmed by measurement of urinary nicotine and cotinine concentrations. Venous blood samples were obtained with minimal haemostasis and with the subject sitting. In the first
Table 1. Mean values for haematological parameters in 30 chronic smokers while smoking and 2 weeks after cessation. The significance of the change has been assessed by a paired t-test
Before
After
Significance
RBC (x10-'2) 4.66 Hb (g/dl) 14.50 Hct 0.43 MCV (fl) 91.6 WBC (xlO-9/l) 8.4 4.3 Neutrophils (x 10-9/1) 3.2 Lymphocytes (xlO-9/l) 0.55 Monocytes (x10-9/l) 0.17 Eosinophils (x 10-9A1) 0.03 Basophils (x10-9/1) Platelet count (xlO-9/l) 289
4.51 14.22 0.41 91.8 7.4 3.75 2.75 0.51 0.14 0.04 275
