1. ¹Department of Emergency and Cardiovascular Medicine, Karolinska Hospital, Stockholm, Sweden
2. ²Department of Nephrology, Karolinska Hospital, Stockholm, Sweden
3. ³Institute of Environmental Medicine, Division of Cardiovascular Epidemiology, Karolinska Institute; Stockholm, Sweden

Correspondence: Gunilla Bolinder, MD, Department of Nephrology, Karolinska Hospital, S-171 76 Stockholm, Sweden; e-mail: gubo@divmed.ks.se

^*The project was funded by grants from the National Institute of Public Health (Project 34121:220), the Swedish Heart-Lung Foundation (Project 15505, 45002, 55003) and the Sigrid de Verdier Memorial fund.

Received 31 July 1997; Revised  0000; Accepted 27 April 1998.

Abstract

Ambulatory 24-h blood pressure monitoring was conducted in 135 healthy, normotensive, middle-aged (35 to 60 years) men, with no antihypertensive medication, to study the influence of habitual smokeless tobacco use (n = 47) and smoking (n = 29) on diurnal blood pressure and heart rate. Comparisons were made with nonusers of tobacco (n = 59). Adjustments were made for differences in age, body mass index, waist-hip ratio, physical fitness, and alcohol intake.

Daytime ambulatory heart rates were significantly (P < .05) elevated in both smokeless tobacco users and smokers compared with nonusers (69 14 and 74 13 beats/min, respectively, versus 63 12 beats/min). In subjects 45 years old, ambulatory daytime diastolic blood pressures were significantly elevated, on average by 5 mm Hg, in both smokeless tobacco users and smokers (P < .001) compared with nonusers. Clinical measurements of heart rate and systolic blood pressure in smokers were significantly lower compared with the ambulatory mean values. Nighttime measurements showed only minor differences between the tobacco habit groups.

The higher heart rates and blood pressures noted during the daytime in smokers and smokeless tobacco users were most likely due to the effects of nicotine. A strong positive relationship was found between cotinine (major nicotine metabolite) and blood pressure in smokeless tobacco users (systolic blood pressure, r = 0.48, P < .001; diastolic blood pressure, r = 0.41, P = .005), whereas an inverse relationship was found in smokers (systolic blood pressure, r = -0.12, P = .47; diastolic blood pressure, r = -0.03, P = .84), indicating additional and more complex influences on vascular tone in smokers than the influence of nicotine in smokeless tobacco users.