Objective: The primary aim of the present study was to evaluate the impact of smoking status on both clinic and ambulatory blood pressure (BP) and heart rate (HR) by using 24-h ambulatory BP monitoring in treated and non-treated hypertensive smokers and non-smokers. A secondary aim was to evaluate the interrelations between BP, smoking status and microalbuminuria.
Design: Five hundred and eighty treated and non-treated hypertensive smokers and non-smokers were consecutively recruited. The patients were divided into groups of non-smokers (n = 414) and smokers (n = 166). We were able to match 115 smokers with 230 non-smokers with regard to clinic BP, gender and age.
Methods: Microalbuminuria (albumin/creatinine ratio on morning spot urine sample), sitting clinic BP (mercury sphygmomanometry) and ambulatory BP (A&D TM 2421) were measured.
Results: In the matched group we found a significant difference in ambulatory systolic and diastolic daytime BP between smokers and non-smokers (146.5 +/- 15.0/90.6 +/- 9.7 mmHg vs 142.3 +/- 12.6/89.0 +/- 9.0 mmHg). The smokers had significantly higher log albumin/creatinine ratio (0.51 +/- 0.93 vs 0.19 +/- 0.87). These results were found to be valid for treated as well as untreated patients. In both the matched and unmatched groups, the smokers had significantly higher HR.
Conclusion: The higher daytime BP and HR as well as microalbuminuria in smokers may contribute to their increased cardiovascular risk. Furthermore, the higher ambulatory BP in smokers implicates that these patients tend to be underdiagnosed and undertreated if only clinic BP is used.