Objective: Few have studied the long-term effects of smoking and smoking cessation on weight gain and blood pressure increase and compared with the age-related increases experienced by most adults. This study compared the development of weight and blood pressure in female never smokers, continuing smokers and smokers who quit smoking.
Design: Weight, systolic (SBP) and diastolic (DBP) blood pressure and smoking habits were assessed at baseline and re-assessed after a mean follow-up of 9.0 +/- 5.8 years.
Setting: Population-based cohort.
Subjects: A total of 2381 female never smokers and 1550 female smokers. At the re-examination, 388 of the smokers had quit smoking.
Results: Mean weight gain was 7.6 +/- 6.1, 3.2 +/- 5.8 and 3.7 +/- 5.2 kg, respectively, in quitters, continuing smokers and never smokers (P < 0.001). In women without blood pressure treatment, mean SBP increase was 20.9 +/- 16.8, 19.1 +/- 15.8 and 16.1 +/- 16.3 mmHg, respectively, in these groups (P < 0.001). Mean DBP increase was 6.2 +/- 8.7, 5.7 +/- 9.3 and 3.1 +/- 8.0 mmHg, respectively (P < 0.001). After adjustments for potential confounders, the increased weight gain in quitters remained highly significant. The differences in SBP and DBP increase were attenuated after adjustments, but remained significant. Incidence of hypertension (> or = 160/95 mmHg or treatment) was significantly higher in quitters [adjusted odds ratio (OR): 1.8; CI: 1.4-2.5] when compared with continuing smokers (OR: 1.3; CI: 1.07-1.6) and never smokers (reference).
Conclusion: Over a long follow-up, weight gain was approximately 3-4 kg higher in quitters when compared with continuing smokers or never smokers. Although the differences in blood pressure increase were moderate, smoking cessation was associated with an increased incidence of hypertension.