Cigarette Smoking and Longitudinal Associations With Blood Pressure: The CARDIA Study

Area of Science:

• Cardiovascular Health
• Public Health
• Epidemiology

Background:

• Associations between chronic smoking and blood pressure (BP) are inconsistent.
• Racial differences in nicotine metabolism and discrimination may influence BP in Black smokers.
• Previous studies may have overlooked racial disparities in smoking's impact on BP.

Purpose of the Study:

• To investigate the long-term effects of cigarette smoking on systolic BP, diastolic BP, and pulse pressure (PP).
• To examine potential racial differences in the association between smoking and BP.
• To analyze changes in BP over 30 years in Black and White adults.

Main Methods:

• Longitudinal study of 4786 Black and White participants from the CARDIA study.
• Repeated-measures regression models used to analyze 30-year changes in BP.
• Comparison of BP metrics between consistent smokers, former smokers, and never smokers, stratified by race.

Main Results:

• Black consistent smokers had higher pulse pressure (PP) than Black never smokers (β=1.01 mmHg, P=0.028).
• White consistent smokers had similar systolic BP, lower diastolic BP (β=-2.27 mmHg, P<0.001), and higher PP (β=1.59 mmHg, P<0.001) than White never smokers.
• No significant BP differences were found between long-term former smokers and never smokers in either racial group.

Conclusions:

• While smoking's direct impact on BP is modest, elevated PP in consistent smokers may partly explain higher cardiovascular disease risk.
• Pulse pressure is a significant predictor of cardiovascular disease risk, particularly after middle age.
• Racial differences in smoking's cardiovascular effects warrant further investigation.