Smoking intensity and lipoprotein abnormalities in active smokers.

BACKGROUND Smoking is associated with decreased high-density lipoprotein cholesterol (HDL-C) and elevated triglycerides. OBJECTIVE To evaluate the effects of five markers of smoking intensity on lipoprotein concentrations and particle sizes in a large, modern cohort of current smokers. METHODS Fasting nuclear magnetic resonance spectroscopy lipoprotein profiles were obtained in a large cohort of current smokers enrolled in a smoking cessation trial. Multivariate linear regression models were constructed to determine predictors of lipoprotein fractions. Models included age, sex, race, waist circumference, level of physical activity and alcohol consumption. Smoking intensity parameters included: current cigarettes smoked/day, pack-years, the Fagerström Test of Nicotine Dependence (FTND) score, and carbon monoxide (CO) levels. RESULTS The 1,504 subjects (58% women, 84% white) had a mean (standard deviation) age of 45 (11.0) years. They smoked 21.4 (8.9) cigarettes/day (29.4 [20.4] pack-years). HDL-C (42.0 [13.5] mg/dL) and total HDL particles (30.3 [5.9] μmol/L) were low. Cigarettes smoked/day independently predicted higher total cholesterol (p=0.009), low-density lipoprotein cholesterol (p=0.023), and triglycerides (p=0.002). CO levels predicted lower HDL-C (p=0.027) and total HDL particles (p=0.009). However, the incremental R(2) for each marker of smoking intensity on each lipoprotein was small. Relationships between the FTND score and lipoproteins were weak and inconsistent. Participants in the lowest quintiles of current smoking, pack-years, and CO had more favorable lipoproteins (all p<0.04). CONCLUSIONS Among current smokers, increased smoking burden is associated with small increases in total cholesterol, LDL-C, and triglycerides. Increased recent smoke exposure is associated with small decreases in HDL-C and HDL particles.