Urine Cotinine level with smoking history predicts a risk of coronary artery calcification.

We investigated whether urine cotinine level, alone or combined with smoking status and cumulative smoking amount, could predict coronary calcium (CAC) score increase over time. The study population included 10,980 subjects. We analysed an association between CAC score increase over time and single or combined smoking-related factors. Urine cotinine level of ≥100 ng/mL, current or ex-smokers, and cumulative smoking amount of ≥1 pack-years (PY) showed significantly higher odds ratios (ORs) for CAC score increase over time. A combination of current smokers with >10 PY and urine cotinine level of ≥100 ng/mL showed the highest OR. Irrespective of smoking status and cumulative smoking amount, all combinations with urine cotinine of ≥100 ng/mL showed higher ORs than other combinations with urine cotinine level of <100 ng/mL. Urine cotinine levels can be useful to predict coronary artery calcification and encourage smokers to quit smoking.