The Association of Waterpipe Smoking and Coronary Artery Calcium in a Community-Based Sample.

BACKGROUND: Waterpipe smoking is increasing in popularity, driven partly by a perception of reduced harm compared to cigarette smoking. This study evaluates the association of waterpipe smoking with coronary artery calcium (CAC), a marker of coronary heart disease (CHD) risk, in a community-based sample.

METHODS: 175 exclusive waterpipe smokers and 170 non-smokers, 35 years and older were recruited from the community in Lebanon and Qatar. Waterpipe smoking was assessed using a validated questionnaire. CAC score was assessed using multidetector computed tomography. The association of waterpipe smoking with the presence and extent of CAC was evaluated using regression analyses adjusted for CHD risk factors.

RESULTS: CAC was present in 41% of waterpipe smokers versus 28% of non-smokers p=0.01, with an average CAC of 90.6 Agatston Units (AU) (SD=400.3) in waterpipe smokers and 52.4AU (SD=218.6) in non-smokers. In adjusted analyses, waterpipe smokers had significantly higher adjusted odds of having CAC (OR=2.20, 95%CI:[1.20-4.01], p=0.01); and being in the high CHD risk category defined by CAC>300AU (OR=3.41, 95%CI:[1.08-10.77], p=0.04) or CAC>75% of age, sex and race-predicted (OR=3.11, 95%CI:[1.55-6.24], p=0.001) compared to non-smokers. CAC extent was significantly associated with waterpipe smoking extent measured by smoking duration (β=0.17/year, 95%CI:[0.05-0.29], p=0.004) or by the product of smoking duration and the number of waterpipe smoked daily (β=0.04/waterpipe-year, 95%CI:[0.003-0.07], p=0.03).

CONCLUSIONS: Exclusive waterpipe smoking was associated with the presence and extent of CAC, with twice the risk of having CAC and three times the risk of being in the high CHD risk category while accounting for other risk factors.