Serum thiocyanate, smoking habits and smoking cessation trial in patients with peripheral atherosclerosis.

The smoking habits in patients with atherosclerosis in the lower limbs and the effect of advising them to stop smoking was studied by means of self-declaration of the number of cigarettes smoked per day and determination of serum thiocyanate. Ninety-six per cent of males and 70 per cent of the females were smokers or ex-smokers. The number of years of smoking was about 40 for the smokers of both sexes and the male ex-smokers and 23 for the female ex-smokers. The number of cigarettes smoked per day reported by the patients was less than that reported by the smokers in a reference population. The serum thiocyanate levels confirmed the smoking status of the non-smokers and showed that about one-sixth of the ex-smokers had smoked in the last month prior to the study, and that the smokers on the average were heavy smokers smoking much more than the self-reported number of cigarettes. The effect of advising the patients to quit smoking was very disappointing. A maximum of 15 per cent of the smokers stopped smoking while some of the ex-smokers resumed smoking.