SMOKING AND ENDOCRINE OPHTHALMOPATHY - IMPACT OF SMOKING SEVERITY ANDCURRENT VS LIFETIME CIGARETTE CONSUMPTION

OBJECTIVE Smoking has been associated with an increased incidence of e ndocrine ophthalmopathy (EO). In this study we examined the relation b etween smoking severity and the incidence of EO symptoms in patients w ith Graves' hyperthyroidism. DESIGN Patients were prospectively follow ed for at least one year after the onset of hyperthyroidism. Smoking a nd EO status were evaluated at 3-6- months intervals. PATIENTS Two hun dred and fifty-three ambulatory patients with recent onset of Graves' hyperthyroidism were studied. MEASUREMENTS The incidence of total EO s ymptoms, proptosis, and diplopia at any time point before and after th e occurrence of Graves' hyperthyroidism was assessed by interview and physical examination. RESULTS Smoking was associated with a 1.3-fold i ncrease in the overall incidence of symptomatic EO, and a 2.6 and 3.1- fold increase in the incidence of proptosis and diplopia, respectively . The relative risk increased in parallel with the current number of c igarettes smoked per day. In contrast, lifetime tobacco use was not an independent risk factor for the development of EO symptoms. Former sm okers had a significantly lower risk for the occurrence of proptosis a nd diplopia than active smokers with a comparable lifetime cigarette c onsumption. CONCLUSIONS Our data suggest that current, but not lifetim e, tobacco consumption constitutes a risk for the incidence of proptos is and diplopia in patients with Graves' hyperthyroidism, and that thi s risk increases with smoking severity.