Graves' ophthalmopathy in relation to cigarette smoking and ethnic origin

OBJECTIVE: We aimed to study the effect of cigarette smoking on the prevalence and severity of Graves' ophthalmopathy (GO). PATIENTS: One hundred and fifty-five newly diagnosed patients with Graves' disease (GD) were diagnosed clinically and by routine biochemical methods. Twenty-five per cent (39) were of Asian origin. METHODS: Eye signs were classified according to the American Thyroid Association Classification. A detailed smoking questionnaire and data from hospital notes were used to calculate an index of cigarette consumption. RESULTS: Thirty-four per cent of all patients had Graves' ophthalmopathy, and the prevalence in males (26%) and females (36%) did not differ significantly. There was a prevalence of 42% among Europeans compared to 7.7% in Asians (P = 0.0002). The overall risk for Europeans for developing Graves' ophthalmopathy was 6.4 (1.78-22.7 confidence interval) times higher than for Asians. Corrected for the ethnic factor the increased risk from smoking for Europeans was 2.4 (1.12-5.18, 95% confidence interval) times higher. There was a significant dose effect (P = 0.008). CONCLUSIONS: The present findings confirm an effect of cigarette smoking on Graves' ophthalmopathy and in addition show that Europeans have a substantially greater risk of developing Graves' ophthalmopathy than have Asians.