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.