A new study implicates smoking in the development of Graves' disease, the thyroid disorder that afflicts George and Barbara Bush and about a million other Americans.
Smoking is especially linked to bulging eyes and blurred vision that affects about one-third of those with Graves' disease, said the lead author of the Dutch study, Dr. Mark F. Prummel, a visiting scientist at the Veterans Affairs Medical Center in San Francisco. Prummel conducted the study with Dr. Wilmar Wiersinga of the University of Amsterdam.
Graves' patients with such eye problems were 7.7 times more likely to be smokers than non-Graves' sufferers in comparison groups closely matched by age and sex, Prummel's team reported in Wednesday's issue of The Journal of the American Medical Assn.
Patients with Graves' disease who had an overactive thyroid alone--the typical symptom of the disease--were 1.9 times more likely to be smokers than members of the comparison group, researchers said.
"Smoking appears to be one of the multiple factors causing Graves' disease in genetically predisposed individuals," researchers wrote.
Graves' disease usually runs in families. Its cause is a mystery.
The disease, which causes the thyroid gland to pump excess hormones that speed processes ranging from heartbeat to metabolism, is potentially fatal but almost 100% curable if treated.
However, eye problems associated with it can persist for years after successful treatment and even require surgery, Prummel said.
He led the study of 300 patients with Graves' disease, 150 with other thyroid disorders and 400 people recruited for comparison at the University of Amsterdam in the Netherlands, where he is an endocrinologist.