Hyperthyroidism is common with a prevalence of 2-19/1,000 women and 1-2/1,000 men. Radioactive iodine (131I) is the most frequent treatment in adults. The Cooperative Thyrotoxicosis Therapy Follow-up Study was begun in 1961 to investigate the long-term effects of hyperthyroidism and its treatment. We evaluated mortality from non-cancer causes of death in 35,593 patients treated between 1946-1964 at one of 26 study clinics. Mean age at study entry was 46 years. Hyperthyroidism was due to Graves disease in 91% of patients, 79% were female, and 65% were treated with 131I. In 738,831 person-years of follow-up, an average of 21 years, there were 16,683 deaths (49.4%) among the 33,748 patients with known date of birth, date of study entry, and sex. Cause of death was known for all but 111 of the deceased subjects. Standardized mortality ratios (SMR) were calculated as the observed number of deaths compared to an expected number based on US mortality rates. Overall risk of death was significantly increased (SMR 1.2; 95% CI 1.2-1.2). Deaths due to arteriosclerotic heart disease were elevated among both men (SMR 1.2; 95% CI 1.2-1.3) and women (SMR 1.4; 95% CI 1.3-1.4). Significantly more deaths than expected were observed from diabetes (SMR 1.5; 95% CI 1.2-1.9 in men; SMR 1.5; 95% CI 1.3-1.6 in women) and chronic nephritis (SMR 1.7; 95% CI 1.1-2.5 in men; SMR 1.4; 95% CI 1.1-1.8 in women). These data show significantly increased mortality from all causes and from deaths due to cardiovascular, endocrine, and kidney diseases.
Learning Objectives:
Keywords: Chronic Diseases, Radiation
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.