The population used as a comparison was obtained from the same database, each hyperthyroid patient matched with 10 non-hyperthyroid persons who were alive on the date of the hyperthyroidism diagnosis. Each subject in the two groups were followed until death, emigration, first diagnosis of a heart event or the end of 2012.
In total, 85,856 patients had a diagnosis of hyperthyroidism. The majority was female (82%) and 27% were younger than 50. A total of 33,941 patients with hyperthyroidism died during follow up. The mortality rate was higher during the first year after diagnosis, with a peak in the first 3 months. Although the risk for death decreased during time, it remained elevated even in the 3-30 year period.
The study also showed that the risk for specific acute heart events was similarly increased, in particular for atrial fibrillation and arterial clots (risk was increased 6-fold in the first 3 months). The risk decreased with time as did mortality, but did not return to normal for atrial fibrillation and arterial clots during long term follow up. Relative risks for death and heart events were higher in younger patients than in patients older than 70.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study shows a clear increased risk of death and acute heart events in patients with hyperthyroidism. However, this study did not present data according to the specific diagnosis and this could be important because the risk likely depends on the severity of hyperthyroidism and Graves’ disease is associated with more severe hyperthyroidism than other causes. This information should be taken into account when considering and discussing the need for treatment of hyperthyroidism, even in patients who present without symptoms.
— Jessie Block-Galarza, MD
ATA THYROID BROCHURE LINKS
Graves’ Disease: http://www.thyroid.org/graves-disease/
Hyperthyroidism (Overactive): http://www.thyroid.org/ hyperthyroidism/