Mild hyperthyroidism may increase risk of death among the elderly
According to a team of Italian researchers from the University of Parma, having mild, asymptomatic hyperthyroidism - a form of thyroid disease in which the gland overproduces thyroid hormones - can dramatically increase the risk of death among the elderly.
Scientists attributed this effect, which was discussed at the Endocrine Society's 93rd Annual Meeting, to changes that hyperthyroidism wrought on the skeletal and cardiovascular health of participants in a recent study.
The investigation was conducted as part of the ongoing Italian Aging in the Chianti Area Study (IACAS). Participants had to be over the age of 65 in order to qualify for the health survey, which took into account an individual's endocrine health when looking at causes of death over the six-year follow-up period.
At the outset of the IACAS, about 9 percent of the study's 950 participants were found to have subclinical hyperthyroidism, meaning that the disease had not yet resulted in any noticeable physical symptoms.
Scientists ultimately found that those who had subclinical hyperthyroidism were 65 percent more likely to die during the study period.
Even after adjusting for variables like age, gender, cardiovascular disease, body mass index, cancer and stroke, this effect remained, suggesting that subclinical hyperthyroidism may increase the risk of dying among older adults.
"There are no current recommendations to test all elderly individuals for subclinical hyperthyroidism," team member Graziano Ceresini told the convocation. He added that physicians who detect particular symptoms - namely weight loss, cardiac arrhythmias, anxiousness or sensitivity to heat - should have their elderly patients tested for subclinical hyperthyroidism.
The team noted that subclinical hypothyroidism may also affect the risk of death, but that the study did not involve enough participants with mildly underactive thyroid function to be sure.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) states that hyperthyroidism is common among people over the age of 60. It is typically related to thyroid nodules and can increase the likelihood of arrhythmias or osteoporosis in the elderly, especially among women.
The NIDDK estimates that U.S. women are between five and 10 times more likely than men to be diagnosed with hyperthyroidism.