Thyroid condition linked to heart problems: study

April 25, 2012 By Randy Dotinga, HealthDay Reporter
Thyroid condition linked to heart problems: study
Risk was especially elevated for atrial fibrillation.

(HealthDay) -- New evidence suggests that a type of overactive thyroid condition appears to boost the risk of heart problems, especially atrial fibrillation (a form of irregular heartbeat) and premature death.

Patients sometimes are reluctant to do anything about the condition, known as , because it often doesn't cause any symptoms. The findings show, however, that "physicians and patients should take it seriously and consider the appropriate way to treat it to prevent increases in heart disease, bone problems and death," said Dr. Kenneth Burman, chief of the endocrine section at Washington Hospital Center, in Washington, D.C.

Patients with subclinical have too much of the hormone created by the , which helps control people's metabolism. An estimated 10 percent of the population has the condition, which is considered to be less serious than overt hyperthyroidism.

Researchers have wondered for years whether subclinical hyperthyroidism puts people at risk of a variety of health problems. Previous research has suggested it does, and a new study takes a closer look and finds more reasons to suspect the condition is dangerous.

The report authors examined the results of 10 studies, which included nearly 53,000 participants. After adjusting their statistics so they wouldn't be skewed by high or low numbers of participants of certain ages or genders, the researchers found that those with subclinical hyperthyroidism were 24 percent more likely to die during the study periods, 29 percent more likely to die of heart-related problems and 68 percent more likely to have atrial fibrillation.

Burman, who wrote a commentary accompanying the study, said the risk of early death and were still low even with the increased risk. The risk of death during the study period, for example, rose overall from 16 percent in those with normal thyroid levels to 18 percent in those with subclinical hyperthyroidism. But the heightened risk of atrial fibrillation was a significant jump, he said. causes the heart to fail to beat properly, putting patients at higher risk of stroke.

What to do? Physicians often turn to medication first, then surgery or treatment with radioactive iodine, Burman said. But medication raises questions, he said: "Do you keep them on medication indefinitely when they feel fine and the medications have side effects?"

Study co-author Dr. Nicolas Rodondi, head of ambulatory care at the University of Bern, in Switzerland, said treatment should be considered if patients are in certain risk groups and only if their thyroid levels remain abnormal after they're rechecked in three to six months.

The next step in research is to confirm the analysis findings and explore how treatment may help patients lower their risks of problems, he said.

The study appears online April 23 in the journal Archives of Internal Medicine. A second study, also published in the journal, examined whether the drug levothyroxine sodium -- a man-made form of the thyroid hormone -- would help reduce the risk of cardiovascular problems in patients with subclinical hypothyroidism.

The study of about 4,800 patients, led by researchers at Newcastle University in England, found that the drug (brand names include Synthroid), appeared to reduce the risk of heart problems in relatively younger patients (aged 40 to 70) but not in older patients (over 70).

In younger patients, about 4 percent of those treated with the drug had heart disease, compared with nearly 7 percent of those who weren't treated with it. After adjusting their statistics so they wouldn't be skewed by various factors, the researchers found that those who took the drug had a 39 percent lower risk of .

The drug can, however, cause a variety of side effects. Researchers could not definitively explain why older patients didn't receive the same health benefit.

A co-author for this study has received a speaking fee from drug manufacturer Merck Serono.

Explore further: Study examines subclinical hyperthyroidism, coronary heart disease and mortality risk

More information: For details about thyroid diseases, try the U.S. National Library of Medicine.

Related Stories

Study examines subclinical hyperthyroidism, coronary heart disease and mortality risk

April 23, 2012
An analysis of individual data from prospective studies assessing the risks of thyroid dysfunction suggests that subclinical hyperthyroidism may be associated with increased risk of total mortality, coronary heart disease ...

Elderly may be more likely to die if they have subclinical hyperthyroidism

June 6, 2011
A common hormone abnormality in older adults -- a mild form of overactive thyroid called subclinical hyperthyroidism -- is linked to a much higher risk of dying, a new study finds. The results will be presented Sunday at ...

Treatment of subclinical hypothyroidism linked with fewer ischemic heart events in younger patients

April 23, 2012
Treatment of subclinical hypothyroidism with the medication levothyroxine appears to be related to fewer ischemic heart disease events in younger patients but this finding was not evident in older patients, according to a ...

Rheumatoid arthritis linked to irregular heart rhythm

March 8, 2012
People with rheumatoid arthritis are at a greater risk of irregular heart rhythm (known as atrial fibrillation) and stroke compared with the general population, finds a study published in the British Medical Journal today.

Recommended for you

Creation of synthetic horsepox virus could lead to more effective smallpox vaccine

January 19, 2018
UAlberta researchers created a new synthetic virus that could lead to the development of a more effective vaccine against smallpox. The discovery demonstrates how techniques based on the use of synthetic DNA can be used to ...

Study ends debate over role of steroids in treating septic shock

January 19, 2018
The results from the largest ever study of septic shock could improve treatment for critically ill patients and save health systems worldwide hundreds of millions of dollars each year.

New approach could help curtail hospitalizations due to influenza infection

January 18, 2018
More than 700,000 Americans were hospitalized due to illnesses associated with the seasonal flu during the 2014-15 flu season, according to federal estimates. A radical new approach to vaccine development at UCLA may help ...

Zika virus damages placenta, which may explain malformed babies

January 18, 2018
Though the Zika virus is widely known for a recent outbreak that caused children to be born with microencephaly, or having a small head, and other malformations, scientists have struggled to explain how the virus affects ...

Certain flu virus mutations may compensate for fitness costs of other mutations

January 18, 2018
Seasonal flu viruses continually undergo mutations that help them evade the human immune system, but some of these mutations can reduce a virus's potency. According to new research published in PLOS Pathogens, certain mutations ...

Study reveals how MRSA infection compromises lymphatic function

January 17, 2018
Infections of the skin or other soft tissues with the hard-to-treat MRSA (methicillin-resistant Staphylococcus aureus) bacteria appear to permanently compromise the lymphatic system, which is crucial to immune system function. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.