Underactive thyroid: Check values - but do not always treat them
At least two percent of women in Germany suffer from an underactive thyroid. Men are affected much less often. According to experts, the disease does not need to be treated in all cases. However, it is important to check the TSH value. This is pointed out by the German Society for Endocrinology (DGE).
Women affected more often than men
According to the Professional Association of German Internists (BDI), at least two percent of all women, but only around 0.1 to 0.2 percent of men, suffer from an underactive thyroid. According to the experts, this is usually discovered between the ages of 40 and 60. "The disease rate increases with age," the experts write on their website "Internists on the Internet". According to the German Society for Endocrinology (DGE), however, not all those affected need to be treated.
Effects on the entire metabolism
Symptoms that may indicate that the thyroid gland no longer controls hormone production properly include fatigue, sensitivity to cold, sleep disorders, hair loss, weight gain and depressive moods.
However, such symptoms alone are not meaningful. Diagnosing an underactive thyroid is not always easy. The TSH value in the blood is usually used for this.
However, the TSH value, which indicates whether there is a thyroid dysfunction, is higher in older people than in younger people than 65.
Higher does not necessarily mean that the underfunction needs to be treated. There can also be a spontaneous normalization of the TSH values, and the guidelines therefore recommend a very cautious approach.
This is pointed out by experts from the German Society for Endocrinology (DGE) in a communication published by the Science Information Service (idw).
Elevated TSH levels are common
The two central hormones, thyroxine (T4) and triiodothyronine (T3), are formed in the thyroid gland, which influence metabolism, the cardiovascular system and growth.
The organ is regulated via the pituitary gland, whose thyreo-stimulating hormone (TSH) stimulates iodine uptake and hormone production in the thyroid gland. For adults, a TSH reference range of around 0.4 to 4.0 mU / l applies.
“Elevated TSH levels are common. If they are above the defined laboratory reference range, doctors often interpret them automatically as a thyroid dysfunction and classify them as latent or subclinical hypothyroidism, ”says Professor Dr. Dr. med. Dagmar Führer, member of the advisory board of the DGE section thyroid.
However, there is not always a pathological finding behind it: "Especially in older people, for whom the TSH value is increased due to their age anyway, for whom the symptoms are variable and often also have concomitant diseases, the treating doctor must interpret the laboratory values include the age factor, ”says Führer, who heads the Clinic for Endocrinology, Diabetology and Metabolism at the University Hospital Essen.
Patients do not benefit from the therapy
Researchers examined the impact of age on the treatment benefits of thyroid hormone replacement in the elderly in a large, five-year study published in the New England Journal of Medicine.
A total of 737 over 65-year-olds took part in the TRUST study, with a TSH value between 4.60 and 19.99 mU / l. Half of the group received the active ingredient levothyroxine for hormone replacement, the other half a placebo.
No improvements in quality of life and fatigue were observed after one year of therapy.
The authors of the TRUST study came to the conclusion that elderly people do not benefit from medication with levothyroxine because nothing changed in the patient's condition.
“However, it would be wrong to derive new recommendations from these results,” explains Führer.
Slightly increased values normalized spontaneously
A differentiated analysis of the study shows well-known control systems of the thyroid hormones.
"60 percent of the study population with an increase in TSH - that was 2,647 people - had normal thyroid values during a repeat examination at a later date," said the expert.
Slightly increased TSH values up to 7 mU / l often spontaneously normalized. This was also shown by previous studies. In everyday clinical practice, this means that a slightly increased TSH value must first be confirmed.
This means that it should be checked after two to three months; Only then is a further investigation for a causative thyroid disorder indicated. If the TSH value is> 10 mU / l, there is an increased risk of fat metabolism disorders, cardiovascular events and an impaired quality of life.
Diagnostic and therapy recommendations
A pragmatic recommendation is therefore to start thyroid hormone replacement from this value in older patients who suffer from other diseases such as high blood pressure, overweight, coronary heart disease or diabetes.
“The value to be achieved should be adjusted based on age; In other words, in the elderly, TSH concentrations of 4 to 6 mU / l, ”said Führer.
“Incidentally, the participants in the TRUST study had an average of TSH values of around 6.4 mU / l before starting therapy. That should explain why there was no treatment benefit, ”adds the expert from Essen.
The TRUST results do not change the valid - also guideline - diagnostic and therapy recommendations. They tend to confirm it. (ad)