Subklinische Hypothyreose

Was ist neu?

Definition und Epidemiologie Die subklinische Hypothyreose ist in der Regel eine Labordiagnose ohne signifikante Symptomatik und definiert durch ein erhöhtes TSH bei normalen Werten für freies T3 und freies T4. Bei Laborkontrollen nach 2–3 Monaten findet sich in 50 % der Fälle eine spontane Normalisierung.

Klinische Bedeutung der subklinischen Hypothyreose Bei persistierend erhöhten TSH-Werten ist die subklinische Hypothyreose mit dem Nachweis von schilddrüsenspezifischen Antikörpern im Sinne einer Autoimmunthyreoiditis assoziiert. Im Alter finden sich physiologisch höhere TSH-Spiegel. Es ist deshalb davon auszugehen, dass die Diagnose einer subklinischen Hypothyreose bei älteren Menschen über 70 Jahre zu häufig gestellt und therapiert wird.

Therapie der subklinischen Hypothyreose Studien konnten bisher keinen positiven Effekt einer Substitutionstherapie der subklinischen Hypothyreose zeigen, insbesondere nicht bei älteren Patienten. Andererseits besteht das nicht unerhebliche Risiko einer Übertherapie mit der Entwicklung einer subklinischen Hyperthyreose. Deren negative Folgen in Form von Vorhofflimmern und Osteoporose beeinträchtigen die Lebensqualität und -dauer. Bei der Indikationsstellung zur Substitutionstherapie einer subklinischen Hypothyreose sollte deshalb zurückhaltend vorgegangen werden.

Subklinische Hypothyreose in der Schwangerschaft Eine Gruppe, bei der Diagnostik und Therapie besondere Sensibilität erfordern, sind schwangere Frauen. Hier müssen mit Mutter und Kind 2 Individuen behandelt werden. Dabei sind veränderliche Zielwerte und Dosierungen bezogen auf das Schwangerschaftsalter zu berücksichtigen.

Abstract

Subclinical hypothyroidism is usually a laboratory diagnosis without significant symptoms and is defined by an elevated thyroid-stimulating hormone (thyrotropin, TSH) with normal thyroid hormone levels. On laboratory checks after two to three months, spontaneous normalization is found in 50 % of all cases in the sense of a transient elevation.

With persistently elevated TSH levels, subclinical hypothyroidism is associated with evidence of thyroid-specific antibodies in the sense of autoimmune thyroiditis. Physiologically higher TSH levels are found in old age. It can therefore be assumed that the diagnosis of subclinical hypothyroidism is made and treated too frequently in older people over 70 years of age.

Studies have so far failed to show a positive effect of substitution therapy of subclinical hypothyroidism, especially in elderly patients. On the other hand, there is a not inconsiderable risk of overtreatment with the development of subclinical hyperthyroidism. Its negative consequences in the form of atrial fibrillation and osteoporosis impair the quality and duration of life. Therefore, the indication for substitution therapy of subclinical hypothyroidism should be made with caution.

One group in which diagnosis and therapy require special sensitivity is pregnant women. Here, two individuals, mother and child, must be treated. Varying target values and dosages in relation to the gestational age must be taken into account.

Schlüsselwörter

Hypothyreose - Hormonersatztherapie - Altersfaktoren - Thyroxin/therapeutische Verwendung

Key words

hypothyroidism - hormone replacement therapy - age factors - thyroxine/therapeutic use

Publikationsverlauf

Artikel online veröffentlicht:
15. März 2022

• Literatur

• 1 Canaris GJ, Manowitz NR, Mayor G. et al. The Colorado thyroid disease prevalence study. Arch Intern Med 2000; 160: 526-534
• 2 Peeters RP. Subclinical Hypothyroidism. N Engl J Med 2017; 376: 2556-2565
• 3 Surks MI, Hollowell JG. Age-specific distribution of serum thyrotropin and antithyroid antibodies in the US population: implications for the prevalence of subclinical hypothyroidism. J Clin Endocrinol Metab 2007; 92: 4575-4582
• 4 Pearce SHS, Razvi S, Yadegarfar ME. et al. Serum Thyroid Function, Mortality and Disability in Advanced Old Age: The Newcastle 85+ Study. J Clin Endocrinol Metab 2016; 101: 4385-4394
• 5 Hansen PS, Brix TH, Sørensen TIA. et al. Major genetic influence on the regulation of the pituitary-thyroid axis: a study of healthy Danish twins. J Clin Endocrinol Metab 2004; 89: 1181-1187
• 6 Meyerovitch J, Rotman-Pikielny P, Sherf M. et al. Serum thyrotropin measurements in the community: five-year follow-up in a large network of primary care physicians. Arch Intern Med 2007; 167: 1533-1538
• 7 Chen X, Zhang N, Cai Y. et al. Evaluation of left ventricular diastolic function using tissue Doppler echocardiography and conventional doppler echocardiography in patients with subclinical hypothyroidism aged < 60 years: a meta-analysis. J Cardiol 2013; 61: 8-15
• 8 Owen PJD, Sabit R, Lazarus JH. Thyroid disease and vascular function. Thyroid 2007; 17: 519-524
• 9 Patil VP, Shilpasree AS, Patil VS. et al. Evaluation of renal function in subclinical hypothyroidism. J Lab Physicians 2018; 10: 50-55
• 10 Liu XL, He S, Zhang SF. et al. Alteration of lipid profile in subclinical hypothyroidism: a meta-analysis. Med Sci Monit 2014; 20: 1432-1441
• 11 Aziz M, Kandimalla Y, Machavarapu A. et al. Effect of Thyroxin Treatment on Carotid Intima-Media Thickness (CIMT) Reduction in Patients with Subclinical Hypothyroidism (SCH): a Meta-Analysis of Clinical Trials. J Atheroscler Thromb 2017; 24: 643-659
• 12 Rodondi N, den Elzen WPJ, Bauer DC. et al. Subclinical hypothyroidism and the risk of coronary heart disease and mortality. JAMA 2010; 304: 1365-1374
• 13 Schübel J, Feldkamp J, Bergmann A. et al. Latent Hypothyroidism in Adults. Dtsch Ärztebl Int 2017; 114: 430-438
• 14 Pasqualetti G, Pagano G, Rengo G. et al. Subclinical Hypothyroidism and Cognitive Impairment: Systematic Review and Meta-Analysis. J Clin Endocrinol Metab 2015; 100: 4240-4248
• 15 Reddy V, Taha W, Kundumadam S. et al. Atrial fibrillation and hyperthyroidism: A literature review. Indian Heart J 2017; 69: 545-550
• 16 Krishnan SK, Dohrmann ML, Brietzke SA. et al. High prevalence of iatrogenic hyperthyroidism in elderly patients with atrial fibrillation in an anticoagulation clinic. Mo Med 2011; 280-283
• 17 Wändell P, Carlsson AC, Li X. et al. Levothyroxine treatment is associated with an increased relative risk of overall and organ specific incident cancers – a cohort study of the Swedish population. Cancer Epidemiol 2020; 66: 101707
• 18 Stott DJ, Rodondi N, Kearney PM. et al. Thyroid Hormone Therapy for Older Adults with Subclinical Hypothyroidism. N Engl J Med 2017; 376: 2534-2544
• 19 Feller M, Snel M, Moutzouri E. et al. Association of Thyroid Hormone Therapy With Quality of Life and Thyroid-Related Symptoms in Patients With Subclinical Hypothyroidism: A Systematic Review and Meta-analysis. JAMA 2018; 320: 1349-1359
• 20 Pearce SHS, Brabant G, Duntas LH. et al. 2013 ETA Guideline: Management of Subclinical Hypothyroidism. Eur Thyroid J 2013; 2: 215-228
• 21 Krassas GE, Poppe K, Glinoer D. Thyroid function and human reproductive health. Endocr Rev 2010; 31: 702-755
• 22 Stagnaro-Green A, Abalovich M, Alexander E. et al. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid 2011; 21: 1081-1125
• 23 Maraka S, Ospina NMS, OʼKeeffe DT. et al. Subclinical Hypothyroidism in Pregnancy: A Systematic Review and Meta-Analysis. Thyroid 2016; 26: 580-590