Non Thyroidal Illness Syndrome

Clinic

• NTIS is a term used to describe alterations in thyroid function tests observed in critically ill patients in the absence of intrinsic thyroid disease.
• Several studies have demonstrated that it has a high prevalence among hospitalized patients and it is significantly associated with the severity and the outcome of the disease.
• In the last decades there has been a shift in our view of the pathogenetic mechanisms underlying the syndrome. It has been increasingly recognized that alterations in the hypothalamus and the pituitary play a predominant role in the pathogenesis of NTIS, whereas the contribution of peripheral pathways, such as deiodinase activity, does not seem to be as significant as considered in the past.
• The majority of studies agree that treatment with thyroid hormone (TH) is not beneficial. However, TH may be reserved as an option for high-risk patients with very low TH levels and protracted disease, in whom some degree of hypothyroidism may be present.