Abnormalities of Thyroid Hormone Metabolism during Systemic Illness: The Low T3 Syndrome in Different Clinical Settings

Table 1

Summary of thyroid hormone abnormalities found in noncritically ill patients.

	Total T3	Free T3	Reverse T3	Total T4	Free T4	TSH
Caloric deprivation	↓	↓	↑	↓	⇔	⇔ or ↓
Heart failure	↓	↓	⇔ or ↑	⇔ or ↓	⇔	⇔ or ↓
HIV infection	⇔	⇔ or ↓	⇔ or ↓	⇔	⇔ or ↓	⇔
Renal diseases	↓	⇔	⇔	⇔ or ↓	⇔ or ↑	⇔
Liver diseases	⇔ or ↑	↓	⇔ or ↑	↑	⇔ or ↓	⇔
Pulmonary diseases	⇔	↓	⇔ or ↑	⇔	⇔	⇔
Diabetes mellitus	↓	↓	⇔ or ↑	↓	⇔ or ↑	⇔
Psychiatric illnesses	↑	⇔ or ↑	⇔	↑	⇔ or ↑	↑

⇔: normal.
↑: increased.
↓: decreased.