The relationship between testosterone deficiency (TD) syndrome and surgical resilience has a great impact in the modern approach to male elderly patients. There is good evidence that low levels of T are a strong marker for cardiovascular risk; also, TD is frequently associated with increased cardiovascular and all-cause mortality especially in cardiac older frail men. Screening for low T should be mandatory in high risk groups candidate to surgery including those with diabetes, metabolic syndrome and obesity, even though benefits from T-treatment on survival rates are unclear.
The low-T3 syndrome, named non-thyroidal illness (NTI) that occurs during critical illness refers to a syndrome with different faces in both sexes. The acute stress or critical illness-induced alterations within the thyroid axis occur in the first days of critical illness i.e. post-surgery and are brought about at least in part by the concomitant macronutrient deficit. The NTI that occurs in prolonged critically ill patients or in post-surgical resilience patients who continue to be dependent on intensive medical care for weeks or months, may have an impact on surgical outcomes because of frequent occurrence of cardiac arrhythmias. Future directions should better routinely investigate circulating thyroid hormones in population at risk before surgery after excluding iatrogenic drug interferences, and investigate the effect of possible treatments on survival rates after surgery.