Effects of testosterone supplementation on clinical and rehabilitative outcomes in older men undergoing on-pump CABG

Testosterone levels decrease with age. This decline is steeper during “critical illnesses”. Cardiac surgery is a particular representativemodel ofmajor clinical condition producing stress responses similar to those observed during severe nonsurgical illness. Cardiac revascularization with extracorporeal circulation is characterized by marked postoperative complications such as insulin resistance, a pro-inflammatory state, acute anemia and renal dysfunction. These phenomena are more evident in older subjects,who are particularly vulnerable in the post-operative state, a condition that has been recently termed as “acute postoperative frailty”. We recently showed that in older men with low ejection fraction undergoing cardiac revascularization with extracorporeal circulation, there is a profound decline in anabolic hormones, including testosterone. After surgery testosterone concentration frequently declines to less than 200 ng/dl, a situation suggestive of overt hypogonadism. Since menwith low testosterone levels have a high probability of developingmobility limitations, we considered this a rationale for the perioperative use of testosterone treatment in oldermen undergoing cardiac revasularization surgery.We hypothesized that testosterone supplementation at this timemight attenuate the impressive post-surgical catabolic hormonal milieu. The aim of thismanuscript is to elucidate an ongoing randomized clinical trial in older men (70+years old) undergoing elective cardiovascular revascularization with extracorporeal circulation. This randomized clinical trial will evaluate the effects of intramuscular testosterone administration on clinical and functional outcomes in this population. The study will also address potential mechanisms underlying the expected beneficial effects of testosterone supplementation including improvement of insulin sensitivity, markers of inflammatory status and improved hemoglobin levels.