Effect of muscle mass, androgens, and glucocorticoids on health outcomes: studies in transplant recipients and the general population

Organ transplantation is the best treatment for patients who suffer from end-stage organ disease. Although transplantation is the best treatment, transplant recipients have a shorter life-expectancy than people from the general population. This can largely be attributed to a higher prevalence comorbidities such as diabetes and hypertension, which subsequently lead to more premature cardiovascular mortality. To date, diabetes and hypertension are treated with lifestyle interventions and medication. Yet, these treatment options have failed to completely eradicate these comorbidities. Therefore, in this thesis we aimed to uncover novel risk factors for diabetes, hypertension, and premature mortality in transplant recipients. Firstly, this thesis shows that a low muscle mass is associated with premature mortality in liver transplant recipients. Additionally, it shows that 24-hour urinary creatinine excretion can be used as marker to improve muscle mass. Secondly, this thesis demonstrates that among male kidney transplant recipients low testosterone values are more common that previously though. This is worrisome as we also show that men with low testosterone values have a higher risk to develop posttransplant diabetes. Lastly, as mentioned previously, hypertension is also prevalent among transplant recipients. Hypertension is however difficult to treat in this population, as recipients are dependent on immunosuppressives which have hypertension as side-effect. Subsequently, we hypothesize that kidney transplant recipients should be switched to a different steroids and have laid the foundation for scientific conformation of this theory. In conclusion, a low muscle mass, low testosterone values and suboptimal use of steroids can impair the health of transplant recipients.