Low Serum Testosterone as a New Risk Factor for Chronic Rejection in Heart Transplanted Men

Changes in post-transplant serum testosterone levels in men undergoing lung transplantation: a pilot study using the TriNetX Research Network

Hypogonadism is understudied in men requiring solid organ transplants, particularly among lung transplant recipients. Improvement in serum testosterone levels has been reported in kidney and liver transplantation. Using the TriNetX Research Network, we performed a retrospective cohort study to evaluate the incidence of peri-transplant hypogonadism and the natural course of serum testosterone following successful lung transplantation. Men aged ≥ 18 with a lung transplant and total testosterone drawn within one year pre- and post-transplant were included. Men with receipt of testosterone therapy were excluded. A low testosterone (<300 ng/dL) and normal testosterone (≥300 ng/dL) cohort was created before employing descriptive and analytic statistics to investigate the incidence of peri-transplant hypogonadism and the change in serum testosterone levels following lung transplantation. In our entire cohort, lung transplantation was not associated with a significant increase in post-transplant serum testosterone (329.86 ± 162.56 ng/dL pre-transplant and 355.13 ± 216.11 ng/dL post-transplant, p = 0.483). The number of men with low testosterone decreased by 9.8% following lung transplantation but was not significant, p = 0.404. In this pilot study, no significant change in the number of hypogonadal men nor serum testosterone levels was observed among men undergoing lung transplantation.

Testosterone deficiency in male organ transplant recipients

Testosterone deficiency is known to affect men with increasing incidence throughout their lifespan. The clinical manifestations of testosterone deficiency, in turn, negatively impact men's quality of life and perception of overall health. The interaction of chronic systemic disease and androgen deficiency represent an area for potential intervention. Here, we explore the topic of testosterone deficiency amongst men with end-stage organ failure requiring transplantation in order to elucidate the underlying pathophysiology of androgen deficiency of chronic disease and discuss whether intervention, including testosterone replacement and organ transplantation, improve patients' outcomes and quality of life.

Implications of renal transplantation on serum testosterone and preoperative factors affecting its levels in the post-transplant period

Objective:

Low serum testosterone is highly prevalent in chronic kidney disease patients. The objective of the study was to determine levels of serum testosterone at the time of transplantation, the prevalence of testosterone deficiency/insufficiency in the pre- and post-transplant periods, and its correlation with patients’ age, serum creatinine, duration of preoperative dialysis, human leukocyte antigen (HLA) matching, and graft outcomes.

Methods:

The study was conducted from January 2019 to April 2020. Forty-five male renal transplant patients were evaluated before and at one and six months following transplant for changes in testosterone and creatinine levels. Six-month follow-up was possible for 28 patients.

Result:

Renal transplantation resulted in significant improvement in testosterone levels as early as one month after transplantation. The duration of preoperative dialysis and HLA match had a negative and positive impact on postoperative serum testosterone levels, respectively. We did not find any impact of testosterone levels on graft function.

Conclusion:

Successful transplantation among the study population produced a positive impact on serum testosterone levels. The duration of preoperative dialysis and HLA match had a negative and positive impact on postoperative serum testosterone levels, respectively.

Level of evidence:

XXX.

Effect of recipient gender and donor-specific antibodies on antibody-mediated rejection after heart transplantation

Gender-difference regarding antibody-mediated rejection (AMR) after heart transplantation has been described. However, no study accounted for the presence of preformed donor-specific antibodies (pfDSA), a known risk factor of AMR, more common among women than men. In a single-institution 6-year cohort (2010-2015), time to AMR was assessed, comparing men with women by survival analysis with a 1-year death-censored follow-up. All AMRs were biopsy proven. Confounding variables that were accounted for included mean intensity fluorescence (MFI) of pfDSA, recipient age, HLA-, size- and sex-mismatch. 463 patients were included. Overall incidence of AMR was 10.3% at 1 year. After adjusting for confounding variables, independent risk factors of AMR were female recipient gender (adjusted hazard-ratio [adj. HR] = 1.78 [1.06-2.99]), P = .03) and the presence of pfDSA (adj. HR = 3.20 [1.80-5.70], P < .001). This association remained significant when considering pfDSA by their MFI; female recipient gender had an adj. HR = 2.2 (P = .026) and MFI of pfDSA (per 1 MFI-increase) adj. HR = 1.0002 (P < .0001). In this cohort, women were at higher risk of AMR than men and this risk increase was additive to that of pfDSA. These findings may suggest a gender-related difference in the severity of pfDSA.

Hand-Grip Strength Is Associated With Serum Testosterone and Albumin Levels in Male Kidney Transplant Recipients

OBJECTIVES

In kidney transplant recipients, reduced muscle mass and hand-grip strength are associated with impaired nutritional status. Serum testosterone is highly associated with muscle strength in the general population. Here, we aimed to determine the associations among serum testosterone, hand-grip strength, and nutritional and inflammatory parameters, as well as graft function.

MATERIALS AND METHODS

Our study included 144 stable male kidney transplant recipients from our renal transplant outpatient clinic. All patients were evaluated for clinical parameters (age, duration of hemodialysis, and posttransplant time), biochemical parameters (calcium, phosphorus, parathyroid hormone, C-reactive protein, albumin, creatinine), and serum testosterone levels. Body composition was analyzed with the bioimpedance spectroscopy analysis technique using a body composition monitor that estimates body mass index and percent fat. Hand-grip strength was analyzed by using a dynamometer (ProHealthcareProducts.com, Park City, UT, USA). We calculated estimated glomerular filtration rate using the Modification of Diet in Renal Disease-4 equation.

RESULTS

Demographic characteristics, duration of dialysis before transplant, biochemical parameters, and estimated glomerular filtration rates were similar among study patients. Mean (standard deviation) serum testosterone was 588.0 (55.5) ng/dL, mean body mass index was 26.8 (0.6) kg/m2, and mean hand-grip strength was 42.2 (1.7) mm2. Serum testosterone levels were positively correlated with hand-grip strength (r = 0.445; P = .033) and serum albumin (r = 0.399; P = .05) and negatively correlated with serum C-reactive protein (r = -0.454; P = .05) and age. In linear multiple regression analysis, serum albumin (P = .033) and testosterone levels (P = .038) were shown to be predictors of hand-grip strength. However, we could not show a significant correlation between graft function and testosterone.

CONCLUSIONS

Serum testosterone level is correlated with hand-grip strength and C-reactive protein and albumin levels, which may indicate that testosterone affects nutritional status and inflammation in male renal transplant recipients.

The Heart as a Psychoneuroendocrine and Immunoregulatory Organ

The heart can be viewed not just as muscle pump but also as an important checkpoint for a complex network of nervous, endocrine, and immune signals. The heart is able to process neurological signals independently from the brain and to crosstalk with the endocrine and immune systems. The heart communicates with the psyche through the neuro-endocrine-immune system in a highly integrated way, in order to maintain the homeostasis of the whole body with peculiarities specific to males and females.

Coronary Microvascular Function and Beyond: The Crosstalk between Hormones, Cytokines, and Neurotransmitters

Beyond its hemodynamic function, the heart also acts as a neuroendocrine and immunoregulatory organ. A dynamic communication between the heart and other organs takes place constantly to maintain cardiovascular homeostasis. The current understanding highlights the importance of the endocrine, immune, and nervous factors to fine-tune the crosstalk of the cardiovascular system with the entire body. Once disrupted, this complex interorgan communication may promote the onset and the progression of cardiovascular diseases. Thus, expanding our knowledge on how these factors influence the cardiovascular system can lead to novel therapeutic strategies to improve patient care. In the present paper, we review novel concepts on the role of endocrine, immune, and nervous factors in the modulation of microvascular coronary function.

Low-serum testosterone levels pre-liver transplantation are associated with reduced rates of early acute allograft rejection in men

BACKGROUND

Low pretransplant serum testosterone has recently been associated with increased mortality in men awaiting liver transplantation, but the potential impact on rejection has not yet been investigated.

METHODS

Pretransplantation serum testosterone, SHBG, and other variables were collected on 190 consecutive men who received a liver transplant between 2007 and 2013. Rates of subsequent acute cellular rejection were recorded. Multivariable analysis was performed to define variables associated with rejection and other clinically important end points.

RESULTS

Thirty (16%) of 190 men experienced acute cellular rejection. Lower pretransplant testosterone was associated with lower rejection rates, -7% (95% confidence interval [CI], -2% to -12%) per nmol/L decrease in total testosterone and -4% (95% CI, -0.5% to -7%) per 10 pmol/L decrease in free testosterone. Total testosterone (correlation 0.29, P=0.04) and free testosterone (correlation 0.37, P=0.01) correlated significantly with the histological severity of rejection. Older age at transplant (+5% [95% CI, 9%-2%]) per year, and nonautoimmune etiology of liver disease (OR, 1.0 for autoimmune, 0.22 [95% CI, 0.07-0.73] for hepatitis C virus, and 0.58 [95% CI, 0.21-1.71] for other etiologies) were also associated with decreased rejection risk. In a generalized linear model including the covariates testosterone, SHBG, age, etiology, and MELD, total testosterone remained a significant predictor of rejection (adjusted OR, 1.06; P=0.03), as did age at transplant (OR, 0.95; P=0.01).

CONCLUSION

Low preliver transplant serum testosterone independently predicts a decreased risk of acute allograft rejection. Whether testosterone is a marker of disease-associated immune dysfunction or has immune-modulatory effects requires further study.

Low testosterone at time of transplantation is independently associated with poor patient and graft survival in male renal transplant recipients

PURPOSE

Low testosterone is common in men with renal disease and it increases the risk of death in those on dialysis. We studied serum testosterone at transplantation and correlated it with patient and graft outcomes.

MATERIALS AND METHODS

We identified serum samples collected and frozen at the time of transplantation in male recipients of primary kidney transplants done more than 6 years ago at our institution. In 197 recipients there was sufficient serum to determine total testosterone. We analyzed contingency outcomes by the Fisher exact test, continuous values by the Student t-test and survival by the Gehan-Breslow-Wilcoxon test.

RESULTS

Mean patient age was 48.9 years (range 14 to 75). There were 100 living and 97 cadaveric donors, and 53 recipients (27%) had diabetes. Mean ± SD serum testosterone was 477 ± 251.3 ng/dl (range 48 to 2,013). Testosterone was low (less than 220 ng/dl) in 24 patients. Age did not correlate with testosterone. Low testosterone recipients had worse 1-year patient survival (75% vs 95%, p = 0.003), 3-year patient survival (62.5% vs 86.1%, p = 0.008), 1-year graft survival (62.5% vs 92.4%) and 3-year graft survival (50% vs 76.3%, p = 0.01). Survival curves showed significantly worse patient survival (p = 0.004) and graft survival (p = 0.02) for low testosterone. On multivariable analysis low testosterone was independently associated with patient death (HR 2.27, 95% CI 1.19-4.32) and graft loss (HR 2.05, 95% CI 1.16-3.62).

CONCLUSIONS

Low testosterone at transplantation is associated with patient death and graft loss. If due to causality, testosterone therapy may impact survival. Without causality low testosterone may still be a marker for posttransplant risk.