Testosterone Deficiency in Men: Systematic Review and Standard Operating Procedures for Diagnosis and Treatment

Diagnosis and treatment of late-onset hypogonadism: systematic review and meta-analysis of TRT outcomes

Late-onset hypogonadism (LOH) is a relatively common conditions affecting the aging male. The aim of this review is to summarize the available evidence regarding LOH and its interaction with general health. LOH is often comorbid to obesity and several chronic diseases. For this reason lifestyle modifications should be strongly encouraged in LOH subjects with obesity, type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) and good treatment balance of chronic diseases. Medical therapy of LOH should be individualized depending on the etiology of the disease and the patient's expectations. Available evidence seems to suggest that testosterone replacement therapy is able to improve central obesity (subjects with MetS) and glycometabolic control (patients with MetS and T2DM), as well as to increase lean body mass (HIV, chronic obstructive pulmonary disease), along with insulin resistance (MetS) and peripheral oxygenation (chronic kidney diseases). However, it should be recognized that the number of studies on benefits of T supplementation is too limited to draw final conclusions. Longer and larger studies are needed to better clarify the role of TRT in such chronic conditions.

Serum PSA as a predictor of testosterone deficiency

INTRODUCTION

The relationship between serum prostate-specific antigen (PSA) and testosterone (T) levels is still controversial. According to the "saturation hypothesis," a significant relationship is apparent only in the low T range.

AIM

To verify whether, in a large sample of male subjects seeking medical care for sexual dysfunction (SD), PSA might represent a reliable marker of T levels.

METHODS

A consecutive series of 3,156 patients attending our unit for SD was studied. Among them, only subjects without history of prostate disease and with PSA levels<4 ng/mL (N=2,967) were analyzed.

MAIN OUTCOME MEASURES

Several hormonal and biochemical parameters were studied, along with structured interview on erectile dysfunction (SIEDY), ANDROTEST, and PsychoANDROTEST.

RESULTS

Receiver operating characteristic curve analysis for predicting severe hypogonadism (T<8 nmol/L) showed an accuracy of PSA=0.612±0.022 (P<0.0001), with the best sensitivity and specificity at PSA<0.65 ng/mL (65.2% and 55.5%, respectively). In the entire cohort, 254 subjects (8.6%) showed T<8 nmol/L and, among them, more than half (N=141, 4.8%) had PSA<0.65 ng/mL. After adjusting for age, low PSA was associated with hypogonadism-related features (i.e., delayed puberty, lower testis volume) and associated conditions, such as metabolic syndrome (hazard ratio [HR]=1.506 [1.241-1.827]; P<0.0001), type 2 diabetes (HR=2.044 [1.675-2.494]; P<0.0001), and cardiovascular diseases (HR=1.275 [1.006-1.617]; P=0.045). Furthermore, low PSA was associated with impaired sex- and sleep-related erections. The association between low PSA and hypogonadal symptoms and signs as well as with metabolic syndrome was retained even after adjusting for T levels. Sensitivity and positive predictive values of low PSA increased, whereas specificity and negative predictive value decreased as a function of age.

CONCLUSIONS

PSA is a marker of T concentrations and it may represent a new tool in confirming hypogonadism. The determination of PSA levels might give insights not only on the circulating levels of total T but also on its active fractions.

Penile rehabilitation after radical prostatectomy: what the evidence really says

The pathophysiology of erectile dysfunction after radical prostatectomy (RP) is believed to include neuropraxia, which leads to temporarily reduced oxygenation and subsequent structural changes in penile tissue. This results in veno-occlusive dysfunction, therefore, penile rehabilitation programmes focus on tissue oxygenation. Animal studies support the use of phosphodiesterase type 5 inhibitors (PDE5Is) after cavernous nerve damage but results from human studies are contradictory. The largest study to date found no long-term effect of either daily or on-demand PDE5I administration after RP compared with placebo. The effects of prostaglandin and vacuum erection devices are questionable and high-quality studies are lacking. Better documentation for current penile rehabilitation and/or better rehabilitation protocols are needed. One must be careful not to repeat the statement that penile rehabilitation improves erectile function after RP so many times that it becomes a truth even without the proper scientific backing.

Erectile dysfunction, penile atherosclerosis, and coronary artery vasculopathy in heart transplant recipients

INTRODUCTION

Vascular erectile dysfunction (ED) is the expression of a systemic vascular disease and in particular of endothelial dysfunction. Dysfunctional endothelium plays also a significant role in the onset and progression of coronary artery vasculopathy (CAV).

AIM

This pilot study was designed to evaluate the prevalence and pathogenesis of ED and its correlation with CAV in heart transplanted male.

METHODS

A total of 77 male heart transplanted patients (HTx) evaluated in our center (mean age 61.6 + 10.6 years) were enrolled in the study.

MAIN OUTCOME MEASURES

All subjects underwent accurate medical history collection, including lifestyle (cigarette smoking, dietary and sedentary habits, drug intake, and erectile function before cardiac transplantation), physical examination (body mass index and arterial pressure), biochemical blood tests (fasting glucose, total cholesterol, high-density lipoprotein cholesterol, and triglycerides), and hormones (prolactin, luteinizing hormone and total testosterone). Furthermore, they were studied with penile, carotid, femoral echo-color Doppler ultrasonography and coronary angiogram.

RESULTS

Incidence of ED was 24% before HTx and increased up to 65% after. Postischemic cardiomiopathy was an indication to HTx in ED group more frequently than in patients without ED (No-ED group) (45.1% vs. 20%). ED patients showed a lower peak systolic velocity, a higher cavernosal intima-media thickness (IMT), a higher prevalence of cavernosal plaques (26.7% vs. 5.2%, P < 0.05), peripheral vascular disease (60.87% vs. 26.1%, P < 0.05) and CAV (45.8% vs. 25.8%, P < 0.05) with respect to No-ED patients. Coronary flow reserve was significantly reduced in ED vs. No-ED patients (2.43 + 0.7 vs. 2.9 + 0.8, P < 0.04). Finally, cavernous plaque and testosterone plasma levels were statistically associated with CAV.

CONCLUSIONS

We showed that ED is a frequent disease in HTx patients, more common when the original pathology is postischemic cardiomiopathy and associated with higher prevalence of cavernous plaques and CAV. Its evaluation should be integral to an HTx rehab program.

Testosterone therapy in hypogonadal men results in sustained and clinically meaningful weight loss

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Hypogonadism is associated with increased fat mass and reduced muscle mass, which contributes to obesity and health risks, such as cardiovascular disease.Testosterone treatment of hypogonadal men improves muscle mass and reduces fat mass; however, many of these studies are of short duration.Thus, the long-term effects of testosterone on body anthropometry are not known.

WHAT THIS STUDY ADDS

Long-term testosterone treatment of hypogonadal men, up to 5 years duration, produced marked and significant decrease in body weight, waist circumference and body mass index. Hypogonadism contributes to reduced muscle mass and increased adiposity. Testosterone treatment ameliorates loss of muscle mass and reduces fat accumulation associated with hypogonadism. In this study, we evaluated the long-term effects of normalizing testosterone (T) levels in hypogonadal men on anthropometric parameters. Open-label, single-center, cumulative, prospective registry study of 261 men (32-84 years, mean 59.5 ± 8.4 years, with T levels ≤12 nmol L^-1 [mean: 7.7 ± 2.1]). Among the 261 men on T treatment, we followed up on 260 men for at least 2 years, 237 for 3 years, 195 for 4 years and 163 for at least 5 years. Subjects received parenteral T undecanoate 1000 mg every 12 weeks after an initial interval of 6 weeks. Body weight (BW), waist circumference (WC) and body mass index (BMI) were measured at baseline and yearly after treatment with T. BW decreased from 100.1 ± 14.0 kg to 92.5 ± 11.2 kg and WC was reduced from 107.7 ± 10.0 cm to 99.0 ± 9.1 cm. BMI declined from 31.7 ± 4.4 m kg^-2 to 29.4 ± 3.4 m kg^-2. All parameters examined were statistically significant vs. baseline and vs. the previous year over 5 years, indicating a continuous weight loss (WL) over the full observation period. The mean per cent WL was 3.2 ± 0.3% after 1 year, 5.6 ± 0.3%, after 2 years, 7.5 ± 0.3% after 3 years, 9.1 ± 0.3% after 4 years and 10.5 ± 0.4% after 5 years. The data obtained from this uncontrolled, observational, registry study suggest that raising serum T to normal physiological levels in hypogonadal men produces consistent loss in BW, WC and BMI. These marked improvements were progressive over the 5 years of the study.

Erectile dysfunction in the cardiovascular patient

Erectile dysfunction is common in the patient with cardiovascular disease. It is an important component of the quality of life and it also confers an independent risk for future cardiovascular events. The usual 3-year time period between the onset of erectile dysfunction symptoms and a cardiovascular event offers an opportunity for risk mitigation. Thus, sexual function should be incorporated into cardiovascular disease risk assessment for all men. A comprehensive approach to cardiovascular risk reduction (comprising of both lifestyle changes and pharmacological treatment) improves overall vascular health, including sexual function. Proper sexual counselling improves the quality of life and increases adherence to medication. This review explores the critical connection between erectile dysfunction and cardiovascular disease and evaluates how this relationship may influence clinical practice. Algorithms for the management of patient with erectile dysfunction according to the risk for sexual activity and future cardiovascular events are proposed.

Negative effects of high glucose exposure in human gonadotropin-releasing hormone neurons

Metabolic disorders are often associated with male hypogonadotropic hypogonadism, suggesting that hypothalamic defects involving GnRH neurons may impair the reproductive function. Among metabolic factors hyperglycemia has been implicated in the control of the reproductive axis at central level, both in humans and in animal models. To date, little is known about the direct effects of pathological high glucose concentrations on human GnRH neurons. In this study, we investigated the high glucose effects in the human GnRH-secreting FNC-B4 cells. Gene expression profiling by qRT-PCR, confirmed that FNC-B4 cells express GnRH and several genes relevant for GnRH neuron function (KISS1R, KISS1, sex steroid and leptin receptors, FGFR1, neuropilin 2, and semaphorins), along with glucose transporters (GLUT1, GLUT3, and GLUT4). High glucose exposure (22 mM; 40 mM) significantly reduced gene and protein expression of GnRH, KISS1R, KISS1, and leptin receptor, as compared to normal glucose (5 mM). Consistent with previous studies, leptin treatment significantly induced GnRH mRNA expression at 5 mM glucose, but not in the presence of high glucose concentrations. In conclusion, our findings demonstrate a deleterious direct contribution of high glucose on human GnRH neurons, thus providing new insights into pathogenic mechanisms linking metabolic disorders to reproductive dysfunctions.