Male hypogonadism: a review

Effects of testosterone replacement on lipid profile, hepatotoxicity, oxidative stress, and cognitive performance in castrated wistar rats

OBJECTIVE

Androgen deficiency is associated with multiple biochemical and behavioral disorders. This study investigated the effects of testosterone replacement and Spirulina Platensis association on testosterone deficiency-induced metabolic disorders and memory impairment.

METHODS

Adult male rats were randomly and equally divided into four groups and received the following treatments for 20 consecutive days.

CONTROL GROUP

non-castrated rats received distilled water. Castrated group received distilled water. Testosterone treated group: castrated rats received 0.20 mg of testosterone dissolved in corn oil by subcutaneous injection (i.p.). Spirulina co-treated group: castrated rats received 0.20 mg of testosterone (i.p.) dissolved in corn oil followed by 1000 mg/kg of Spirulina per os.

RESULTS

Data showed that castration induced an increase in plasma ALT, AST, alkaline phosphatase (PAL), cholesterol, and triglycerides level. Castrated rats showed a great elevation in SOD and CAT activities and MDA and H2O2 levels in the prostate, seminal vesicles, and brain. Testosterone deficiency was also associated with alteration of the spatial memory and exploratory behaviour. Testosterone replacement either alone or with Spirulina combination efficiently improved most of these biochemical parameters and ameliorated cognitive abilities in castrated rats.

CONCLUSIONS

Testosterone replacement either alone or in combination with Spirulina improved castration-induced metabolic, oxidative, and cognitive alterations.

Summary of the clinical practice manual for late-onset hypogonadism

Testosterone plays an important role in maintaining both physical and mental function. Age-related testosterone depletion contributes to the development of angina, arteriosclerosis, obesity, metabolic syndrome, dementia, frailty, and a range of other conditions. A condition involving age-related testosterone depletion and the associated clinical symptoms is defined as late-onset hypogonadism (LOH). LOH is treated by testosterone replacement therapy. Indications for testosterone replacement therapy are determined by evaluating symptoms and signs.

Different Factors Are Associated With Sex Hormones and Leydig Cell Function in Israelis and Palestinians in Jerusalem

Total testosterone (TT) is known to influence health and virility in men. Among men from United States and Europe, numerous sociodemographic and lifestyle factors were reported to be associated with TT. However, associations with TT and Leydig cell function in the Middle East are poorly described. A cross-sectional, population-based sample had a structured interview, physical examinations, and blood tests in two hospitals in Jerusalem, Israel. A subsample (25- to 44-year-old men, n = 286: 124 Israelis, 162 Palestinians) had sex hormone measurements. The primary outcomes were TT and free testosterone/luteinizing hormone (FT/LH) ratio, representing Leydig cell function. Associations with sociodemographic and lifestyle factors, body mass index (BMI), and physical activity (PA) were evaluated using multivariable linear regression. Compared with Palestinians, Israelis had similar TT (4.81 vs. 5.09 ng/mL, p = .405) and higher FT/LH (31.2 vs. 25.8 ng/IU, p = .002). In ln-transformed values, marital status had a stronger association in Palestinians (P for interaction = 0.03). Age, BMI, and PA had a stronger association with TT in Israelis with significant interactions with ethnicity. BMI <25 and a higher PA quartile were associated with a higher TT (p < .001). Among Israelis, age (p = .007), married marital status (p = .007), and BMI <25 were significantly associated with FT/LH. No associations of any factors were identified among Palestinians. Associations with several modifiable factors identified in Western samples were replicated in Israelis and to a lesser degree in Palestinians. Different relationships of several factors with TT and FT/LH could result from ethnically diverse genetic, sociodemographic, and behavioral characteristics that warrant further research.

Population Pharmacokinetic Modeling and Simulations to Evaluate a Potential Dose Regimen of Testosterone Undecanoate in Hypogonadal Males

Intramuscular testosterone undecanoate is indicated as testosterone replacement in adult males with a deficiency in or absence of endogenous testosterone (hypogonadism). Intramuscular testosterone undecanoate 750 mg is approved to be administered at initiation and at 4 weeks, followed by a maintenance dose every 10 weeks. However, a more frequent maintenance regimen may improve symptom management of low testosterone at the end of each dosing interval. The current objective was to develop a population pharmacokinetic (PK) model for intramuscular testosterone undecanoate 750 mg and to perform PK simulations to assess the impact of an 8-week maintenance regimen on testosterone exposure. A 1-compartment model with first-order absorption and first-order elimination best described the PK of testosterone undecanoate. The model included time-dependent suppression and gradual recovery of endogenous testosterone production during testosterone undecanoate administration. Significant covariates included body weight and sex hormone binding globulin level. With the final PK model, simulations were performed to evaluate the impact of an 8-week versus a 10-week maintenance regimen on testosterone exposure. The 8-week testosterone undecanoate regimen had a predicted 11% increase in C_avg and C_trough and a 5% increase in C_max . This translated into an ≈10% increase in the percentage of patients predicted to have C_trough >300 ng/dL, minimal change in the percentage of patients with C_avg in the normal range, and a low likelihood of C_max >2500 ng/dL. These simulations suggest that more frequent administration of intramuscular testosterone undecanoate may be beneficial in some patients. Further clinical evaluation of an 8-week dose regimen is warranted. This article is protected by copyright. All rights reserved.

Treatment of male hypogonadism partially reverses oxidative stress in patients with hypogonadism

There are some studies regarding the presence/absence of oxidative stress in patients with hypogonadism with limited number of parameters. We aimed to investigate the effects of male hypogonadism and its treatment on oxidative stress parameters. Thirteen male patients with hypogonadotropic hypogonadism and 20 healthy subjects were involved in the study. Patients with hypogonadism were evaluated before and after six months of therapy. Markers indicating lipid and protein oxidation, total oxidant status (TOS) and total anti-oxidant capacity (TAC) were evaluated. Control subjects had significantly higher serum testosterone levels in comparison to hypogonadal patients before the treatment period. After the treatment of hypogonadism serum testosterone levels increased significantly. Myeloperoxidase (MPO) activity, levels of advanced oxidation protein products (AOPP), total lipid hydroperoxide and protein carbonyl compounds (PCC) were similar between the control subjects and the patient group before treatment. Pyrrolized protein and TOS were significantly lower and thiol levels and TAC were significantly higher in the control subjects than in patients with hypogonadism. Treatment of hypogonadism resulted in a significant decrease in AOPP levels while a significant increase was determined in TAC. No significant change was found in MPO activity. In conclusion, patients with hypogonadism have an increased status of oxidative stress which is at least partially improved after appropriate therapy.

Borderline-low testosterone levels are associated with lower left ventricular wall thickness in firefighters: An exploratory analysis

Background

Low endogenous testosterone has been associated with increased cardiovascular risk in men.

Objectives

To determine the prevalence of low serum testosterone level (TT) in a cohort of male US career firefighters and to examine its relation with left ventricular wall thickness (LVWT).

Materials and Methods

We conducted a cross‐sectional study among 341 career firefighters, (age: 37.5 ± 10.3 years; BMI: 28.9 ± 4.5 kg/m²), who underwent an occupational medical screening examination. TT quartiles were determined, and LVWT distribution among them was plotted. Then, TT values were categorized as low (<264 ng/dL), borderline (264‐399 ng/dL), reference range (400‐916 ng/dL), and high (>916 ng/dL). To further investigate the association of mildly decreased TT on LVWT, we divided the borderline group into borderline‐low (264‐319 ng/dL) and borderline‐high (320‐399 ng/dL) ranges. LVWT values were classified as low LVWT when <0.6 cm. A multivariate model was used to compare LVWT, age, BMI, systolic blood pressure (SBP), and HbA1c among groups by TT values.

Results

The prevalence of low TT was 10.6% and of borderline was 26.4%, while 58.7% had levels in the reference range. The low‐TT group was older and had higher BMI and SBP as compared to the reference group (P < .01). LVWT values were different among groups (P = .04) and significantly lower in firefighters with borderline‐low TT as compared to the reference group (P < .05). This finding also occurred within obese firefighters (P = .03). The borderline‐low group had a higher adjusted risk for a low LVWT as compared to the reference group [OR: 4.11 (95% CI: 1.79‐9.43)].

Discussion

Our findings highlight the possible relationship between a mild reduction in testosterone levels (borderline) and lower LVWT.

Conclusions

A high prevalence of subnormal TT levels (low and borderline: 37%) was observed in this relatively homogeneous cohort of career firefighters. Mildly decreased TT levels and lower LVWT might represent a preclinical condition and a window of opportunity for cardiovascular preventive interventions in firefighters.