Testosterone replacement therapy and cardiovascular risk factors modification

Analysis of cardiovascular risk factors associated with serum testosterone levels according to the US 2011-2012 National Health and Nutrition Examination Survey

OBJECTIVE

To investigate associations between cardiovascular disease risk factors, including fasting glucose, cholesterol, high density lipoprotein cholesterol (HDL-c), LDL-c, blood pressure, body mass index (BMI), C-peptide, creatinine kinase, smoking, alcohol use, physical activity, C-reactive protein as well as homocysteine levels and cardiovascular events.

METHODS

Data from 1545 men aged ≥40 years, with testosterone deficiency (TD) (<300 ng/dL) and non-TD (≥300 ng/dL) which were extracted from the National Health and Nutrition Examination Survey database 2011-2012 and analyzed.

RESULTS

Multivariate logistic regression analysis showed positive associations between TD and BMI (≥35 vs. < 18.5: OR = 2.51, 95% CI: 1.19-5.32, p = .016), HDL-c (<0.91 vs. ≥0.91: OR = 1.60, 95% CI: 1.14-2.24, p = .006) and diabetes (diabetes vs. non-diabetes: OR = 1.48, 95% CI: 1.14-1.92, p = .004) as well as negative associations between TD and metabolic equivalent scores (≥12 vs. <12: OR = 0.69, 95% CI: 0.52-0.91, p = .009) and smoking (Ever vs. never: OR = 0.69, 95% CI: 0.51-0.94, p = .018). Furthermore, total serum testosterone levels were lower in patients with heart failure (p = .04) and angina/angina pectoris (p = .001) compared with subjects without these cardiac problems.

CONCLUSION

Low serum testosterone was associated with multiple risk factors for CHD.

Effect of Degarelix, a Gonadotropin-Releasing Hormone Receptor Antagonist for the Treatment of Prostate Cancer, on Cardiac Repolarisation in a Randomised, Placebo and Active Comparator Controlled Thorough QT/QTc Trial in Healthy Men

BACKGROUND AND OBJECTIVES

Degarelix is a gonadotropin-releasing hormone antagonist registered for the treatment of advanced hormone-dependent prostate cancer. Treatment causing androgen deprivation is associated with QT prolongation and this study investigated whether degarelix at supratherapeutic concentrations has an intrinsic effect per se on cardiac repolarisation and the QT interval.

METHODS

This was a single-centre, randomised, crossover study comparing the effect of degarelix, placebo, and the positive control moxifloxacin on the QT interval. Degarelix and placebo treatments were double-blind, whereas moxifloxacin treatment was open-label. Eighty healthy men, aged 18-45 years, received single intravenous doses of degarelix 2.8 mg, and placebo, as well as a single oral dose of moxifloxacin 400 mg. Electrocardiograms were collected up to 24 h after the start of administration, with the QT interval assessed and plasma concentrations of degarelix concomitantly analysed.

RESULTS

Time-matched, one-sided 95% upper confidence boundaries for baseline-corrected average changes from placebo for the QT interval, corrected using the Fridericia method (ΔΔQTcF), did not exceed 10 ms at any timepoint, with maximum degarelix concentrations reaching approximately threefold the concentrations seen in the treatment of prostate cancer. Furthermore, concentration-exposure analysis indicated absence of any QT prolongation effects of degarelix. No significant effect on any other cardiac parameter was observed. The lower bound of the 98.3% confidence interval for moxifloxacin ΔΔQTcF exceeded 5 ms, thus verifying assay sensitivity.

CONCLUSION

The results showed that the study was validated to detect a significant effect on the QT interval, and that degarelix by itself does not have any effect on the QT interval and cardiac repolarisation at supratherapeutic concentrations.

Emerging medication for the treatment of male hypogonadism

INTRODUCTION

Male hypogonadism is characterized by inadequate production of Testosterone (T) (hypoandrogenism) and deficiencies in spermatogenesis. The main treatment of male hypogonadism is T replacement therapy (TRT), but for some of the patients, alternative drugs may be more suitable.

AREAS COVERED

The available literature of T and alternative treatments for male hypogonadism are discussed.

EXPERT OPINION

Transdermal application of T gels are the most commonly used route of T administration. Some oral T formulations are either associated with hepatic toxicity (i.e. methyltestosterone) or short half-lives that require multiple doses per day (i.e. oral testosterone undecanoate). Short acting, injectable T formulations are also available. If the patient prefers not to use daily drugs or short acting injectable formulations, depot formulations such as injectable testosterone undecanoate (TU) may be a good alternative. If the patient has hypogonadotropic hypogonadism and desires fertility or if he is adolescent, instead of TRT, gonadotropins can be started to stimulate testicular growth and spermatogenesis. In obese patients or for the patients having high risks for TRT, off label aromatase inhibitors (AI) and clomiphene citrate (CC), may be considered to stimulate LH, FSH and T levels. In patients with high prostate disease risk, selective androgen receptor modulators may be an alternative treatment but these latter treatments have not had high level evidence.

Risks of testosterone replacement therapy in men

Testosterone replacement therapy (TRT) is a widely used treatment for men with symptomatic hypogonadism. The benefits seen with TRT, such as increased libido and energy level, beneficial effects on bone density, strength and muscle as well as cardioprotective effects, have been well-documented. TRT is contraindicated in men with untreated prostate and breast cancer. Men on TRT should be monitored for side-effects such as polycythemia, peripheral edema, cardiac and hepatic dysfunction.

Effects of three different medications on metabolic parameters and testicular volume in patients with hypogonadotropic hypogonadism: 3-year experience

INTRODUCTION

The aim of this study was to demonstrate the influences of three different treatment strategies on biochemical parameters and testicular volume (TV) in patients with idiopathic hypogonadotropic hypogonadism (IHH).

SUBJECTS DESIGN AND METHODS

Seventy-seven never-treated patients with IHH and age and body mass index (BMI)-matched 42 healthy controls were analysed in a retrospective design. Twenty-eight patients were treated with testosterone esters (TE), 25 patients were treated with human chorionic gonadotropin (hCG) and 24 patients were treated with testosterone gel (TG). Biochemical parameters, tanner stages (TS) and TV were evaluated before and after 6 months of treatment.

RESULTS

Pretreatment TV, TS and biochemical test results were similar among the three treatment subgroup. In the TE-treated group, BMI, haemoglobin, haematocrit, creatinine, triglyceride, total testosterone (TT), TS and TV increased, but HDL-cholesterol (C) and urea level decreased significantly. In the hCG-treated group, triglyceride level decreased, and luteinizing hormone level, TS and TV increased significantly. BMI, TT, TS and TV increased, and leucocyte count, total-C, HDL-C levels decreased significantly in the TG-treated patients. No treatment type resulted in any changes in insulin resistance markers.

CONCLUSION

hCG treatment resulted in favourable effects particularly on TV and lipid parameters. When TV improvement is considered less important, TG treatment may be a better option for older patients with IHH because of its easy use, neutral effects on triglyceride, haemoglobin and haematocrit, and its beneficial effects on total cholesterol level.

Circulating testosterone and estradiol, autonomic balance and baroreflex sensitivity in middle-aged and elderly men with heart failure

BACKGROUND

Heart failure (HF) is considered as a cardiogeriatric syndrome. Its fundamental pathophysiological feature is autonomic imbalance (and associated abnormalities within cardiovascular reflex control), but recent evidence suggests the involvement of deranged hormone metabolism. Both these neural and endocrine pathologies have serious clinical and prognostic consequences in patients with HF. We investigated the relations between autonomic status, baroreflex sensitivity (BRS) and hormone status in men with mild systolic HF.

METHODS

We examined 46 men with stable systolic HF (age: 62 ± 10 years, NYHA class I/II: 10/36 [22%/78%], ischemic aetiology: 72%, left ventricular ejection fraction: 32 ± 8%). Serum hormone levels (i.e. total testosterone [TT], dehydroepiandrosterone sulphate [DHEAS], oestradiol [E2], insulin-like growth factor type 1 [IGF-1] and cortisol) were assessed using immunoassays. Estimated free testosterone (eFT) was estimated using the Vermeulen's equation. Heart rate variability (HRV) was assessed in time and frequency domains, based on 10-min resting recordings. BRS was estimated using the sequence method (BRS-Seq) and the phenylephrine test (BRS-Phe).

RESULTS

Deficiencies in circulating TT, eFT, DHEAS and IGF-1 (defined as a serum hormone ≤the 10th percentile calculated for the adequate age category in the cohort of healthy men) were found in respectively 13%, 30%, 55% and 93% of men with systolic HF. Serum SHBG ≥50 nmol/L and cortisol ≥700 nmol/L characterised, respectively 44% and 29% of men with HF. In multivariable models after the adjustment for clinical variables, the following relationships were found in examined men: DHEAS and SDNN (time domain of HRV defined as a standard deviation of average R-R intervals) (β = 0.29, p = 0.03); E2 and: HRV-LF (ms(2)) (β = 0.37, p = 0.01), HRV-HF (ms2) (β = 0.44, p = 0.02) and BRS-Phe (β = 0.51, p = 0.008); TT and: HRV-HF (%) (β = 0.35, p = 0.02), HRV-LF/HF ratio (β = -0.35, p = 0.02) and BRS-Seq (β = 0.33, p = 0.04).

CONCLUSIONS

The observed associations between reduced circulating androgens, oestrogens and lower HRV and depleted BRS, irrespectively of HF severity suggest the pathophysiological links between these two mechanisms. These results constitute the premises to investigate whether the pharmacological supplementation of depleted hormones would enable to restore the autonomic balance and improve the efficacy of reflex control within the cardiovascular system in men with systolic HF.

Frailty, sarcopenia, and hormones

Frailty is now a definable clinical syndrome with a simple screening test. Age-related changes in hormones play a major role in the development of frailty by reducing muscle mass and strength (sarcopenia). Selective Androgen Receptor Molecules and ghrelin agonists are being developed to treat sarcopenia. The role of Activin Type IIB soluble receptors and Follistatin-like 3 mimetics is less certain because of side effects. Exercise (resistance and aerobic), vitamin D and protein supplementation, and reduction of polypharmacy are keys to the treatment of frailty.

Testosterone replacement therapy improves QTaVI in hypogonadal men with spinal cord injury

AIM

To determine the effect of a 12-month intent-to-treat testosterone (T) replacement therapy (TRT) trial on QTa interval variability (QTaVI) in hypogonadal (HG) men with spinal cord injury (SCI).

METHOD

A prospective, controlled 12-month TRT trial was completed in 22 healthy, chronic, nonambulatory men with SCI. Based on serum T concentration, subjects were designated as HG (≤ 11.3 nmol/l) or eugonadal (EG ≥ 11.4 nmol/l). Digital 3-lead electrocardiograms were performed. Heart rate (RR), heart rate variability [including total power (TPRR), low frequency (LFRR) and high frequency (HFRR)], QTa, QTe, and RT intervals, QTC (Bazett formula), QTVN, and QTaVI were calculated and evaluated at baseline and at 12 months. Lipoprotein profiles (triglycerides, total cholesterol, low-density and high-density lipoproteins) were obtained at the respective time points.

RESULTS

Based on serum T concentration, 13 subjects were designated as HG and 11 as EG. During the trial, there were no group differences for RR, QTa, QTe or RT intervals, QTC, TPRR, HFRR, or lipoproteins. The HG group was older (p < 0.05) and their LFRR was lower (p < 0.05) at baseline. At baseline, QTaVI was significantly greater in the HG group compared to the EG group [-0.17 (0.92) vs. -1.07 (0.90); p < 0.05]. After TRT, this group difference was no longer present [-0.44 (0.87) vs. -0.65 (0.85)] and the change in the HG group was significant (p < 0.05).

CONCLUSION

Hypogonadism in men with SCI was associated with elevated QTaVI at baseline. After 12 months of physiological TRT, the QTaVI improved in association with raising T into the normal range. These findings occurred independently of the prolongation of the QT interval.

Androgen therapy in men with testosterone deficiency: can testosterone reduce the risk of cardiovascular disease?

Obesity, hypertension, insulin resistance (IR), dyslipidaemia, impaired coagulation profile and chronic inflammation characterize cardiovascular risk factors in men. Adipose tissue is an active endocrine organ producing substances that suppress testosterone (T) production and visceral fat plays a key role in this process. Low T leads to further accumulation of fat mass, thus perpetuating a vicious circle. In this review, we discuss reduced levels of T and increased cardiovascular disease (CVD) risk factors by focusing on evidence derived from three different approaches. (i) epidemiological/ observational studies (without intervention); (ii) androgen deprivation therapy (ADT) studies (standard treatment in advanced prostate cancer); and (iii) T replacement therapy (TRT) in men with T deficiency (TD). In epidemiological studies, low T is associated with obesity, inflammation, atherosclerosis and the progression of atherosclerosis. Longitudinal epidemiological studies showed that low T is associated with an increased cardiovascular mortality. ADT brings about unfavourable changes in body composition, IR and dyslipidaemia. Increases in fibrinogen, plasminogen activator inhibitor 1 and C-reactive protein have also been observed. TRT in men with TD has consistently shown a decrease in fat mass and simultaneous increase in lean mass. T is a vasodilator and in long-term studies, it was shown to reduce blood pressure. There is increasing evidence that T treatment improves insulin sensitivity and lipid profiles. T may possess anti-inflammatory and anti-coagulatory properties and therefore TRT contributes to reduction of carotid intima media thickness. We suggest that T may have the potential to decrease CVD risk in men with androgen deficiency.

Plasma testosterone is associated with Framingham risk score

INTRODUCTION

The Framingham risk score predicts a patient's 10-year risk of developing cardiovascular disease. Many risk factors included in its calculation influence or are influenced by circulating testosterone. To investigate the possible association between testosterone and cardiovascular risk, as defined by the Framingham score, a Veterans Affairs (VA) database was analyzed.

METHODS

A retrospective chart review was performed. Inclusion criteria were male sex and age ≥ 20 years. Exclusion criteria included pre-existing cardiovascular disease, stroke, and diabetes. Data were collected on veterans who had total plasma testosterone checked in the year 2008.

RESULTS

The study included 1,479 patients (mean age 61 years). Framingham score was negatively associated with both total testosterone (p < 0.0001) and free testosterone (p = 0.0003). There was a positive association between total testosterone and high-density lipoprotein and negative associations between total testosterone and body mass index (BMI), total cholesterol, triglycerides, and blood pressure medication use. Free testosterone was positively associated with total cholesterol, low-density lipoprotein, and current smoking status and negatively associated with age, BMI, and blood pressure medication use. The BMI was not associated with Framingham score.

CONCLUSIONS

Lower plasma testosterone may suggest the presence of cardiovascular risk factors and potentially increased risk for heart disease.

Testosterone replacement therapy improves erythrocyte membrane lipid composition in hypogonadal men

AIM

The aim of this study was to investigate the effects of testosterone replacement therapy (TRT) on erythrocyte membrane (EM) lipid composition and physico-chemical properties in hypogonadal men.

METHODS

EM isolated from three patients before and after TRT with injectable testosterone undecanoate or testosterone gel were used for analysis of the phospholipid and fatty acid composition, cholesterol/phospholipid ratio, membrane fluidity, ceramide level and enzyme activities responsible for sphingomyelin metabolism.

RESULTS

TRT induced increase of phosphatidylethanolamine (PE) in the EMs and sphingomyelin. Reduction of the relative content of the saturated palmitic and stearic fatty acids and a slight increase of different unsaturated fatty acids was observed in phosphatidylcholine (PC). TRT also induced decrease of the cholesterol/total phospholipids ratio and fluidization of the EM.

DISCUSSION

The TRT induced increase of PE content and the reduction of saturation in the PC acyl chains induced alterations in the structure of EM could result in higher flexibility of the erythrocytes. The increase of the SM-metabolizing enzyme neutral sphingomyelinase, which regulates the content of ceramide in membranes has a possible impact on the SM signaling pathway.

CONCLUSION

We presume that the observed effect of TRT on the composition and fluidity of the EM contributes for improvement of blood rheology and may diminish the thrombosis risk. Larger studies are needed to confirm the findings of this pilot study.

Hypogonadism in the aging male diagnosis, potential benefits, and risks of testosterone replacement therapy

Hypogonadism in older men is a syndrome characterized by low serum testosterone levels and clinical symptoms often seen in hypogonadal men of younger age. These symptoms include decreased libido, erectile dysfunction, decreased vitality, decreased muscle mass, increased adiposity, depressed mood, osteopenia, and osteoporosis. Hypogonadism is a common disorder in aging men with a significant percentage of men over 60 years of age having serum testosterone levels below the lower limits of young male adults. There are a variety of testosterone formulations available for treatment of hypogonadism. Data from many small studies indicate that testosterone therapy offers several potential benefits to older hypogonadal men. A large multicenter NIH supported double blind, placebo controlled study is ongoing, and this study should greatly enhance the information available on efficacy and side effects of treatment. While safety data is available across many age groups, there are still unresolved concerns associated with testosterone therapy. We have reviewed the diagnostic methods as well as benefits and risks of testosterone replacement therapy for hypogonadism in aging men.