Testosterone and metabolic syndrome

Testosterone and aging male, a perspective from a developing country

PURPOSE

Hypogonadism is associated with a wide range of physical and psychological symptoms that can affect the overall health of men. However, in a developing country, there are several imposing challenges in the diagnosis and treatment of hypogonadism, including a lack of awareness and understanding of the condition among healthcare providers and patients, limited resources and the high cost of treatment. This review aimed to examine the potential benefits and risks of testosterone replacement therapy (TRT) and provides a perspective of a developing country on the topic.

MATERIALS AND METHODS

A comprehensive literature review was conducted to gather relevant information on the impact of testosterone deficiency on ageing males and the effectiveness of TRT for treating hypogonadism. Published peer-reviewed articles were analyzed to evaluate the benefits and risks of TRT. Additionally, the unique challenges faced in the diagnosis and treatment of hypogonadism in a developing country were considered.

RESULTS

Testosterone replacement therapy has been shown to be an effective treatment for hypogonadism, particularly in symptomatic men with low testosterone levels. It offers potential benefits such as improvements in symptoms and overall quality of life. However, there are associated risks and side effects that need to be considered. In a developing country, challenges such as limited awareness and understanding of hypogonadism, resource constraints, and high treatment costs pose additional barriers to accessing TRT and comprehensive care.

CONCLUSION

In conclusion, TRT holds promise as a treatment for hypogonadism, but its implementation and accessibility face significant challenges in a developing country. Addressing these challenges, including raising awareness, allocating resources, and finding cost-effective solutions, is crucial for ensuring that men with hypogonadism in such settings receive appropriate diagnosis and treatment. Further research and efforts are needed to improve the management of hypogonadism in developing countries and optimize the potential benefits of TRT for affected individuals.

Valproate-Induced Metabolic Syndrome

Valproic acid (VPA) and its salts (sodium calcium magnesium and orotic) are psychotropic drugs that are widely used in neurology and psychiatry. The long-term use of VPA increases the risk of developing adverse drug reactions (ADRs), among which metabolic syndrome (MetS) plays a special role. MetS belongs to a cluster of metabolic conditions such as abdominal obesity, high blood pressure, high blood glucose, high serum triglycerides, and low serum high-density lipoprotein. Valproate-induced MetS (VPA-MetS) is a common ADR that needs an updated multidisciplinary approach to its prevention and diagnosis. In this review, we consider the results of studies of blood (serum and plasma) and the urinary biomarkers of VPA-MetS. These metabolic biomarkers may provide the key to the development of a new multidisciplinary personalized strategy for the prevention and diagnosis of VPA-MetS in patients with neurological diseases, psychiatric disorders, and addiction diseases.

Association of blood metals with serum sex hormones in adults: A cross-sectional study

Heavy metals such as lead, mercury, and cadmium have been identified to have negative impacts on human health. Although the individual effects of these metals have been extensively researched, the present study aims to explore their combined effects and their association with serum sex hormones among adults. Data for this study were obtained from the general adult population of the 2013-2016 National Health and Nutrition Survey (NHANES) and included five metal (mercury, cadmium, manganese, lead, and selenium) exposures and three sex hormones (total testosterone [TT], estradiol [E2], and sex hormone-binding globulin [SHBG]) levels. The free androgen index (FAI) and TT/E2 ratio were also calculated. The relationships between blood metals and serum sex hormones were analysed using linear regression and restricted cubic spline regression. The effect of blood metal mixtures on sex hormone levels was examined using the quantile g-computation (qgcomp) model. There were 3,499 participants in this study, including 1,940 males and 1,559 females. In males, positive relationships between blood cadmium and serum SHBG (β=0.049 [0.006, 0.093]), lead and SHBG (β=0.040 [0.002, 0.079]), manganese and FAI (β=0.080 [0.016, 0.144]), and selenium and FAI (β=0.278 [0.054, 0.502]) were observed. In contrast, manganese and SHBG (β=-0.137 [-0.237, -0.037]), selenium and SHBG (β=-0.281 [-0.533, -0.028]), and manganese and TT/E2 ratio (β=-0.094 [-0.158, -0.029]) were negative associations. In females, blood cadmium and serum TT (β=0.082 [0.023, 0.141]), manganese and E2 (β=0.282 [0.072, 0.493]), cadmium and SHBG (β=0.146 [0.089, 0.203]), lead and SHBG (β=0.163 [0.095, 0.231]), and lead and TT/E2 ratio (β=0.174 [0.056, 0.292]) were positive relationships, while lead and E2 (β=-0.168 [-0.315, -0.021]) and FAI (β=-0.157 [-0.228, -0.086]) were negative associations. This correlation was stronger among elderly women (>50 years old). The qgcomp analysis revealed that the positive effect of mixed metals on SHBG was mainly driven by cadmium, while the negative effect of mixed metals on FAI was mainly driven by lead. Our findings indicate that exposure to heavy metals may disrupt hormonal homeostasis in adults, particularly in older women.

The effects of alcohol on testosterone synthesis in men: a review

INTRODUCTION

Testosterone concentrations in men decline with advancing age, with low testosterone concentrations being associated with multiple morbidities, an increased risk of early mortality, and a reduced quality of life. The purpose of this study was to examine the effects of alcohol on testosterone synthesis in men by investigating its effects on each level of the hypothalamic-pituitary-gonadal axis.

AREAS COVERED

Acute consumption of a low-to-moderate amount of alcohol increases testosterone concentrations in men, while consumption of a large volume of alcohol is associated with a reduction in serum testosterone concentrations. Elevated testosterone concentrations result from the increased activity of detoxification enzymes in the liver. Conversely, the primary mechanisms of action involved in the reduction of testosterone are increased hypothalamic-pituitary-adrenal axis activity, inflammation, and oxidative stress. When alcohol is consumed in excess, particularly chronically, it negatively affects testosterone production in men.

EXPERT OPINION

Since testosterone is an important component of men's health and wellbeing, current levels of alcohol consumption in many countries of the world require urgent attention. Elucidating the relationship between alcohol consumption and testosterone may be useful in identifying strategies to attenuate the testosterone-reducing effects of excessive or chronic alcohol consumption.

Effects of perchlorate, nitrate, and thiocyanate exposures on serum total testosterone in children and adolescents

Perchlorate, nitrate, and thiocyanate are common thyroid disruptors in daily life and alter testosterone levels in animals. However, little is known about the effects of perchlorate, nitrate, and thiocyanate on serum total testosterone (TT) in the general population. The study was designed to assess the associations between urinary levels of perchlorate, nitrate, and thiocyanate and serum total testosterone (TT) in the general population. The present study utilized data from the 2011-2016 National Health and Nutritional Examination Survey (NHANES). A total of 6201 participants aged 6-79 with information on urinary perchlorate, nitrate, thiocyanate, and serum total testosterone were included. We conducted multiple linear regression models and Bayesian Kernel Machine Regression (BKMR) models to estimate the associations by sex-age groups. Children (ages 6-11) have higher levels of perchlorate and nitrate than the rest. After adjusting for covariates, urinary perchlorate was significantly negatively associated with serum TT in male adolescents (β = -0.1, 95 % confidence interval: -0.2, -0.01) and female children [-0.13, (-0.21, -0.05)]. Urinary nitrate was significantly negatively associated with serum TT in female children, while urinary thiocyanate was significantly positively associated with serum TT in female adults aged 20 to 49 [0.05 (0.02, 0.08)]. BKMR analysis indicated that no other interactions were found between urinary perchlorate, nitrate, and thiocyanate. Our findings suggested that urinary perchlorate, nitrate, and thiocyanate levels may relate to serum total testosterone levels in specific sex-age groups. We identified male adolescents and female children as are most sensitive subgroups where testosterone is susceptible to interference.

The Mechanisms and Management of Age-Related Oxidative Stress in Male Hypogonadism Associated with Non-communicable Chronic Disease

Androgens have diverse functions in muscle physiology, lean body mass, the regulation of adipose tissue, bone density, neurocognitive regulation, and spermatogenesis, the male reproductive and sexual function. Male hypogonadism, characterized by reduced testosterone, is commonly seen in ageing males, and has a complex relationship as a risk factor and a comorbidity in age-related noncommunicable chronic diseases (NCDs), such as obesity, metabolic syndrome, type 2 diabetes, and malignancy. Oxidative stress, as a significant contributor to the ageing process, is a common feature between ageing and NCDs, and the related comorbidities, including hypertension, dyslipidemia, hyperglycemia, hyperinsulinemia, and chronic inflammation. Oxidative stress may also be a mediator of hypogonadism in males. Consequently, the management of oxidative stress may represent a novel therapeutic approach in this context. Therefore, this narrative review aims to discuss the mechanisms of age-related oxidative stress in male hypogonadism associated with NCDs and discusses current and potential approaches for the clinical management of these patients, which may include conventional hormone replacement therapy, nutrition and lifestyle changes, adherence to the optimal body mass index, and dietary antioxidant supplementation and/or phytomedicines.

Obesity Is Strongly Associated With Low Testosterone and Reduced Penis Growth During Development

CONTEXT

Growth of male genitalia represents an important marker of sexual development. Testicle size is the primary measure and little is known regards penile length changes during puberty.

OBJECTIVE

This work aims to assess penis growth and testosterone levels in obese vs normal-weight children and adolescents, to evaluate a possible influence of obesity on genital development in boys, and to establish a new method for measuring penis length that allows comparison of normal-weight and overweight boys.

METHODS

We assessed anthropometric and genital development in 1130 boys from birth to age 20 years. Testosterone levels were also measured. A new method for penile length measurement was employed to minimize errors when comparing obese and nonobese children. Penis length was measured with a gentle, painless, straight positioning on a centimetric ruler without stretching, which is doable from the first years of life until the end of adolescence.

RESULTS

Penis length and testosterone are strongly related in children during puberty. Penile length growth is significantly decreased (by about 10%) in obese boys when compared to normal-weight boys, with concomitantly reduced testosterone levels, across puberal phases.

CONCLUSION

Childhood obesity represents an important determinant of lower testosterone level and reduced penis development. A new method should be employed to improve penis measurement in normal-weight and overweight/obese boys. The possible significance of these observations for adult genital development and reproductive potential will require large longitudinal studies.

Association Between Low Serum Testosterone and the Development of Metabolic Syndrome in Elderly Taiwanese Men

PURPOSE

To assess the association between serum testosterone (T) and metabolic syndrome (MS) in different age groups in Taiwanese men.

MATERIALS AND METHODS

Male participants, regardless of age or any underlying disease, were identified from MJ Health Screening Center in Taiwan from 2007 to 2016 for this cross-sectional study. They were divided into three groups according to age, and further classified according to MS diagnosis. Basic patient characteristics with relevant parameters were obtained. One-way ANOVA of mean T values between different numbers of measures that exceeds the cut-off values of MS components was performed to assess the relationship of T and MS. Logistic regression analysis was also used to estimate the risk for MS with each increment in T, age, and BMI.

RESULTS

A total of 4,931 men were included. The MS group had significantly lower serum T levels compared to the non-MS group in each age group. The one-way ANOVA found the mean value of T was significantly higher in patients without MS component (6.19±2.12 ng/mL) than those with 1-5 MS components (with one MS component: 5.48±2.13 ng/mL, two MS components: 4.93±2.03 ng/mL, three MS components: 4.37±1.60 ng/mL, four MS components: 4.13±2.89 ng/mL, five MS components: 3.74±1.27 ng/mL, and P<0.001). There was no significant difference between the patients with three components and the patients with four or five components. Logistic regression models with age stratification showed T with lower odds ratio (OR) for MS after adjusting for BMI in those ≥65 years old (OR=0.693; 95% CI=0.559-0.858; P<0.001); 50-64 years old (OR=0.868; 95% CI=0.802-0.940; P<0.001) and <50 years old (OR=0.810; 95% CI=0.758-0.865; P<0.001).

CONCLUSION

Lower serum T was strongly associated with MS, with the predictive value increasing with age in Taiwanese men.

Association between sex hormones and kidney stones: analysis of the National Health and Nutrition Examination Survey

PURPOSE

Increasing age, male gender, and metabolic syndrome are associated with kidney stone formation. As sex hormones change with age, gender, and metabolic syndrome, we hypothesized that sex hormones may underlie the physiologic changes affecting stone formation.

METHODS

We analyzed the relationships between testosterone, estradiol, and history of kidney stones using data from 10,193 participants in the Continuous National Health and Nutrition Examination Survey (NHANES) database from 2013-2016. We performed logistic regression analysis to analyze the predictive value of low testosterone and low estradiol on the history of kidney stones in both males and females. Self-reported history of kidney stone diagnosis was the outcome.

RESULTS

After adjusting for risk factors known to be associated with nephrolithiasis such as age, race, BMI, and medical comorbidities including: gout, angina, coronary disease, stroke, asthma, hypertension, and diabetes, multiple regression analysis demonstrated that there is no independent association between sex hormones (testosterone and estradiol) and history of kidney stones in either males or females.

CONCLUSIONS

There appears to be no association between sex hormones and history of kidney stones. Whether there is a more complex interaction of sex hormone levels and the shared association with factors such as metabolic syndrome requires additional investigation. Further studies matching menopausal status for women are necessary to further investigate the potential relationship between estrogen and kidney stones.

The Effects of Androgens on Cardiometabolic Syndrome: Current Therapeutic Concepts

INTRODUCTION

Cardiometabolic syndrome (CMS), as a bunch of metabolic disorders mainly characterized by type 2 diabetes mellitus (T2DM), hypertension, atherosclerosis, central adiposity, and abdominal obesity triggering androgen deficiency, is one of the most critical threats to men. Although many significant preclinical and clinical findings explain CMS, new approaches toward common pathophysiological mechanisms and reasonable therapeutic targets are lacking.

AIM

To gain a further understanding of the role of androgen levels in various facets of CMS such as the constellation of cardiometabolic risk factors including central adiposity, dyslipidemia, insulin resistance, diabetes, and arterial hypertension and to define future directions for development of effective therapeutic modalities.

METHODS

Clinical and experimental data were searched through scientific literature databases (PubMed) from 2009 to October 2019.

MAIN OUTCOME MEASURE

Evidence from basic and clinical research was gathered with regard to the causal impact and therapeutic roles of androgens on CMS.

RESULTS

There are important mechanisms implicated in androgen levels and the risk of CMS. Low testosterone levels have many signs and symptoms on cardiometabolic and glycometabolic risks as well as abdominal obesity in men.

CLINICAL IMPLICATIONS

The implications of the findings can shed light on future improvements in androgen levels and add potentially predictive risk for CMS, as well as T2DM, abdominal obesity to guide clinical management in the early stage.

STRENGTHS & LIMITATIONS

This comprehensive review refers to the association between androgens and cardiovascular health. A limitation of this study is the lack of large, prospective population-based studies that analyze the effects of testosterone treatment on CMS or mortality.

CONCLUSION

Low testosterone levels have several common features with metabolic syndrome. Thus, testosterone may have preventive role in the progress of metabolic syndrome and subsequent T2DM, abdominal obesity, and cardiovascular disease and likely affect aging men's health mainly through endocrine and vascular mechanisms. Further studies are necessary to evaluate the therapeutic interventions directed at preventing CMS in men. Kirlangic OF, Yilmaz-Oral D, Kaya-Sezginer E, et al. The Effects of Androgens on Cardiometabolic Syndrome: Current Therapeutic Concepts. Sex Med 2020;8:132-155.

Association of Changes in Metabolic Syndrome Status With the Incidence of Thyroid Nodules: A Prospective Study in Chinese Adults

Although several cross-sectional studies have shown an association of metabolic syndrome (MetS) with nodular thyroid disease, related prospective studies are scarce. This study investigated the association of MetS with thyroid nodule (TN) incidence in Chinese adults, and explored whether the development of or recovery from MetS is associated with changes in the risk of developing TNs. A total of 4,749 Chinese aged 18-65 years were involved in this 6-year prospective study. The association of MetS with TN prevalence was examined. TN-free individuals at baseline (n = 3,133) were further examined. TN incidence rates in groups with different MetS statuses (MetS-free, MetS-developed, MetS-recovery and MetS-chronic) were analyzed. Of all participants, 18.21 and 31.65% had MetS and TNs, respectively. MetS patients had a higher TN prevalence than the non-MetS group (31.08 vs. 19.81% in males, p < 0.01; 59.52 vs. 39.59% in females, p < 0.01). Sex, age and MetS were independent risk factors for TNs. At a median follow up of 5.94 years, the MetS-chronic group (4.37/100 person-years) had a higher risk of TNs (adjusted incidence rate ratio [IRR] = 1.288 [95% CI 1.014-1.636]) compared with the MetS-free group (2.72/100 person-years) in the whole cohort. In males, the MetS-chronic group (3.76/100 person-years) had a higher risk of TNs (adjusted IRR = 1.367 [95% CI 1.017-1.835]) compared with the MetS-free group (2.31/100 person-years). In females, the risk of TNs was significantly higher in the MetS-chronic (6.44/100 person-years) and MetS-developed (6.31/100 person-years) groups compared with the MetS-free group (3.23/100 person-years).

Associations between Handgrip Strength with Adverse Cardiometabolic Health among Representative Korean Adults

Reduced muscle mass and strength are notable features of aging. Loss of muscle mass contributes to cardiometabolic health. Although many studies have focused on skeletal muscle mass, it remains unclear whether muscle strength is beneficial for cardiometabolic health. We aimed to investigate the association between handgrip strength and the risk of adverse cardiometabolic health in middle-aged and older adults in the Korean general population. The study participants included 7602 adults from the Korea National Health and Nutritional Examination Survey (KNHANES). The odds ratio for adverse cardiometabolic health significantly and linearly decreased according to the category of handgrip strength adjusted for potential confounding factors (p-Value < 0.05). In the stratified models by sex we also observed significant associations between handgrip strength and cardiometabolic health in men (p-Value < 0.001), but not in women. Our findings suggest that maintaining higher handgrip strength may contribute to improved cardiometabolic health.

Factors Associated with Bothersome Lower Urinary Tract Symptoms in Middle-Aged Men Receiving Health Checkup

The prospective study is to investigate the associations between serum testosterone levels and LUTS among middle-aged men ≥40 years receiving health check-up. Lower urinary tract symptoms were evaluated by the self-administered International Prostate Symptom Score questionnaire. Serum prostate specific antigen and total testosterone level were checked in all subjects. A total of 1752 men were enrolled into the study. The mean age was 55.6 ± 9.7 years. All study subjects were stratified into low, medium and high testosterone levels by two cut-off, 3.0 and 4.11 ng/mL. We found that testosterone levels were significantly associated with metabolic syndrome and body fat components. Compared to those with low testosterone levels, subjects with high and medium testosterone had a significantly higher IPSS (5.84 ± 5.55 vs 6.71 ± 5.68 and 6.34 ± 5.66, p = 0.032) and storage score (2.76 ± 2.29 vs 3.20 ± 2.49 and 2.90 ± 2.49; p = 0.009), and a more moderate/severe LUTS (IPSS ≧ 8) (26.5% vs 35.7% and 29.9%; p = 0.002). Multivariate analyses showed that high vs low testosterone levels (OR, 1.76; 95% CI, 1.26–2.45) and prostate volume ≧25 vs <25 mL (OR, 1.38; 95% CI, 1.04–1.82) significantly associated with the presence of moderate/severe LUTS. Pearson correlation analyses showed significantly positive correlations between testosterone level and IPSS in whole study sample (Pearson correlation coefficient, 0.066; p < 0.01) and in the subgroup of moderate/severe LUTS (Pearson correlation coefficient, 0.038; p < 0.05). In conclusion, high testosterone and prostate volume adversely impacted LUTS in our target population.

Sexual functioning and depressive symptoms in men with various types of prediabetes: a pilot study

No study has compared sexual functioning and depressive symptoms in male subjects with various types of prediabetes. Our study included four age- and weight-matched groups of apparently healthy men (25-50 years old): subjects with isolated impaired fasting glucose (IFG) (n = 16), men with isolated impaired glucose tolerance (n = 17), individuals with the presence of both IFG and impaired glucose tolerance (n = 16), as well as men with normal glucose tolerance (n = 18). All included men completed questionnaires evaluating male sexual functioning (IIEF-15) and assessing the presence and severity of depressive symptoms (BDI-II). Men with both IFG and impaired glucose tolerance obtained lower domain scores for erectile function, sexual desire, and overall satisfaction, as well as the higher overall BDI-II score. Individuals with isolated impaired glucose tolerance (IGT) and IFG were characterized by lower domain score only for sexual desire. In all study groups, domain score for erectile function correlated with the BDI-II score, while scores for erectile function and sexual desire correlated with a degree of insulin resistance. The obtained results suggest that prediabetes may impair sexual functioning in young men. The risk is particularly high in individuals with the presence of both IFG and IGT.

Impact of Testosterone Deficiency and Testosterone Therapy on Lower Urinary Tract Symptoms in Men with Metabolic Syndrome

Lower urinary tract function is modulated by neural, vascular and urethral and bladder structural elements. The pathophysiological mechanisms of lower urinary tract symptoms (LUTS) encompass prostate enlargement, alterations in urethra histological structure bladder fibrosis and alterations in pelvic neuronal and vascular networks, The complex pathophysiological relationship between testosterone (T) deficiency (TD) and the constellations LUTS, and metabolic dysfunction manifested in the metabolic syndrome (Met S) remains poorly understood. TD has emerged as one the potential targets by which Met S may contribute to the onset and development as well as worsening of LUTS. Because it has been recognized that treatment of men with Met S with T therapy ameliorates Met S components, it is postulated that T therapy may represent a therapeutic target in improving LUTS. Furthermore, the effect of TD on the prostate remains unclear, and often debatable. It is believed that T exclusively promotes prostate growth, however recent evidence has strongly contradicted this belief. The true relationship between benign prostatic hyperplasia, TD, and LUTS remains elusive and further research will be required to clarify the role of T in both benign prostatic hypertrophy (BPH) and LUTS as a whole. Although there is conflicting evidence about the benefits of T therapy in men with BPH and LUTS, the current body of literature supports the safety of using this therapy in men with enlarged prostate. As the population afflicted with obesity epidemic continues to age, the number of men suffering from Met S and LUTS together is expected to increase.

The 13C-Glucose Breath Test for Insulin Resistance Assessment in Adolescents: Comparison with Fasting and Post-Glucose Stimulus Surrogate Markers of Insulin Resistance

OBJECTIVE

To evaluate the use of the 13C-glucose breath test (13C-GBT) for insulin resistance (IR) detection in adolescents through comparison with fasting and post-glucose stimulus surrogates.

METHODS

One hundred thirty-three adolescents aged between 10 and 16 years received an oral glucose load of 1.75 g per kg of body weight dissolved in 150 mL of water followed by an oral dose of 1.5 mg/kg of U-13C-Glucose, without a specific maximum dose. Blood samples were drawn at baseline and 120 minutes, while breath samples were obtained at baseline and at 30, 60, 90, 120, 150, and 180 minutes. The 13C-GBT was compared to homeostasis model assessment (HOMA) IR (≥p95 adjusted by gender and age), fasting plasma insulin (≥p90 adjusted by gender and Tanner stage), results of 2-h oral glucose tolerance test (OGTT), insulin levels (≥65 μU/mL) in order to determine the optimal cut-off point for IR diagnosis.

RESULTS

13C-GBT data, expressed as adjusted cumulative percentage of oxidized dose (A% OD), correlated inversely with fasting and post-load IR surrogates. Sexual development alters A% OD results, therefore individuals were stratified into pubescent and post-pubescent. The optimal cut-off point for the 13C-GBT in pubescent individuals was 16.3% (sensitivity=82.8% & specificity=60.6%) and 13.0% in post-pubescents (sensitivity=87.5% & specificity=63.6%), when compared to fasting plasma insulin. Similar results were observed against HOMA and 2-h OGTT insulin.

CONCLUSION

The 13C-GBT is a practical and non-invasive method to screen for IR in adolescents with reasonable sensitivity and specificity.

Testosterone deficiency in the aging male

Treatment for hypogonadism is on the rise, particularly in the aging population. Yet treatment in this population represents a unique challenge to clinicians. The physiology of normal aging is complex and often shares the same, often vague, symptoms of hypogonadism. In older men, a highly prevalent burden of comorbid medical conditions and polypharmacy complicates the differentiation of signs and symptoms of hypogonadism from those of normal aging, yet this differentiation is essential to the diagnosis of hypogonadism. Even in older patients with unequivocally symptomatic hypogonadism, the clinician must navigate the potential benefits and risks of treatment that are not clearly defined in older men. More recently, a greater awareness of the potential risks associated with treatment in older men, particularly in regard to cardiovascular risk and mortality, have been appreciated with recent changes in the US Food and Drug Administration recommendations for use of testosterone in aging men. The aim of this review is to provide a framework for the clinician evaluating testosterone deficiency in older men in order to identify correctly and treat clinically significant hypogonadism in this unique population while minimizing treatment-associated harm.

Controversies in testosterone supplementation therapy

Testosterone has now become one of the most widely used medications throughout the world. The rapid growth of the testosterone market in the past 10 years is due to many factors. We currently have a worldwide aging population. In the US, the number of men 65 years old or older is increasing 2–3 times faster than the number of men younger than 65 years. In addition, poor general health and certain medical conditions such as diabetes/metabolic syndrome (MetS), cardiovascular disease (CVD), and osteoporosis have been associated with low serum testosterone levels.123 There are now fewer concerns regarding the development of prostate cancer (PCa) after testosterone therapy, making it a more attractive treatment option. Finally, the introduction of different forms of testosterone supplementation therapy (TST) with increased promotion, marketing, and direct-to-consumer advertising is also driving market growth. As the demand for TST continues to grow, it is becoming more important for clinicians to understand how to diagnose and treat patients with low testosterone.

Protective effects of metformin on reproductive function in obese male rats induced by high-fat diet

PURPOSE

The study aims to elucidate the changes in testicular spermatogenic function in high-fat diet (HFD)-induced obese rats and to evaluate the protective effects of metformin intervention.

METHODS

Male Sprague-Dawley rats (n = 18) were randomly divided into a control group (standard diet), an HFD group, and a metformin group (HFD + metformin at 100 mg/kg, once daily by oral gavage). After 8 weeks, rats were euthanized, and the weights of body and testes were measured. Testis and epididymis were dissected and hematoxylin-eosin-stained for histopathological examination and semen parameter analysis. Blood samples were collected for assessment of sex hormones and metabolic parameters (serum glucose, insulin, and leptin). Spermatogenic cell apoptosis was accessed by TUNEL.

RESULTS

Compared with the control group, the final body weight and weight gain were significantly higher in HFD rats, while the testicle weight and coefficients were lower. In HFD rats, metformin treatment induced weight loss and increased testicle weight (P < 0.05). In HFD rats, obvious pathological changes in the testicular tissue were characterized by small, atrophic, and distorted seminiferous tubules and destroyed basement membrane. Metformin treatment protected against the HFD-induced decrease in the number of spermatogonia, Sertoli cells, and Leydig cells (P < 0.05); ameliorated the HFD-induced increases in serum glucose, insulin, leptin, and estrogen; and decreased serum testosterone (P < 0.05) and reduced the rate of testicular cell apoptosis in obese male rats. Finally, metformin significantly improved semen parameters (including concentration, viability, motility, and normal morphology) in HFD rats (P < 0.05).

CONCLUSIONS

HFD-induced obesity in rats results in detrimental effects on spermatogenesis, semen quality, endogenous hormones, and testicular cell apoptosis. Metformin intervention improved the semen parameters, possibly due to its effects on weight loss, increased testicular weight, reduced testicular cell apoptosis, and resulted in restoration of hormonal homeostasis and correction of metabolic disorder.

Can Serum Testosterone Be Used as a Marker of Overall Health?

Low serum testosterone has been associated with obesity, type 2 diabetes, metabolic syndrome, and atherosclerosis. Individuals with these comorbidities are at increased risk of premature death and other adverse health effects. Clinical data portend low testosterone as a risk factor for developing these conditions which are supported by the hypogonadal-obesity-adipocytokine hypothesis. The authors support comprehensive evaluation for these comorbid conditions in men found to have low serum testosterone.