Evaluation of the hypothalamic-pituitary-gonadal axis in eugonadal men with type 2 diabetes mellitus

Impact of metabolic syndrome factors on sperm DNA fragmentation in males from infertile couples: A systematic review and meta-analysis

PURPOSE

To investigate the impact of metabolic syndrome factors on sperm DNA fragmentation (sDF) in males from infertile couples.

METHODS

A systematic literature search was performed across ten databases for literature published from January 1, 2013 until September 13, 2023. The protocol has been registered on PROSPERO (CRD42023458359), and the literature search strategy is adhered to the PRISMA framework. Studies that evaluated sDF, as indicated by DNA fragmentation index (%DFI), in males from infertile couples in relation to metabolic syndrome factors were included. Meta-analysis, using random effects model and Bayesian framework network, was performed, and data were presented as Standardized Mean Differences (SMD) with corresponding 95 % Confidence Interval (CI).

RESULTS

Of the 2579 citations identified, eleven studies were included in this meta-analysis. The findings revealed that the %DFI was not associated with overall metabolic syndrome factors (p-tot = 0.235; SMD = 0.57 [95 %CI: -0.37, 1.52]), metabolic syndrome status (p-tot = 0.337; SMD = 0.08 [95 %CI: -0.08, 0.24), increased body mass index (p-tot = 0.237; SMD = 0.71 [95 %CI: -0.47, 1.89]), or glycaemic profile (p-tot = 0.93; SMD = 0.13 [95 %CI: -2.72, 2.98]). High levels of heterogeneity were observed (p < 0.01) in all subgroups, except for metabolic syndrome status.

CONCLUSION

The association between metabolic syndrome factors and sDF is conflicting. However, interpreting the association requires caution, as confounding factors, indicated by high heterogeneity, may conceal the outcome. Metabolic syndrome may influence other factors contributing to male infertility, highlighting the importance of promoting a healthy lifestyle.

Synergistic Effects of Vitamin D and Exercise on Diabetes-induced Gonadotoxicity in Male Wistar Rats: Role of Xanthine Oxidase/Uric Acid and Nrf2/NfkB Signaling

Type 2 Diabetes mellitus (T2DM) is one of the oldest known chronic diseases, characterized by elevated fasting blood sugar (FBS). T2DM is a metabolic disorder that can distort the activities of multiple physiological systems, including the reproductive system. Although different drugs have been designed for managing this disorder, these drugs have been reported to have negative side effects. Hence, this study was designed to explore the possible synergistic effect of vitamin D and exercise on T2DM-induced testicular dysfunction. Thirty-six male Wistar rats were randomized into six (6) groups: control, diabetes untreated, diabetes treated with 1000 IU/kg of vitamin D, diabetes treated with 5 min/day of physical exercise, diabetes treated with vitamin D and exercise, diabetes treated with 180 mg/kg of metformin. T2DM induction led to a significant increase in FBS, lactate, and lactate dehydrogenase, and was reversed by vitamin D supplementation and exercise. Also, vitamin D and exercise synergistically blunted T2DM-induced oxido-inflammatory response evidenced by a significant decrease in testicular malondialdehyde, interleukin 1β, interleukin 6, and tumor necrosis factor alpha, and an increase in superoxide dismutase, catalase, glutathione peroxidase, and interleukin 10. These events were associated with a decrease in T2DM-induced increase in XO, UA, and Nf-κb and an increase in T2DM-induced decrease in Nrf2. Also, vitamin D and EX reversed the observed impairment in sperm quality and testicular histology following T2DM-induction. This study revealed the synergistic effect of vitamin D and exercise on T2DM-induced testicular dysfunction.

Role of sex hormones in diabetic nephropathy

Diabetic nephropathy (DN) is the most common microvascular complication in diabetes and one of the leading causes of end-stage renal disease. The standard treatments for patients with classic DN focus on blood glucose and blood pressure control, but these treatments can only slow the progression of DN instead of stopping or reversing the disease. In recent years, new drugs targeting the pathological mechanisms of DN (e.g., blocking oxidative stress or inflammation) have emerged, and new therapeutic strategies targeting pathological mechanisms are gaining increasing attention. A growing number of epidemiological and clinical studies suggest that sex hormones play an important role in the onset and progression of DN. Testosterone is the main sex hormone in males and is thought to accelerate the occurrence and progression of DN. Estrogen is the main sex hormone in females and is thought to have renoprotective effects. However, the underlying molecular mechanism by which sex hormones regulate DN has not been fully elucidated and summarized. This review aims to summarize the correlation between sex hormones and DN and evaluate the value of hormonotherapy in DN.

Testosterone deficiency and the aging male

Testosterone deficiency (TD), also known as male hypogonadism, is a complex syndrome encompassing physical, biochemical, and social aspects that increasingly affects the aging population. TD has been analyzed over recent decades, with an enhanced focus on etiologies relating to aging males. There is debate whether testosterone decline leading to hypogonadism is directly and primarily related to age-specific processes or if it is the subsequent result of accumulating comorbidities throughout a lifetime. Several studies have been done to further characterize this distinction. Chronic comorbidities that have commonly been associated with TD include hypertension (HTN), cardiovascular disease (CVD), diabetes mellitus (DM), obesity, metabolic syndrome (MetS), chronic kidney disease (CKD), and tobacco use. Although clear associations between hypogonadism and aging have been biochemically demonstrated, many large studies have illustrated the concomitant effects of highly prevalent chronic diseases and social behaviors in aging men. Given the significant impact of hypogonadism on the physical and mental health of men, this paper aims to delve into these studies and further define the complex relationship of testosterone deficiency in the aging male.

Effect of spermidine on ameliorating spermatogenic disorders in diabetic mice via regulating glycolysis pathway

Diabetes mellitus (DM), a high incidence metabolic disease, is related to the impairment of male spermatogenic function. Spermidine (SPM), one of the biogenic amines, was identified from human seminal plasma and believed to have multiple pharmacological functions. However, there exists little evidence that reported SPM's effects on moderating diabetic male spermatogenic function. Thus, the objective of this study was to investigate the SPM's protective effects on testicular spermatogenic function in streptozotocin (STZ)-induced type 1 diabetic mice. Therefore, 40 mature male C57BL/6 J mice were divided into four main groups: the control group (n = 10), the diabetic group (n = 10), the 2.5 mg/kg SPM-treated diabetic group (n = 10) and the 5 mg/kg SPM-treated diabetic group (n = 10), which was given intraperitoneally for 8 weeks. The type 1 diabetic mice model was established by a single intraperitoneal injection of STZ 120 mg/kg. The results showed that, compare to the control group, the body and testis weight, as well the number of sperm were decreased, while the rate of sperm malformation was significantly increased in STZ-induced diabetic mice. Then the testicular morphology was observed, which showed that seminiferous tubule of testis were arranged in mess, the area and diameter of which was decreased, along with downregulated anti-apoptotic factor (Bcl-2) expression, and upregulated pro-apoptotic factor (Bax) expression in the testes. Furthermore, testicular genetic expression levels of Sertoli cells (SCs) markers (WT1, GATA4 and Vimentin) detected that the pathological changes aggravated observably, such as the severity of tubule degeneration increased. Compared to the saline-treated DM mice, SPM treatment markedly improved testicular function, with an increment in the body and testis weight as well as sperm count. Pro-apoptotic factor (Bax) was down-regulated expression with the up-regulated expression of Bcl-2 and suppression of apoptosis in the testes. What's more, expression of WT1, GATA4, Vimentin and the expressions of glycolytic rate-limiting enzyme genes (HK2, PKM2, LDHA) in diabetic testes were also upregulated by SPM supplement. The evidence derived from this study indicated that the SMP's positive effect on moderating spermatogenic disorder in T1DM mice's testis. This positive effect is delivered via promoting spermatogenic cell proliferation and participating in the glycolytic pathway's activation.

Overt hypogonadism is a cardiovascular risk factor in type 2 diabetic males: An observational study

We aimed to evaluate the effects of hypogonadism on metabolic and chronic complications in type 2 diabetic males. 261 nonobese males with type 2 diabetes aged 18-70 were involved in the study. Hypononadal males were divided into 2 groups as overt hypogonadism (total testosterone≤230 ng/dl) and borderline hypogonadism (230-345 ng/dl). The control group involved eugonadal diabetic males. Micro-macrovascular complications were recorded. 101 patients had hypogonadism (38.7%), and 160 patients were eugonadal (61.3%). Microvascular complication rate was not different, but macrovascular complication rate was significantly higher in hypogonadal males (42.6%/31.3%, p = 0.042). Optimal glycosylated haemoglobin (HbA1c) achievement(<7%) was significantly lower in hypogonadal patients (20.8%/31.3%, p = 0.043). Poor glycaemic control (HbA1c≥7%), presence of microvascular complication and increased triglyceride levels were independent risk factors for hypogonadism (OR: 1.5, p = 0.044;OR:3.89,p = 0.025 and OR: 1.0, p = 0.016 respectively). Overt hypogonadism, hypertension, hypercholesterolaemia and severe hypoglycaemia were independent risk factors for macrovascular complications (OR: 1.0, p = 0.027; OR:2.6, p = 0.002; OR: 1.8, p = 0.047 and OR: 1.0, p = 0.007 respectively), diabetes duration (≥5 years) and poor glycaemic control for microvascular complication (OR: 1.0, p = 0.031 and OR:2.0, p = 0.028). As a result, hypogonadism is frequent among diabetic males and poor glycaemic control may be an important contributing factor. Furthermore overt hypogonadism is an important cardiovascular risk marker. Therefore, ensuring eugonadism in diabetic patients may positively affect both glycaemic control and complications.

Effects of testicular sperm aspiration upon first cycle ICSI-ET for type 2 diabetic male patients

Male diabetes mellitus (DM) can affect erectile function and sperm quality. In severe cases, DM can lead to retrograde or no ejaculation, so testicular sperm aspiration (TESA) is combined with intracytoplasmic sperm injection (ICSI) to treat subfertility and infertility for DM couples. However, the effect of TESA upon ICSI (TESA-ICSI) for DM patients remains unclear. This research investigated the effect of TESA-ICSI on first cycle ICSI-embryo transfer (ICSI-ET) for type 2 diabetic mellitus (T2DM) patients and the potential mechanisms. The subjects consisted of 1219 male patients with azoospermia or retrograde ejaculation who were treated with TESA-ICSI from 2015.01 to 2019.11. They were classified into two groups, the T2DM group (n = 54) and non-diabetic control group (n = 1165). Sperm selection for injection was performed using motile sperm organelle morphology examination criteria. The number of available embryos and the high-quality embryo rates following a single ET as well as cleavage, fertilization, implantation, clinical pregnancy and the abortion rates were noted. Compared with the non-diabetic group, the available embryo rate (75.20 ± 26.40% vs.78.36 ± 23.25%) and high-quality embryo rate (46.49 ± 30.37% vs. 47.55 ± 28.57%) in the T2DM group were lower and the abortion rate (20.83% vs. 8.88%) was higher, but these differences were not statistically significant. There were no significant differences in clinical pregnancy, implantation, normal fertilization, and cleavage rates between the two groups. The results show that TESA for male T2DM patients does not influence the effect of ICSI. For T2DM patients with severe oligozoospermia, asthenospermia, teratozoospermia, or retrograde ejaculation that do not meet ICSI criteria, TESA-ICSI may perhaps be considered for reproductive assistance.

ABBREVIATIONS

DM: diabetes mellitus; TESA: testicular sperm aspiration; ICSI: intracytoplasmic sperm injection; ICSI-ET; ICSI-embryo transfer; LH: luteinizing hormone; mL: milliliter; TES: testosterone; FSH: follicle-stimulating hormone; P: progesterone; HCG: human chorionic gonadotropin.

Late-onset hypogonadism and lifestyle-related metabolic disorders

BACKGROUND

Late-onset hypogonadism (LOH) is a condition defined by low levels of testosterone (T), occurring in advanced age. LOH is promoted by senescence, which, in turn, has negative effects on male fertility. Interestingly, the impact of metabolic disorders on the male reproductive system has been the topic of several studies, but the association with LOH is still debatable.

OBJECTIVES

Herein, we discuss the hypothesis that the prevalence of metabolic abnormalities potentiates the effects of LOH on the male reproductive system, affecting the reproductive potential of those individuals.

MATERIAL AND METHODS

We analyzed the bibliography available, until June 2019, about LOH in relation to metabolic and hormonal dysregulation, sperm quality profiles and assisted-reproduction treatment outcomes.

RESULTS

LOH affects the hypothalamic-pituitary testis (HPT) axis. Additionally, metabolic disorders can also induce T deficiency, which is reflected in decreased male fertility, highlighting a possible connection. Indeed, T replacement therapy (TRT) is widely used to restore T levels. Although this therapy is unable to reverse all deleterious effects promoted by LOH on male reproductive function, it can improve metabolic and reproductive health.

DISCUSSION AND CONCLUSIONS

Emerging new evidence suggests that metabolic disorders may aggravate LOH effects on the fertility potential of males in reproductive age, by enhancing T deficiency. These results clearly show that metabolic disorders, such as obesity and diabetes, have a greater impact on causing hypogonadotropic hypogonadism than tissue senescence. Further, TRT and off-label alternatives capable of restoring T levels appear as suitable to improve LOH, while also counteracting comorbidities related with metabolic diseases.

Some of the Factors Involved in Male Infertility: A Prospective Review

Infertility is defined as the inability of couples to have a baby after one year of regular unprotected intercourse, affecting 10 to 15% of couples. According to the latest WHO statistics, approximately 50-80 million people worldwide sufer from infertility, and male factors are responsible for approximately 20-30% of all infertility cases. The diagnosis of infertility in men is mainly based on semen analysis. The main parameters of semen include: concentration, appearance and motility of sperm. Causes of infertility in men include a variety of things including hormonal disorders, physical problems, lifestyle problems, psychological issues, sex problems, chromosomal abnormalities and single-gene defects. Despite numerous efforts by researchers to identify the underlying causes of male infertility, about 70% of cases remain unknown. These statistics show a lack of understanding of the mechanisms involved in male infertility. This article focuses on the histology of testicular tissue samples, the male reproductive structure, factors affecting male infertility, strategies available to find genes involved in infertility, existing therapeutic methods for male infertility, and sperm recovery in infertile men.

Testosterone Replacement Therapy and the Risk of Hypoglycemia

We report the case of a 45-year-old man with a history of Klinefelter syndrome undergoing testosterone replacement therapy, and with type 2 diabetes treated with metformin with poor metabolic control. When vildagliptin was added to his treatment, he presented hypoglycemia after the testosterone injection. We highlight this not widely reported drug interaction between hypoglycemic agents and testosterone.

Lower circulating kisspeptin and primary hypogonadism in men with type 2 diabetes

Introduction

Kisspeptin influence on male androgens is partially understood. We aimed to evaluate serum concentrations of kisspeptin among Ghanaian men with type 2 diabetes and to identify related factors that may contribute to altering circulating kisspeptin.

Methods

A cross‐sectional, observational study. Sixty persons with type 2 diabetes and 60 nondiabetic controls were included in this study. Blood pressure, body mass index (BMI), kisspeptin, luteinizing hormone (LH), follicle‐stimulating hormone (FSH), total testosterone (T), glucose (FBG), glycated haemoglobin (HbA1c) and lipid levels were assessed.

Results

Type 2 diabetic men had lower kisspeptin and T concentrations than controls (P = 0.001 for both). Levels of LH and FSH were, respectively, higher in diabetic men compared with their control counterparts (P = 0.003; P = 0.017). There were negative associations within the diabetic group for kisspeptin vs age (r = −0.590, P = 0.0001) and kisspeptin vs BMI (r = −0.389, P = 0.002). Positive associations were also found within the diabetic group for kisspeptin vs T (r = 0.531, P = 0.001), kisspeptin vs LH (r = 0.423, P = 0.001) and kisspeptin vs FSH (r = 0.366, P = 0.004). Lower T (OR = 1.473, P = 0.003) and advancing age (OR = 0.890, P = 0.004) contributed to decreased kisspeptin levels among Ghanaian males with type 2 diabetes.

Conclusion

Our data demonstrate that circulating kisspeptin and T concentrations are lower among men with type 2 diabetes and highlight the importance of considering kisspeptin concentrations in the management of hypogonadism and type 2 diabetes.

The effect of metabolic syndrome on male reproductive health: A cross-sectional study in a group of fertile men and male partners of infertile couples

This study aimed to determine the effect of metabolic syndrome (MS) on the reproductive function in fertile (FM) and male partners of infertile couples (MPIC). We performed a cross-sectional study formatting two study groups: partners of pregnant women (n = 238; mean age 32.0) as FM and male partners of infertile couples (n = 2642; mean age 32.6) as MPIC. A standard semen analysis was performed and clinical, laboratory and lifestyle data were analysed. The adapted NCEP-ATPIII criteria were used to define MS. 12.2% of FM and 17.8% of MPIC had MS. In both groups, men with MS were older, they were centrally obese and had higher triglycerides, systolic and diastolic blood pressure and decreased HDL cholesterol values as compared to men without MS. However, glucose concentrations as well as fasting insulin levels were significantly higher only in the MPIC-MS⁺ group. MS was not associated with semen parameters. Testosterone levels were negatively correlated to MS in both groups. This negative association persisted within the BMI categories between MPIC-MS^- and MPIC-MS⁺ groups. LH was negatively correlated to MS but only in MPIC. FSH and oestradiol were not correlated to MS. Smoking and alcohol consumption were higher among men with MS. This study shows that except for testosterone, MS has no independent effect on major fertility parameters in different subgroups of men.

[Klinefelter syndrome and cardiovascular risk]

We present a 45-year-old patient with Klinefelter syndrome, with a history of type 2 diabetes mellitus, obesity, dyslipidemia, obstructive sleep apnoea syndrome and masked arterial hypertension. The purpose of this presentation is to draw attention to the increased cardiovascular risk in these patients and to review the data in the literature on this risk.

Intranasal Insulin Administration Does Not Affect LH Concentrations in Men with Diabetes

A quarter of men with obesity or type 2 diabetes have hypogonadotropic hypogonadism. Animal studies and in vitro data have shown that insulin action and insulin responsiveness in the brain are necessary for the maintenance of the functional integrity of the hypothalamo-hypophyseal-gonadal axis. We conducted a randomized, placebo-controlled trial to evaluate the effect of one dose of intranasal insulin (40 IU of regular insulin) or saline on LH concentrations in 14 men (8 with type 2 diabetes and 6 healthy lean men). Insulin or saline was administered intranasally on two different occasions, at least one week apart. Blood samples were collected to measure LH concentrations every 15 minutes for 5 hours. Study drug was administered intranasally after a 2-hour baseline sampling period. Patients remained fasting throughout the procedure. The primary endpoint of the study was to compare the change in LH concentrations after intranasal insulin as compared to placebo (intranasal saline). Change was defined as the difference between baseline LH concentrations (average of the 9 samples collected in two hours prior to drug administration) and average LH concentrations following drug administration (average of the 12 samples collected in 3 hours). There was no change in LH concentrations following insulin administration as compared to placebo in men with diabetes or in lean men. We conclude that one dose of 40 IU of regular insulin administered intranasally does not change LH concentrations acutely in men.

Male gonadal axis function in patients with type 2 diabetes

Patients with type 2 diabetes have lower serum testosterone levels and a higher prevalence of hypogonadism than non-diabetic patients, independently of the metabolic control of disease. The mechanisms underlying a decrease in testosterone might be related to age, obesity and insulin resistance, often present in patients with type 2 diabetes. The increase in estrogens due to higher aromatase enzyme activity in increased adipose tissue might exert negative-feedback inhibition centrally. Insulin stimulates gonadal axis activity at all three levels and therefore insulin resistance might account for the lower testosterone production. Leptin exerts a central stimulatory effect but inhibits testicular testosterone secretion. Thus, resistance to leptin in obese subjects with type 2 diabetes determines lower central effects of leptin with lower gonadotropin-releasing hormone (GnRH) secretion and, on the other hand, hyperleptinemia secondary to leptin resistance inhibits testosterone secretion at the testicular level. However, lower testosterone levels in patients with diabetes are observed independently of age, weight and body mass index, which leads to the assumption that hyperglycemia per se might play a role in the decrease in testosterone. Several studies have shown that an overload of glucose results in decreased serum testosterone levels. The aim of this review is to assess changes in the male gonadal axis that occur in patients with type 2 diabetes.

Human chorionic gonadotropin stimulation gives evidence of differences in testicular steroidogenesis in Klinefelter syndrome, as assessed by liquid chromatography-tandem mass spectrometry

BACKGROUND

Men with Klinefelter syndrome (KS) show hypergonadotropic hypogonadism, but the pathogenesis of hypotestosteronemia remains unclear. Testicular steroidogenesis in KS men was evaluated over three decades ago after human chorionic gonadotropin (hCG) stimulation, but inconclusive results were obtained. Intriguingly, some recent studies show increased intratesticular testosterone concentrations in men with KS.

OBJECTIVE

To analyze serum steroid profile, as a proxy of testicular steroidogenesis, after hCG stimulation in KS compared with control men.

DESIGN

A prospective, longitudinal, case-control, clinical trial.

METHODS

Thirteen KS patients (36±9 years) not receiving testosterone (TS) replacement therapy and 12 eugonadic controls (32±8 years) were enrolled. Serum steroids were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline and for five consecutive days after intramuscular injection of 5000IU hCG.

RESULTS

Progesterone (P), 17-hydroxyprogesterone (17OHP), TS, and estradiol (E2) showed a significant increase (P<0.001) after hCG stimulation in both groups. On the contrary, androstenedione (AS) and dehydroepiandrosterone did not increase after hCG stimulation. The 17OHP/P ratio increased in both groups (P<0.001), the TS/AS ratio (17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) activity) did not increase after hCG in any group, and the E2/TS ratio (aromatase activity) increased significantly in both groups (P=0.009 in KS and P<0.001 in controls). Luteinizing hormone decreased after hCG in both groups (P=0.014 in KS and P<0.001 in controls), whereas follicle-stimulating hormone decreased only in control men (P<0.001).

CONCLUSION

This study demonstrates for the first time using LC-MS/MS that Leydig cells of KS men are able to respond to hCG stimulation and that the first steps of steroidogenesis are fully functional. However, the TS production in KS men is impaired, possibly related to reduced hydroxysteroid deydrogenase activity due to an unfavorable intratesticular metabolic state.

Effects of high-fat diet-induced obesity and diabetes on Kiss1 and GPR54 expression in the hypothalamic-pituitary-gonadal (HPG) axis and peripheral organs (fat, pancreas and liver) in male rats

Recent data indicates that kisspeptin, encoded by the KISS1 gene, could play a role in transducing metabolic information into the hypothalamic-pituitary-gonadal (HPG) axis, the mechanism that controls reproductive functions. Numerous studies have shown that in a state of negative energy balance, the hypothalamic kisspeptin system is impaired. However, data concerning positive energy balance (e.g. diabetes and obesity) and the role of kisspeptin in the peripheral tissues is scant. We hypothesized that: 1) in diet-induced obese (DIO) male rats and/or rats with diabetes type 1 (DM1) and type 2 (DM2), altered reproductive functions are related to an imbalance in Kiss1 and GPR54 mRNA in the HPG axis; and 2) in DIO and/or DM1 and/or DM2 rats, Kiss1 and GPR 54 expression are altered in the peripheral tissues involved in metabolic functions (fat, pancreas and liver). Animals were fed a high-fat or control diets and STZ (streptozotocin - toxin, which destroys the pancreas) was injected in high or low doses to induce diabetes type 1 (DM1) or diabetes type 2 (DM2), respectively. RT-PCR and Western blot techniques were used to assess the expression of Kiss1 and GRP54 in tissues. At the level of mRNA, we found that diabetic but not obese rats have alterations in Kiss1 and/or GPR54 mRNA levels in the HPG axis as well as in peripheral tissues involved in metabolic functions (fat, pancreas and liver). The most severe changes were seen in DM1 rats. However, in the case of protein levels in the peripheral tissues (fat, pancreas and liver), changes in Kiss1/GPR54 expression were noticed in DIO, DM1 and DM2 animals and were tissue-specific. Our data support the hypothesis that alterations in Kiss1/GPR54 balance may account for both reproductive and metabolic abnormalities reported in obese and diabetic rats.

Risk Factors for Hypogonadism in Male Patients with Type 2 Diabetes

BACKGROUND

Male hypogonadism is an endocrine disease characterized by low levels of serum testosterone and is closely related to the development of diabetes. The purpose of the present study was to observe the risk factors for hypogonadism in male patients with type 2 diabetes.

METHODS

A total of 213 patients with type 2 diabetes were enrolled and divided into a low total testosterone (TT) group (=75) and a normal TT group (=138). The patients' blood glucose, blood lipids, serum insulin, and sex hormones were measured. The correlations between the patients' metabolic index and sex hormone levels were analyzed.

RESULTS

Compared with the normal TT group, body mass index (BMI), fasting insulin (FINS), and HOMA insulin resistance index (HOMA-IR) levels were significantly higher, but the luteinizing hormone (LH) levels were significantly lower in the low TT group (p < 0.05). Correlation analyses found that TT was negatively correlated with BMI, waist circumference (WC), FINS, and HOMA-IR. TT was positively correlated with LH and follicle-stimulating hormone (FSH).

CONCLUSIONS

Several risk factors of diabetes associated closely with hypogonadism. BMI, metabolic syndrome (MS), HOMA-IR, and LH are independent risk factors for hypogonadism in male patients with type 2 diabetes.

Obesity and late-onset hypogonadism

Obesity and male hypogonadism (HG) are often associated, as demonstrated in all cross-sectional studies. Prospective studies have indicated that i) having HG at baseline increases the risk of visceral obesity (and metabolic syndrome) and that ii) obesity induces incident HG. Hence, there is a bidirectional relationship between the two conditions. This is the main topic of this review, along with some pathogenic considerations. Meta-analysis of intervention studies indicates that treating obesity is a very efficient treatment for obesity-induced HG. The mechanism by which obesity induces HG has not yet been completely understood, but dietary-induced hypothalamic inflammation, along with a decreased GnRH release, is plausible. Among patients seeking medical care for obesity, the proportion of HG is relatively high. The prevalence of obesity among patients referring for sexual dysfunction is also elevated. Hence, in symptomatic, obese, hypogonadal subjects, testosterone supplementation (TS) can be considered. Whereas long-term uncontrolled register studies suggest that TS could decrease weight, analysis of controlled studies only support a parallel increase in lean mass and decrease in fat mass, with a resulting null effect on weight. Considering that T induces an increase in muscle mass, it is conceivable that the amount of activity obese people can undertake after TS will increase, allowing a closer adherence to physical exercise programs. Some studies, here meta-analyzed, support this concept.

[The "obese" and "old" male patient in dermatological practice. When should hypogonadism be considered?]

Hypogonadism refers to reduced endocrine function of the testicles and leads to testosterone deficiency. It is often observed in older and obese men. Symptoms with the highest predictive value are reduced sexual thoughts, decreased spontaneous erections, and erectile dysfunction. After excluding contraindications (e.g., desire for children), various forms of replacement therapy are available. Studies have shown that testosterone therapy is safe if regularly checked.

Blood inorganic mercury is directly associated with glucose levels in the human population and may be linked to processed food intake

Background:

The goals of the study were (1) to determine the impact of inorganic mercury exposure on glucose homeostasis; and (2) to evaluate the effectiveness of two community-based interventions in promoting dietary changes among American Indian college students to reduce risk factors for Type-2 Diabetes including fasting glucose, insulin, and mercury levels, weight, and body mass index.

Methods:

To accomplish goal one, the National Health and Nutrition Examination Survey (NHANES) dataset was analyzed using a previously published method to determine if there is a relationship between inorganic blood mercury and fasting glucose. To accomplish goal two, ten college students were recruited and randomly assigned to a group receiving the online macroepigenetics nutrition course and the support group for eliminating corn sweeteners. Participants in both groups were assessed for diet patterns, weight, body mass index (BMI), fasting glucose, insulin, and mercury levels. The interventions were implemented over a 10-week period.

Results:

Analysis of the NHANES data (n=16,232) determined a direct relationship between inorganic mercury in blood and fasting glucose levels (p<0.001). The participants who took the online macroepigenetics nutrition intervention course significantly improved their diets (p<0.01), and fasting blood glucose levels (p<0.01) while having lower levels of inorganic mercury in their blood compared to the subjects in the group who eliminated corn sweeteners from their diet and participated in the support group. The trend in lower blood inorganic mercury was strong with p=0.052. The participants in the support group who eliminated corn sweeteners from their diet achieved significant weight loss (p<0.01) and reduced their body mass index (p<0.01).

Conclusion:

Total blood mercury levels may be influenced by dietary intake of highly processed foods and lower inorganic mercury levels are associated with lower fasting glucose levels. Alternative community-based interventions emphasizing the role food ingredients and toxic substances play in gene modulation and the development of diseases can result in significant dietary improvements and reductions in risk factors associated with type-2 diabetes. A healthier diet can be promoted among community members using a novel online nutrition course. Consumption of corn sweeteners may be a risk factor in the development of obesity.

Age, insulin requirements, waist circumference, and triglycerides predict hypogonadotropic hypogonadism in patients with type 1 diabetes

INTRODUCTION

The prevalence of hypogonadotropic hypogonadism (HH) in patients with type 2 diabetes mellitus is higher than in the general population and leads to detrimental effects on metabolic control, lipid profile, and body composition. Few studies have examined its role in type 1 diabetes mellitus.

AIM

To determine the prevalence of HH in patients with type 1 diabetes and associated risk factors.

MAIN OUTCOME MEASURES

Clinical and biochemical parameters were gathered on initial evaluation. An HH score creating different experimental models was devised to calculate the risk of HH for an individual with type 1 diabetes.

METHODS

Cross-sectional study of 181 male patients with type 1 diabetes consecutively admitted to the Diabetes outpatient clinics of three urban hospitals. All participants were Caucasians aged ≥ 18 years with type 1 diabetes duration of more than 6 months.

RESULTS

One hundred and eighty-one male patients with a mean age of 44.2 ± 13.2 years and a type 1 diabetes duration of 18.9 ± 12.7 years were included. Fifteen patients had HH, representing a prevalence of 8.3% (95% confidence interval [CI]: 4.3-12.3%). Age (odds ratio [OR] 1.066 [95% CI: 1.002-1.134]), waist circumference (OR 1.112 [95% CI: 1028-1203]), and insulin requirements ([IU/Kg] ×10 [OR 1.486 {95% CI: 1052-2.098}]) were independently associated with the presence of HH. The model that best predicted HH generated this formula: HH-score = (1.060 × age) + (1.084 × waist circumference) + (14.00 × insulin requirements) + triglycerides, where age was expressed in years, waist circumference in cm, insulin requirements in IU/kg/d, and triglycerides in mg/dL. An HH score > 242.4 showed 100% sensitivity and 53.2% specificity for HH diagnosis; positive and negative predictive values were 17.0 % and 100%, respectively.

CONCLUSIONS

One in 10 men with type 1 diabetes presents HH. This condition is associated with age, waist circumference, and insulin requirements. A simple formula based on clinical parameters can rule out its presence.

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.