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

Negative correlation between metabolic score for insulin resistance index and testosterone in male adults

BACKGROUND

Insulin resistance (IR) is strongly correlated with the decreased deficiency of testosterone levels in males. The metabolic score for insulin resistance (METS-IR) index is regarded as an innovative measure for the assessment on IR. The research aims to explore the correlation between the METS-IR index and the testosterone levels in males.

METHODS

In this study, a cross-sectional design was made through the data obtained from the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2020. Besides, the METS-IR index was derived from serum triglyceride levels, fasting plasma glucose, HDL-C and BMI.

RESULTS

A total of 2082 participants were included in the final analysis. After controlling for confounding variables, it was found that METS-IR was independently and negatively correlated with testosterone levels (β = -3.88, 95% CI = -4.49, -3.27, P < 0.001). As shown by the generalized smooth curve fitting, METS-IR had a linear correlation with testosterone levels without threshold or saturation effects, which was consistently observed across all subgroups through stratified analysis (all P > 0.05). As revealed by the analysis on the ROC curve, the area under the curve (AUC) for the METS-IR index (0.732, 95% CI = 0.705, 0.760) was significantly larger than that of homeostatic model assessment of insulin resistance (HOMA-IR), TG/HDL ratio, triglyceride-glucose index (TyG) and body mass index (BMI).

CONCLUSION

The findings suggest a negative relationship between the METS-IR index and the testosterone levels in male adults. Furthermore, the METS-IR index demonstrates superior predictive ability for testosterone deficiency in comparison to HOMA-IR, TG/HDL ratio, TyG and BMI.

A negative association between triglyceride glucose-body mass index and testosterone in adult males: a cross-sectional study

Background and objectives

Insulin resistance (IR) is closely related to the decline or deficiency of testosterone in males. Triglyceride glucose-body mass (TyG-BMI) is considered to be a novel indicator of IR. We conducted this analysis to investigate the association between TyG-BMI and male testosterone, and to explore whether its ability to predict testosterone deficiency is superior to HOMA-IR and TyG.

Methods

This was a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES, 2011-2016). The TyG-BMI index was calculated from serum triglyceride, fasting plasma glucose and BMI. The association of TyG-BMI with male testosterone was estimated by weighted multivariable regression.

Results

We included 3394 participants for the final analysis. After adjusting for confounders, TyG-BMI was found to show an independent negative association with testosterone (β=-1.12, 95%CI: -1.50, -0.75, P<0.0001). Multivariate-adjusted beta also showed testosterone levels were significantly lower in the two highest TyG-BMI group (Q3, Q4) compared to the lowest group (Q1). Similar results were seen in all of the subgroup populations by stratified analysis (all P-interaction >0.05). Furthermore, ROC curve analysis indicated that the area under the curve of TyG-BMI index (0.73, 95% CI: 0.71, 0.75) was larger than that of HOMA-IR index (0.71, 95% CI: 0.69, 0.73) and TyG index (0.66, 95% CI: 0.64, 0.68).

Conclusion

Our result suggested a negative association between TyG-BMI index and testosterone in adult males. The predictability of the TyG-BMI index for testosterone deficiency is better than that of HOMA-IR index and TyG index.

Benzo[a]pyrene impairs the migratory pattern of human gonadotropin-releasing-hormone-secreting neuroblasts

Benzo[a]pyrene (BaP) is a widespread pollutant that can act as an endocrine disrupting compound (EDC) and interferes with reproductive function. The central regulatory network of the reproductive system is mediated by gonadotropin-releasing hormone (GnRH) neurons, which originate in the olfactory placode and, during ontogenesis, migrate into the hypothalamus. Given the importance of the migratory process for GnRH neuron maturation, we investigated the effect of BaP (10 μM for 24 h) on GnRH neuroblasts isolated from the human fetal olfactory epithelium (FNCB4). BaP exposure significantly reduced the mRNA level of genes implicated in FNCB4 cell migration and affected their migratory ability. Our findings demonstrate that BaP may interfere with the central neuronal network controlling human reproduction affecting GnRH neuron maturation.

Prostatic alterations associated to early weaning and its relation with cocoa powder supplementation. Experimental study in adult wistar rats

Early weaning can predispose the offspring to greater risk of developing chronic diseases in adulthood. It is believed that the consumption of functional foods is able to prevent these effects. The aim of this study is to evaluate the effects of maternal and postnatal cocoa powder supplementation on body mass, metabolism, and morphology of the prostate of early weaned Wistar rats. The animals were divided into four experimental groups according to lactation time (21 or 18 days, n=6, each) as follows: control group (C), cocoa control group (CCa), early weaning group (EW), and cocoa early weaning group (EWCa). The animals were euthanized at 90 days of age. Serum biochemical analysis and prostate histomorphometric evaluation were performed. The animals supplemented with cocoa powder were heavier than their respective controls (p <0.05), although with no difference in food intake among the groups. Likewise, these same groups showed a reduction in the serum glucose in relation to C and EW groups (p <0.0001). With respect to the prostate, there was no difference in smooth muscle and lumen area densities, while the EW group had a lower epithelial height and a higher percentage of mast cells than the C group (p <0.05). On the other hand, the EWCa group managed to reverse these parameters, leveling with the controls. Early weaning resulted in hyperglycemia and important morphological changes in the prostate. In contrast, dietary supplementation with cocoa powder attenuated these effects on the metabolism and prostatic histoarchitecture, proving to be a good nutritional treatment strategy.

Hippocampus kuda protein hydrolysate improves male reproductive dysfunction in diabetic rats

The global prevalence of diabetes mellitus is rapidly increasing. This disease is associated with many complications including male reproductive dysfunctions and infertility. Seahorse ( Hippocampus kuda) is a marine teleost fish well known for its beneficial effects on the reproductive system in traditional Chinese medicine books. Recently, several studies have been shown that the enzymatic hydrolysate of seahorse has multiple pharmacological activities. This study aimed to investigate the seahorse peptide hydrolysate (SH) ameliorative effects on the diabetic-induced male reproductive dysfunction in rat models. The in vivo studies were carried out with three different doses of SH (4, 8, and 20 mg/kg) and the diabetes condition was induced by administrating with streptozotocin (35 mg/kg) and fed a 40% high-fat diet. Seahorse hydrolysate (20 mg/kg) inhibited lipid peroxidation, increased antioxidant enzyme activity, and restored seminiferous tubules morphology in testis. Moreover, it improved reproductive dysfunction by increasing the level of testosterone, follicle-stimulating hormone, luteinizing hormone, sperm count, and motility. According to these results, we suggested that SH exhibited amelioration effects on the reproductive dysfunction.

Frequency and Correlates of Hypogonadism in Adult Males with Type 2 Diabetes Mellitus

BACKGROUND AND AIMS

There is increasing awareness about an association between type 2 diabetes mellitus (T2DM) and male hypogonadism. However, data are sparse and less uniform with respect to factors associated with hypogonadism in males with T2DM. This study aimed to assess the frequency and correlates of hypogonadism in these subjects.

MATERIALS AND METHODS

This cross-sectional study included 130 males with T2DM, age 25-60 years. Study subjects were screened for hypogonadal symptoms using androgen deficiency in aging male (ADAM) questionnaire. Serum total testosterone was measured in subjects with positive ADAM score. Hypogonadism was defined as the presence of positive ADAM score and low serum total testosterone (<3 ng/mL). Clinical and biochemical variables were compared between T2DM subjects with and without hypogonadism.

RESULTS

Hypogonadism was observed in 26.9% of the study subjects. Hypogonadal symptoms most frequently observed in patients with T2DM and hypogonadism were erectile dysfunction (96.4%), reduced libido (64.3%) and deterioration in work performance (53.6%). Group with T2DM and hypogonadism had higher (i) duration of T2DM (8.9 ± 5.03 vs. 4.8 ± 4.76 years; P = .001), (ii) frequency of diabetic retinopathy (58.3% vs. 27.3%; P = .008), (iii) frequency of diabetic neuropathy (42.9% vs. 19.7%; P = .024), (iv) proportion of subjects on insulin therapy (46.4% vs. 22.4%; P = .027), and (v) HbA1c (10.9 ± 2.63% vs. 9.3 ± 2.42%; P = .006), compared to group without hypogonadism.

CONCLUSION

Hypogonadism was present in nearly one-fourth of the study subjects with T2DM. Compared to the subjects without hypogonadism, group with hypogonadism had longer duration of diabetes, higher HbA1c, greater frequencies of diabetic retinopathy and diabetic neuropathy, and more subjects on insulin therapy.

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 gonadal function in obese adolescents: review

This review deals with the relationship between obesity in male adolescents and gonadal function. The article is structured in two main paragraphs; the first one is about population studies that have assessed puberty timing and its mode of onset in relation with body weight to evaluate if and how the latter can influence the gonadal function in this phase of life. These studies analyze issues such as increased BMI and early onset of male puberty, gender differences, secular trend toward early onset of puberty in males, effects of a different body composition on male puberty and consequences of a different stage of childhood obesity on the onset of male puberty. The second paragraph examines the possible mechanisms through which, obesity may alter the timing of puberty in young males, including the role of SHBG, leptin, insulin resistance, ghrelin, GH-IGF-1 axis, AR polymorphisms, primary testicular dysfunction, retinol binding protein 4 (RBP-4) and liver function abnormalities. However, despite the numerous studies in the literature, the etiology of gonadal disfunction in obese adolescents on puberty remains uncertain.

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.