Relationship between visceral adiposity index and male infertility

Association between the age-adjusted visceral adiposity index (AVAI) and female infertility status: a cross-sectional analysis of the NHANES 2013-2018

BACKGROUND

Obesity stands as an essential factor contributing to infertility in women. Early identification of obese individuals leads to favorable results for female infertility. The objective of this research is to assess the association between the age-adjusted visceral adiposity index (AVAI) and female infertility.

METHODS

This study was conducted using NHANES data from 2013 to 2018, in which 1,231 women aged 20-45 were selected. Infertility was defined by survey questions. AVAI was calculated using anthropometric and serum data. Covariates included demographics and lifestyle factors. Statistical analysis with R, adjusting for covariates, and assessing nonlinearity and cutoff effects.

RESULTS

The study of 1,231 women from the NHANES database revealed that 11.94% were diagnosed with infertility. Individuals with higher AVAI scores showed increased age, WC, BMI, and reduced HDL levels, with a positive correlation between AVAI and female infertility (OR = 1.42, 95%CI: 1.26-1.60). AVAI quartiles showed a pronounced relationship with female infertility risk, with the highest quartile showing the greatest risk(OR = 9.35,95% CI: 2.96-29.55). Nonlinear and threshold effects in the relationship between AVAI and female infertility were identified, with an inflection point at -9.70. Subgroup analyses indicated significant interactions between AVAI and educational status and BMI, particularly in women with a BMI below 25 kg/m2, where a high AVAI level was closely related to increased infertility risk(OR = 1.92, 95%CI: 1.44-2.58).

CONCLUSION

The study identifies a strong association between elevated AVAI scores and female infertility risk, especially in women with a BMI under 25 kg/m2. This suggests that AVAI could be a valuable predictor in female fertility assessments.

The impact of sex hormones on metabolic syndrome: univariable and multivariable Mendelian randomization studies

BACKGROUND

Observational studies have found associations between sex hormones and metabolic syndrome(Mets), but the causal relationships remains unclear. This study utilizes univariable and multivariable Mendelian randomization (MR) to elucidate the associations between sex hormones (including sex hormone-binding globulin(SHBG), estradiol(E2), testosterone(T)) and Mets and its subtypes (including waist circumference(WC), fasting blood glucose(FBG), high blood pressure(HBP), high-density lipoprotein(HDL-C), triglycerides(TG)).

METHODS

We utilized summary data from large-scale genome-wide association studies. Univariable Mendelian randomization (UMVMR) analysis was primarily conducted using the inverse variance weighted method (IVW), with secondary analyses employing the weighted median, MR-Egger regression, simple mode method, and weighted mode method. Subsequently, multivariable Mendelian randomization (MVMR) was employed to assess the causal relationships between SHBG, T, E2, and MetS and its components: WC, FPG, HBP, HDL-C, and TG. Sensitivity analyses were conducted to assess result reliability.

RESULTS

Genetically predicted SHBG was significantly negatively associated with MetS (UMVMR: β=-0.72; 95% CI = 0.41 to 0.57; P = 1.28e-17; MVMR: β=-0.60; 95% CI=-0.83 to -0.38; P < 0.001). Positive causal relationships were observed between SHBG and WC(MVMR: β = 0.10; 95% CI = 0.03 to 0.17; P = 0.01) and HDL-C (MVMR: β = 0.41; 95% CI = 0.21 to 0.60; P < 0.001), while negative causal relationships were found between SHBG and HBP (MVMR: β=-0.02; 95% CI=-0.04 to -0.00; P = 0.02), TG (MVMR: β=-0.48; 95% CI=-0.70 to -0.26; P < 0.001). Genetically predicted E2 exhibited a negative association with TG (MVMR: β=-1.49; 95% CI=-2.48 to -0.50; P = 0.003). Genetically predicted T was negatively associated with TG (MVMR: β=-0.36; 95% CI=-0.71 to -0.00; P = 0.049) and WC (MVMR: β=-0.13; 95% CI=-0.24 to -0.02; P = 0.02), with inconsistent sensitivity analyses. Additionally, No other causal associations were found.

CONCLUSION

Our study indicates that SHBG is a protective factor for MetS, potentially delaying its onset and progression through improvements in HBP and TG. Furthermore, T and E2 may improve TG levels, with T also reducing WC levels. Importantly, our study provides new insights for the prevention and treatment of MetS.

Male infertility risk and plasma lipidome: a Mendelian randomization study

Background

In recent years, the decline in sperm quality in men has become a global trend. There is a close relationship between sperm quality and pregnancy outcome. There is a large body of literature supporting the role of plasma lipidome in male infertility, while the complex mechanisms between them and male infertility are still less clear. Systematic study of the causal relationship between plasma lipidome and MI can help to provide new therapeutic ideas and targets for male infertility.

Methods

In this study, we used a two-sample Mendelian randomization analysis based on Genome-wide association studies pooled data of 179 causal relationships between plasma lipidome and male infertility. We used employed the inverse variance weighted method as the main analysis to assess causality between exposure and outcome, in addition to MR-Egger, Weighted median as complementary methods, and tests for multiplicity and heterogeneity.

Results

We identified 13 plasma lipidome comprising 4 types of plasma lipidome that were associated with male infertility. Among these, 9 plasma lipidome were found to be protective factors, while 4 were risk factors. Notably, the largest proportion of these plasma lipidome were triglyceride types, with Sphingomyelin (d40:1) exhibiting the strongest association with male infertility.

Conclusion

These findings contribute to the current better understanding of male infertility and provide new perspectives on the underlying etiology of male infertility as well as prevention and treatment strategies. In addition, clinical trial validation is needed to assess the potential of these plasma lipidome as biomarkers.

Pathophysiology of obesity-related infertility and its prevention and treatment by potential phytotherapeutics

BACKGROUND

Obesity is a complex multifactorial disease in which the accumulation of excess body fat has adverse health effects, as it can increase the risk of several problems, including infertility, in both men and women. Obesity and infertility have risen together in recent years. Against this background, the present review aims to highlight the impact of obesity on infertility and the underlying pathophysiology of obesity-related infertility (ORI) in men and women, and to provide readers with knowledge of current trends in the effective development of phytotherapeutics for its treatment.

METHODS

We thoroughly searched in PubMed, MEDLINE, Scopus, EMBASE, and Google Scholar to find all relevant papers on ORI and the therapeutic effects of phytotherapeutics on ORI in men and women.

RESULTS

The extensive search of the available literature revealed that obesity affects reproductive function through several complex mechanisms such as hyperlipidaemia, hyperinsulinaemia, hyperandrogenism, increased body mass index, disruption of the hormonal milieu, systemic inflammation, oxidative stress, alterations in epigenetics and dysbiosis. On the other hand, several studies reported that phytotherapeutics has a broad therapeutic spectrum of action by improving sex hormone homeostasis, ovarian dysfunction, menstrual cycle and inhibiting ovarian hyperplasia, as well as down-regulating ovarian apoptosis, inflammation and oxidative stress, and controlling metabolic dysfunction in obese women. Male infertility is also addressed by phytotherapeutics by suppressing lipogenesis, increasing testosterone, 3β-HSD and 17β-HSD levels, improving sperm parameters and attenuating testicular dyslipidaemia, oxidative stress, inflammation and germ cell apoptosis.

CONCLUSIONS

In the present review, we discussed the effects of obesity on reproductive dysfunction in men and women and the underlying pathophysiology of ORI. In addition, the therapeutic effect of phytotherapeutics against ORI was highlighted.

Correlation between visceral adiposity index and erectile dysfunction in American adult males: a cross-sectional study based on NHANES

Background

The risk of visceral obesity on erectile function has recently attracted much attention. The visceral adiposity index (VAI) is a brief and reliable indicator of visceral obesity measurement. Nevertheless, the association between VAI and erectile dysfunction (ED) is not completely clarified.

Methods

Data from NHANES 2001-2004 were enrolled in this study. Erectile function was assessed by a database-self-administered questionnaire. VAI was calculated with body mass index (BMI), waist circumference (WC), triglyceride (TG), and high-density lipoprotein (HDL) cholesterol. The weighted logistic regression model was performed to evaluate the association between VAI and ED.

Results

Ultimately, 3380 participants were enrolled in the study, including 900 with ED and 2480 without ED. Compared to participants without ED, those with ED generally had higher levels of VAI (1.76 vs. 1.53). The weighted logistic regression analyses demonstrated increased odds of developing ED in participants within the 4th quartile (Q4) of VAI compared to the 1st quartile (Q1) of VAI (OR = 2.023; 95% CI, 1.534-2.669; P < 0.001). Similar results were still obtained after adjusting for the relevant covariates (OR = 1.404; 95% CI, 1.008-1.954; P = 0.044). In subgroup analyses grouped by smoking status, higher VAI was associated with increased odds of developing ED only in the current smoking group (OR = 1.092; 95% CI, 1.021-1.167; P = 0.010).

Conclusion

This study indicated that higher VAI is independently related to ED risk and that early intervention is necessary to reduce the progression of ED with high VAI levels.

Sperm DNA damage: The possible link between obesity and male infertility, an update of the current literature

Obesity prevalence worldwide is increasing significantly. Whilst maternal obesity has clear detrimental impacts on fertility, pregnancy and foetal outcomes, more recently there has been an increasing focus on the role of paternal obesity in human fertility. Recent meta-analyses have indicated that obesity in men negatively affects basic sperm parameters such as sperm count, concentration and motility, increases the incidence of infertility and reduces the chances of conception. Sperm DNA damage, typically characterised by DNA strand breaks and oxidation of DNA nucleotides, is a specialised marker of sperm quality that has been independently associated with recurrent miscarriage, reduced assisted reproduction success and increased mutational loads in subsequent offspring. Whilst, there are still conflicting data in humans as to the association of obesity in men with sperm DNA damage, evidence from rodent models is clear, indicating that male obesity increases sperm DNA damage. Human data are often conflicting because of the large heterogeneity amongst studies, the use of body mass index as the indicator of obesity and the methods used for detection of sperm DNA damage. Furthermore, comorbidities of obesity (i.e., heat stress, adipokines, insulin resistance, changes in lipids, hypogonadism and obstructive sleep apnoea) are also independently associated with increased sperm DNA damage that is not always modified in men with obesity, and as such may provide a causative link to the discrepancies amongst human studies. In this review, we provide an update on the literature regarding the associations between obesity in men and fertility, basic sperm parameters and sperm DNA damage. We further discuss potential reasons for the discrepancies in the literature and outline possible direct and indirect mechanisms of increased sperm DNA damage resulting from obesity. Finally, we summarise intergenerational obesity through the paternal linage and how sperm DNA damage may contribute to the transmission.

The impact of dietary fructose on gut permeability, microbiota, abdominal adiposity, insulin signaling and reproductive function

The excessive intake of fructose in the regular human diet could be related to global increases in metabolic disorders. Sugar-sweetened soft drinks, mostly consumed by children, adolescents, and young adults, are the main source of added fructose. Dietary high-fructose can increase intestinal permeability and circulatory endotoxin by changing the gut barrier function and microbial composition. Excess fructose transports to the liver and then triggers inflammation as well as de novo lipogenesis leading to hepatic steatosis. Fructose also induces fat deposition in adipose tissue by stimulating the expression of lipogenic genes, thus causing abdominal adiposity. Activation of the inflammatory pathway by fructose in target tissues is thought to contribute to the suppression of the insulin signaling pathway producing systemic insulin resistance. Moreover, there is some evidence that high intake of fructose negatively affects both male and female reproductive systems and may lead to infertility. This review addresses dietary high-fructose-induced deteriorations that are obvious, especially in gut permeability, microbiota, abdominal fat accumulation, insulin signaling, and reproductive function. The recognition of the detrimental effects of fructose and the development of relevant new public health policies are necessary in order to prevent diet-related metabolic disorders.

Relationship between testosterone-estradiol ratio and some anthropometric and metabolic parameters among Nigerian men

Background

Alterations in sex hormone levels are implicated in the regulation of metabolic processes in men. In recent years, the prevalence of metabolic disorders, such as obesity, insulin resistance, and type 2 diabetes, has risen in Nigeria. In men, these disorders may be associated with the ratio of serum testosterone to estradiol levels. Therefore, we investigated the relationship between the testosterone-estradiol (T/E2) ratio, anthropometry, and metabolic parameters in Nigerian men.

Method

Eighty-five adult men were recruited for this study. Participants' data such as age, weight, height, BMI, and waist circumference were collected. Plasma total testosterone and estradiol levels, as well as metabolic parameters such as fasting blood sugar, creatinine, urea, HDL cholesterol, total cholesterol, and triglycerides levels, were determined. The data were analyzed using SPSS version 25 software.

Results

Anthropometric parameters such as weight, height, BMI, and waist circumference showed a negative correlation with plasma T/E2 (r = -0.265, -0.288, -0.106, -0.204; p = 0.007, 0.004, 0.167, 0.061 respectively). However, the T/E2 ratio showed a positive correlation with the metabolic parameters such as fasting blood sugar, HDL cholesterol levels, plasma creatinine, and urea (r = 0.219, 0.096, 0.992, 0.152; p = 0.022, 0.192, <0.001, 0.082 respectively), while there were negative correlations with total cholesterol and triglycerides levels (r = -0.200, -0.083; p = 0.034, 0.226 respectively).

Conclusion

These findings show that there are significant correlations between the T/E2 ratio and weight, height, fasting blood sugar, creatinine, and urea, while there are no significant correlations between T/E2 ratio and BMI, waist circumference, HDL-cholesterol, and triglycerides.

Testosterone deficiency in non-obese type 2 diabetic male patients

BACKGROUND AND AIMS

it is unclear whether male hypogonadism is ascribable to the diabetic state per se, or because of other factors, such as obesity or age. We aimed to investigate the prevalence and identify the predictors for testosterone deficiency among non-obese type 2 diabetic males.

METHODS

This cross-sectional study was conducted on 95 nonobese type 2 diabetic males with BMI below 30. We evaluated the total testosterone (TT) levels to determine prevalence and risk factors of testosterone deficiency. Serum TT ≤ 300 ng/dl defined testosterone deficiency.

RESULTS

The prevalence of testosterone deficiency was 29.1%. Testosterone deficient patients had statistically significantly higher visceral adiposity index (VAI), waist, and triglyceride in comparison with normal testosterone patients. TT level correlated with VAI, waist, BMI, LH, and age. VAI was the only significant predictor of TT levels even after adjustment for age and BMI in regression analysis. Furthermore, VAI was a statistically significant risk factor for testosterone deficiency in binary logistic analysis.

CONCLUSIONS

testosterone deficient non-obese type 2 diabetic male patients had elevated VAI, waist, and triglyceride. Moreover, elevated VAI was a risk factor for testosterone deficiency. VAI could be an easily applicable and reliable index for the evaluation and prediction in type 2 non-obese diabetic males.

Association between hypertriglyceridemic waist phenotype and hypogonadism in Taiwanese adult men

Background

Aging-related hypogonadism in men is related to the deterioration of overall health. Those with this disease rarely receive treatment. The hypertriglyceridemic waist (HTGW) phenotype is a tool for predicting abnormalities of cardiovascular metabolism. However, the relationship between the HTGW phenotype and hypogonadism remains undetermined. This study aimed to determine the association between HTGW phenotype and hypogonadism in different age groups.

Methods

Data of this cross-sectional study were obtained from MJ Health Screening Center in Taiwan from 2007 to 2016. The HTGW phenotype was divided into four categories based on whether the waist circumference (WC) and triglyceride levels were normal. WC of <90 cm and triglyceride level of <150 mg/dL were defined as normal. Hypogonadism was defined as a testosterone level of <300 ng/dL.

Results

Overall, 6442 male participants were divided into three age groups: <50, 50–64, and ≥65 years (n = 4135, 1958, and 349; age groups 1, 2, and 3, respectively). The overall prevalence of hypogonadism was 10.6%. In group 1, participants with HTGW (odds ratio, 1.98; 95% confidence interval (CI), 1.354–2.896) had a higher risk of hypogonadism than those with normal WC and normal triglyceride levels after adjustment for body mass index and fasting blood glucose level. In group 2, participants with HTGW (odds ratio, 1.873; 95% CI, 1.099–3.193) had an increased risk of hypogonadism after adjustment for body mass index, fasting blood glucose level, Cholesterol levels, high-density lipoprotein (HDL) levels, low-density lipoprptein (LDL) levels and smoking status. However, no relationship was observed between HTGW phenotype and hypogonadism in group 3.

Conclusion

HTGW phenotype was highly associated with hypogonadism in Taiwanese adult men. More attention should be paid to men aged <50 years with HTGW.

Can Annual Daylight Cycles and Seasons Have an Effect on Male Sexual Functions?

Introduction Mammals' sexual functions exhibit seasonal variations that have been attributed to changes in the daylight. In this study, taking into consideration endocrine and psychogenic status, we aimed to investigate whether human males experience changes in erectile functions and sexual desire depending on daylight periods and seasons, and whether periodicity exists in human sexual behavior. Materials and methods International Index of Erectile Function (IIEF) and psychiatric scale scores of 221 male patients were evaluated. In addition, hormonal parameters of the patients were examined. These data were first evaluated in two groups (summer and winter) according to local daylight amounts the participants received. Then IIEF scores were also analyzed according to four conventional seasons (winter, spring, summer, and autumn). Results There was no significant difference in laboratory data, psychiatric scale scores and IIEF evaluations between summer and winter groups. Moreover, no significant difference was found in terms of sexual desire and erectile functions in terms of four seasons (p > 0.05). Conclusion According to the results of this study, there is no periodicity in human sexual functions both in relation to daylight and four seasons.