Resveratrol and male infertility: a systematic review of the literature

INTRODUCTION

The aim of this study is to provide an updated and comprehensive systematic review on the effects of resveratrol (RSV) in male infertility and sperm preservation.

EVIDENCE ACQUISITION

This systematic review followed the MOOSE guidelines for Meta-analyses and Systematic Reviews of Observational Studies and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P). Only original articles evaluating the effect of RSV on human spermatozoa in vivo or in vitro were included.

EVIDENCE SYNTHESIS

Of the 1806 abstracts evaluated for eligibility, only 12 studies were included in the qualitative synthesis, of which three were prospective in-vivo studies and nine were in-vitro studies. Out of three human studies on RSV, only two studies administered RSV alone, one of them reported a positive impact and the other reported no significant impact on semen parameters. Overall, the in-vitro studies have reported the ability of RSV to protect spermatozoa against damage due to freeze-thaw cycles during cryopreservation. Other in-vitro studies have reported positive effects of RSV in fresh samples and protective effects in cell lines.

CONCLUSIONS

Available in-vivo studies are controversial with regard to the effect of RSV in improving semen parameters. In-vitro studies support the use of RSV before sperm cryopreservation. Further well-designed prospective studies on large sample sizes are needed to fully understand the role of RSV in the treatment of male infertility in vivo.

Dapagliflozin improves erectile dysfunction in patients with type 2 diabetes mellitus: An open-label, non-randomized pilot study

INTRODUCTION

The role of dapagliflozin on erectile dysfunction (ED), a condition widely affecting patients with type 2 diabetes mellitus (T2DM), has not yet been studied.

AIM

The aim of the study was to evaluate the effects of dapagliflozin alone or in combination with tadalafil on ED in patients with T2DM.

METHODS

This was an open-label, non-randomized pilot study involving 30 Caucasian male patients with T2DM and severe ED. They were equally divided into three groups, assigned to treatment with tadalafil 5 mg/day (Group 1), tadalafil 5 mg/day plus dapagliflozin 10 mg/day (Group 2) and dapagliflozin 10 mg/day (Group 3) for 3 months. The presence and the severity of ED were evaluated at enrolment and after treatment, by the International Index of Erectile Function 5-item (IIEF-5) questionnaire and the dynamic penile echo colour Doppler ultrasound (PCDU) examination.

RESULTS

At the end of treatment, the three groups showed a significant improvement in IIEF-5 score, by 294%, 375% and 197%, in Groups 1, 2 and 3, respectively. PCDU evaluation showed a significant increase in peak systolic velocity by 178.9%, 339% and 153%; acceleration time was significantly shortened in Group 2 (-26.2%) and was significantly lower than in Group 1 and 3 (-7.2% and -6.6%), while no significant difference was found in end-diastolic velocity after treatment. The greatest rates of improvement were observed in Group 2 for all the end points.

CONCLUSIONS

Dapagliflozin improves ED in patients with T2DM and enhances the efficacy of tadalafil. Further studies are needed to confirm our results explain the mechanism(s) by which dapagliflozin exerts its effects on ED.

The Role of Irisin throughout Women's Life Span

Since its discovery, much attention has been drawn to irisin's potential role in metabolic and reproductive diseases. This narrative review summarizes and updates the possible role played by this fascinating molecule in different physiological (puberty and menopause) and pathological (polycystic ovary syndrome (PCOS), functional hypothalamic amenorrhea (FHA), endometriosis, and gestational diabetes) conditions that can affect women throughout their entire lives. Irisin appears to be an important factor for the hypothalamic-pituitary-gonadal axis activation, and appears to play a role in the timing of puberty onset. Serum irisin levels have been proposed as a biomarker for predicting the future development of gestational diabetes (GDM). Its role in PCOS is still controversial, although an "irisin resistance" mechanism has been hypothesized. In addition to its impact on metabolism, irisin also appears to influence bone health. Irisin levels are inversely correlated with the prevalence of fractures in postmenopausal women. Similar mechanisms have also been postulated in young women with FHA. In clinical settings, further controlled, prospective and randomized clinical trials are needed to investigate the casual relationship between irisin levels and the conditions described and, in turn, to establish the role of irisin as a prognostic/diagnostic biomarker or a therapeutic target.

Predictive role of 17α-hydroxy-progesterone serum levels of response to follicle-stimulating hormone in patients with abnormal sperm parameters

OBJECTIVES

To study the possible role of serum 17α-hydroxy-progesterone (17αOH-P) levels in predicting favorable responses to follicle-stimulating hormone (FSH) administration in patients with normal serum FSH levels and idiopathic abnormal sperm parameters.

DESIGN

Prospective cohort study.

SETTING

University-affiliated fertility center.

PATIENTS

Fifty patients with oligozoospermia, asthenozoospermia, and/or teratozoospermia and normal serum levels of gonadotropins and total testosterone (TT).

INTERVENTION

Treatment with exogenous FSH is administered subcutaneously at a dose of 150 IU 3 times a week for 3 consecutive months.

MAIN OUTCOME MEASURE(S)

Luteinizing hormone levels, FSH levels, TT levels, 17αOH-P levels, testicular volume, conventional sperm parameters, and seminal spermatid concentration were evaluated before and after therapy. To evaluate the predictive role of pretreatment serum 17αOH-P levels on FSH responsiveness, the doubling of sperm concentration at the end of the FSH administration was considered a positive outcome.

RESULTS

After therapy, patients showed a significant increase in sperm concentration, total sperm count (TSC), progressive motility, percentage of normal forms, FSH levels, TT levels, and testicular volume. There was a negative correlation between pretreatment 17αOH-P levels and the posttreatment increase in sperm concentration, TSC, progressive motility, and normal morphology, and a positive correlation with the posttreatment increase in spermatids. Predictive analysis showed that 17αOH-P levels (<1.18 ng/mL) foretold a doubling of sperm concentration with a sensitivity of 90.0% and a specificity of 73.3%, and of TSC with a sensitivity of 91.3% and a specificity of 81.48%.

CONCLUSION

The results of this study suggest that pretreatment serum levels of 17αOH-P, a marker of steroidogenic function, appear to be able to predict the success of subcutaneous administration of exogenous FSH in terms of spermatogenesis improvement. Receiver operating characteristic curves indicated that 17αOH-P levels (<1.18 ng/mL) predict a doubling of sperm concentration and TSC after exogenous FSH administration to patients with idiopathic abnormal sperm parameters and normal gonadotropin levels.

Relationship between Iron Deficiency and Thyroid Function: A Systematic Review and Meta-Analysis

Objective: Iron deficiency (ID) is the most prevalent nutritional deficiency worldwide. Low levels of serum ferritin (SF) could affect the thyroid gland and its functioning. The purpose of this systematic review and meta-analysis is to summarize the main currently available evidence and analyze data on the relationship between ID and thyroid function. Methods: This study included all articles evaluating the relationship between ID and thyroid function. Quality assessment was performed using Cambridge Quality Checklists. The search strategy included the following combination of Medical Subjects Headings terms and keywords: "iron deficiency", "thyroid function", "thyroid disease", "thyroid dysfunction", and "hypothyroidism". A meta-analysis was performed to evaluate whether thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) levels differed between patients with ID and healthy controls without ID. For statistical comparison between cases and controls, the mean difference (MD) was calculated, and a subgroup analysis of pregnant and non-pregnant women was performed. Cochran's Q testing and heterogeneity indices (I2) were used to assess statistical heterogeneity. Sensitivity analysis and publication bias analyses were also performed, both qualitatively and quantitatively. Finally, a meta-regression analysis was performed to evaluate the correlation between serum TSH or FT4 levels and SF in the study population. Results: Ten cross-sectional studies were identified and reviewed. Patients with ID showed TSH (MD: -0.24 mIU/L; 95% CI -0.41, -0.07; I2 = 100%, p = 0.005), FT4 (MD: -1.18 pmol/L; 95% CI -1.43, -0.94; I2 = 99%, p < 0.000001), and FT3 (MD: -0.22 pmol/L; 95% CI -0.32, -0.12; I2 = 99%, p < 0.00001) levels that were significantly lower. Subgroup analysis confirmed significantly lower TSH, FT4, and FT3 levels in pregnant women. Non-pregnant women showed significantly lower serum FT4 and FT3 levels but no difference in TSH values. Meta-regression analysis showed that serum TSH and FT4 levels were positively correlated with SF levels. Our systematic review of the literature found that ID significantly increases the prevalence of thyroid autoantibody (anti-thyroglobulin antibodies and anti-thyroid peroxidase antibodies) positivity both individually and collectively. Conclusion: Studies currently published in the literature indicate a possible relationship between ID, thyroid function, and autoimmunity, especially in some patient groups. Data analysis shows that thyroid hormone levels are lower in patients with ID and, in particular, in pregnant women. Further studies are needed to understand the role played by iron in thyroid metabolism.

Testosterone replacement therapy and vascular thromboembolic events: a systematic review and meta-analysis

ABSTRACT

To evaluate the relationship between testosterone replacement therapy (TRT) and arterial and/or venous thrombosis in patients with pre-treatment total testosterone (TT) <12 nmol l-1, we performed a meta-analysis following the Population Intervention Comparison Outcome model. Population: men with TT <12 nmol l-1 or clear mention of hypogonadism in the inclusion criteria of patients; intervention: TRT; comparison: placebo or no therapy; outcomes: arterial thrombotic events (stroke, myocardial infarction [MI], upper limbs, and lower limbs), VTE (deep vein thrombosis [DVT], portal vein thrombosis, splenic thrombosis, and pulmonary embolism), and mortality. A total of 2423 abstracts were assessed for eligibility. Twenty-four studies, including 14 randomized controlled trials (RCTs), were finally included, with a total of 4027 and 310 288 hypotestosteronemic male patients, from RCTs and from observational studies, respectively. Based on RCT-derived data, TRT did not influence the risk of arterial thrombosis (odds ratio [OR] = 1.27, 95% confidence interval [CI]: 0.47-3.43, P = 0.64), stroke (OR = 1.34, 95% CI: 0.09-18.97, P = 0.83), MI (OR = 0.51, 95% CI: 0.11-2.31, P = 0.39), VTE (OR = 1.42, 95% CI: 0.22-9.03, P = 0.71), pulmonary embolism (OR = 1.38, 95% CI: 0.27-7.04, P = 0.70), and mortality (OR = 0.70, 95% CI: 0.20-2.38, P = 0.56). Meanwhile, when only observational studies are considered, a significant reduction in the risk of developing arterial thrombotic events, MI, venous thromboembolism, and mortality was observed. The risk for DVT remains uncertain, due to the paucity of RCT-based data. TRT in men with TT <12 nmol l-1 is safe from the risk of adverse cardiovascular events. Further studies specifically assessing the risk of DVT in men on TRT are needed.

Effects of the ketogenic diet on bone health: A systematic review

OBJECTIVE

To carry out a systematic review of published studies to evaluate the relationship between different type of ketogenic diet (KD) and bone health as supported by the scientific literature.

METHODS

The study involved all articles that assessed the relationship between the use of KD for the treatment of overweight or obesity and bone health. The quality assessment was evaluated with using the Cambridge Quality Checklists. The search strategy included the following combination of Medical Subjects Headings terms and keywords: "osteoporosis", "bone health, "bone function", "bone mineral density", and "ketogenic diet".

RESULTS

Seven trials were identified and reviewed. No significant changes in bone mass density (BMD) were observed after KD. The results showed no significant effect on bone resorption by measuring urinary N-telopeptide levels, on bone formation by measuring bone-specific alkaline phosphatase, or alterations in overall bone turnover in patients who followed KD. Only in female subject after a 10% weight loss, bone resorption increases while new bone synthesis decreases, but without increasing the risk of osteoporosis. Finally, patients on KD lost significantly more weight than controls, associated with an increase in serum vitamin D levels and a reduction in plasma parathyroid hormone (PTH) levels.

CONCLUSION

No human studies have currently been conducted with adequate and powerful experimental designs to definitively understand the impact of KD therapy on bone health.

Resistance to Thyroid Hormones: A Case-Series Study

The aim of the study is to describe the clinical features of two unrelated patients with resistance to thyroid hormones (RTH), the first, a total thyroidectomized patient, and the second, a pregnant woman. We report the features found in her newborn who also showed RTH. Patient 1 is a 38-year-old man with total thyroidectomy managed for excessive thyroid stimulating hormone (TSH) production, which poorly responded to the replacement therapy. He was found with a THRβ c.1378G>A p.(Glu460Lys) heterozygous mutation, which was also present in other members of his family (son, brother, and father). Interestingly, Patient 1 had hypertension, dyslipidemia, and hepatic steatosis, which have been recently suggested as RTH-related comorbidities. Patient 2 is a 32-year-old pregnant woman with multinodular goiter, and the THRβ heterozygous variant c.959G>C, that, to the best of our knowledge, has been reported in literature only once. Her newborn had tachycardia and increased thyroid hormone levels, and showed the same mutation. After delivery, high parathyroid hormone (PTH) and calcium serum levels were found in Patient 2 and the scintigraphy showed the presence of adenoma of a parathyroid gland. This case-series study provides a practical example of the management of RTH in a thyroidectomized patient, a pregnant woman, and a newborn. A novel RTH pathogenic mutation is described for the second time in literature. Furthermore, the importance of metabolic assessment in patients with RTHβ has been highlighted and the possible correlation between RTH and primary hyperparathyroidism is discussed.

Management of antiplatelet or anticoagulant therapy in endoscopy: A review of literature

Endoscopic procedures hold a basal risk of bleeding that depends on the type of procedure and patients’ comorbidities. Moreover, they are often performed in patients taking antiplatelet and anticoagulants agents, increasing the potential risk of intraprocedural and delayed bleeding. Even if the interruption of antithrombotic therapies is undoubtful effective in reducing the risk of bleeding, the thromboembolic risk that follows their suspension should not be underestimated. Therefore, it is fundamental for each endoscopist to be aware of the bleeding risk for every procedure, in order to measure the risk-benefit ratio for each patient. Moreover, knowledge of the proper management of antithrombotic agents before endoscopy, as well as the adequate timing for their resumption is essential.

This review aims to analyze current evidence from literature assessing, for each procedure, the basal risk of bleeding and the risk of bleeding in patients taking antithrombotic therapy, as well as to review the recommendation of American society for gastrointestinal endoscopy, European society of gastrointestinal endoscopy, British society of gastroenterology, Asian pacific association of gastroenterology and Asian pacific society for digestive endoscopy guidelines for the management of antithrombotic agents in urgent and elective endoscopic procedures.

Nonlinear diffusion and thermo-electric coupling in a two-variable model of cardiac action potential

This work reports the results of the theoretical investigation of nonlinear dynamics and spiral wave breakup in a generalized two-variable model of cardiac action potential accounting for thermo-electric coupling and diffusion nonlinearities. As customary in excitable media, the common Q₁₀ and Moore factors are used to describe thermo-electric feedback in a 10° range. Motivated by the porous nature of the cardiac tissue, in this study we also propose a nonlinear Fickian flux formulated by Taylor expanding the voltage dependent diffusion coefficient up to quadratic terms. A fine tuning of the diffusive parameters is performed a priori to match the conduction velocity of the equivalent cable model. The resulting combined effects are then studied by numerically simulating different stimulation protocols on a one-dimensional cable. Model features are compared in terms of action potential morphology, restitution curves, frequency spectra, and spatio-temporal phase differences. Two-dimensional long-run simulations are finally performed to characterize spiral breakup during sustained fibrillation at different thermal states. Temperature and nonlinear diffusion effects are found to impact the repolarization phase of the action potential wave with non-monotone patterns and to increase the propensity of arrhythmogenesis.

Effect of taurine supplementation on fat and energy absorption in cystic fibrosis

In 10 children with cystic fibrosis and persisting steatorrhoea, supplementation with taurine (30-40 mg/kg/day) was given for two months as an adjunct to the usual pancreatic enzyme treatment. A three day fat and energy balance was performed in patients with cystic fibrosis, before and after the supplementation, and in seven healthy controls who did not receive taurine. Faecal fat was measured by a gravimetric method and stool energy was determined using a bomb calorimeter. Patients with cystic fibrosis, before and after taurine, and healthy controls received the same fat and energy intake (calculated by a dietitian). In patients with cystic fibrosis taurine did not produce any improvement of steatorrhoea (mean (SD) faecal fat 8.7 (3.3) v 11.2 (7.0) g/day, respectively before and after the supplementation), of faecal energy loss (0.978 (0.468) v 1.133 (0.539) MJ/day), of faecal fat expressed as percent of fat intake (13.4 (5.6) v 15.1 (9.8)%), and of faecal energy expressed as percent of energy intake (9.9 (3.6) v 11.2 (5.7)%). Healthy controls had significant lower fat (3.5 (2.3) g/day) and energy 0.576 (0.355) MJ/day faecal losses. In conclusion, taurine failed to decrease significantly fat and energy losses. Our study does not support the use of taurine supplementation in the nutritional management of cystic fibrosis.