-
Cancer Causes & Control : CCC Aug 2022Observational studies and randomized controlled trials (RCTs) have shown an association between vitamin D levels and prostate cancer progression. However, evidence of... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Observational studies and randomized controlled trials (RCTs) have shown an association between vitamin D levels and prostate cancer progression. However, evidence of direct causality is sparse and studies have not examined biological mechanisms, which can provide information on plausibility and strengthen the evidence for causality.
METHODS
We used the World Cancer Research Fund International/University of Bristol two-stage framework for mechanistic systematic reviews. In stage one, both text mining of published literature and expert opinion identified testosterone as a plausible biological mechanism. In stage two, we performed a systematic review and meta-analysis to assess the evidence from both human and animal studies examining the effect of vitamin D on testosterone, and testosterone on advanced prostate cancer (diagnostic Gleason score of ≥ 8, development of metastasis) or prostate cancer-specific mortality.
RESULTS
A meta-analysis of ten human RCTs showed evidence of an effect of vitamin D on total testosterone (standardised mean difference (SMD) = 0.133, 95% CI = - 0.003-0.269, I = 0.0%, p = 0.056). Five human RCTs showed evidence of an effect of vitamin D on free testosterone (SMD = 0.173, 95% CI = - 0.104-0.450, I = 52.4%, p = 0.220). Three human cohort studies of testosterone on advanced prostate cancer or prostate cancer-specific mortality provided inconsistent results. In one study, higher levels of calculated free testosterone were positively associated with advanced prostate cancer or prostate cancer-specific mortality. In contrast, higher levels of dihydrotestosterone were associated with lowering prostate cancer-specific mortality in another study. No animal studies met the study eligibility criteria.
CONCLUSION
There is some evidence that vitamin D increases levels of total and free testosterone, although the effect of testosterone levels within the normal range on prostate cancer progression is unclear. The role of testosterone as a mechanism between vitamin D and prostate cancer progression remains inconclusive.
Topics: Humans; Male; Prostate; Prostatic Neoplasms; Testosterone; Vitamin D; Vitamins
PubMed: 35752985
DOI: 10.1007/s10552-022-01591-w -
The World Journal of Men's Health Oct 2020Since its discovery in December 2019, the novel coronavirus SARS-CoV-2 has spread globally, causing the current COVID-19 (coronavirus disease-19) pandemic. As there is...
PURPOSE
Since its discovery in December 2019, the novel coronavirus SARS-CoV-2 has spread globally, causing the current COVID-19 (coronavirus disease-19) pandemic. As there is an increase of infections in the male population, concerns have emerged about the potential impact of COVID-19 on male reproductive organs and male fertility. Therefore, this study systematically investigates the current evidence of SARS-CoV-2 impact on male reproduction and pregnancy outcomes, discussing them in light of the evidence published on other coronaviruses.
MATERIALS AND METHODS
Literature search was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 24 original articles were included for the analysis, investigating the effects of the infection on semen parameters, male reproductive hormones, and pregnancy outcomes. Further, a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis was conducted based on the available evidence linking the virus with male reproduction and conception.
RESULTS
Although there is limited data, viral mRNA has been identified in semen of infected men, with some evidence of altered seminal parameters. Low testosterone and dihydrotestosterone with raised luteinizing hormone has been reported as well as preterm delivery in pregnant women; however, data regarding vertical transmission remains contradictory and inconclusive.
CONCLUSIONS
The recent literature provides evidence that male gonads may be potentially vulnerable to SARS-CoV-2 infection, recommending caution to pregnant women and couples planning natural pregnancy or assisted reproduction.
PubMed: 32814369
DOI: 10.5534/wjmh.200134 -
Skin Health and Disease Jun 2021Androgenetic alopecia (AGA) is the most common form of non-scarring alopecia in humans. Several studies have used different laboratory models to study the pathogenesis...
BACKGROUND
Androgenetic alopecia (AGA) is the most common form of non-scarring alopecia in humans. Several studies have used different laboratory models to study the pathogenesis and interventions for AGA. These study models have proved beneficial and have led to the approval of two drugs. However, the need to build on existing knowledge remains by examining the relevance of study models to the disease.
OBJECTIVE
We sought to appraise laboratory or pre-clinical models of AGA.
METHOD
We searched through databases (PubMed, ScienceDirect, Web of Science, World CAT, Scopus and Google Scholar) for articles on AGA-related studies from 1942 to March 2019 with a focus on study models.
RESULTS
The search rendered 101 studies after screening and deduplication. Several studies (70) used in vitro models, mostly consisting of two-dimensional monolayer cells for experiments involving the characterization of androgen and 5-alpha reductase (5AR) and inhibition thereof, the effects of dihydrotestosterone (DHT) and biomarker(s) of AGA. Twenty-seven studies used in vivo models of mice and monkeys to investigate DHT synthesis, the expression and inhibition of 5AR and hair growth. Only four studies used AGA-related or healthy excisional/punch biopsy explants as ex vivo models to study the action of 5AR inhibitors and AGA-associated genes. No study used three-dimensional [3-D] organoids or organotypic human skin culture models.
CONCLUSION
We recommend clinically relevant laboratory models like human or patient-derived 3-D organoids or organotypic skin in AGA-related studies. These models are closer to human scalp tissue and minimize the use of laboratory animals and could ultimately facilitate novel therapeutics.
PubMed: 35664985
DOI: 10.1002/ski2.15 -
Diagnostics (Basel, Switzerland) Aug 2023The aim of this systematic review is to provide a comprehensive overview of the role of fluoro-5α-dihydrotestosterone ([F]-FDHT) for the in vivo imaging of androgen... (Review)
Review
The aim of this systematic review is to provide a comprehensive overview of the role of fluoro-5α-dihydrotestosterone ([F]-FDHT) for the in vivo imaging of androgen receptors (AR) through positron emission tomography (PET) in metastatic breast (mBC) and metastatic castration-resistant prostate cancer (mCRPC). Relevant studies published from 2013 up to May 2023 were selected by searching Scopus, PubMed and Web of Science. The selected imaging studies were analyzed using a modified version of the critical Appraisal Skills Programme (CASP). Eleven studies encompassing 321 patients were selected. Seven of the eleven selected papers included 266 subjects (82.2%) affected by mCRPC, while four encompassed 55 (17.2%) patients affected by mBC. [F]-FDHT PET showed a satisfying test/retest reproducibility, and when compared to a histochemical analysis, it provided encouraging results for in vivo AR quantification both in mCRPC and mBC. [F]-FDHT PET had a prognostic relevance in mCRPC patients submitted to AR-targeted therapy, while a clear association between [F]-FDHT uptake and the bicalutamide response was not observed in women affected by AR-positive mBC. Further studies are needed to better define the role of [F]-FDHT PET, alone or in combination with other tracers (i.e., [F]-FDG/[F]-FES), for patients' selection and monitoring during AR-targeted therapy, especially in the case of mBC.
PubMed: 37568977
DOI: 10.3390/diagnostics13152613