Prof. Ralf Henkel
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| Position: | Head of Department and Deputy Dean for Postgraduate Studies |
| Department: | Medical BioScience |
| Faculty: | Natural Sciences |
| Qualifications: | BEd, PhD, Habil |
| My publications in this repository | |
| Tel: | 021 959 2332 |
| Fax: | 021 959 3125 |
| Email: | rhenkel@uwc.ac.za |
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Browsing by Author "Leisegang, Kristian"
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Item Effect of the metabolic syndrome on male reproductive function: a case-controlled pilot study(Wiley, 2014) Leisegang, Kristian; Bouic, Patrick J.D.; Henkel, RalfThe metabolic syndrome (MetS) is a constellation of various risk factors. This study aimed to investigate the effect of MetS on testosterone and progesterone, and semen parameters, in a case-controlled pilot study. Male patients (n = 54) had body mass index, waist-to-hip ratio (WHR) and blood pressure recorded. Blood was analysed for HDL cholesterol, triglycerides and glucose. Saliva was assayed for free testosterone and free progesterone. Ejaculates were analysed for volume, sperm concentration, total sperm count, motility, vitality, mitochondrial membrane potential (MMP), DNA fragmentation and leucocyte concentration. Participants were divided into the control group (n = 28) and the MetS group (n = 26). Differences were found between the groups for body mass index, WHR, blood pressure, high-density lipoprotein (HDL), triglycerides and glucose. The MetS group showed significant reductions in sperm concentration (P = 0.0026), total sperm count (P = 0.0034), total motility (P = 0.0291), sperm vitality (P = 0.002), MMP (P = 0.0039), free testosterone (P = 0.0093) and free progesterone (P = 0.0130), while values for DNA fragmentation increased (P = 0.0287). Results indicate that patients with MetS have compromised sperm parameters in the absence of leucocytospermia. A reduction in free progesterone suggests that steroidogenesis cascades may be compromised. It is hypothesised that a systemic pro-inflammatory state with oxidative stress associated with MetS may provide a novel explanation.Item The impact of Covid-19 vaccines on male semen parameters: A retrospective cohort study(University of the Western Cape, 2023) Henkel, Ralf; Leisegang, Kristian; Finelli, RenataThe emergence of SARS-CoV-2 and the subsequent COVID-19 pandemic necessitated the development of adequate vaccines. Despite vaccines being demonstrated to be safe and effective for preventing severe disease and death, vaccine hesitancy remains. Reasons include concerns over adverse effects on male fertility, which have not been widely investigated. Therefore, this study is aimed at determining the impact of COVID-19 vaccination on semen parameters in a retrospective cohort study of South African males undergoing fertility assessment. The patients for this study were adult men who have previously undergone routine semen analysis for fertility assessment at Androcryos Andrology Laboratory (Johannesburg, South Africa) between March 2021 and March 2022. They also received vaccination within 3 months following a semen analysis and underwent a second semen analysis any time post-COVID-19 vaccination. From 277 records analysed, 46 patients met the inclusion criteria, receiving the Pfizer-BioNTech (BNT162b1) (63%), Johnson and Johnson (JNJ-78436735/Ad26.COV2S) (34.8%), and the AstraZeneca (AZD1222) (2.2%) vaccines. Sperm concentration significantly increased postvaccination (P = 0:0001), with no significant changes in semen pH, volume, total sperm count, progressive motility, normal sperm morphology, or chromatin condensation. Results were not influenced by age, type of vaccine received, and the number of days following vaccination, as depicted by multiple regression analysis. In conclusion, there is no evidence of a negative impact of COVID-19 vaccination on male semen parameters, which is consistent with the emerging literature on COVID-19 vaccination and male fertility. COVID-19 vaccinations should not be dismissed based on fear of adverse effects on male fertility parameters.Item The impact of male overweight on semen quality and outcome of assisted reproduction(Medknow Publications, 2014) Leisegang, Kristian; Henkel, RalfThe impact of obesity on male reproductive health remains a contested topic as evidence is inconclusive and inconsistent. Even more debatable is the effect of male obesity in assisted reproduction. In the manuscript, “the impact of male overweight on semen quality and outcome of assisted reproduction” published in Asian Journal of Andrology, Thomsen et al. investigated the effect of male obesity on fertilization outcomes in intrauterine insemination, in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) programs further contributes to the increasing body of evidence in this field.Item Obesity is associated with increased seminal insulin and leptin alongside reduced fertility parameters in a controlled male cohort(BioMed Central, 2014) Leisegang, Kristian; Menkveld, Roelof; Bouic, Patrick J.D.; Henkel, RalfObesity appears to be associated with male reproductive dysfunction and infertility, although this has been inconsistent and inconclusive. Insulin and leptin are known mediators and modulators of the hypothalamus-pituitary-testes axis, contributing to the regulation of male reproductive potential and overall wellbeing. These hormones are also present in semen influencing sperm functions. Although abdominal obesity is closely associated with insulin resistance (hyperinsulinaemia), hyperleptinaemia and glucose dysfunction, changes in seminal plasma concentrations of insulin, leptin and glucose in obese males has not previously been investigated.