Imperial College London

ProfessorWaljitDhillo

Faculty of MedicineDepartment of Metabolism, Digestion and Reproduction

Professor of Endocrinology & Metabolism
 
 
 
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Contact

 

+44 (0)20 7594 3487w.dhillo Website

 
 
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Assistant

 

Ms Suzanne Wheeler +44 (0)20 7594 3487

 
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Location

 

6N6ECommonwealth BuildingHammersmith Campus

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Summary

 

Publications

Publication Type
Year
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359 results found

Barratt J, Sharp D, Dhillo WS, Pugh Cet al., 2024, Unwelcome changes to the Specialised Foundation Programme recruitment., Lancet, Vol: 403

Journal article

Eng PC, Phylactou M, Qayum A, Woods C, Lee H, Aziz S, Moore B, Miras AD, Comninos AN, Tan T, Franks S, Dhillo WS, Abbara Aet al., 2024, Obesity-related hypogonadism in women, Endocrine Reviews, Vol: 45, Pages: 171-189, ISSN: 0079-9963

Obesity-related hypogonadotropic hypogonadism is a well-characterized condition in men (termed male obesity-related secondary hypogonadism; MOSH); however, an equivalent condition has not been as clearly described in women. The prevalence of polycystic ovary syndrome (PCOS) is known to increase with obesity, but PCOS is more typically characterized by increased gonadotropin-releasing hormone (GnRH) (and by proxy luteinizing hormone; LH) pulsatility, rather than by the reduced gonadotropin levels observed in MOSH. Notably, LH levels and LH pulse amplitude are reduced with obesity, both in women with and without PCOS, suggesting that an obesity-related secondary hypogonadism may also exist in women akin to MOSH in men. Herein, we examine the evidence for the existence of a putative non-PCOS “female obesity-related secondary hypogonadism” (FOSH). We précis possible underlying mechanisms for the occurrence of hypogonadism in this context and consider how such mechanisms differ from MOSH in men, and from PCOS in women without obesity. In this review, we consider relevant etiological factors that are altered in obesity and that could impact on GnRH pulsatility to ascertain whether they could contribute to obesity-related secondary hypogonadism including: anti-Müllerian hormone, androgen, insulin, fatty acid, adiponectin, and leptin. More precise phenotyping of hypogonadism in women with obesity could provide further validation for non-PCOS FOSH and preface the ability to define/investigate such a condition.

Journal article

Hanassab S, Abbara A, Yeung AC, Voliotis M, Tsaneva-Atanasova K, Kelsey TW, Trew GH, Nelson SM, Heinis T, Dhillo WSet al., 2024, The prospect of artificial intelligence to personalize assisted reproductive technology, npj Digital Medicine, Vol: 7, Pages: 1-19, ISSN: 2398-6352

Infertility affects 1-in-6 couples, with repeated intensive cycles of assisted reproductive technology (ART) required by many to achieve a desired live birth. In ART, typically, clinicians and laboratory staff consider patient characteristics, previous treatment responses, and ongoing monitoring to determine treatment decisions. However, the reproducibility, weighting, and interpretation of these characteristics are contentious, and highly operator-dependent, resulting in considerable reliance on clinical experience. Artificial intelligence (AI) is ideally suited to handle, process, and analyze large, dynamic, temporal datasets with multiple intermediary outcomes that are generated during an ART cycle. Here, we review how AI has demonstrated potential for optimization and personalization of key steps in a reproducible manner, including: drug selection and dosing, cycle monitoring, induction of oocyte maturation, and selection of the most competent gametes and embryos, to improve the overall efficacy and safety of ART.

Journal article

Garg A, Zielinska AP, Yeung AC, Abdelmalak R, Chen R, Hossain A, Israni A, Nelson SM, Babwah AV, Dhillo WS, Abbara Aet al., 2024, Luteal phase support in assisted reproductive technology., Nat Rev Endocrinol, Vol: 20, Pages: 149-167

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.

Journal article

Hernández R, de Silva NL, Hudson J, Cruickshank M, Quinton R, Manson P, Dhillo WS, Bhattacharya S, Brazzelli M, Jayasena CNet al., 2024, Cost-effectiveness of testosterone treatment utilising individual patient data from randomised controlled trials in men with low testosterone levels., Andrology, Vol: 12, Pages: 477-486

BACKGROUND: Testosterone is safe and highly effective in men with organic hypogonadism, but worldwide testosterone prescribing has recently shifted towards middle-aged and older men, mostly with low testosterone related to age, diabetes and obesity, for whom there is less established evidence of clinical safety and benefit. The value of testosterone treatment in middle-aged and older men with low testosterone is yet to be determined. We therefore evaluated the cost-effectiveness of testosterone treatment in such men with low testosterone compared with no treatment. METHODS: A cost-utility analysis comparing testosterone with no treatment was conducted following best practices in decision modelling. A cohort Markov model incorporating relevant care pathways for individuals with hypogonadism was developed for a 10-year-time horizon. Clinical outcomes were obtained from an individual patient meta-analysis of placebo-controlled, double-blind randomised studies. Three starting age categories were defined: 40, 60 and 75 years. Cost utility (quality-adjusted life years) accrued and costs of testosterone treatment, monitoring and cardiovascular complications were compared to estimate incremental cost-effectiveness ratios and cost-effectiveness acceptability curves for selected scenarios. RESULTS: Ten-year excess treatment costs for testosterone compared with non-treatment ranged between £2306 and £3269 per patient. Quality-adjusted life years results depended on the instruments used to measure health utilities. Using Beck depression index-derived quality-adjusted life years data, testosterone was cost-effective (incremental cost-effectiveness ratio <£20,000) for men aged <75 years, regardless of morbidity and mortality sensitivity analyses. Testosterone was not cost-effective in men aged >75 years in models assuming increased morbidity and/or mortality. CONCLUSIONS AND FUTURE RESEARCH: Our data suggest that testosterone is cost-effective in men &l

Journal article

Mowla S, Farahani L, Tharakan T, Davies R, Correia G, Lee Y, Kundu S, Khanjani S, Sindi ERB, Rai R, Regan L, Khalifa D, Henkel R, Minhas S, Dhillo W, Nagi JB, Bennett P, MacIntyre D, Jayasena Cet al., 2024, Characterisation and comparison of semen microbiota and sperm function in men with infertility, recurrent miscarriage, or proven fertility, eLife, ISSN: 2050-084X

Journal article

Sharma A, Papanikolaou N, Abou Sherif S, Dimakopoulou A, Thaventhiran T, Go C, Holtermann Entwistle O, Brown A, Luo R, Jha R, Prakash A, Khalifa D, Lewis H, Ramaraju S, Leeds A, Chahal H, Purkayastha S, Henkel R, Minhas S, Frost G, Dhillo W, Jayasena Cet al., 2024, Improvements in sperm motility following low or high intensity dietary interventions in men with obesity, Journal of Clinical Endocrinology and Metabolism, Vol: 109, Pages: 449-460, ISSN: 0021-972X

Introduction:Obesity increases risks of male infertility, but bariatric surgery does not improve semen quality. Recent uncontrolled studies suggest that a low-energy diet (LED) improves semen quality. Further evaluation within a randomized, controlled setting is warranted.Methods:Men with obesity (18-60 years) with normal sperm concentration (normal count) (n = 24) or oligozoospermia (n = 43) were randomized 1:1 to either 800 kcal/day LED for 16 weeks or control, brief dietary intervention (BDI) with 16 weeks’ observation. Semen parameters were compared at baseline and 16 weeks.Results:Mean age of men with normal count was 39.4 ± 6.4 in BDI and 40.2 ± 9.6 years in the LED group. Mean age of men with oligozoospermia was 39.5 ± 7.5 in BDI and 37.7 ± 6.6 years in the LED group. LED caused more weight loss than BDI in men with normal count (14.4 vs 6.3 kg; P < .001) and men with oligozoospermia (17.6 vs 1.8 kg; P < .001). Compared with baseline, in men with normal count total motility (TM) increased 48 ± 17% to 60 ± 10% (P < .05) after LED, and 52 ± 8% to 61 ± 6% (P < .0001) after BDI; progressive motility (PM) increased 41 ± 16% to 53 ± 10% (P < .05) after LED, and 45 ± 8% to 54 ± 65% (P < .001) after BDI. In men with oligozoospermia compared with baseline, TM increased 35% [26] to 52% [16] (P < .05) after LED, and 43% [28] to 50% [23] (P = .0587) after BDI; PM increased 29% [23] to 46% [18] (P < .05) after LED, and 33% [25] to 44% [25] (P < .05) after BDI. No differences in postintervention TM or PM were observed between LED and BDI groups in men with normal count or oligozoospermia.Conclusion:LED or BDI may be sufficient to improve sperm motility in men with obesity. The effects of paternal dietary intervention on fertility outcomes requires investigation.

Journal article

Voliotis M, Abbara A, Prague JK, Veldhuis JD, Dhillo WS, Tsaneva-Atanasova Ket al., 2024, HormoneBayes: A novel Bayesian framework for the analysis of pulsatile hormone dynamics., PLoS Comput Biol, Vol: 20

The hypothalamus is the central regulator of reproductive hormone secretion. Pulsatile secretion of gonadotropin releasing hormone (GnRH) is fundamental to physiological stimulation of the pituitary gland to release luteinizing hormone (LH) and follicle stimulating hormone (FSH). Furthermore, GnRH pulsatility is altered in common reproductive disorders such as polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea (HA). LH is measured routinely in clinical practice using an automated chemiluminescent immunoassay method and is the gold standard surrogate marker of GnRH. LH can be measured at frequent intervals (e.g., 10 minutely) to assess GnRH/LH pulsatility. However, this is rarely done in clinical practice because it is resource intensive, and there is no open-access, graphical interface software for computational analysis of the LH data available to clinicians. Here we present hormoneBayes, a novel open-access Bayesian framework that can be easily applied to reliably analyze serial LH measurements to assess LH pulsatility. The framework utilizes parsimonious models to simulate hypothalamic signals that drive LH dynamics, together with state-of-the-art (sequential) Monte-Carlo methods to infer key parameters and latent hypothalamic dynamics. We show that this method provides estimates for key pulse parameters including inter-pulse interval, secretion and clearance rates and identifies LH pulses in line with the widely used deconvolution method. We show that these parameters can distinguish LH pulsatility in different clinical contexts including in reproductive health and disease in men and women (e.g., healthy men, healthy women before and after menopause, women with HA or PCOS). A further advantage of hormoneBayes is that our mathematical approach provides a quantified estimation of uncertainty. Our framework will complement methods enabling real-time in-vivo hormone monitoring and therefore has the potential to assist translation of personalized, data-driv

Journal article

Abbara A, Adams S, Phylactou M, Izzi-Engbeaya C, Mills EG, Thurston L, Koysombat K, Hanassab S, Heinis T, M-M Tan T, Tsaneva-Atanasova K, Comninos AN, Voliotis M, Dhillo WSet al., 2024, Quantifying the variability in the assessment of reproductive hormone levels, Fertility and Sterility, Vol: 121, Pages: 334-345, ISSN: 0015-0282

OBJECTIVE: To quantify how representative a single measure of reproductive hormone is of the daily hormonal profile using data from detailed hormonal sampling in the saline placebo-treated arm conducted over several hours. DESIGN: Retrospective analysis of data from previous interventional research studies evaluating reproductive hormones. SUBJECTS: Overall, 266 individuals including healthy men and women (n=142), and those with reproductive disorders/states (n=124) [11 with functional hypothalamic amenorrhoea (FHA), 6 with polycystic ovary syndrome (PCOS), 62 women and 32 men with hypoactive sexual desire disorder (HSDD), and 13 post-menopausal women] were included in the analysis. INTERVENTIONS: Data from 266 individuals who had undergone detailed hormonal sampling in the saline placebo-treated arms of previous research studies was used to quantify the variability in reproductive hormones due to pulsatile secretion, diurnal variation, and feeding using coefficient of variation (CV) and entropy. MAIN OUTCOME MEASURES: The ability of a single measure of reproductive hormone to quantify the variability in reproductive hormones due to pulsatile secretion, diurnal variation, and nutrient-intake. RESULTS: The initial morning value of reproductive hormones was typically higher than the mean value throughout the day (percentage decrease from initial morning measure to daily mean: LH 18.4%, FSH 9.7%, testosterone 9.2%, and estradiol 2.1%). LH was the most variable (CV 28%), followed by sex-steroids (testosterone 12%, estradiol 13%), whereas FSH was the least variable reproductive hormone (CV 8%). In healthy men, testosterone fell between 9am and 5pm by 14.9% (95% CI 4.2, 25.5%), although morning levels correlated with (and could be predicted from) late afternoon levels in the same individual (r2=0.53, p<0.0001). Testosterone was reduced more after a mixed meal (by 34.3%) than during ad libitum feeding (9.5%), or after an oral glucose load (6.0%), or an intravenous gluco

Journal article

Zhang L, Verwer RWH, van Heerikhuize J, Lucassen PJ, Nathanielsz PW, Hol EM, Aronica E, Dhillo WS, Meynen G, Swaab DFet al., 2024, Progesterone receptor distribution in the human hypothalamus and its association with suicide., Acta Neuropathol Commun, Vol: 12

The human hypothalamus modulates mental health by balancing interactions between hormonal fluctuations and stress responses. Stress-induced progesterone release activates progesterone receptors (PR) in the human brain and triggers alterations in neuropeptides/neurotransmitters. As recent epidemiological studies have associated peripheral progesterone levels with suicide risks in humans, we mapped PR distribution in the human hypothalamus in relation to age and sex and characterized its (co-) expression in specific cell types. The infundibular nucleus (INF) appeared to be the primary hypothalamic structure via which progesterone modulates stress-related neural circuitry. An elevation of the number of pro-opiomelanocortin+ (POMC, an endogenous opioid precursor) neurons in the INF, which was due to a high proportion of POMC+ neurons that co-expressed PR, was related to suicide in patients with mood disorders (MD). MD donors who died of legal euthanasia were for the first time enrolled in a postmortem study to investigate the molecular signatures related to fatal suicidal ideations. They had a higher proportion of PR co-expressing POMC+ neurons than MD patients who died naturally. This indicates that the onset of endogenous opioid activation in MD with suicide tendency may be progesterone-associated. Our findings may have implications for users of progesterone-enriched contraceptives who also have MD and suicidal tendencies.

Journal article

Koysombat K, McGown P, Nyunt S, Abbara A, Dhillo WSet al., 2024, New advances in menopause symptom management, Best Practice and Research: Clinical Endocrinology and Metabolism, Vol: 38, Pages: 1-17, ISSN: 1521-690X

Vasomotor symptoms (VMS) are characteristic of menopause experienced by over 75% of postmenopausal women with significant health and socioeconomic implications. Although the average duration of symptoms is seven years, 10% of women experience symptoms for more than a decade. Although menopausal hormone therapy (MHT) remains an efficacious and cost-effective treatment, its use may not be suitable in all women, such as those at an increased risk of breast cancer or gynaecological malignancy. The neurokinin B (NKB) signaling pathway, together with its intricate connection to the median preoptic nucleus (MnPO), has been postulated to provide integrated reproductive and thermoregulatory responses, with a central role in mediating postmenopausal VMS. This review describes the physiological hypothalamo-pituitary-ovary (HPO) axis, and subsequently the neuroendocrine changes that occur with menopause using evidence derived from animal and human studies. Finally, data from the latest clinical trials using novel therapeutic agents that antagonise NKB signaling are reviewed.

Journal article

Abbara A, Ufer M, Voors-Pette C, Berman L, Ezzati M, Wu R, Lee T-Y, Arjona Ferreira JC, Migoya E, Dhillo WSet al., 2024, Endocrine profile of the kisspeptin receptor agonist MVT-602 in healthy premenopausal women with and without ovarian stimulation: results from two randomized, placebo-controlled clinical trials, Fertility and Sterility, Vol: 121, Pages: 95-106, ISSN: 0015-0282

Kisspeptin is an essential regulator of hypothalamic gonadotropin-releasing hormone release and is required for physiological ovulation. Native kisspeptin-54 (KP54) can induce oocyte maturation during in vitro fertilization treatment, including in women at high risk of ovarian hyperstimulation syndrome. MVT-602 is a potent kisspeptin receptor agonist with prospective utility to treat anovulatory disorders by triggering oocyte maturation and ovulation during medically assisted reproduction (MAR). Currently, the endocrine profile of MVT-602 during ovarian stimulation is unreported.ObjectiveTo determine the endocrine profile of MVT-602 in the follicular phase of healthy premenopausal women (Phase-1 trial), and after minimal ovarian stimulation to more closely reflect the endocrine milieu encountered during MAR (Phase-2a trial).DesignTwo randomized, placebo-controlled, parallel group, dose-finding trials.SettingClinical trials unit, Netherlands.ParticipantsHealthy women aged 18-35 years, either without (Phase-1; n=24), or with ovarian stimulation (Phase-2a; n=75).InterventionsPhase-1: Single subcutaneous dose of MVT-602 (0.3, 1.0, or 3.0 μg) or placebo, (n=6 per dose).Phase-2a: Single subcutaneous dose of MVT-602 (0.1, 0.3, 1.0, or 3.0 μg; n=16-17 per dose), triptorelin 0.2 mg (n=5; active comparator), or placebo (n=5).Main Objectives and Outcome MeasuresPhase-1: Safety/tolerability; pharmacokinetics; pharmacodynamics (LH and other reproductive hormones).Phase-2a: Safety/tolerability; pharmacokinetics; pharmacodynamics (LH and other reproductive hormones); time to ovulation assessed by transvaginal ultrasound.ResultsIn both trials, MVT-602 was safe and well-tolerated across the entire dose-range. It was rapidly absorbed and eliminated, with a mean elimination half-life of 1.3-2.2 hours.In the Phase-2a trial, LH concentrations increased dose-dependently; mean maximum change from baseline of 82.4 IU/L at 24.8 hours was observed after administration of 3μg MVT-602

Journal article

Grant B, Campbell J, Pradeep A, Burns AD, Bassett P, Abbara A, Saket P, Minhas S, Dhillo WS, McVeigh J, Bhasin S, Jayasena CNet al., 2023, Factors predicting normalization of reproductive hormones after cessation of anabolic-androgenic steroids in men: a single center retrospective study., Eur J Endocrinol, Vol: 189, Pages: 601-610

OBJECTIVE: Symptomatic hypogonadism discourages men from stopping anabolic-androgenic steroids (AAS). Some men illicitly take drugs temporarily stimulating endogenous testosterone following AAS cessation (post-cycle therapy; PCT) to lessen hypogonadal symptoms. We investigated whether prior PCT use was associated with the normalization of reproductive hormones following AAS cessation. METHODS: Retrospective analysis of 641 men attending a clinic between 2015-2022 for a single, nonfasting, random blood test <36 months following AAS cessation, with or without PCT. Normalized reproductive hormones (ie, a combination of reference range serum luteinizing hormone, follicle-stimulating hormone, and total testosterone levels) were the surrogate marker of biochemical recovery. RESULTS: Normalization of reproductive hormones was achieved in 48.2% of men. PCT use was associated with faster biochemical recovery (13.0 (IQR8.0-19.0) weeks, PCT; 26.0 (IQR10.5-52) weeks, no-PCT; P < .001). Odds of biochemical recovery during multivariable analysis were: (1) higher with PCT (OR3.80) vs no-PCT (P = .001), in men stopping AAS ≤3 months previously; (2) reduced when 2 (OR0.55), 3 (OR0.46), or 4 (OR0.25) AAS were administered vs 1 drug (P = .009); (3) lower with AAS >6 vs ≤3 months previously (OR0.34, P = .01); (4) higher with last reported AAS >3 months (OR 5.68) vs ≤3 months (P = .001). PCT use was not associated with biochemical recovery in men stopping AAS >3 months previously. CONCLUSION: Without evidence-based withdrawal protocols, men commonly try avoiding post-AAS hypogonadism with PCT, which is illicit, ill-defined, and not recommended. Only half of men had complete biochemical testicular recovery after stopping AAS. The surprising association of self-reported PCT use with short-term biochemical recovery from AAS-induced hypogonadism warrants further investigation.

Journal article

Grant B, Kean J, Vali N, Campbell J, Maden L, Prun B, Dhillo W, McVeigh J, Quinton R, Jayasena Cet al., 2023, The use of post-cycle therapy is associated with reduced withdrawal symptoms from anabolic-androgenic steroid use: a survey of 470 users, Substance Abuse Treatment, Prevention, and Policy, Vol: 18, ISSN: 1747-597X

Background: Anabolic-androgenic steroids (AAS) mimic the effects of testosterone and may include testosterone itself; they are used for body enhancement within the general population. AAS use has been linked with increased mortality, cardiovascular disease, mental health disorders, and infertility. AAS-induced hypogonadism can persist for an uncertain time period despite cessation, during which men may report physical and neuropsychiatric symptoms. In an attempt to mitigate these symptoms and expedite testicular recovery, many men self-administer post-cycle-therapy (PCT), typically involving human chorionic gonadotrophin (hCG) and selective oestrogen receptor modulators (SERMs), which are known to potently stimulate testicular function. However, this practice has no objective evidence of effectiveness to lessen the severity or duration of hypogonadal symptoms. Methods: An anonymous survey of four-hundred-and-seventy men using AAS explored the symptoms they experienced when ceasing AAS use; the effect of PCT on relieving their symptoms, and their perceived role for health service support. Results: The majority of respondents were white, aged 18-30 years old, and working in skilled manual work. 51.7% (n=243) reported no issues with AAS use, but 35.3% reported increased aggression. 65.1% (n=306) of respondents had attempted AAS cessation and 95.1% of these experienced at least one symptom upon AAS cessation. Low mood, tiredness and reduced libido were reported in 72.9%, 58.5% and 57.0% of men stopping AAS use, respectively, with only 4.9% reporting no symptoms. PCT had been used by 56.5% of respondents with AAS cessation and mitigated cravings to restart AAS use, withdrawal symptoms and suicidal thoughts by 60%, 60% and 50%, respectively. The effect of stopping AAS on body composition and recovery of testosterone or fertility was a concern in 60.5% and 52.4%, respectively. Most respondents felt PCT should be prescribed under medical supervision in the community. Conclu

Journal article

Eng P, Forlano R, Tan T, Manousou P, Dhillo W, Izzi-Engbeaya Cet al., 2023, Non-alcoholic fatty liver disease in women – current knowledge and emerging concepts, JHEP Reports, Vol: 5, ISSN: 2589-5559

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease worldwide, affecting up to 30% of adults. Progression to non-alcoholic steatohepatitis (NASH) is a key risk factor for cirrhosis, hepatocellular carcinoma and cardiovascular events. Alterations in reproductive hormones are linked to the development and/or progression of NAFLD/NASH in women. Women with Polycystic Ovary Syndrome (PCOS) and those with estrogen deficiency are at increased risk of NAFLD/NASH, with higher mortality rates in older women compared to men of similar ages. NAFLD/NASH is currently the leading indication for liver transplantation in women without hepatocellular carcinoma. Therefore, a better understanding of NAFLD in women is needed to improve outcomes. In this review, we discuss the hormonal and non-hormonal factors contributing to NAFLD development and progression in women. Furthermore, we highlight areas of focus for clinical practice and for future research.

Journal article

Hudson J, Cruickshank M, Quinton R, Aucott L, Wu F, Grossmann M, Bhasin S, Snyder PJ, Ellenberg SS, Travison TG, Brock GB, Gianatti EJ, van der Schouw YT, Emmelot-Vonk MH, Giltay EJ, Hackett G, Ramachandran S, Svartberg J, Hildreth KL, Antonic KG, Tenover JL, Tan HM, Ho Chee Kong C, Tan WS, Marks LS, Ross RJ, Schwartz RS, Manson P, Roberts SA, Skovsager Andersen M, Velling Magnussen L, Aceves-Martins M, Gillies K, Hernández R, Oliver N, Dhillo WS, Bhattacharya S, Brazzelli M, Jayasena CNet al., 2023, Symptomatic benefits of testosterone treatment in patient subgroups: a systematic review, individual participant data meta-analysis, and aggregate data meta-analysis., Lancet Healthy Longev, Vol: 4, Pages: e561-e572

BACKGROUND: Testosterone replacement therapy is known to improve sexual function in men younger than 40 years with pathological hypogonadism. However, the extent to which testosterone alleviates sexual dysfunction in older men and men with obesity is unclear, despite the fact that testosterone is being increasingly prescribed to these patient populations. We aimed to evaluate whether subgroups of men with low testosterone derive any symptomatic benefit from testosterone treatment. METHODS: We did a systematic review and meta-analysis to evaluate characteristics associated with symptomatic benefit of testosterone treatment versus placebo in men aged 18 years and older with a baseline serum total testosterone concentration of less than 12 nmol/L. We searched major electronic databases (MEDLINE, Embase, Science Citation Index, and the Cochrane Central Register of Controlled Trials) and clinical trial registries for reports published in English between Jan 1, 1992, and Aug 27, 2018. Anonymised individual participant data were requested from the investigators of all identified trials. Primary (cardiovascular) outcomes from this analysis have been published previously. In this report, we present the secondary outcomes of sexual function, quality of life, and psychological outcomes at 12 months. We did a one-stage individual participant data meta-analysis with a random-effects linear regression model, and a two-stage meta-analysis integrating individual participant data with aggregated data from studies that did not provide individual participant data. This study is registered with PROSPERO, CRD42018111005. FINDINGS: 9871 citations were identified through database searches. After exclusion of duplicates and publications not meeting inclusion criteria, 225 full texts were assessed for inclusion, of which 109 publications reporting 35 primary studies (with a total 5601 participants) were included. Of these, 17 trials provided individual participant data (3431 participants; m

Journal article

Sauve F, Nampoothiri S, Clarke SA, Fernandois D, Ferreira Coêlho CF, Dewisme J, Mills EG, Ternier G, Cotellessa L, Iglesias-Garcia C, Mueller-Fielitz H, Lebouvier T, Perbet R, Florent V, Baroncini M, Sharif A, Ereño-Orbea J, Mercado-Gómez M, Palazon A, Mattot V, Pasquier F, Catteau-Jonard S, Martinez-Chantar M, Hrabovszky E, Jourdain M, Deplanque D, Morelli A, Guarnieri G, Storme L, Robil C, Trottein F, Nogueiras R, Schwaninger M, Pigny P, Poissy J, Chachlaki K, Maurage C-A, Giacobini P, Dhillo W, Rasika S, Prevot Vet al., 2023, Long-COVID cognitive impairments and reproductive hormone deficits in men may stem from GnRH neuronal death, EBioMedicine, Vol: 96, ISSN: 2352-3964

BACKGROUND: We have recently demonstrated a causal link between loss of gonadotropin-releasing hormone (GnRH), the master molecule regulating reproduction, and cognitive deficits during pathological aging, including Down syndrome and Alzheimer's disease. Olfactory and cognitive alterations, which persist in some COVID-19 patients, and long-term hypotestosteronaemia in SARS-CoV-2-infected men are also reminiscent of the consequences of deficient GnRH, suggesting that GnRH system neuroinvasion could underlie certain post-COVID symptoms and thus lead to accelerated or exacerbated cognitive decline. METHODS: We explored the hormonal profile of COVID-19 patients and targets of SARS-CoV-2 infection in post-mortem patient brains and human fetal tissue. FINDINGS: We found that persistent hypotestosteronaemia in some men could indeed be of hypothalamic origin, favouring post-COVID cognitive or neurological symptoms, and that changes in testosterone levels and body weight over time were inversely correlated. Infection of olfactory sensory neurons and multifunctional hypothalamic glia called tanycytes highlighted at least two viable neuroinvasion routes. Furthermore, GnRH neurons themselves were dying in all patient brains studied, dramatically reducing GnRH expression. Human fetal olfactory and vomeronasal epithelia, from which GnRH neurons arise, and fetal GnRH neurons also appeared susceptible to infection. INTERPRETATION: Putative GnRH neuron and tanycyte dysfunction following SARS-CoV-2 neuroinvasion could be responsible for serious reproductive, metabolic, and mental health consequences in long-COVID and lead to an increased risk of neurodevelopmental and neurodegenerative pathologies over time in all age groups. FUNDING: European Research Council (ERC) grant agreements No 810331, No 725149, No 804236, the European Union Horizon 2020 research and innovation program No 847941, the Fondation pour la Recherche Médicale (FRM) and the Agence Nationale de la Recherche e

Journal article

Hanassab S, Abbara A, Kelsey TW, Yeung ACY, Hramyka A, Alhamwi T, Salim R, Comninos AN, Trew GH, Nelson SM, Heinis T, Dhillo WSet al., 2023, OPTIMIZING OOCYTE YIELD: UNVEILING THE IDEAL FOLLICLE SIZES ON THE DAY OF TRIGGER USING INTERPRETABLE MACHINE LEARNING, 79th Scientific Congress of the American-Society-for-Reproductive-Medicine (ASRM), Publisher: ELSEVIER SCIENCE INC, Pages: E34-E35, ISSN: 0015-0282

Conference paper

Izzi-Engbeaya C, Patel B, Mills E, Phylactou M, Clarke S, Comninos A, Abbara A, Tan T, Dhillo Wet al., 2023, The effects of kisspeptin on food intake in women with overweight or obesity, Diabetes, Obesity and Metabolism: a journal of pharmacology and therapeutics, Vol: 25, Pages: 2393-2397, ISSN: 1462-8902

Journal article

Patel B, Koysombat K, Mills EG, Tsoutsouki J, Comninos AN, Abbara A, Dhillo WSet al., 2023, The Emerging Therapeutic Potential of Kisspeptin and Neurokinin B, ENDOCRINE REVIEWS, ISSN: 0163-769X

Journal article

Papanikolaou N, Millar O, Coulden A, Parker N, Sit L, Kelly C, Cox J, Dhillo WS, Meeran K, Al Memar M, Anderson R, Rees DA, Karavitaki N, Jayasena CNet al., 2023, Clinical characteristics of functioning gonadotroph adenoma in women presenting with ovarian hyperstimulation: Audit of UK pituitary centres, CLINICAL ENDOCRINOLOGY, ISSN: 0300-0664

Journal article

Abbara A, Phylactou M, Eng PC, Clarke S, Pham T, Ho TM, Ng KY, Mills E, Purugganan K, Hunjan T, Salim R, Comninos A, Vuong L, Dhillo WSet al., 2023, Endocrine responses to triptorelin in healthy women, women with polycystic ovary syndrome and hypothalamic amenorrhea, Journal of Clinical Endocrinology and Metabolism, Vol: 108, Pages: 1666-1675, ISSN: 0021-972X

ContextLimited data exist regarding whether the endocrine response to the gonadotropin-releasing hormone receptor agonist (GnRHa) triptorelin differs in women with polycystic ovary syndrome (PCOS) compared with healthy women or those with hypothalamic amenorrhea (HA).ObjectiveWe compared the gonadotropin response to triptorelin in healthy women, women with PCOS, or those with HA without ovarian stimulation, and in women with or without polycystic ovaries undergoing oocyte donation cycles after ovarian stimulation.MethodsThe change in serum gonadotropin levels was determined in (1) a prospective single-blinded placebo-controlled study to determine the endocrine profile of triptorelin (0.2 mg) or saline-placebo in healthy women, women with PCOS, and those with HA, without ovarian stimulation; and (2) a retrospective analysis from a dose-finding randomized controlled trial of triptorelin (0.2-0.4 mg) in oocyte donation cycles after ovarian stimulation.ResultsIn Study 1, triptorelin induced an increase in serum luteinizing hormone (LH) of similar amplitude in all women (mean peak LH: healthy, 52.3; PCOS, 46.2; HA, 41.3 IU/L). The AUC of change in serum follicle-stimulating hormone (FSH) was attenuated in women with PCOS compared with healthy women and women with HA (median AUC of change in serum FSH: PCOS, 127.2; healthy, 253.8; HA, 326.7 IU.h/L; P = 0.0005). In Study 2, FSH levels 4 hours after triptorelin were reduced in women with at least one polycystic morphology ovary (n = 60) vs normal morphology ovaries (n = 91) (34.0 vs 42.3 IU/L; P = 0.0003). Serum anti-Müllerian hormone (AMH) was negatively associated with the increase in FSH after triptorelin, both with and without ovarian stimulation.ConclusionFSH response to triptorelin was attenuated in women with polycystic ovaries, both with and without ovarian stimulation, and was negatively related to AMH levels.

Journal article

de Silva NL, Dissanayake H, Suarez C, Wickramarachchi RE, Ramasamy R, Dhillo WS, Minhas S, Corona G, Jayasena CNet al., 2023, Effect of oestrogen modulation on semen parameters in men with secondary hypogonadism: Systematic review and meta-analysis, ANDROLOGY, ISSN: 2047-2919

Journal article

Hanassab S, Abbara A, Alhamwi T, Comninos A, Salim R, Trew G, Nelson S, Kelsey T, Heinis T, Dhillo Wet al., 2023, P-623 Using machine learning to determine follicle sizes on the day of trigger most likely to yield oocytes, Human Reproduction, Vol: 38, Pages: 1-2, ISSN: 0268-1161

Study questionWhich follicle sizes on the day of trigger (DoT) are most likely to yield oocytes after different IVF treatment protocols and trigger types?Summary answerFollicles sized 11-19mm on DoT are most likely to yield oocytes in both 'long' and 'short' protocols after using either hCG or GnRH agonist triggers.What is known alreadyOn the DoT, both follicles that are too small, or too large, are less likely to yield oocytes, but the precise range of follicle sizes that are most contributory to oocyte yield remains uncertain. Knowledge of this optimal follicle size range can aid in selecting the DoT and in quantifying the efficacy of the trigger by benchmarking the expected number of oocytes to be retrieved. Machine learning can aid in the analysis of large complex datasets and thus could be used to determine the follicle sizes on the DoT that are most predictive of the number of oocytes retrieved.Study design, size, durationWe applied machine learning techniques to data from 8030 patients aged under 35 years who underwent autologous fresh IVF and ICSI cycles between 2011-2021 in a single IVF clinic. The DoT was determined by 2-3 leading follicles reaching ≥ 18mm in size. Follicle sizes from ultrasound scans performed on the DoT (n = 3056), a day prior to DoT (n = 2839), or two days prior to DoT (n = 2135), were evaluated in relation to the number of oocytes retrieved.Participants/materials, setting, methodsA two-stage random forest pipeline was developed, with the number of follicles of a certain size on DoT as input, and the number of oocytes retrieved as output. First, a variable preselection model to determine the most contributory follicle sizes. Second, a model to identify the optimal range of follicle sizes to yield oocytes. Both models were trained and cross-validated with fixed hyperparameters. The pipeline was run for each protocol and trigger type independently.Main results and the role of chanceThe machine

Journal article

Koysombat K, Dhillo WS, Abbara A, 2023, Assessing hypothalamic pituitary gonadal function in reproductive disorders, Clinical Science, Vol: 137, Pages: 863-879, ISSN: 0143-5221

Reproductive conditions secondary to disorders of the hypothalamic–pituitary–gonadal (HPG) axis are common and are associated with important health implications and considerable psychosocial impact. Basal and dynamic tests enable interrogation of individual components of the HPG axis, facilitating diagnosis and understanding of the pathophysiology of reproductive disorders. Onset of puberty is controlled by hypothalamic gonadotrophin-releasing hormone (GnRH) neuronal function. To date, a dynamic test of hypothalamic function is not yet available. Therefore, accurate differentiation of pubertal disorders such as constitutional delay of growth and puberty (CDGP) and congenital hypogonadotrophic hypogonadism (CHH) as causes of delayed puberty is challenging due to similar clinical presentations and hormonal profiles. Likewise, although the two commonest reproductive disorders in women, polycystic ovary syndrome (PCOS) and functional hypothalamic amenorrhoea (FHA) have disparate hypothalamic function, oligo/amenorrhoea frequently poses a diagnostic conundrum owing to the overlap in the criteria used to define both conditions. This review aims to describe pubertal and reproductive disorders secondary to pathologies affecting the HPG axis. Challenges encountered in clinical practice in differentiating pubertal and reproductive conditions are reviewed in conjunction with the utility of baseline and dynamic endocrine tests to interrogate specific components of the HPG axis. We also highlight putative hypothalamic, pituitary, and gonadal markers in development that could improve the diagnosis of patients presenting with disorders of puberty or reproduction.

Journal article

Ramos-Pittol J, Fernandes-Freitas I, Milona A, Manchishi SM, Rainbow K, Lam BYH, Tadross JA, Beucher A, Colledge WH, Cebola I, Murphy KG, Miguel-Aiaga I, Yeo GSH, Owen B, Dhillo Wet al., 2023, Dax1 modulates ERα-dependent hypothalamic estrogen sensing in female mice, Nature Communications, Vol: 14, Pages: 1-10, ISSN: 2041-1723

Coupling the release of pituitary hormones to the developmental stage of the oocyte is essential for female fertility. It requires estrogen to restrain kisspeptin (KISS1)-neuron pulsatility in the arcuate hypothalamic nucleus, while also exerting a surge-like effect on KISS1-neuron activity in the AVPV hypothalamic nucleus. However, a mechanistic basis for this region-specific effect has remained elusive. Our genomic analysis in female mice demonstrate that some processes, such as restraint of KISS1-neuron activity in the arcuate nucleus, may be explained by region-specific estrogen receptor alpha (ERα) DNA binding at gene regulatory regions. Furthermore, we find that the Kiss1-locus is uniquely regulated in these hypothalamic nuclei, and that the nuclear receptor co-repressor NR0B1 (DAX1) restrains its transcription specifically in the arcuate nucleus. These studies provide mechanistic insight into how ER may control the KISS1-neuron, and Kiss1 gene expression, to couple gonadotropin release to the developmental stage of the oocyte.

Journal article

Phylactou M, Comninos A, salih A, labib M, chia eng P, Clarke S, Moore P, Tan T, Cegla J, Dhillo W, Abbara Aet al., 2023, Derivation and comparison of formulae for the adjustment of total calcium, Frontiers in Endocrinology, Vol: 14, Pages: 1-10, ISSN: 1664-2392

Background: Free ionized calcium (Ca2+) is the biologically active component of total calcium (TCa) and hence responsible for its biological action. TCa is routinely adjusted for albumin using several formulae (e.g. James, Orell, Payne and Berry) to more closely reflect Ca2+. Here, we derive a novel formula to estimate Ca2+ and compare its performance to established formulae.Methods: Cohort for prediction of Ca2+: 2806 serum samples (TCa) taken contemporaneously with blood gas samples (Ca2+) at Imperial College Healthcare NHS Trust were used to derive formulae to estimate Ca2+ using multivariable linear regression. Cohort for prediction of PTH: Performance of novel and existing formulae to predict PTH in 5510 patients was determined by Spearman correlation.Results: Ca2+ prediction Cohort: Adjusted calcium (r2 = 0.269) was less strongly associated with Ca2+, than TCa (r2 = 0.314). Prediction of Ca2+ from a newly derived formula incorporating TCa, potassium, albumin, and hematocrit had an improved r2 of 0.327, whereas inclusion of all available parameters increased the r2 further to 0.364. Of the established formulae, James performed best in predicting Ca2+ (r2 = 0.27). PTH prediction cohort: Berry resulted in higher whereas Orell in lower adjusted calcium levels. Prediction of PTH was strongest in the setting of hypercalcemia, with James having the highest Spearman correlation coefficient (+0.496) similar to including all parameters (+0.499).Conclusion: Adjustment of calcium for albumin using established formulae does not always outperform unadjusted TCa in the reflection of Ca2+. Further prospective studies are needed to optimise adjustment of TCa and to establish bounds for validity.

Journal article

Mills EG, Abbara A, Dhillo WS, Comninos ANet al., 2023, Effects of distinct Polycystic Ovary Syndrome phenotypes on bone health, Frontiers in Endocrinology, Vol: 14, ISSN: 1664-2392

Polycystic Ovary Syndrome (PCOS) is a highly prevalent and heterogenous endocrinopathy affecting 5-18% of women. Although its cardinal features include androgen excess, ovulatory dysfunction, and/or polycystic ovarian morphology, women often display related metabolic manifestations, including hyperinsulinaemia, insulin resistance, and obesity. Emerging data reveal that the hormonal alterations associated with PCOS also impact bone metabolism. However, inconsistent evidence exists as to whether PCOS is a bone-protective or bone-hindering disorder with an accumulating body of clinical data indicating that hyperandrogenism, hyperinsulinaemia, insulin resistance, and obesity may have a relative protective influence on bone, whereas chronic low-grade inflammation and vitamin D deficiency may adversely affect bone health. Herein, we provide a comprehensive assessment of the endocrine and metabolic manifestations associated with PCOS and their relative effects on bone metabolism. We focus principally on clinical studies in women investigating their contribution to the alterations in bone turnover markers, bone mineral density, and ultimately fracture risk in PCOS. A thorough understanding in this regard will indicate whether women with PCOS require enhanced surveillance of bone health in routine clinical practice.

Journal article

Cotellessa L, Marelli F, Duminuco P, Adamo M, Papadakis GE, Bartoloni L, Sato N, Lang-Muritano M, Troendle A, Dhillo WS, Morelli A, Guarnieri G, Pitteloud N, Persani L, Bonomi M, Giacobini P, Vezzoli Vet al., 2023, Defective jagged-1 signaling affects GnRH development and contributes to congenital hypogonadotropic hypogonadism, JCI Insight, Vol: 8, ISSN: 2379-3708

In vertebrate species, fertility is controlled by gonadotropin-releasing hormone (GnRH) neurons. GnRH cells arise outside the central nervous system, in the developing olfactory pit, and migrate along olfactory/vomeronasal/terminal nerve axons into the forebrain during embryonic development. Congenital hypogonadotropic hypogonadism (CHH) and Kallmann syndrome are rare genetic disorders characterized by infertility, and they are associated with defects in GnRH neuron migration and/or altered GnRH secretion and signaling. Here, we documented the expression of the jagged-1/Notch signaling pathway in GnRH neurons and along the GnRH neuron migratory route both in zebrafish embryos and in human fetuses. Genetic knockdown of the zebrafish ortholog of JAG1 (jag1b) resulted in altered GnRH migration and olfactory axonal projections to the olfactory bulbs. Next-generation sequencing was performed in 467 CHH unrelated probands, leading to the identification of heterozygous rare variants in JAG1. Functional in vitro validation of JAG1 mutants revealed that 7 out of the 9 studied variants exhibited reduced protein levels and altered subcellular localization. Together our data provide compelling evidence that Jag1/Notch signaling plays a prominent role in the development of GnRH neurons, and we propose that JAG1 insufficiency may contribute to the pathogenesis of CHH in humans.

Journal article

Mills E, Ertl N, Wall M, Thurston L, Yang L, Suladze S, Hunjan T, Phylactou M, Patel B, Muzi B, Ettehad D, Bassett P, Howard J, Rabiner E, Bech P, Abbara A, Goldmeier D, Comninos A, Dhillo Wet al., 2023, Effects of kisspeptin on sexual brain processing and penile tumescence in men with hypoactive sexual desire disorder: a randomized clinical trial, Jama Network Open, Vol: 6, Pages: 1-16, ISSN: 2574-3805

Importance The human physiological sexual response is crucial for reward, satisfaction, and reproduction. Disruption of the associated neurophysiological pathways predisposes to low sexual desire; the most prevalent psychological form is hypoactive sexual desire disorder (HSDD), which affects 8% of men but currently has no effective pharmacological treatment options. The reproductive neuropeptide kisspeptin offers a putative therapeutic target, owing to emerging understanding of its role in reproductive behavior.Objective To determine the physiological, behavioral, neural, and hormonal effects of kisspeptin administration in men with HSDD.Design, Setting, and Participants This double-blind, 2-way crossover, placebo-controlled randomized clinical trial was performed at a single academic research center in the UK. Eligible participants were right-handed heterosexual men with HSDD. Physiological, behavioral, functional magnetic resonance imaging (fMRI), and hormonal analyses were used to investigate the clinical and mechanistic effects of kisspeptin administration in response to visual sexual stimuli (short and long video tasks). The trial was conducted between January 11 and September 15, 2021, and data analysis was performed between October and November 2021.Interventions Participants attended 2 study visits at least 7 days apart, in balanced random order, for intravenous infusion of kisspeptin-54 (1 nmol/kg/h) for 75 minutes or for administration of a rate-matched placebo.Main Outcomes and Measures Changes in (1) brain activity on whole-brain analysis, as determined by fMRI blood oxygen level–dependent activity in response to visual sexual stimuli during kisspeptin administration compared with placebo, (2) physiological sexual arousal (penile tumescence), and (3) behavioral measures of sexual desire and arousal.Results Of the 37 men randomized, 32 completed the trial. Participants had a mean (SD) age of 37.9 (8.6) years and a mean (SD) body mass i

Journal article

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