Imperial College London

DrTriciaTan

Faculty of MedicineDepartment of Metabolism, Digestion and Reproduction

Professor of Practice (Metabolic Medicine & Endocrinology)
 
 
 
//

Contact

 

+44 (0)20 3313 8038t.tan

 
 
//

Location

 

6N6ECommonwealth BuildingHammersmith Campus

//

Summary

 

Publications

Publication Type
Year
to

138 results found

Choudhury SM, Tan TMM, Lazarus K, Meeran Ket al., 2021, The Use of Prednisolone versus Dual-Release Hydrocortisone in the Treatment of Hypoadrenalism, Endocrine Connections, ISSN: 2049-3614

<jats:p>The introduction of adrenocortical extract in 1930, improved life expectancy to between two and five years with further increases seen with the introduction of cortisone acetate from 1948. Most patients are now treated with synthetic hydrocortisone, and incremental advances have been made with optimisation of daily dosing and the introduction of multi-dose regimens. Today there remains a significant mortality gap between individuals with treated hypoadrenalism and the general population. It is unclear whether this gap is a result of glucocorticoid over-replacement, under-replacement or loss of the circadian and ultradian rhythm of cortisol secretion, with detrimental risk of excess glucocorticoid at later times in the day. The way forwards involves replacement of the diurnal cortisol rhythm with better glucocorticoid replacement regimens. The steroid profile produced by both prednisolone and dual-release hydrocortisone (Plenadren), provide a smoother glucocorticoid profile than standard oral multidose regimens of hydrocortisone and cortisone acetate. The individualisation of prednisolone doses and lower bioavailability of Plenadren offer reductions in total steroid exposure. Although there is emerging evidence of both treatments offering better cardiometabolic outcomes than standard glucocorticoid replacement regimens, there is a paucity of evidence involving very low dose prednisolone (2-4 mg daily) compared to the larger doses (~7.5 mg) historically used. Data from upcoming clinical studies on prednisolone will therefore be of key importance in informing future practice.</jats:p>

Journal article

Izzi-Engbeaya C, Distaso W, Amin A, Kenkre J, Abdel-Malek M, Hope D, Oliver N, Misra S, Tan T, Hill N, Salem Vet al., 2021, Adverse outcomes in COVID-19 and diabetes – a retrospective cohort study from three London Teaching hospitals, BMJ Open Diabetes Research and Care, ISSN: 2052-4897

INTRODUCTION: Patients with diabetes mellitus admitted to hospital with COVID-19 have poorer outcomes. However, the drivers for this are not fully elucidated. We performed detailed characterisation of COVID-19 patients to determine clinical and biochemical factors that may be the drivers of poorer outcomes. RESEARCH DESIGN AND METHODS: Retrospective cohort study of 889 consecutive inpatients diagnosed with COVID-19 between 9th March 2020 and 22nd April 2020 in a large London NHS Trust. Unbiased multivariate logistic regression analysis was performed to determine variables that were independently and significantly associated with increased risk of death and/or ICU admission within 30 days of COVID-19 diagnosis. RESULTS: 62% of patients in our cohort were of non-White ethnic backgrounds and the diabetes prevalence was 38%. 323 (36%) patients met the primary outcome of death/admission to the intensive care unit (ICU) within 30 days of COVID-19 diagnosis. Male gender, lower platelet count, advancing age and higher Clinical Frailty Scale (CFS) score (but not diabetes) independently predicted poor outcomes on multivariate analysis. Antiplatelet medication was associated with a lower risk of death/ICU admission. Factors that were significantly and independently associated with poorer outcomes in patients with diabetes were co-existing ischaemic heart disease, increasing age and lower platelet count. CONCLUSIONS: In this large study of a diverse patient population, comorbidity (i.e. diabetes with ischaemic heart disease; increasing CFS score in older patients) were major determinants of poor outcomes with COVID-19. Antiplatelet medication should be evaluated in randomised clinical trials amongst high-risk patient groups.

Journal article

Misra S, Khozoee B, Huang-Jiawei P, Mitsaki K, Reddy M, Salem V, Tan T, Tharakan G, Gable D, Bravis V, Valabhji Jet al., 2020, Comparison of diabetic ketoacidosis in adults, during the SARS-CoV-2 outbreak and over the same time period for the 3 preceding years, Diabetes Care, ISSN: 0149-5992

Journal article

Ilesanmi I, Tharakan G, Alexiadou K, Behary P, Alessimii H, Bovill-Taylor C, Kenkre J, Choudhury S, Doyle C, Purkayastha S, Miras A, Tsironis C, Chahal H, Bloom SR, Oliver NS, Ahmed AR, Khoo B, Tan TM-Met al., 2020, Roux-en-Y Gastric Bypass Increases Glycemic Variability and Time in Hypoglycemia in Patients With Obesity and Prediabetes or Type 2 Diabetes: A Prospective Cohort Study., Diabetes Care

OBJECTIVE: Roux-en-Y gastric bypass (RYGB) is an established treatment for type 2 diabetes and obesity. The study objective was to establish RYGB's effects on glycemic variability (GV) and hypoglycemia. RESEARCH DESIGN AND METHODS: This was a prospective observational study of 10 participants with obesity and prediabetes or type 2 diabetes who underwent RYGB. Patients were studied before RYGB (Pre) and 1 month, 1 year, and 2 years postsurgery with continuous glucose measurement (CGM). A mixed-meal test (MMT) was conducted at Pre, 1 month, and 1 year. RESULTS: After RYGB, mean CGM decreased (at 1 month, 1 year, and 2 years), and GV increased (at 1 year and 2 years). Five of the 10 participants had a percent time in range (%TIR) <3.0 mmol/L (54 mg/dL) greater than the international consensus target of 1% at 1 or 2 years. Peak glucagon-like peptide-1 (GLP-1) and glucagon area under the curve during MMT were positively and negatively associated, respectively, with contemporaneous %TIR <3.0 mmol/L. CONCLUSIONS: Patients undergoing RYGB are at risk for development of postbariatric hypoglycemia due to a combination of reduced mean glucose level, increased GV, and increased GLP-1 response.

Journal article

Khoo B, Tan T, Clarke S, Mills E, Patel B, Modi M, Phylactou M, Eng PC, Thurston L, Alexander E, Meeran K, Comninos A, Abbara A, Dhillo Wet al., 2020, Thyroid function before, during and after COVID-19, Journal of Clinical Endocrinology and Metabolism, ISSN: 0021-972X

Context: The effects of COVID-19 on the thyroid axis remain uncertain. Recent evidence has been conflicting, with both thyrotoxicosis and suppression of thyroid function reported. Objective: We aimed to detail the acute effects of COVID-19 on thyroid function and determine if these effects persisted upon recovery from COVID-19. Design: Cohort observational study. Participants and setting: Adult patients admitted to Imperial College Healthcare National Health Service Trust, London, UK with suspected COVID-19 between March 9 to April 22, 2020 were included, excluding those with pre-existing thyroid disease and those missing either free thyroxine (FT4) or TSH measurements. Of 456 patients, 334 had COVID-19 and 122 did not.Main Outcome Measures: TSH and FT4 measurements at admission, and where available, those taken in 2019 and at COVID-19 follow-up. Results: Most patients (86·6%) presenting with COVID-19 were euthyroid, with none presenting with overt thyrotoxicosis. Patients with COVID-19 had a lower admission TSH and FT4 compared to those without COVID-19. In the COVID-19 patients with matching baseline thyroid function tests from 2019 (n=185 for TSH and 104 for FT4), both TSH and FT4 were reduced at admission compared to baseline. In a complete cases analysis of COVID-19 patients with TSH measurements at follow-up, admission and baseline (n=55), TSH was seen to recover to baseline at follow-up. Conclusions: Most patients with COVID-19 present with euthyroidism. We observed mild reductions in TSH and FT4 in keeping with a non-thyroidal illness syndrome. Furthermore, in survivors of COVID-19, thyroid function tests at follow-up returned to baseline.

Journal article

Jones B, Fang Z, Chen S, Manchanda Y, Bitsi S, Pickford P, David A, Shchepinova MM, Corrêa Jr IR, Hodson DJ, Broichhagen J, Tate EW, Reimann F, Salem V, Rutter GA, Tan T, Bloom SR, Tomas Aet al., 2020, Ligand-specific factors influencing GLP-1 receptor post-endocytic trafficking and degradation in pancreatic beta cells, International Journal of Molecular Sciences, Vol: 212, Pages: 1-24, ISSN: 1422-0067

The glucagon-like peptide-1 receptor (GLP-1R) is an important regulator of blood glucose homeostasis. Ligand-specific differences in membrane trafficking of the GLP-1R influence its signalling properties and therapeutic potential in type 2 diabetes. Here, we have evaluated how different factors combine to control the post-endocytic trafficking of GLP-1R to recycling versus degradative pathways. Experiments were performed in primary islet cells, INS-1 832/3 clonal beta cells and HEK293 cells, using biorthogonal labelling of GLP-1R to determine its localisation and degradation after treatment with GLP-1, exendin-4 and several further GLP-1R agonist peptides. We also characterised the effect of a rare GLP1R coding variant, T149M, and the role of endosomal peptidase endothelin-converting enzyme-1 (ECE-1), in GLP1R trafficking. Our data reveal how treatment with GLP-1 versus exendin-4 is associated with preferential GLP-1R targeting towards a recycling pathway. GLP-1, but not exendin-4, is a substrate for ECE-1, and the resultant propensity to intra-endosomal degradation, in conjunction with differences in binding affinity, contributes to alterations in GLP-1R trafficking behaviours and degradation. The T149M GLP-1R variant shows reduced signalling and internalisation responses, which is likely to be due to disruption of the cytoplasmic region that couples to intracellular effectors. These observations provide insights into how ligand- and genotype-specific factors can influence GLP-1R trafficking.

Journal article

Miras A, Kamocka A, Pérez-Pevida B, Purkayastha S, Moorthy K, Patel A, Chahal H, Frost G, Bassett P, Castagnetto-Gissey L, Coppin L, Jackson N, Umpleby M, Bloom S, Tan T, Ahmed A, Rubino Fet al., 2020, The effect of standard versus longer intestinal bypass on GLP-1 regulation and glucose metabolism in patients with type 2 diabetes undergoing roux-en-Y gastric bypass. The long-limb study, Diabetes Care, ISSN: 0149-5992

ObjectiveRoux-en-Y gastric bypass (RYGB) characteristically enhances post-prandial levels of Glucagon-like peptide 1 (GLP-1), a mechanism that contributes to its profound glucose-lowering effects. This enhancement is thought to be triggered by bypass of food to the distal small intestine with higher densities of neuroendocrine L-cells. We hypothesised that if this is the predominant mechanism behind the enhanced secretion of GLP-1, a longer intestinal bypass would potentiate the post-prandial peak in GLP-1, translating into higher insulin secretion and thus additional improvements in glucose tolerance. To investigate this, we conducted a mechanistic study comparing two variants of RYGB that differ in the length of intestinal bypass.Research Design and MethodsFifty-three patients with type 2 diabetes and obesity were randomised to either ‘standard limb’ RYGB (50cm biliopancreatic limb) or ‘long limb’ RYGB (150cm biliopancreatic limb). They underwent measurements of GLP-1 and insulin secretion following a mixed meal and insulin sensitivity using euglycaemic hyperinsulinaemic clamps at baseline, 2 weeks and at 20% weight loss after surgery.ResultsBoth groups exhibited enhancement in post-prandial GLP-1 secretion and improvements in glycaemia compared to baseline. There were no significant differences in post-prandial peak concentrations of GLP-1, time to peak, insulin secretion, and insulin sensitivity. ConclusionThe findings of this study demonstrate that lengthening of the intestinal bypass in RYGB does not affect GLP-1 secretion. Thus, the characteristic enhancement of GLP-1 response after RYGB might not depend on delivery of nutrients to more distal intestinal segments.

Journal article

Hameed S, Salem V, Alessimii H, Scholtz S, Dar O, Miras AD, Meeran K, Bloom SR, Ahmed AR, Purkayastha S, Chahal H, Tan Tet al., 2020, Imperial Satiety Protocol: A new non-surgical weight-loss programme, delivered in a health care setting, produces improved clinical outcomes for people with obesity, DIABETES OBESITY & METABOLISM, Vol: 23, Pages: 270-275, ISSN: 1462-8902

Journal article

Tan T, Khoo B, Mills EG, Phylactou M, Patel B, Eng PC, Thurston L, Muzi B, Meeran K, Prevost AT, Comninos AN, Abbara A, Dhillo WSet al., 2020, Cortisol concentrations and mortality from COVID-19 - Authors' reply, The Lancet Diabetes and Endocrinology, Vol: 8, Pages: 809-810, ISSN: 2213-8595

Journal article

Khoo B, Tan TM-M, 2020, Combination gut hormones: prospects and questions for the future of obesity and diabetes therapy, Journal of Endocrinology, Vol: 246, Pages: R65-R74, ISSN: 0022-0795

Obesity represents an important public health challenge for the twenty-first century: globalised, highly prevalent and increasingly common with time, this condition is likely to reverse some of the hard-won gains in mortality accomplished in previous centuries. In the search for safe and effective therapies for obesity and its companion, type 2 diabetes mellitus (T2D), the gut hormone glucagon-like peptide-1 (GLP-1) has emerged as a forerunner and analogues thereof are now widely used in treatment of obesity and T2D, bringing proven benefits in improving glycaemia and weight loss and, notably, cardiovascular outcomes. However, GLP-1 alone is subject to limitations in terms of efficacy, and as a result, investigators are evaluating other gut hormones such as glucose-dependent insulinotropic peptide (GIP), glucagon and peptide YY (PYY) as possible partner hormones that may complement and enhance GLP-1's therapeutic effects. Such combination gut hormone therapies are in pharmaceutical development at present and are likely to make it to market within the next few years. This review examines the physiological basis for combination gut hormone therapy and presents the latest clinical results that underpin the excitement around these treatments. We also pose, however, some hard questions for the field which need to be answered before the full benefit of such treatments can be realised.

Journal article

Chen Q, Alexiadou K, Jones B, Sands C, Lewis MR, Bloom SR, Tan T, Li Jet al., 2020, Low-calorie intake: a key mechanism contributing to the metabolic impacts of Roux-en-Y gastric bypass surgery, 56th Annual Meeting of the European-Association-for-the-Study-of-Diabetes (EASD), Publisher: SPRINGER, Pages: S263-S264, ISSN: 0012-186X

Conference paper

Tan T, Khoo B, Mills EG, Phylactou M, Patel B, Eng PC, Thurston L, Muzi B, Meeran K, Prevost AT, Comninos AN, Abbara A, Dhillo WSet al., 2020, Association between high serum total cortisol concentrations and mortality from COVID-19, The Lancet Diabetes and Endocrinology, Vol: 8, Pages: 659-660, ISSN: 2213-8595

Journal article

Suba K, Patel YS, Alonso AM, Scott R, Minnion JS, Leclerc I, Owen B, Distaso W, Tan TM, Murphy K, Bloom S, Rutter GA, Salem Vet al., 2020, Chronic Administration of a Long-Acting Glucagon Analogue Results in Enhanced Insulin Secretory Activity in a Directly-Observed Murine Model, 80th Scientific Sessions of the American-Diabetes-Association (ADA), Publisher: AMER DIABETES ASSOC, ISSN: 0012-1797

Conference paper

Izzi-Engbeaya C, Mills E, Yang L, Minnion J, Tharakan G, Abbara A, Comninos A, Tan T, Dhillo Wet al., 2020, Acute effects of glucagon on reproductive hormone secretion in healthy men, Journal of Clinical Endocrinology and Metabolism, Vol: 105, ISSN: 0021-972X

ContextGlucagon increases energy expenditure; consequently, glucagon receptor agonists are in development for the treatment of obesity. Obesity negatively affects the reproductive axis, and hypogonadism itself can exacerbate weight gain. Therefore, knowledge of the effects of glucagon receptor agonism on reproductive hormones is important for developing therapeutics for obesity; but reports in the literature about the effects of glucagon receptor agonism on the reproductive axis are conflicting.ObjectiveThe objective of this work is to investigate the effect of glucagon administration on reproductive hormone secretion in healthy young men.DesignA single-blinded, randomized, placebo-controlled crossover study was conducted.SettingThe setting of this study was the Clinical Research Facility, Imperial College Healthcare NHS Trust.ParticipantsEighteen healthy eugonadal men (mean ± SEM: age 25.1 ± 1.0 years; body mass index 22.5 ± 0.4 kg/m2; testosterone 21.2 ± 1.2 nmol/L) participated in this study.InterventionAn 8-hour intravenous infusion of 2 pmol/kg/min glucagon or rate-matched vehicle infusion was administered.Main Outcome MeasuresLuteinizing hormone (LH) pulsatility; LH, follicle-stimulating hormone (FSH), and testosterone levels were measured.ResultsAlthough glucagon administration induced metabolic effects (insulin area under the curve: vehicle 1065 ± 292 min.µU/mL vs glucagon 2098 ± 358 min.µU/mL, P < .001), it did not affect LH pulsatility (number of LH pulses/500 min: vehicle 4.7 ± 0.4, glucagon 4.2 ± 0.4, P = .22). Additionally, there were no significant differences in circulating LH, FSH, or testosterone levels during glucagon administration compared with vehicle administration.ConclusionsAcute administration of a metabolically active dose of glucagon does not alter reproductive hormone secretion in healthy men. These data are important for the continued development of glucagon-based tre

Journal article

Alexiadou K, Tan TM-M, 2020, Gastrointestinal peptides as therapeutic targets to mitigate obesity and metabolic syndrome, Current Diabetes Reports, Vol: 20, Pages: 1-7, ISSN: 1534-4827

Purpose of ReviewObesity affects over than 600 million adults worldwide resulting in multi-organ complications and major socioeconomic impact. The purpose of this review is to summarise the physiological effects as well as the therapeutic implications of the gut hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin, peptide YY (PYY), and glucose-dependent insulinotropic peptide (GIP) in the treatment of obesity and type 2 diabetes.Recent FindingsClinical trials have proven that the widely used GLP-1 analogues have pleotropic effects beyond those on weight and glucose metabolism and appear to confer favourable cardiovascular and renal outcomes. However, GLP-1 analogues alone do not deliver sufficient efficacy for the treatment of obesity, being limited by their dose-dependent gastrointestinal side effects. Novel dual agonists for GLP-1/glucagon and GLP-1/GIP are being developed by the pharmaceutical industry and have demonstrated some promising results for weight loss and improvement in glycaemia over and above GLP-1 analogues. Triagonists (for example GLP-1/GIP/glucagon) are currently in pre-clinical or early clinical development.SummaryGastrointestinal hormones possess complementary effects on appetite, energy expenditure, and glucose metabolism. We highlight the idea that combinations of these hormones may represent the way forward in obesity and diabetes therapeutics.

Journal article

Kamocka A, McGlone ER, Pérez-Pevida B, Moorthy K, Hakky S, Tsironis C, Chahal H, Miras AD, Tan T, Purkayastha S, Ahmed ARet al., 2020, Candy cane revision after Roux-en-Y gastric bypass, Surgical Endoscopy, Vol: 34, Pages: 2076-2081, ISSN: 0930-2794

BACKGROUND: An excessively long-blind end of the alimentary limb following a Roux-en-Y gastric bypass (RYGB), known as a 'candy cane' (CC), may cause symptoms including abdominal pain, regurgitation and vomiting. Very few studies have examined the efficacy of surgical resection of the CC. OBJECTIVES: The aim of this study was to assess sensitivity of preoperative diagnostic tools for CC, as well as perioperative outcomes and symptom resolution after CC revision surgery. SETTING: High volume bariatric centre of excellence, United Kingdom. METHODS: Observational study of CC revisions from 2010 to 2017. RESULTS: Twenty-eight CC revision cases were identified (mean age 45 ± 9 years, female preponderance 9:1). Presenting symptoms were abdominal pain (86%), regurgitation/vomiting (43%), suboptimal weight loss (36%) and acid reflux (21%). Preoperative tests provided correct diagnosis in 63% of barium contrast swallows, 50% of upper gastrointestinal endoscopies and 29% computed tomographies. Patients presenting with pain had significantly higher CC size as compared with pain-free group (4.2 vs. 2 cm, p = 0.001). Perioperative complications occurred in 25% of cases. Complete or partial symptom resolution was documented in 73% of patients undergoing CC revision. Highest success rates were recorded in the regurgitation/vomiting group (67%). CONCLUSION: Surgical revision of CC is associated with good symptom resolution in the majority of patients, especially those presenting with regurgitation/vomiting. However, it carries certain risk of complications. CC diagnosis may frequently be missed; hence more than one diagnostic tool should be considered when investigating symptomatic patients after RYGB.

Journal article

Fang Z, Chen S, Pickford P, Broichhagen J, Hodson DJ, Corrêa IR, Kumar S, Görlitz F, Dunsby C, French PMW, Rutter GA, Tan T, Bloom SR, Tomas A, Jones Bet al., 2020, The influence of peptide context on signaling and trafficking of glucagon-like peptide-1 receptor biased agonists, ACS Pharmacology & Translational Science, Vol: 3, Pages: 345-360, ISSN: 2575-9108

Signal bias and membrane trafficking have recently emerged as important considerations in the therapeutic targeting of the glucagon-like peptide-1 receptor (GLP-1R) in type 2 diabetes and obesity. In the present study, we have evaluated a peptide series with varying sequence homology between native GLP-1 and exendin-4, the archetypal ligands on which approved GLP-1R agonists are based. We find notable differences in agonist-mediated cyclic AMP signaling, recruitment of β-arrestins, endocytosis, and recycling, dependent both on the introduction of a His → Phe switch at position 1 and the specific midpeptide helical regions and C-termini of the two agonists. These observations were linked to insulin secretion in a beta cell model and provide insights into how ligand factors influence GLP-1R function at the cellular level.

Journal article

Alexiadou K, Cuenco J, Howard J, Albrechtsen NJW, Ilesanmi I, Kamocka A, Tharakan G, Behary P, Bech PR, Ahmed AR, Purkayastha S, Wheller R, Fleuret M, Holst JJ, Bloom SR, Khoo B, Tan TM-Met al., 2020, Proglucagon peptide secretion profiles in type 2 diabetes before and after bariatric surgery: 1-year prospective study, BMJ Open Diabetes Research and Care, Vol: 8, Pages: 1-10, ISSN: 2052-4897

Introduction Hyperglucagonemia is a key pathophysiological driver of type 2 diabetes. Although Roux-en-Y gastric bypass (RYGB) is a highly effective treatment for diabetes, it is presently unclear how surgery alters glucagon physiology. The aim of this study was to characterize the behavior of proglucagon-derived peptide (glucagon, glucagon-like peptide-1 (GLP-1), oxyntomodulin, glicentin) secretion after RYGB surgery.Research design and methods Prospective study of 19 patients with obesity and pre-diabetes/diabetes undergoing RYGB. We assessed the glucose, insulin, GLP-1, glucose-dependent insulinotropic peptide (GIP), oxyntomodulin, glicentin and glucagon responses to a mixed-meal test (MMT) before and 1, 3 and 12 months after surgery. Glucagon was measured using a Mercodia glucagon ELISA using the ‘Alternative’ improved specificity protocol, which was validated against a reference liquid chromatography combined with mass spectrometry method.Results After RYGB, there were early improvements in fasting glucose and glucose tolerance and the insulin response to MMT was accelerated and amplified, in parallel to significant increases in postprandial GLP-1, oxyntomodulin and glicentin secretion. There was a significant decrease in fasting glucagon levels at the later time points of 3 and 12 months after surgery. Glucagon was secreted in response to the MMT preoperatively and postoperatively in all patients and there was no significant change in this postprandial secretion. There was no significant change in GIP secretion.Conclusions There is a clear difference in the dynamics of secretion of proglucagon peptides after RYGB. The reduction in fasting glucagon secretion may be one of the mechanisms driving later improvements in glycemia after RYGB.

Journal article

Kamocka A, Miras AD, Perez-Pevida B, Umpleby AM, Chahal H, Moorthy K, Purkayastha S, Patel A, Bloom S, Tan T, Ahmed AR, Rubino Fet al., 2020, Long versus standard biliopancreatic limb in the Roux-en-Y gastric bypass. The LONG LIMB Trial., 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S4-S4, ISSN: 0960-8923

Conference paper

Izzi-Engbeaya C, Dhillo W, Tan T, Abbara A, Comninos A, Bech P, Minnion Jet al., 2020, Effects of glucagon-like peptide-1 on the reproductive axis in healthy men, Journal of Clinical Endocrinology and Metabolism, Vol: 105, Pages: 1-7, ISSN: 0021-972X

ContextGlucagon-like peptide-1 (GLP-1) potently reduces food intake and augments glucose-stimulated insulin secretion. Recent animal data suggest that GLP-1 may also influence reproduction. As GLP-1 receptor agonists are currently widely used in clinical practice to treat obesity/type 2 diabetes, it is necessary to determine the effects of GLP-1 on the reproductive system in humans.ObjectiveTo investigate the effects of GLP-1 administration on the reproductive axis in humans.DesignSingle-blind, randomized, placebo-controlled crossover study.SettingClinical Research Facility, Imperial College Healthcare NHS Trust.ParticipantsEighteen healthy men (mean age 24.7 ± 0.1years, mean BMI 22.1 ± 0.4kg/m2).InterventionEight-hour intravenous infusion of 0.8 pmol/kg/min GLP-1 or rate-matched vehicle infusion.Main Outcome MeasuresNumber of luteinizing hormone (LH) pulses, LH, follicle-stimulating hormone (FSH), and testosterone levels.ResultsThe number of LH pulses (number of LH pulses/500 min: vehicle 4.2 ± 0.4, GLP-1 4.5 ± 0.3, P = 0.46), LH area under the curve (AUC) (vehicle 1518 ± 88min.IU/L, GLP-1 1524 ± 101min.IU/L, P = 0.95), follicle-stimulating hormone AUC (vehicle 1210 ± 112 min IU/L, GLP-1 1216 ± 112 min IU/L, P = 0.86), and testosterone AUC (vehicle 10893 ± 615 min nmol/L, GLP-1 11088 ± 792 min nmol/L, P = 0.77) did not significantly differ during vehicle and GLP-1 administration. Glucagon-like peptide-1 significantly reduced food intake (vehicle 15.7 ± 1.3 kcal/kg, GLP-1 13.4 ± 1.3 kcal/kg, P = 0.01).ConclusionsIn contrast to the animal literature, our data demonstrate that acute GLP-1 administration does not affect reproductive hormone secretion in healthy men.

Journal article

Miras AD, Ravindra S, Humphreys A, Lascaratos G, Quartey KNK, Ahmed AR, Cousins J, Moorthy K, Purkayastha S, Hakky S, Tan T, Chahal HSet al., 2019, Metabolic changes and diabetes microvascular complications 5 years after obesity surgery., Obesity Surgery, Vol: 29, Pages: 3907-3911, ISSN: 0960-8923

BACKGROUND: Obesity surgery has pronounced effects on metabolic profile of patients with type 2 diabetes mellitus (T2DM); however, reports on long-term remission rates based on the standardised and holistic criteria by the International Diabetes Federation (IDF) and effects on T2DM microvascular complications are scarce in the literature. In this retrospective clinical trial, our objectives were to assess these variables 5 years after surgery. METHODS: Clinical data and direct measurements of renal and retinal damage were collected prospectively and analysed retrospectively for 82 patients with T2DM who underwent obesity surgery and were followed up for 5 years. RESULTS: The cohort of 82 patients with T2DM that were followed up 5 years after obesity surgery was predominantly female (71%) with a median age of 51 years, weight of 133.5 kg, BMI of 46.8 kg/m2 and pre-operative duration of T2DM of 8 years; 6% of patients had diet-controlled T2DM, 57% were on non-insulin treatment and 37% were on insulin treatment pre-operatively. Of the total 82 patients, 59 patients underwent Roux-en-Y gastric bypass, 15 sleeve gastrectomy and 8 patients underwent gastric band operations. At 5 years, 5% and 15% patients achieved optimisation and improvement of the metabolic state based on the IDF criteria respectively. Surgery was associated with almost halving of the albumin-creatinine ratio in 22 patients with pre-existing albuminuria (follow-up data available for 64 patients) and an overall stabilisation of retinopathy in 24 patients with retinal images available at 5 years. CONCLUSION: Whilst the findings on microvascular complications are encouraging, the rates of metabolic remission were lower than expected and raise the need for validated protocols to assist clinicians in managing these patients more aggressively post-operatively to achieve optimum cardio-metabolic risk factor control and hopefully further reduction in microvascular an

Journal article

Izzi-Engbeaya C, Jones S, Crustna Y, Machenahalli PC, Papadopoulou D, Modi M, Panayi C, Starikova J, Eng PC, Phylactou M, Mills E, Yang L, Ratnasabapathy R, Sykes M, Plumptre I, Coumbe B, Wing V, Pacuszka E, Bech P, Minnion J, Tharakan G, Tan T, Veldhuis J, Abbara A, Comninos AN, Dhillo WSet al., 2019, Effects of peptide-YY on the hypothalamic-pituitary-gonadal axis in healthy men, Journal of Clinical Endocrinology and Metabolism, Vol: 105, Pages: 1-6, ISSN: 0021-972X

ContextCentral and peripheral administration of peptide-YY (PYY) has potent anorectic effects, and PYY analogues are under development as anti-obesity treatments. Recent animal data suggest PYY may also influence the reproductive axis, however the effects of PYY on the human reproductive system are unknown.ObjectiveTo investigate the effects of PYY administration on the reproductive axis in healthy young men.DesignSingle-blind, randomised, placebo-controlled crossover study.SettingClinical Research Facility, Imperial College Healthcare NHS Trust.ParticipantsEighteen healthy eugonadal men (mean age 24.1±0.9years, mean BMI 22.2±0.4kg/m2).InterventionEight-hour intravenous infusion of 0.4pmol/kg/min PYY3-36 or rate-matched vehicle infusion.ResultsThe number of LH pulses (mean number of LH pulses/8hours: PYY 4.4±0.3 vs vehicle 4.4±0.4, p>0.99), LH area under the curve (AUC) (PYY 1503±79IU.min/L vs vehicle 1574±86IU.min/L, p=0.36), FSH AUC (PYY 1158±513IU.min/L vs vehicle 1199±476IU.min/L, p=0.49) and testosterone AUC (PYY 10485±684IU.min/L vs vehicle 11133±803IU.min/L, p=0.24) were similar during PYY and vehicle infusions.ConclusionsAcute intravenous infusion of 0.4pmol/kg/min PYY does not affect the reproductive axis in healthy men.

Journal article

Perez-Pevida B, Kamocka A, Aldhwayan M, Kopanou A, Miras AD, Tan T, Scholtz Set al., 2019, IMPACT OF EATING BEHAVIOURS ON POSTOPERATIVE OUTCOMES IN SUBOPTIMAL RESPONDERS AFTER OBESITY SURGERY Psychology and bariatric surgery - pre and post-op challenges, 24th World Congress of the International-Federation-for-the-Surgery-of-Obesity-and-Metabolic-Disorders (IFSO) / 21st SECO Congress, Publisher: SPRINGER, Pages: 247-247, ISSN: 0960-8923

Conference paper

Mcglone ER, Siebert M, Minnion J, Owen B, Goldin R, Li J, Carling D, Bado A, Bloom S, Le Gall M, Tan Tet al., 2019, SLEEVE GASTRECTOMY IS ASSOCIATED WITH WEIGHT LOSS-INDEPENDENT IMPROVEMENT IN HEPATIC STEATOSIS Basic science and research in bariatric surgery, 24th World Congress of the International-Federation-for-the-Surgery-of-Obesity-and-Metabolic-Disorders (IFSO) / 21st SECO Congress, Publisher: SPRINGER, Pages: 479-479, ISSN: 0960-8923

Conference paper

Kamocka A, Miras AD, Perez-Pevida B, Umpleby AM, Chahal H, Moorthy K, Purkayastha S, Patel A, Tan T, Bloom S, Ahmed AR, Rubino Fet al., 2019, LONG VS STANDARD BILIOPANCREATIC LIMB ROUX-EN-Y GASTRIC BYPASS FOR TYPE 2 DIABETES. THE LONG LIMB TRIAL Type 2 diabetes and metabolic surgery, 24th World Congress of the International-Federation-for-the-Surgery-of-Obesity-and-Metabolic-Disorders (IFSO) / 21st SECO Congress, Publisher: SPRINGER, Pages: 234-234, ISSN: 0960-8923

Conference paper

Rose F, Bloom S, Tan T, 2019, Novel approaches to anti-obesity drug discovery with gut hormones over the past 10 years, EXPERT OPINION ON DRUG DISCOVERY, ISSN: 1746-0441

Journal article

McGlone ER, Tan T, Bloom SR, Walters JRFet al., 2019, What Can We Learn From Mouse Models About Bile Acid–Mediated Changes After Bariatric Surgery?, Gastroenterology, Vol: 157, Pages: 4-8, ISSN: 0016-5085

Journal article

Behary P, Tharakan G, Alexiadou K, Johnson N, Wewer Albrechtsen NJ, Kenkre J, Cuenco J, Hope D, Anyiam O, Choudhury S, Alessimii H, Poddar A, Minnion J, Doyle C, Frost G, Le Roux C, Purkayastha S, Moorthy K, Dhillo W, Holst JJ, Ahmed AR, Prevost AT, Bloom SR, Tan TMet al., 2019, Combined GLP-1, oxyntomodulin, and peptide YY improves body weight and glycemia in obesity and prediabetes/type 2 diabetes: a randomized single-blinded placebo controlled study, Diabetes Care, Vol: 42, Pages: 1446-1453, ISSN: 0149-5992

OBJECTIVE: Roux-en-Y gastric bypass (RYGB) augments postprandial secretion of glucagon-like peptide 1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY). Subcutaneous infusion of these hormones ("GOP"), mimicking postprandial levels, reduces energy intake. Our objective was to study the effects of GOP on glycemia and body weight when given for 4 weeks to patients with diabetes and obesity. RESEARCH DESIGN AND METHODS: In this single-blinded mechanistic study, obese patients with prediabetes/diabetes were randomized to GOP (n = 15) or saline (n = 11) infusion for 4 weeks. We also studied 21 patients who had undergone RYGB and 22 patients who followed a very low-calorie diet (VLCD) as unblinded comparators. Outcomes measured were 1) body weight, 2) fructosamine levels, 3) glucose and insulin during a mixed meal test (MMT), 4) energy expenditure (EE), 5) energy intake (EI), and 6) mean glucose and measures of glucose variability during continuous glucose monitoring. RESULTS: GOP infusion was well tolerated over the 4-week period. There was a greater weight loss (P = 0.025) with GOP (mean change -4.4 [95% CI -5.3, -3.5] kg) versus saline (-2.5 [-4.1, -0.9] kg). GOP led to a greater improvement (P = 0.0026) in fructosamine (-44.1 [-62.7, -25.5] µmol/L) versus saline (-11.7 [-18.9, -4.5] µmol/L). Despite a smaller weight loss compared with RYGB and VLCD, GOP led to superior glucose tolerance after a mixed-meal stimulus and reduced glycemic variability compared with RYGB and VLCD. CONCLUSIONS: GOP infusion improves glycemia and reduces body weight. It achieves superior glucose tolerance and reduced glucose variability compared with RYGB and VLCD. GOP is a viable alternative for the treatment of diabetes with favorable effects on body weight.

Journal article

Buckley AJ, Suliman M, Al Tikriti A, Lessan N, Le Roux C, Tan TM, Barakat MTet al., 2019, Liraglutide 3 mg for Weight Loss in a Real-World Setting: Clinical Outcomes after 56 Weeks, 79th Scientific Sessions of the American-Diabetes-Association (ADA), Publisher: AMER DIABETES ASSOC, ISSN: 0012-1797

Conference paper

Suliman M, Buckley A, Al Tikriti A, Tan T, le Roux CW, Lessan N, Barakat Met al., 2019, Routine clinical use of liraglutide 3 mg for the treatment of obesity: Outcomes in non-surgical and bariatric surgery patients, DIABETES OBESITY & METABOLISM, Vol: 21, Pages: 1498-1501, ISSN: 1462-8902

Journal article

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=00539776&limit=30&person=true