Imperial College London

Mr Ahmed R. Ahmed PhD FRCS

Faculty of MedicineDepartment of Surgery & Cancer

Clinical Senior Lecturer in Bariatric Surgery
 
 
 
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Contact

 

+44 (0)20 8846 1081a.ahmed07

 
 
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Location

 

Charing Cross HospitalCharing Cross Campus

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Summary

 

Publications

Publication Type
Year
to

211 results found

Eslam M, Ahmed A, Despres J-P, Jha V, Halford JCG, Chieh JTW, Harris DCH, Nangaku M, Colagiuri S, Targher G, Joshi S, Byrne CD, Khunti K, Nguyen MH, Gish RG, George Jet al., 2021, Incorporating fatty liver disease in multidisciplinary care and novel clinical trial designs for patients with metabolic diseases, LANCET GASTROENTEROLOGY & HEPATOLOGY, Vol: 6, Pages: 743-753

Journal article

Jones B, Sands C, Alexiadou K, Minnion J, Tharakan G, Behary P, Ahmed A, Purkayastha S, Lewis M, Bloom S, Li J, Tan Tet al., 2021, The metabolomic effects of tripeptide gut hormone infusion compared to Roux-en-Y gastric bypass and caloric restriction, Journal of Clinical Endocrinology and Metabolism, ISSN: 0021-972X

Context: The gut-derived peptide hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY) are regulators of energy intake and glucose homeostasis, and are thought to contribute to the glucose-lowering effects of bariatric surgery. Objective: To establish the metabolomic effects of a combined infusion of GLP-1, OXM and PYY (tripeptide “GOP”) in comparison to a placebo infusion, Roux-en-Y gastric bypass (RYGB) surgery, and a very low-calorie diet (VLCD). Design and setting: Sub-analysis of a single-blind, randomised, placebo-controlled study of GOP infusion (ClinicalTrials.gov NCT01945840), including VLCD and RYGB comparator groups. Patients and interventions: 25 obese patients with type 2 diabetes or prediabetes were randomly allocated to receive a 4-week subcutaneous infusion of GOP (n=14) or 0.9% saline control (SAL; n=11). An additional 22 patients followed a VLCD, and 21 underwent RYGB surgery. Main outcome measures: Plasma and urine samples collected at baseline and 4 weeks into each intervention were subjected to cross-platform metabolomic analysis, followed by unsupervised and supervised modelling approaches to identify similarities and differences between the effects of each intervention. Results: Aside from glucose, very few metabolites were affected by GOP, contrasting with major metabolomic changes seen with VLCD and RYGB. Conclusions: Treatment with GOP provides a powerful glucose-lowering effect but does not replicate the broader metabolomic changes seen with VLCD and RYGB. The contribution of these metabolomic changes to the clinical benefits of RYGB remains to be elucidated.

Journal article

Moussa O, Ortega P, Mansour S, Flod S, Cousins J, Hameed S, Tan T, Miras A, Chahal H, Hakky S, Moorthy K, Tsironis C, Ahmed A, Purkayastha Set al., 2021, Bariatric surgical services within a pandemic can continue safely: the initial experience of a UK centre of excellence., Obesity Surgery, ISSN: 0960-8923

Journal article

Salem V, Demetriou L, Behary P, Alexiadou K, Scholtz S, Tharakan G, Miras A, Purkayastha S, Ahmed A, Bloom S, Wall M, Dhillo W, Tan Tet al., 2021, Weight loss by low calorie diet versus gastric bypass surgery in people with diabetes results in divergent brain activation patterns: an functional MRI study, Diabetes Care, Vol: 44, Pages: 1842-1851, ISSN: 0149-5992

OBJECTIVE: Weight loss achieved with very-low-calorie diets (VLCDs) can produce remission of type 2 diabetes (T2D), but weight regain very often occurs with reintroduction of higher calorie intakes. In contrast, bariatric surgery produces clinically significant and durable weight loss, with diabetes remission that translates into reductions in mortality. We hypothesized that in patients living with obesity and prediabetes/T2D, longitudinal changes in brain activity in response to food cues as measured using functional MRI would explain this difference.RESEARCH DESIGN AND METHODS: Sixteen participants underwent gastric bypass surgery, and 19 matched participants undertook a VLCD (meal replacement) for 4 weeks. Brain responses to food cues and resting-state functional connectivity were assessed with functional MRI pre- and postintervention and compared across groups.RESULTS: We show that Roux-en-Y gastric bypass surgery (RYGB) results in three divergent brain responses compared with VLCD-induced weight loss: 1) VLCD resulted in increased brain reward center food cue responsiveness, whereas in RYGB, this was reduced; 2) VLCD resulted in higher neural activation of cognitive control regions in response to food cues associated with exercising increased cognitive restraint over eating, whereas RYGB did not; and 3) a homeostatic appetitive system (centered on the hypothalamus) is better engaged following RYGB-induced weight loss than VLCD.CONCLUSIONS: Taken together, these findings point to divergent brain responses to different methods of weight loss in patients with diabetes, which may explain weight regain after a short-term VLCD in contrast to enduring weight loss after RYGB.

Journal article

Ahmed A, Morales-Conde S, Legrand M, Nienhuijs S, Himpens J, Jiao LR, Facy Oet al., 2021, Clinical outcomes of pre-attached reinforced stapler reloads in bariatric surgery: A prospective case series, INTERNATIONAL JOURNAL OF SURGERY OPEN, Vol: 32, ISSN: 2405-8572

Journal article

Samarasinghe S, Sudlow A, Dimitriadis GK, Ahmed AR, Purkayastha S, Tsironis C, Hakky S, Moorthy K, Aylwin SJB, Panagiotopoulos S, El-Hassani S, Patel AG, Chahal H, Hameed S, le Roux CW, Pournaras DJ, Miras ADet al., 2021, Simple tool to prioritize access to bariatric surgery for people living with obesity during the COVID-19 pandemic, British Journal of Surgery, Vol: 108, Pages: e179-e180, ISSN: 0007-1323

Journal article

Ghanem A, Emile S, Cousins J, Kerrigan D, Ahmed ARet al., 2021, Bariatric surgery during COVID-19 in the UK: a British Obesity and Metabolic Surgery Society (BOMSS) survey, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, ISSN: 0930-2794

Journal article

Kenkre J, Ahmed A, Purkayastha S, Mallalah K, Bloom S, Blakemore A, Prevost A, Tan Tet al., 2021, Who will benefit from bariatric surgery for diabetes? A protocol for an observational cohort study, BMJ Open, Vol: 11, ISSN: 2044-6055

Introduction Type 2 diabetes mellitus (T2DM) and obesity are pandemic diseases that lead to a great deal of morbidity and mortality. The most effective treatment for obesity and T2DM is bariatric or metabolic surgery; it can lead to long-term diabetes remission with 4 in 10 of those undergoing surgery having normal blood glucose on no medication 1 year postoperatively. However, surgery carries risks and, additionally, due to resource limitations, there is a restricted number of patients who can access this treatment. Moreover, not all those who undertake surgery respond equally well metabolically. The objective of the current research is to prospectively investigate predictors of T2DM response following metabolic surgery, including those directly involved in its aetiopathogenesis such as fat distribution and genetic variants. This will inform development of a clinically applicable model to help prioritise this therapy to those predicted to have remission.Methods and analysis A prospective multicentre observational cohort study of adult patients with T2DM and obesity undergoing Roux-en-Y gastric bypass surgery. Patients will be comprehensively assessed before surgery to determine their clinical, metabolic, psychological, genetic and fat distribution profiles. A multivariate logistic regression model will be used to assess the value of the factors derived from the preoperative assessment in terms of prediction of diabetes remission.Ethics and dissemination Formal ethics review was undertaken with a favourable opinion (UK HRA RES reference number 18/LO/0931). The dissemination plan is to present the results at conferences, in peer-reviewed journals as well as to lay media and to patient organisations.Trial registration details ClinicalTrials.gov, Identifier: NCT03842475.

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., 2021, 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, Vol: 44, Pages: 614-617, ISSN: 0149-5992

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., 2021, 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, Vol: 44, Pages: 1-9, 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

McGlone ER, Malallah K, Cuenco J, Wewer Albrechtsen NJ, Holst JJ, Vincent RP, Ling C, Khan OA, Verma S, Ahmed AR, Walters JR, Khoo B, Bloom SR, Tan TM-Met al., 2021, DIFFERENTIAL EFFECTS OF BILE ACIDS ON THE POST-PRANDIAL SECRETION OF GUT HORMONES: a randomised crossover study., Am J Physiol Endocrinol Metab

AIMS Bile acids (BA) regulate post-prandial metabolism directly and indirectly by affecting the secretion of gut hormones like glucagon-like peptide-1 (GLP-1). The post-prandial effects of BA on the secretion of other metabolically active hormones are not well understood. The objective of this study was to investigate the effect of oral ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) on post-prandial secretion of GLP-1, oxyntomodulin (OXM), peptide YY (PYY), glucose-dependent insulinotropic peptide (GIP), glucagon and ghrelin. METHODS Twelve healthy volunteers underwent a mixed meal test 60 minutes after ingestion of UDCA (12-16 mg/kg), CDCA (13-16 mg/kg) or no BA in a randomised cross-over study. Glucose, insulin, GLP-1, OXM, PYY, GIP, glucagon, ghrelin and fibroblast growth factor 19 were measured prior to BA administration at -60, 0 (just prior to mixed meal) and 15, 30, 60, 120, 180 and 240 minutes after the meal. RESULTS UDCA and CDCA provoked differential gut hormone responses: UDCA did not have any significant effects, but CDCA provoked significant increases in GLP-1 and OXM and a profound reduction in GIP. CDCA increased fasting GLP-1 and OXM secretion in parallel with an increase in insulin. On the other hand, CDCA reduced post-prandial secretion of GIP, with an associated reduction in post-prandial insulin secretion. CONCLUSIONS Exogenous CDCA can exert multiple salutary effects on the secretion of gut hormones; if these effects are confirmedin obesity and type 2 diabetes, CDCA may be a potential therapy for these conditions.

Journal article

Lerner A, Kewada D, Ahmed A, Hardy K, Christian M, Franks Set al., 2021, Androgen reduces mitochondrial respiration in mouse brown adipocytes: a model for disordered energy balance in polycystic ovary syndrome, International Journal of Molecular Sciences, Vol: 22, ISSN: 1422-0067

Polycystic ovary syndrome (PCOS) is a common endocrinopathy that is associated with an adverse metabolic profile including reduced postprandial thermogenesis. Although abnormalities in adipose tissue function have been widely reported in women with PCOS, less is known about direct effects of androgen on white and, particularly, brown adipocytes. The purpose of this study was to investigate the effect of the nonaromatizable androgen dihydrotestosterone (DHT) on (1) lipid accumulation and expression of adipogenic markers in immortalized mouse brown adipose cell lines (IMBATs), (2) mitochondrial respiration in IMBATs, (3) mitochondrial DNA content and gene expression, (4) expression of brown adipose tissue (BAT) markers and thermogenic activation. In addition, we profiled the relative levels of 38 adipokines secreted from BAT explants and looked at androgen effects on adipokine gene expression in both IMBATs and immortalized mouse white adipose (IMWATs) cell lines. Androgen treatment inhibited IMBAT differentiation in a dose-dependent manner, reduced markers of adipogenesis, and attenuated the β-adrenoceptor-stimulated increase in uncoupling protein-1 (UCP1) expression. In explants of mouse interscapular BAT, androgen reduced expression of UCP1, peroxisome proliferator-activated receptor-γ coactivator-1 (PCG-1) and Cidea. Significantly, as well as affecting genes involved in thermogenesis in BAT, androgen treatment reduced mitochondrial respiration in IMBATs, as measured by the Seahorse XF method. The results of this study suggest a role for excess androgen in inhibiting brown adipogenesis, attenuating the activation of thermogenesis and reducing mitochondrial respiration in BAT. Together, these data provide a plausible molecular mechanism that may contribute to reduced postprandial thermogenesis and the tendency to obesity in women with PCOS.

Journal article

McGlone ER, Carey I, Velickovic V, Chana P, Mahawar K, Batterham RL, Hopkins J, Walton P, Kinsman R, Byrne J, Somers S, Kerrigan D, Menon V, Borg C, Ahmed A, Sgromo B, Cheruvu C, Bano G, Leonard C, Thom H, le Roux CW, Reddy M, Welbourn R, Small P, Khan OAet al., 2020, Bariatric surgery for patients with type 2 diabetes mellitus requiring insulin: Clinical outcome and cost-effectiveness analyses, PLoS Medicine, Vol: 17, Pages: 1-22, ISSN: 1549-1277

BackgroundAlthough bariatric surgery is well established as an effective treatment for patients with obesity and type 2 diabetes mellitus (T2DM), there exists reluctance to increase its availability for patients with severe T2DM. The aims of this study were to examine the impact of bariatric surgery on T2DM resolution in patients with obesity and T2DM requiring insulin (T2DM-Ins) using data from a national database and to develop a health economic model to evaluate the cost-effectiveness of surgery in this cohort when compared to best medical treatment (BMT).Methods and findingsClinical data from the National Bariatric Surgical Registry (NBSR), a comprehensive database of bariatric surgery in the United Kingdom, were extracted to analyse outcomes of patients with obesity and T2DM-Ins who underwent primary bariatric surgery between 2009 and 2017. Outcomes for this group were combined with data sourced from a comprehensive literature review in order to develop a state-transition microsimulation model to evaluate cost-effectiveness of bariatric surgery versus BMT for patients over a 5-year time horizon. The main outcome measure for the clinical study was insulin cessation at 1-year post-surgery: relative risks (RR) summarising predictive factors were determined, unadjusted, and after adjusting for variables including age, initial body mass index (BMI), duration of T2DM, and weight loss. Main outcome measures for the economic evaluation were total costs, total quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) at willingness-to-pay threshold of GBP£20,000.A total of 2,484 patients were eligible for inclusion, of which 1,847 had 1-year follow-up data (mean age of 51 years, mean initial BMI 47.2 kg/m2, and 64% female). 67% of patients no longer required insulin at 1-year postoperatively: these rates persisted for 4 years. Roux-en-Y gastric bypass (RYGB) was associated with a higher rate of insulin cessation (71.7%) than sleeve gastr

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 and Metabolism: a journal of pharmacology and therapeutics, Vol: 23, Pages: 270-275, ISSN: 1462-8902

‘Imperial Satiety Protocol’ (I-SatPro) is a new multifaceted approach to weight loss for people with obesity (PwO), encompassing dietary advice, time-restricted eating, physical activity and coaching to support behaviour change. Participants (n = 84) attended fortnightly I-SatPro group sessions for 30 weeks, with 70% of participants completing. On completion at 30 weeks, the mean weight loss was 15.2 ± 1.1 kg (13.2 ± 0.8% from baseline, P < .0001), which was maintained to 52 weeks (16.6 ± 1.5 kg, 14.1 ± 1.2%, P < .0001). Weight loss was not associated with reduced energy expenditure. In participants with type 2 diabetes and pre-diabetes (n = 16), glycated haemoglobin fell from 50 to 43 mmol/mol (P < .01). Systolic blood pressure fell by 12 mmHg (P < .0001). Triglycerides fell by 0.37 mmol/L (P < .01) and high-density lipoprotein rose by 0.08 mmol/L (P < .01). Short Form-36 (SF-36) functioning and wellbeing scores increased in all domains post I-SatPro intervention. For selected PwO, I-SatPro delivers clinically meaningful weight loss, and the potential for long-term health and wellbeing improvements.

Journal article

Wiggins T, Guidozzi N, Welbourn R, Ahmed AR, Marker SRet al., 2020, Association of bariatric surgery with all-cause mortality and incidence of obesity-related disease at a population level: A systematic review and meta-analysis, PLoS Medicine, Vol: 17, ISSN: 1549-1277

BackgroundPrevious clinical trials and institutional studies have demonstrated that surgery for the treatment of obesity (termed bariatric or metabolic surgery) reduces all-cause mortality and the development of obesity-related diseases such as type 2 diabetes mellitus (T2DM), hypertension, and dyslipidaemia. The current study analysed large-scale population studies to assess the association of bariatric surgery with long-term mortality and incidence of new-onset obesity-related disease at a national level.Methods and findingsA systematic literature search of Medline (via PubMed), Embase, and Web of Science was performed. Articles were included if they were national or regional administrative database cohort studies reporting comparative risk of long-term mortality or incident obesity-related diseases for patients who have undergone any form of bariatric surgery compared with an appropriate control group with a minimum follow-up period of 18 months. Meta-analysis of hazard ratios (HRs) was performed for mortality risk, and pooled odds ratios (PORs) were calculated for discrete variables relating to incident disease. Eighteen studies were identified as suitable for inclusion. There were 1,539,904 patients included in the analysis, with 269,818 receiving bariatric surgery and 1,270,086 control patients. Bariatric surgery was associated with a reduced rate of all-cause mortality (POR 0.62, 95% CI 0.55 to 0.69, p < 0.001) and cardiovascular mortality (POR 0.50, 95% CI 0.35 to 0.71, p < 0.001). Bariatric surgery was strongly associated with reduced incidence of T2DM (POR 0.39, 95% CI 0.18 to 0.83, p = 0.010), hypertension (POR 0.36, 95% CI 0.32 to 0.40, p < 0.001), dyslipidaemia (POR 0.33, 95% CI 0.14 to 0.80, p = 0.010), and ischemic heart disease (POR 0.46, 95% CI 0.29 to 0.73, p = 0.001). Limitations of the study include that it was not possible to account for unmeasured variables, which may not have been equally distributed between patient groups given the n

Journal article

Flor Prades L, Ahmed A, Lopes MM, Kaur V, Bansi Det al., 2020, USE OF THE OVERSTICH DEVICE FOR ENDOSCOPIC REVISION OF ROUX-EN -Y GASTRIC BY-PASS: AN UPDATE FROM THE LARGEST UK SERIES, GI Fellows Sessions at Digestive Disease Week / 61st Annual Meeting of the Society-for-Surgery-of-the-Alimentary-Tract, Publisher: MOSBY-ELSEVIER, Pages: AB231-AB231, ISSN: 0016-5107

Conference paper

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

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

Shakweh E, Ghanem A, Ahmed A, Mansour Set al., 2020, Gastrojejunostomy redo after complicated Rouxen-Y gastric Bypass, 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S19-S20, ISSN: 0960-8923

Conference paper

Tankel J, Ahmed A, 2020, Gastrojejunostomy in Roux-En-Y gastric bypass for morbid obesity: Linear stapler length does not affect outcomes, 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S69-S70, ISSN: 0960-8923

Conference paper

Clark J, Tsironis C, Hakky S, Purkayastha S, Moorthy K, Ahmed Aet al., 2020, Chronic Pain post Roux-en Y Gastric Bypass Surgery; defining a clear management strategy., 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S31-S32, ISSN: 0960-8923

Conference paper

Mansour S, Shakweh E, Tsironis C, Hakky S, Moorthy K, Purkayastha S, Ahmed Aet al., 2020, The Perfect Sleeve- How to avoid and manage Sleeve Gastrectomy Leak based on Current Best Evidence, 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S47-S47, ISSN: 0960-8923

Conference paper

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

Mansour S, Shakweh E, Tsironis C, Hakky S, Moorthy K, Purkayastha S, Ahmed Aet al., 2020, Standard-steps approach improves safety and efficacy in training bariatric fellowships, 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S29-S30, ISSN: 0960-8923

Conference paper

Wiggins T, Markar S, Jamel S, Hakky S, Ahmed A, Hanna Get al., 2020, Assurance of surgical quality within multicentre randomised controlled trials for bariatric and metabolic surgery: a systematic review, 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S31-S31, ISSN: 0960-8923

Conference paper

Copley SJ, Jones LC, Soneji ND, Cousins J, Edey A, Ahmed AR, Wells AUet al., 2020, Lung Parenchymal and Tracheal CT Morphology: Evaluation before and after Bariatric Surgery, RADIOLOGY, Vol: 294, Pages: 669-675, ISSN: 0033-8419

Journal article

Ghanem A, Kabbani J, Abrams S, Ahmed Aet al., 2020, Cyanoacrylate Glue in closure of mesenteric defects after Laparoscopic Roux-en-Y Gastric Bypass, early results of a new technique., 11th Annual Scientific Meeting of the British-Obesity-and-Metabolic-Surgery-Society (BOMSS), Publisher: SPRINGER, Pages: S58-S59, ISSN: 0960-8923

Conference paper

Murphy J, Uttamlal T, Schmidtke KA, Vlaev I, Taylor D, Ahmad M, Alsters S, Purkayastha P, Scholtz S, Ramezani R, Ahmed AR, Chahal H, Darzi A, Blakemore AIFet al., 2020, Tracking physical activity using smart phone apps: assessing the ability of a current app and systematically collecting patient recommendations for future development, BMC Medical Informatics and Decision Making, Vol: 20, ISSN: 1472-6947

BACKGROUND: Within the United Kingdom's National Health System (NHS), patients suffering from obesity may be provided with bariatric surgery. After receiving surgery many of these patients require further support to continue to lose more weight or to maintain a healthy weight. Remotely monitoring such patients' physical activity and other health-related variables could provide healthworkers with a more 'ecologically valid' picture of these patients' behaviours to then provide more personalised support. The current study assesses the feasibility of two smartphone apps to do so. In addition, the study looks at the barriers and facilitators patients experience to using these apps effectively. METHODS: Participants with a BMI > 35 kg/m2 being considered for and who had previously undergone bariatric surgery were recruited. Participants were asked to install two mobile phone apps. The 'Moves' app automatically tracked participants' physical activity and the 'WLCompanion' app prompted participants to set goals and input other health-related information. Then, to learn about participants' facilitators and barriers to using the apps, some participants were asked to complete a survey informed by the Theoretical Domains Framework. The data were analysed using regressions and descriptive statistics. RESULTS: Of the 494 participants originally enrolled, 274 participants data were included in the analyses about their activity pre- and/or post-bariatric surgery (ages 18-65, M = 44.02, SD ± 11.29). Further analyses were performed on those 36 participants whose activity was tracked both pre- and post-surgery. Participants' activity levels pre- and post-surgery did not differ. In addition, 54 participants' survey responses suggested that the main facilitator to their continued use of the Moves app was its automatic nature, and the main barrier was its battery drain. CONCLUSIONS: The current study tracked physical activity in patien

Journal article

Ahmad SJ, Ahmed AR, Kowalewski KF, Nickel F, Rostami K, Stocker CJ, Hakky SM, Archid R, McWhinnie D, Mohajer-Bastami A, Seimenis DS, Ahmad S, Mansour S, Ahmed MH, Mital D, Exadaktylos AKet al., 2020, Citation classics in general medical journals: assessing the quality of evidence; a systematic review., Gastroenterol Hepatol Bed Bench, Vol: 13, Pages: 101-114, ISSN: 2008-2258

Aim: This review provides a comprehensive overview of more than 100 of the most cited studies in general medical journals and evaluates whether citations predict the quality of a scientific article. Background: The number of citations is commonly used as a measure of the quality and impact of a scientific article. However, it is often criticised that the number of citations is in fact a poor indicator of the true quality, as it can be influenced by different factors such as current trends. Methods: This review was conducted in line with the PRISMA guidelines. The Journal Citation Report (JCR) within Incites allowed the evaluation and comparison of articles, published in general medical journals, using far-reaching citation data drawn from scholarly and technical journals and conference proceedings. All steps of the review were performed in duplicate and conflicts were resolved through consensus. Results: The 100 most cited articles published from 1963 until the end of 2018 were identified. The number of citations ranged from 4012 to 31853. Most of the articles were published in the 2000's, followed by the 1990's, 1980's, 1970's and 1960's, respectively. All of the articles were published in five journals. There were 50 studies at level II, 28 at level V, 10 at level IV, 7 at level III, and 5 at Level I. Conclusion: This systematic review provides an overview of the most cited articles, published in general medical journals. The number of citations provides an indication of the quality of evidence. However, researchers and clinicians should use standardized assessment tools rather than solely rely on the number of citations in order to judge the quality of published articles.

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

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