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3. Multichromatic Near-Infrared Imaging to Assess Interstitial Lymphatic and Venous Uptake In Vivo

Author

Thanh N. Doan, Jarred Kaiser, Dixon Jb, Nick J. Willett, Zhanna Nepiyushchikh, Raval Sk, and Bernard Fc

Subjects
Lymphatic system, Interstitial space, In vivo, Chemistry, Interstitial fluid, PEG ratio, Drug delivery, Clearance rate, In vitro, Biomedical engineering
Abstract

SignificanceChanges in interstitial fluid clearance are implicated in many diseases. Using NIR imaging with properly sized tracers could enhance our understanding of how venous and lymphatic drainage are involved in disease progression or enhance drug delivery strategies.AimWe investigated multichromatic NIR imaging with multiple tracers to assess in vivo microvascular clearance kinetics and pathways in different tissue spaces.ApproachWe used a chemically inert IR Dye 800CW (free dye) to target venous capillaries and a purified conjugate of IR Dye 680RD with a 40 kDa PEG (PEG) to target lymphatic capillaries in vivo. Optical imaging settings were validated and tuned in vitro using tissue phantoms. We investigated multichromatic NIR imaging’s utility in two in vivo tissue beds – the mouse tail and rat knee joint. We then tested the ability of the approach to detect interstitial fluid perturbations due to exercise.ResultsIn an in vitro simulated tissue environment, free dye and PEG mixture allowed for simultaneous detection without interference. Co-injected NIR tracers cleared from the interstitial space via distinct routes allowed assessment lymphatic and venous uptake in the mouse tail. We determined that exercise after injection transiently increased lymphatic drainage as measured by lower normalized intensity immediately after exercise, while exercise pre-injection exhibited a transient delay in clearance from the jointConclusionsNIR imaging enables of simultaneous imaging of lymphatic and venous-mediated fluid clearance with great sensitivity and can be used to measure transient changes in clearance rates and pathways.

Published
2021

6. Comparison of endothelial function and sympathetic nervous system activity along the glucose continuum in individuals with differing metabolic risk profiles and low dietary sodium intake

Author

Baqar, S, Straznicky, NE, Lambert, G, Kong, YW, Dixon, JB, Jerums, G, Ekinci, EI, Lambert, E, Baqar, S, Straznicky, NE, Lambert, G, Kong, YW, Dixon, JB, Jerums, G, Ekinci, EI, and Lambert, E

Abstract

OBJECTIVE: Low sodium intake may trigger sympathetic nervous system (SNS) activation and endothelial dysfunction. Studies have not explored these associations along the glucose continuum. Accordingly, we compared endothelial function and SNS activity in individuals with low sodium intake and differing categories of metabolic risk along the glucose continuum. We hypothesized that low sodium intake is associated with (1) impairment of endothelial function and (2) higher SNS activity in individuals with higher metabolic risk. RESEARCH DESIGN AND METHODS: In this prospective observational study, participants (n=54) with low sodium intake (single 24 hours urine sodium excretion <150 mmol/24 hours) were categorized based on oral glucose tolerance testing as: normal glucose tolerance (NGT, n=10), impaired glucose tolerance (IGT, n=15), treatment naive type 2 diabetes (T2D-) (n=12) or treated type 2 diabetes (T2D+) (n=17). We assessed endothelial function using pulse amplitude tonometry (PAT) derived reactive hyperemic index and PAT ratio; arterial stiffness via augmentation index; muscle sympathetic nerve activity (MSNA) using microneurography; cardiac baroreflex; heart rate; blood pressure; glycosylated hemoglobin A1c (HbA1c) and lipid profile. RESULTS: Mean (SD) sodium excretion was 110.6 (26) mmol/24 hours. Compared with NGT, IGT and T2D-, the T2D+ group had lower MSNA (p=0.005), PAT ratio (p=0.04) and baroreflex sensitivity (p=0.0002) and an augmented heart rate (p=0.02). The T2D+ group had appropriate mean (SD) glycemic (HbA1c 7.2 (1.72)%), total cholesterol (4.2 (1.0) mmol/L), low-density lipoprotein (2.2 (1.0) mmol/L) and blood pressure (systolic 136 (13), diastolic 78 (12)) (mm Hg) control. CONCLUSIONS: Individuals with T2D+ have impaired endothelial and baroreflex function, despite low sodium intake, appropriately managed cardiometabolic risk factors and lower SNS activity, compared with others along the glucose continuum. Whether low sodium intake is associated w

Published
2019

7. Associations between systemic bone mineral density and early knee cartilage changes in middle-aged adults without clinical knee disease: a prospective cohort study

Author

Teichtahl, AJ, Wang, Y, Wluka, A, Strauss, BJ, Proietto, J, Dixon, JB, Jones, G, Cicuttini, FM, Teichtahl, AJ, Wang, Y, Wluka, A, Strauss, BJ, Proietto, J, Dixon, JB, Jones, G, and Cicuttini, FM

Abstract

BACKGROUND: Osteoarthritis has a high prevalence in people with high bone mineral density (BMD). Nevertheless, whether high systemic BMD predates early structural features of knee osteoarthritis is unclear. This study examined the association between systemic BMD and knee cartilage defect progression and cartilage volume loss in middle-aged people without clinical knee disease. METHODS: Adults (n = 153) aged 25-60 years had total body, lumbar spine, and total hip BMD assessed by dual-energy X-ray absorptiometry at baseline (2005-2008), and tibial cartilage volume and tibiofemoral cartilage defects assessed by magnetic resonance imaging at baseline and follow up (2008-2010). RESULTS: Higher spine BMD was associated with increased risk for progression of medial (OR = 1.45, 95% CI 1.10, 1.91) and lateral (OR = 1.30, 95% CI 1.00, 1.67) tibiofemoral cartilage defects. Total hip BMD was also positively associated with the progression of medial (OR = 1.63, 95% CI 1.10, 2.41) and lateral (OR = 1.53, 95% CI 1.08, 2.18) tibiofemoral cartilage defects. Greater total body, spine, and total hip BMD were associated with increased rate of lateral tibial cartilage volume loss (for every 1 g/10 cm2 increase in total body BMD: B = 0.44%, 95% CI 0.17%, 0.71%; spine BMD: 0.17%, 95% CI 0.04%, 0.30%; total hip BMD: 0.29%, 95% CI 0.13%, 0.45%), with no significant associations for medial tibial cartilage volume loss. CONCLUSION: In middle-aged people without clinical knee disease, higher systemic BMD was associated with increased early knee cartilage damage. Further work is needed to clarify the effect of systemic BMD at different stages of the pathway from health through to disease in knee osteoarthritis, as new therapies targeting bone are developed for the management of knee osteoarthritis.

Published
2017

8. Norepinephrine transporter expression is inversely associated with glycaemic indices: a pilot study in metabolically diverse persons with overweight and obesity

Author

Straznicky, NE, Guo, L, Corcoran, SJ, Esler, MD, Phillips, SE, Sari, CI, Grima, MT, Karapanagiotidis, S, Wong, CY, Eikelis, N, Mariani, JA, Kobayashi, D, Dixon, JB, Lambert, GW, Lambert, EA, Straznicky, NE, Guo, L, Corcoran, SJ, Esler, MD, Phillips, SE, Sari, CI, Grima, MT, Karapanagiotidis, S, Wong, CY, Eikelis, N, Mariani, JA, Kobayashi, D, Dixon, JB, Lambert, GW, and Lambert, EA

Abstract

OBJECTIVE: The objective of this study was to examine the cross-sectional relationship between the expression of norepinephrine transporter (NET), the protein responsible for neuronal uptake-1, and indices of glycaemia and hyperinsulinaemia, in overweight and obese individuals. METHODS: Thirteen non-medicated, non-smoking subjects, aged 58 ± 1 years (mean ± standard error of the mean), body mass index (BMI) 31.4 ± 1.0 kg m-2, with wide-ranging plasma glucose and haemoglobin A1c (HbA1c, range 5.1% to 6.5%) participated. They underwent forearm vein biopsy to access sympathetic nerves for the quantification of NET by Western blot, oral glucose tolerance test (OGTT), euglycaemic hyperinsulinaemic clamp, echocardiography and assessments of whole-body norepinephrine kinetics and muscle sympathetic nerve activity. RESULTS: Norepinephrine transporter expression was inversely associated with fasting plasma glucose (r = -0.62, P = 0.02), glucose area under the curve during OGTT (AUC0-120, r = -0.65, P = 0.02) and HbA1c (r = -0.67, P = 0.01), and positively associated with steady-state glucose utilization during euglycaemic clamp (r = 0.58, P = 0.04). Moreover, NET expression was inversely related to left ventricular posterior wall dimensions (r = -0.64, P = 0.02) and heart rate (r = -0.55, P = 0.05). Indices of hyperinsulinaemia were not associated with NET expression. In stepwise linear regression analysis adjusted for age, body mass index and blood pressure, HbA1c was an independent inverse predictor of NET expression, explaining 45% of its variance. CONCLUSIONS: Hyperglycaemia is associated with reduced peripheral NET expression. Further studies are required to identify the direction of causality.

Published
2016

9. The functional and clinical outcomes of exercise training following a very low energy diet for severely obese women: study protocol for a randomised controlled trial

Author

Miller, CT, Fraser, SF, Selig, SE, Rice, T, Grima, M, Straznicky, NE, Levinger, I, Lambert, EA, van den Hoek, DJ, Dixon, JB, Miller, CT, Fraser, SF, Selig, SE, Rice, T, Grima, M, Straznicky, NE, Levinger, I, Lambert, EA, van den Hoek, DJ, and Dixon, JB

Abstract

BACKGROUND: Clinical practice guidelines globally recommend lifestyle modification including diet and exercise training as first-line treatment for obesity. The clinical benefits of exercise training in adults with obesity is well-documented; however, there is no strong evidence for the effectiveness of exercise training for weight loss in class II and class III obesity. The purpose of the randomised controlled trial described in this protocol article is to examine the effect of exercise training, in addition to a very low energy diet (VLED), in clinically severe obese women for changes in body composition, physical function, quality of life, and markers of cardiometabolic risk. METHODS/DESIGN: Sixty women, aged 18-50 years with a body mass index (BMI) greater than 34.9 kg.m(2) and at least one obesity-related co-morbidity, will be recruited for this 12-month study. Participants will be randomised to either exercise plus energy restriction (n = 30), or energy restriction alone (n = 30). All participants will follow an energy-restricted individualised diet incorporating a VLED component. The exercise intervention group will also receive exercise by supervised aerobic and resistance training and a home-based exercise programme totalling 300 minutes per week. Primary outcome measures include body composition and aerobic fitness. Secondary outcome measures include: physical function, cardiometabolic risk factors, quality of life, physical activity, and mental health. All outcome measures will be conducted at baseline, 3, 6 and 12 months. DISCUSSION: Previous research demonstrates various health benefits of including exercise training as part of a healthy lifestyle at all BMI ranges. Although clinical practice guidelines recommend exercise training as part of first-line treatment for overweight and obesity, there are few studies that demonstrate the effectiveness of exercise in class II and class III obesity. The study aims to determine whether the addition of exercise t

Published
2016

10. Determinants of Diabetes Remission and Glycemic Control After Bariatric Surgery

Author

Panunzi, S, Carlsson, L, De Gaetano, A, Peltonen, M, Rice, T, Sjöström, L, Mingrone, Geltrude, Dixon, Jb, Mingrone, Geltrude (ORCID:0000-0003-2021-528X), Panunzi, S, Carlsson, L, De Gaetano, A, Peltonen, M, Rice, T, Sjöström, L, Mingrone, Geltrude, Dixon, Jb, and Mingrone, Geltrude (ORCID:0000-0003-2021-528X)

Abstract

Eligibility criteria for bariatric surgery in diabetes include BMI ≥35 kg/m(2) and poorly controlled glycemia. However, BMI does not predict diabetes remission, and thus, predictors need to be identified.

Published
2016

11. Bariatric surgery: an IDF statement for obese Type 2 diabetes

Author

Dixon, JB, Zimmet, P, Alberti, KG, and Rubino, F

Abstract

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m² or more. A Força-Tarefa para Epidemiologia e Prevenção da International Diabetes Federation reuniu um grupo de trabalho com diabetologistas, endocrinologistas, cirurgiões e especialistas em saúde pública para revisar o papel correto da cirurgia e outras intervenções gastrointestinais no tratamento e prevenção do diabetes tipo 2 em obesos. Os objetivos específicos foram: desenvolver recomendações práticas para a seleção dos pacientes; identificar barreiras ao acesso à cirurgia e sugerir intervenções para mudanças das políticas de saúde que garantam equidade de acesso à cirurgia, quando indicada, e identificar prioridades para a pesquisa. A cirurgia bariátrica pode gerar uma melhora significativa no controle glicêmico em pacientes com obesidade grave e diabetes tipo 2. Ela é um tratamento efetivo, seguro e de bom custo-benefício para pacientes obesos com diabetes tipo 2. A cirurgia pode ser considerada um tratamento apropriado para pessoas com diabetes tipo 2 e obesidade que não consigam atingir as metas recomendadas de tratamento com terapias medicamentosas, especialmente na presença de outras comorbidades maiores. Os procedimentos devem ser executados por meio de diretrizes aceitas e requerem uma avaliação multidisciplinar, um processo amplo de educação do paciente e cuidados contínuos, além de procedimentos cirúrgicos seguros e padronizados. As diretrizes nacionais para a cirurgia bariátrica devem ser desenvolvidas para pacientes com diabetes tipo 2 e IMC de 35 kg/m² ou mais.

Published
2011

12. Promises and ethical pitfalls of surgical innovation:the case of bariatric surgery

Author

Dixon, JB, Logue, J, Komesaroff, PA, Dixon, JB, Logue, J, and Komesaroff, PA

Abstract

The last two decades have seen remarkable advances in and acceptance of bariatric surgery. These advances include quality assurance, certification of surgeons and their institutions and the development of national bariatric registries. Yet, in spite of these advances, an urgent need to improve ethical standards in bariatric surgery remains. In particular, surgical innovation must be subjected to adequate scrutiny and sufficient safeguards. New procedures and the processes by which they are assessed should be subject to review and approval by the ethics committees operating under clearly defined guidelines. The public must be able to have confidence that the surgery itself, and the innovative practices that are introduced within it, are not subject to distortions associated with personal, wider professional, industry or institutional interests.

Published
2013

13. Severely obese people with diabetes experience impaired emotional well-being associated with socioeconomic disadvantage: Results from diabetes MILES - Australia

Author

Dixon, JB, Browne, JL, Lambert, GW, Jones, KM, Reddy, P, Pouwer, F, Speight, J, Dixon, JB, Browne, JL, Lambert, GW, Jones, KM, Reddy, P, Pouwer, F, and Speight, J

Abstract

Aim: To examine the emotional well-being of severely obese Australians with type 2 diabetes, along with markers of social and economic disadvantage, using the Diabetes MILES - Australia dataset. Methods: Diabetes MILES - Australia was a national survey of 3338 adults with diabetes that focused on psychosocial issues; 1795 had type 2 diabetes and reported BMI. We extracted data regarding depression (PHQ-9), anxiety (GAD-7), obesity- and diabetes-related comorbidities, and demographics. The severely obese group (SOG) (BMI ≥ 35; median BMI = 41.6) constituted 530 (30%) of the type 2 diabetes respondents and was matched with 530 controls (CG) (BMI < 35; median BMI = 28.2). Within- and between-group trends were examined. Results: The SOG had higher depression scores (median (IQR) 6.0 (3-12)) than CG (5.0 (2-10)); p< 0.001, and were more likely to report moderate-severe depressive symptoms (37% versus 27%; p< 0.001). The groups did not differ on anxiety. The SOG, compared with the CG, were more likely to live alone (21% versus 17%), receive a disability pension (21% versus 15%), earn ≤$40.000/year (51% versus 41%; all p< 0.05), and were less likely to be employed (46% versus 53%), university or higher educated (17% versus 26%), or have health insurance (50% versus 60%; all p≤ 0.01). Moderate-severe depression was positively associated with cumulative stressors of severe obesity, socioeconomic disadvantage, and obesity- and diabetes-related comorbidity. Conclusions: Severely obese people living with type 2 diabetes have cumulative stressors related to health, disability, demographic and socioeconomic factors, and impaired emotional well-being. © 2013 Elsevier Ireland Ltd.

Published
2013

14. Neuroadrenergic Dysfunction Along the Diabetes Continuum A Comparative Study in Obese Metabolic Syndrome Subjects

Author

Straznicky, NE, Grima, MT, Sari, CI, Eikelis, N, Lambert, EA, Nestel, PJ, Esler, MD, Dixon, JB, Chopra, R, Tilbrook, AJ, Schlaich, MP, Lambert, GW, Straznicky, NE, Grima, MT, Sari, CI, Eikelis, N, Lambert, EA, Nestel, PJ, Esler, MD, Dixon, JB, Chopra, R, Tilbrook, AJ, Schlaich, MP, and Lambert, GW

Abstract

Neuroadrenergic function in type 2 diabetic (T2D) patients without neuropathy is poorly characterized. We therefore compared sympathetic nervous system activity at rest and during an oral glucose tolerance test in obese metabolic syndrome (MetS) subjects classified as glucose intolerant (impaired glucose tolerance [IGT]; n = 17) or treatment-naive T2D (n = 17). Untreated subjects, matched for age (mean 59 ± 1 year), sex, BMI (32.4 ± 0.6 kg/m(2)), and family history of diabetes were studied. We measured resting muscle sympathetic nerve activity (MSNA) by microneurography, whole-body norepinephrine kinetics by isotope dilution, insulin sensitivity by euglycemic-hyperinsulinemic clamp (steady-state glucose utilization adjusted for fat-free mass and steady-state insulin concentration [M/I]), and MetS components. T2D subjects had higher resting MSNA burst incidence (67 ± 4 versus 55 ± 3 bursts per 100 heartbeats; P = 0.05) and arterial norepinephrine levels (264 ± 33 versus 167 ± 16 pg/mL; P = 0.02), lower plasma norepinephrine clearance (by 17%; P = 0.03), and reduced neuronal reuptake compared with IGT subjects (by 46%; P = 0.04). Moreover, norepinephrine spillover responses to glucose ingestion were blunted in T2D subjects. The M/I value independently predicted whole-body norepinephrine spillover (r = -0.47; P = 0.008), whereas fasting insulin level related to neuronal norepinephrine reuptake (r = -0.35, P = 0.047). These findings demonstrate that progression to T2D is associated with increased central sympathetic drive, blunted sympathetic responsiveness, and altered norepinephrine disposition.

Published
2012

15. Cost-Effectiveness of Surgically Induced Weight Loss for the Management of Type 2 Diabetes: Modeled Lifetime Analysis

Author

Keating, CL, Dixon, JB, Moodie, ML, Peeters, A, Bulfone, L, Maglianno, DJ, O'Brien, PE, Keating, CL, Dixon, JB, Moodie, ML, Peeters, A, Bulfone, L, Maglianno, DJ, and O'Brien, PE

Abstract

OBJECTIVE: To estimate the cost-effectiveness of surgically induced weight loss relative to conventional therapy for the management of recently diagnosed type 2 diabetes in class I/II obese patients. RESEARCH DESIGN AND METHODS: This study builds on a within-trial cost-efficacy analysis. The analysis compares the lifetime costs and quality-adjusted life-years (QALYs) between the two intervention groups. Intervention costs were extrapolated based on observed resource utilization during the trial. The proportion of patients in each intervention group with remission of diabetes at 2 years was the same as that observed in the trial. Health care costs for patients with type 2 diabetes and outcome variables required to derive estimates of QALYs were sourced from published literature. A health care system perspective was adopted. Costs and outcomes were discounted annually at 3%. Costs are presented in 2006 Australian dollars (AUD) (currency exchange: 1 AUD = 0.74 USD). RESULTS: The mean number of years in diabetes remission over a lifetime was 11.4 for surgical therapy patients and 2.1 for conventional therapy patients. Over the remainder of their lifetime, surgical and conventional therapy patients lived 15.7 and 14.5 discounted QALYs, respectively. The mean discounted lifetime costs were 98,900 AUD per surgical therapy patient and 101,400 AUD per conventional therapy patient. Relative to conventional therapy, surgically induced weight loss was associated with a mean health care saving of 2,400 AUD and 1.2 additional QALYs per patient. CONCLUSIONS: Surgically induced weight loss is a dominant intervention (it both saves health care costs and generates health benefits) for managing recently diagnosed type 2 diabetes in class I/II obese patients in Australia.

Published
2009

19. Neuroadrenergic dysfunction along the diabetes continuum: a comparative study in obese metabolic syndrome subjects.

Author

Straznicky NE, Grima MT, Sari CI, Eikelis N, Lambert EA, Nestel PJ, Esler MD, Dixon JB, Chopra R, Tilbrook AJ, Schlaich MP, Lambert GW, Straznicky, Nora E, Grima, Mariee T, Sari, Carolina I, Eikelis, Nina, Lambert, Elisabeth A, Nestel, Paul J, Esler, Murray D, and Dixon, John B

Abstract

Neuroadrenergic function in type 2 diabetic (T2D) patients without neuropathy is poorly characterized. We therefore compared sympathetic nervous system activity at rest and during an oral glucose tolerance test in obese metabolic syndrome (MetS) subjects classified as glucose intolerant (impaired glucose tolerance [IGT]; n = 17) or treatment-naive T2D (n = 17). Untreated subjects, matched for age (mean 59 ± 1 year), sex, BMI (32.4 ± 0.6 kg/m(2)), and family history of diabetes were studied. We measured resting muscle sympathetic nerve activity (MSNA) by microneurography, whole-body norepinephrine kinetics by isotope dilution, insulin sensitivity by euglycemic-hyperinsulinemic clamp (steady-state glucose utilization adjusted for fat-free mass and steady-state insulin concentration [M/I]), and MetS components. T2D subjects had higher resting MSNA burst incidence (67 ± 4 versus 55 ± 3 bursts per 100 heartbeats; P = 0.05) and arterial norepinephrine levels (264 ± 33 versus 167 ± 16 pg/mL; P = 0.02), lower plasma norepinephrine clearance (by 17%; P = 0.03), and reduced neuronal reuptake compared with IGT subjects (by 46%; P = 0.04). Moreover, norepinephrine spillover responses to glucose ingestion were blunted in T2D subjects. The M/I value independently predicted whole-body norepinephrine spillover (r = -0.47; P = 0.008), whereas fasting insulin level related to neuronal norepinephrine reuptake (r = -0.35, P = 0.047). These findings demonstrate that progression to T2D is associated with increased central sympathetic drive, blunted sympathetic responsiveness, and altered norepinephrine disposition. [ABSTRACT FROM AUTHOR]

Published
2012

20. Surgical vs conventional therapy for weight loss treatment of obstructive sleep apnea: a randomized controlled trial.

Author

Dixon JB, Schachter LM, O'Brien PE, Jones K, Grima M, Lambert G, Brown W, Bailey M, Naughton MT, Dixon, John B, Schachter, Linda M, O'Brien, Paul E, Jones, Kay, Grima, Mariee, Lambert, Gavin, Brown, Wendy, Bailey, Michael, and Naughton, Matthew T

Abstract

Context: Obstructive sleep apnea (OSA) is strongly related to obesity. Weight loss is recommended as part of the overall management plan for obese patients diagnosed with OSA.Objective: To determine whether surgically induced weight loss is more effective than conventional weight loss therapy in the management of OSA.Design, Setting, and Patients: A randomized controlled trial of 60 obese patients (body mass index: >35 and <55) with recently diagnosed (<6 months) OSA and an apnea-hypopnea index (AHI) of 20 events/hour or more. These patients had been prescribed continuous positive airway pressure (CPAP) therapy to manage OSA and were identified via accredited community sleep clinics. The trial was conducted between September 2006 and March 2009 by university- and teaching hospital-based clinical researchers in Melbourne, Australia. Patients with obesity hypoventilation syndrome, previous bariatric surgery, contraindications to bariatric surgery, or significant cardiopulmonary, neurological, vascular, gastrointestinal, or neoplastic disease were excluded.Interventions: Patients were randomized to a conventional weight loss program that included regular consultations with a dietitian and physician, and the use of very low-calorie diets as necessary (n = 30) or to bariatric surgery (laparoscopic adjustable gastric banding; n = 30).Main Outcome Measures: The primary outcome was baseline to 2-year change in AHI on diagnostic polysomnography scored by staff blinded to randomization. Secondary outcomes were changes in weight, CPAP adherence, and functional status.Results: Patients lost a mean of 5.1 kg (95% CI, 0.8 to 9.3 kg) in the conventional weight loss program compared with 27.8 kg (95% CI, 20.9 to 34.7 kg) in the bariatric surgery group (P < .001). The AHI decreased by 14.0 events/hour (95% CI, 3.3 to 24.6 events/hour) in the conventional weight loss group and by 25.5 events/hour (95% CI, 14.2 to 36.7 events/hour) in the bariatric surgery group. The between-group difference was -11.5 events/hour (95% CI, -28.3 to 5.3 events/hour; P = .18). CPAP adherence did not differ between the groups. The bariatric surgery group had greater improvement in the Short Form 36 physical component summary score (mean, 9.3 [95% CI, 0.5 to 18.0]; P = .04).Conclusion: Among a group of obese patients with OSA, the use of bariatric surgery compared with conventional weight loss therapy did not result in a statistically greater reduction in AHI despite major differences in weight loss.Trial Registration: anzctr.org Identifier: 12605000161628. [ABSTRACT FROM AUTHOR]

Published
2012
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24. Laparoscopic adjustable gastric banding in severely obese adolescents: a randomized trial.

Author

O'Brien PE, Sawyer SM, Laurie C, Brown WA, Skinner S, Veit F, Paul E, Burton PR, McGrice M, Anderson M, Dixon JB, O'Brien, Paul E, Sawyer, Susan M, Laurie, Cheryl, Brown, Wendy A, Skinner, Stewart, Veit, Friederike, Paul, Eldho, Burton, Paul R, and McGrice, Melanie

Abstract

Context: Adolescent obesity is a common and serious health problem affecting more than 5 million young people in the United States alone. Bariatric surgery is being evaluated as a possible treatment option. Laparoscopic adjustable gastric banding (gastric banding) has the potential to provide a safe and effective treatment.Objective: To compare the outcomes of gastric banding with an optimal lifestyle program on adolescent obesity.Design, Setting, and Patients: A prospective, randomized controlled trial of 50 adolescents between 14 and 18 years with a body mass index (BMI) higher than 35, recruited from the Melbourne, Australia, community, assigned either to a supervised lifestyle intervention or to undergo gastric banding, and followed up for 2 years. The study was performed between May 2005 and September 2008.Main Outcome Measures: Weight loss. Secondary outcomes included change in metabolic syndrome, insulin resistance, quality of life, and adverse outcomes.Results: Twenty-four of 25 patients in the gastric banding group and 18 of 25 in lifestyle group completed the study. Twenty-one (84%) in the gastric banding and 3 (12%) in the lifestyle groups lost more than 50% of excess weight, corrected for age. Overall, the mean changes in the gastric banding group were a weight loss of 34.6 kg (95% CI, 30.2-39.0), representing an excess weight loss of 78.8% (95% CI, 66.6%-91.0%), 12.7 BMI units (95% CI, 11.3-14.2), and a BMI z score change from 2.39 (95% CI, 2.05-2.73) to 1.32 (95% CI, 0.98-1.66). The mean losses in the lifestyle group were 3.0 kg (95% CI, 2.1-8.1), representing excess weight loss of 13.2% (95% CI, 2.6%-21.0%), 1.3 BMI units (95% CI, 0.4-2.9), and a BMI z score change from 2.41 (95% CI, 2.21-2.66) to 2.26 (95% CI, 1.91-2.43). At entry, 9 participants (36%) in the gastric banding group and 10 (40%) in the lifestyle group had the metabolic syndrome. At 24 months, none of the gastric banding group had the metabolic syndrome (P = .008; McNemar chi(2)) compared with 4 of the 18 completers (22%) in the lifestyle group (P = .13). The gastric banding group experienced improved quality of life with no perioperative adverse events. However, 8 operations (33%) were required in 7 patients for revisional procedures either for proximal pouch dilatation or tubing injury during follow-up.Conclusions: Among obese adolescent participants, use of gastric banding compared with lifestyle intervention resulted in a greater percentage achieving a loss of 50% of excess weight, corrected for age. There were associated benefits to health and quality of life.Trial Registration: ANZCTR Identifier: 12605000160639. [ABSTRACT FROM AUTHOR]

Published
2010
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25. Cost-efficacy of surgically induced weight loss for the management of type 2 diabetes: a randomized controlled trial.

Author

Keating CL, Dixon JB, Moodie ML, Peeters A, Playfair J, O'Brien PE, Keating, Catherine L, Dixon, John B, Moodie, Marjory L, Peeters, Anna, Playfair, Julie, and O'Brien, Paul E

Abstract

Objective: To determine the within-trial cost-efficacy of surgical therapy relative to conventional therapy for achieving remission of recently diagnosed type 2 diabetes in class I and II obese patients.Research Design and Methods: Efficacy results were derived from a 2-year randomized controlled trial. A health sector perspective was adopted, and within-trial intervention costs included gastric banding surgery, mitigation of complications, outpatient medical consultations, medical investigations, pathology, weight loss therapies, and medication. Resource use was measured based on data drawn from a trial database and patient medical records and valued based on private hospital costs and government schedules in 2006 Australian dollars (AUD). An incremental cost-effectiveness analysis was undertaken.Results: Mean 2-year intervention costs per patient were 13,400 AUD for surgical therapy and 3,400 AUD for conventional therapy, with laparoscopic adjustable gastric band (LAGB) surgery accounting for 85% of the difference. Outpatient medical consultation costs were three times higher for surgical patients, whereas medication costs were 1.5 times higher for conventional patients. The cost differences were primarily in the first 6 months of the trial. Relative to conventional therapy, the incremental cost-effectiveness ratio for surgical therapy was 16,600 AUD per case of diabetes remitted (currency exchange: 1 AUD = 0.74 USD).Conclusions: Surgical therapy appears to be a cost-effective option for managing type 2 diabetes in class I and II obese patients. [ABSTRACT FROM AUTHOR]

Published
2009
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26. Adjustable gastric banding and conventional therapy for type 2 diabetes: a randomized controlled trial.

Author

Dixon JB, O'Brien PE, Playfair J, Chapman L, Schachter LM, Skinner S, Proietto J, Bailey M, Anderson M, Dixon, John B, O'Brien, Paul E, Playfair, Julie, Chapman, Leon, Schachter, Linda M, Skinner, Stewart, Proietto, Joseph, Bailey, Michael, and Anderson, Margaret

Abstract

Context: Observational studies suggest that surgically induced loss of weight may be effective therapy for type 2 diabetes.Objective: To determine if surgically induced weight loss results in better glycemic control and less need for diabetes medications than conventional approaches to weight loss and diabetes control.Design, Setting, and Participants: Unblinded randomized controlled trial conducted from December 2002 through December 2006 at the University Obesity Research Center in Australia, with general community recruitment to established treatment programs. Participants were 60 obese patients (BMI >30 and <40) with recently diagnosed (<2 years) type 2 diabetes.Interventions: Conventional diabetes therapy with a focus on weight loss by lifestyle change vs laparoscopic adjustable gastric banding with conventional diabetes care.Main Outcome Measures: Remission of type 2 diabetes (fasting glucose level <126 mg/dL [7.0 mmol/L] and glycated hemoglobin [HbA1c] value <6.2% while taking no glycemic therapy). Secondary measures included weight and components of the metabolic syndrome. Analysis was by intention-to-treat.Results: Of the 60 patients enrolled, 55 (92%) completed the 2-year follow-up. Remission of type 2 diabetes was achieved by 22 (73%) in the surgical group and 4 (13%) in the conventional-therapy group. Relative risk of remission for the surgical group was 5.5 (95% confidence interval, 2.2-14.0). Surgical and conventional-therapy groups lost a mean (SD) of 20.7% (8.6%) and 1.7% (5.2%) of weight, respectively, at 2 years (P < .001). Remission of type 2 diabetes was related to weight loss (R2 = 0.46, P < .001) and lower baseline HbA1c levels (combined R2 = 0.52, P < .001). There were no serious complications in either group.Conclusions: Participants randomized to surgical therapy were more likely to achieve remission of type 2 diabetes through greater weight loss. These results need to be confirmed in a larger, more diverse population and have long-term efficacy assessed.Trial Registration: actr.org Identifier: ACTRN012605000159651. [ABSTRACT FROM AUTHOR]

Published
2008
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27. Treatment of mild to moderate obesity with laparoscopic adjustable gastric banding or an intensive medical program: a randomized trial.

Author

O'Brien PE, Dixon JB, Laurie C, Skinner S, Proietto J, McNeil J, Strauss B, Marks S, Schachter L, Chapman L, Anderson M, O'Brien, Paul E, Dixon, John B, Laurie, Cheryl, Skinner, Stewart, Proietto, Joe, McNeil, John, Strauss, Boyd, Marks, Sharon, and Schachter, Linda

Abstract

Background: Obesity is a major, growing health problem. Observational studies suggest that bariatric surgery is more effective than nonsurgical therapy, but no randomized, controlled trials have confirmed this.Objective: To ascertain whether surgical therapy for obesity achieves better weight loss, health, and quality of life than nonsurgical therapy.Design: Randomized, controlled trial.Setting: University departments of medicine and surgery and an affiliated private hospital.Patients: 80 adults with mild to moderate obesity (body mass index, 30 kg/m2 to 35 kg/m2) from the general community.Interventions: Patients were assigned to a program of very-low-calorie diets, pharmacotherapy, and lifestyle change for 24 months (nonsurgical group) or to placement of a laparoscopic adjustable gastric band (LAP-BAND System, INAMED Health, Santa Barbara, California) (surgical group).Measurements: Outcome measures were weight change, presence of the metabolic syndrome, and change in quality of life at 2 years.Results: At 2 years, the surgical group had greater weight loss, with a mean of 21.6% (95% CI, 19.3% to 23.9%) of initial weight lost and 87.2% (CI, 77.7% to 96.6%) of excess weight lost, while the nonsurgical group had a loss of 5.5% (CI, 3.2% to 7.9%) of initial weight and 21.8% (CI, 11.9% to 31.6%) of excess weight (P < 0.001). The metabolic syndrome was initially present in 15 (38%) patients in each group and was present in 8 (24%) nonsurgical patients and 1 (3%) surgical patient at the completion of the study (P < 0.002). Quality of life improved statistically significantly more in the surgical group (8 of 8 subscores of Short Form-36) than in the nonsurgical group (3 of 8 subscores).Limitations: The study included mildly and moderately obese participants, was not powered for comparison of adverse events, and examined outcomes only for 24 months.Conclusions: Surgical treatment using laparoscopic adjustable gastric banding was statistically significantly more effective than nonsurgical therapy in reducing weight, resolving the metabolic syndrome, and improving quality of life during a 24-month treatment program. [ABSTRACT FROM AUTHOR]

Published
2006
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30. Predicting sleep apnea and excessive day sleepiness in the severely obese: indicators for polysomnography.

Author

Dixon JB, Schachter LM, O'Brien PE, Dixon, John B, Schachter, Linda M, and O'Brien, Paul E

Abstract

Background: Obstructive sleep apnea (OSA) is common in severely obese subjects (body mass index [BMI] > 35). Overnight polysomnography (OPS) is the "gold standard" method of evaluating this condition; however, it is time-consuming, inconvenient, and expensive. Selection of patients for OPS would be enhanced if we could better predict those likely to have clinically significant OSA.Study Objective: To look for clinical and biochemical predictors of OSA in symptomatic patients presenting for obesity surgery.Design and Patients: Symptoms suggestive of OSA were sought in a structured interview. We report OPS results of 99 consecutive subjects in whom OSA was clinically suspected. Predictors of apnea-hypopnea index (AHI) were sought from an extensive preoperative data collection. Multivariate linear and logistic analysis was used to identify independent predictors of AHI.Results: Symptoms were poor predictors of AHI, with observed sleep apnea the only positive predictor. Four clinical and two biochemical factors independently predicted AHI: observed sleep apnea, male sex, higher BMI, age, fasting insulin, and glycosylated hemoglobin A(Ic) (r(2) = 0.42). Neck circumference (the best single measure) could replace BMI and sex in the analysis (r(2) = 0.43). With cutoffs selected, a simple scoring system using these six factors provides a method of predicting those with moderate or severe OSA. A score > or = 3 provides a sensitivity and specificity of 89% and 81%, and 96% and 71% for AHIs of > or = 15 and > or = 30, respectively. None of the 31 subjects with scores of 0 or 1 were found to have an AHI > or = 15.Conclusion: We explore sleep disturbance and report a simple method of predicting OSA in severely obese symptomatic subjects. This should assist in limiting the use of OPS to those with greater risk and provide a method of assessing risk in those not presenting primarily with a sleep problem. [ABSTRACT FROM AUTHOR]

Published
2003
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33. Transplantation immunology. A review of some biological and veterinary implications. 1. Detection and inheritance of some antigens affecting graft survival

Author

Dixon Jb

Subjects
Graft Rejection, Male, Veterinary medicine, media_common.quotation_subject, Mice, Inbred Strains, Major Histocompatibility Complex, Mice, Antigen, Histocompatibility Antigens, Medicine, Animals, Lymphocytes, media_common, Recombination, Genetic, Transplantation, General Veterinary, Graft rejection, business.industry, Graft Survival, General Medicine, Immunology, Graft survival, Female, Inheritance, business
Abstract

Transplant immunology has been neglected in veterinary medicine because of lack of the more obvious applications. However, the subject has now acquired an importance which transcends the problems of transplantation as such and affects the understanding of how foreignness is perceived and how the lymphoid system develops and is organised. There may be implications for almost every biological field.

Published
1982

38. Hunger Control and Regular Physical Activity Facilitate Weight Loss After Laparoscopic Adjustable Gastric Banding

Author

Paul E. O'Brien, John Dixon, Susan Leigh Colles, Colles, Susan Leigh, Dixon, JB, and O'Brien, P

Subjects
Adult, Male, medicine.medical_specialty, Time Factors, Gastroplasty, Endocrinology, Diabetes and Metabolism, physical activity, predictor, eating behavior, Weight loss, Weight Loss, medicine, Humans, Prospective Studies, Prospective cohort study, Exercise, Life Style, Nutrition and Dietetics, exercise, Appetite Regulation, business.industry, Behavior change, Beck Depression Inventory, Feeding Behavior, Middle Aged, Emotional eating, medicine.disease, Obesity, Obesity, Morbid, obesity surgery, Treatment Outcome, Physical therapy, Female, Laparoscopy, Surgery, medicine.symptom, business, Body mass index, Three-Factor Eating Questionnaire, Follow-Up Studies
Abstract

Bariatric surgery facilitates substantial and durable weight loss; however, outcomes vary. In addition to physiological and technical factors, weight loss efficacy is dependent on modification of behavior to maintain a long-term change in energy balance. This study aimed to assess the extent and nature of change in energy intake and physical activity and identify factors associated with percentage weight loss (%WL) 12 months after laparoscopic adjustable gastric banding (LAGB). 129 bariatric surgery candidates (26 men/103 women, mean age 45.2 ± 11.5, mean body mass index [BMI] 44.3 ± 6.8, range 31.9 to 66.7) completed the study. Data were collected at baseline and 12 months. Validated questionnaires included the Cancer Council Victoria Food Frequency Questionnaire, Three Factor Eating Questionnaire, Short Form-36, Baecke Physical Activity Questionnaire, and Beck Depression Inventory. Symptoms of “non-hungry eating,” “emotional eating,” and “grazing” were assessed. Mean %WL was 20.8 ± 8.5%, and excess weight loss was 50.0 ± 20.7 (p

Published
2008

39. Grazing and loss of control related to eating: two high-risk factors following bariatric surgery

Author

Paul E. O'Brien, Susan Leigh Colles, John Dixon, Colles, Susan Leigh, Dixon, JB, and O'Brien, P

Subjects
Adult, Male, medicine.medical_specialty, Time Factors, Endocrinology, Diabetes and Metabolism, Health Behavior, Gastric Bypass, Medicine (miscellaneous), gastric restrictive surgery, Percentage weight loss, Night eating syndrome, Feeding and Eating Disorders, Endocrinology, binge eating, Binge-eating disorder, Weight loss, Intervention (counseling), Surveys and Questionnaires, Grazing, Weight Loss, medicine, Humans, Psychology, grazing, Obesity, Prospective Studies, Nutrition and Dietetics, business.industry, Appetite Regulation, High risk factors, Feeding Behavior, Middle Aged, medicine.disease, Surgery, Treatment Outcome, Observational study, Female, medicine.symptom, weight loss, business, postoperative eating behavior, Stress, Psychological
Abstract

background: Gastric restrictive surgery induces a marked change in eating behavior. However, the relationship between preoperative and postoperative eating behavior and weight loss outcome has received limited attention. objective: This study assessed a range of eating behaviors before and 1 year after laparoscopic adjustable gastric banding (LAGB) and explored the nature and extent of change in eating patterns, their clinical associates, and impact on weight loss. Methods and Procedures: A 12-month observational study assessed presurgical and postsurgical binge eating disorder (BED), uncontrolled eating, night eating syndrome (NES), grazing, nutrient intake and eating-related behaviors, and markers of psychological distress. A total of 129 subjects (26 male and 103 female, mean age 45.2 ± 11.5 and BMI 44.3 ± 6.8) participated in this study. Results: Presurgical BED, uncontrolled eating, and NES occurred in 14%, 31%, and 17.1% of subjects, which reduced after surgery to 3.1%, 22.5%, and 7.8%, respectively (P = 0.05 for all). Grazing was prevalent before (26.3%) and after surgery (38.0%). Preoperative BED most frequently became grazers (P = 0.029). The average percentage weight loss (%WL) was 20.8 ± 8.5%; range −0.67 to 50.0% and percentage of excess weight loss (%EWL) 50.0 ± 20.7%; range −1.44 to 106.9% (P < 0.001). Uncontrolled eating and grazing after surgery showed high overlap and were associated with poorer %WL (P = 0.008 and P < 0.001, respectively) and elevated psychological distress. Discussion: Consistent with recent studies, uncontrolled eating and grazing were identified as two high-risk eating patterns after surgery. Clearer characterization of favorable and unfavorable postsurgical eating behaviors, reliable methods to assess their presence, and empirically tested postsurgical intervention strategies are required to optimize weight loss outcomes and facilitate psychological well-being in at-risk groups.

Published
2008

40. Loss of control is central to psychological disturbance associated with binge eating disorder

Author

Paul E. O'Brien, Susan Leigh Colles, John Dixon, Colles, Susan Leigh, Dixon, JB, and O'Brien, P

Subjects
Adult, Male, medicine.medical_specialty, Diet, Reducing, Endocrinology, Diabetes and Metabolism, Medicine (miscellaneous), Bariatric Surgery, Body Mass Index, Endocrinology, Quality of life, Binge-eating disorder, Weight loss, Intervention (counseling), Surveys and Questionnaires, Adaptation, Psychological, medicine, Body Image, binge eating disorder, Humans, Psychology, Obesity, Psychiatry, Bulimia Nervosa, Aged, binge episodes, eating behaviour, Nutrition and Dietetics, Binge eating, business.industry, Bulimia nervosa, Appetite Regulation, Depression, Feeding Behavior, Middle Aged, medicine.disease, Distress, Self-Help Groups, Cross-Sectional Studies, Quality of Life, Female, medicine.symptom, business, Body mass index, Stress, Psychological
Abstract

Objective: Binge eating disorder (BED) is positively associated with obesity and psychological distress, yet the behavioral features of BED that drive these associations are largely unexplored. The primary aim of this study was to investigate which core behavioral features of binge eating are most strongly related to psychological disturbance. Methods and Procedures: A cross-sectional study involved 180 bariatric surgery candidates, 93 members of a non-surgical weight loss support group, and 158 general community respondents (81 men/350 women, mean age 45.8 ± 13.3, mean BMI 34.8 ± 10.8, BMI range 17.7–66.7). Validated questionnaires assessed BED and binge eating, symptoms of depression, appearance dissatisfaction (AD), quality of life (QoL) and eating-related behaviors. Features of binge eating were confirmed by interview. BMI was determined by clinical assessment and self-report. Results: The loss of control (LOC) over eating, that is, being unable to stop eating or control what or how much was consumed was most closely related to psychological markers of distress common in BED. In particular, those who experienced severe emotional disturbance due to feelings of LOC reported higher symptoms of depression (P < 0.001), AD (P = 0.009), and poorer mental health–related QoL (P = 0.027). Discussion: Persons who report subjective binge episodes or do not meet BED frequency criteria for objective binge episodes may still be at elevated risk of psychological disturbance and benefit from clinical intervention. Feelings of LOC could drive binge eaters to seek bariatric surgery in an attempt to gain control over body weight and psychologically disturbing eating behavior.

Published
2008

41. Night eating syndrome and nocturnal snacking: Association with obesity, binge eating and psychological distress

Author

John Dixon, Paul E. O'Brien, Susan Leigh Colles, Colles, Susan Leigh, Dixon, JB, and O'Brien, P

Subjects
Adult, Male, medicine.medical_specialty, Evening, Hunger, viruses, Endocrinology, Diabetes and Metabolism, Medicine (miscellaneous), Bariatric Surgery, Hyperphagia, environment and public health, Night eating syndrome, Body Mass Index, Binge-eating disorder, Risk Factors, medicine, binge eating disorder, Humans, Obesity, Psychiatry, Bulimia Nervosa, sleep disorder, Sleep disorder, Nutrition and Dietetics, Binge eating, Snacking, business.industry, Depression, digestive, oral, and skin physiology, Feeding Behavior, Syndrome, Middle Aged, medicine.disease, Circadian Rhythm, nocturnal eating, eating disorder, night eating syndrome, Quality of Life, Female, lipids (amino acids, peptides, and proteins), medicine.symptom, business, Body mass index, Stress, Psychological, Demography
Abstract

Objective: Night eating syndrome (NES) is characterized by a time-delayed pattern of eating relative to sleep, where most foodis consumed in the evening and night. This study aimed to investigate the clinical significance of NES and nocturnal snacking byexploring the relationship between NES and (1) obesity, (2) binge eating disorder (BED) and (3) psychological distress.Subjects: One hundred and eighty bariatric surgery candidates, 93 members of a non-surgical weight loss support group and158 general community respondents (81 males/350 females, mean age: 45.8713.3 years, mean body mass index (BMI):34.8710.8 and BMI range: 17.7–66.7).Methods: NES diagnosis required within the previous 3 months: (1) no appetite for breakfast, (2) consumption of X50% ofdaily energy after 1900 hours and (3) sleep difficulties X3 nights/week. Nocturnal snacking (awakening to eat) was recorded.Validated questionnaires assessed BED, symptoms of depression, appearance dissatisfaction (AD) and mental health-relatedquality of life (MHQoL). NES and binge eating (BE) (X1 episode/week) were confirmed by interview.Results: NES criteria were met by 11.1% of the total cohort. Across all groups, BE (P¼0.001), BMI (P¼0.003) and male gender(P¼0.013) explained 10% of NES variance. Individuals with co-morbid NES and BE reported similarly elevated psychologicaldistress as other binge eaters. NES alone was not associated with psychological distress. Those with NES who consumednocturnal snacks reported poorer MHQoL (P¼0.007) and greater depressive symptoms (P¼0.039) and hunger (P¼0.013)than others with NES. Low MHQoL (P¼0.007) and male gender (P¼0.022) explained 27% of the variance in the nocturnalsnacking group.Discussion: In this study, NES was positively associated with BMI, BE and male gender. Elevated psychological distress was onlyapparent in those who consumed nocturnal snacks. Further characterization and understanding of the clinical significance ofNES and nocturnal snacking is required.

Published
2007

42. Night eating syndrome: impact on bariatric surgery

Author

Susan Leigh Colles, John Dixon, Colles, Susan Leigh, and Dixon, JB

Subjects
Sleep Wake Disorders, obesity, medicine.medical_specialty, viruses, Endocrinology, Diabetes and Metabolism, Clinical Sciences, Bariatric Surgery, environment and public health, Night eating syndrome, Weight loss, Medicine, Humans, Clinical significance, Psychiatry, Depression (differential diagnoses), Sleep disorder, Nutrition and Dietetics, Binge eating, business.industry, Feeding Behavior, medicine.disease, Obesity, Surgery, Circadian Rhythm, Obesity, Morbid, Distress, eating disorder, night eating syndrome, depression, lipids (amino acids, peptides, and proteins), medicine.symptom, business
Abstract

Individuals with night eating syndrome (NES) display a time-delayed pattern of food intake, outside the natural circadian rhythm. High prevalence estimates have been reported among bariatric surgery candidates, and some evidence suggests that NES is positively associated with obesity, negatively associated with weight loss efficacy, and follows a chronic course. In order to evaluate current NES theory, and the association between NES and bariatric surgery, literature searches were conducted to identify relevant literature published in English up to 2005. Because of inconsistencies in NES characterization, and significant heterogeneity in study design and methods, a qualitative assessment of NES and its relation to bariatric surgery was then undertaken. Within the literature, variable NES definitions highlight the distinct lack of clarity as to which behavioral features constitute a clinically meaningful entity. Prevalence estimates appear high among persons seeking bariatric surgery; however, no consistent pre- or postoperative demographic, clinical, or psychological factors reliably differentiate NES from non-NES. Further examination of the clinical significance, correlates, and course of NES in general and surgical samples is important, given the link with obesity. The ways in which NES departs from "normal" eating behavior must be clarified. Behavioral and psychological traits of NES need elucidation, and the establishment of agreed diagnostic criteria is essential for research to move forward. Therapy options should focus on aspects of the syndrome that cause greatest impairment, distress, or health risk.

Published
2006

43. Preoperative weight loss with a very-low-energy diet: quantitation of changes in liver and abdominal fat by serial imaging

Author

Colles, Susan Leigh, Dixon, JB, Marks, P, Strauss, BJ, and O'Brien, P

Subjects
surgery, body composition, Nutrition and Dietetics, VLED, laparoscopy, very-low-energy diet, weight loss, Severe obesity, fatty liver
Abstract

Background: A very-low-energy diet (VLED) can result in substantial,rapid weight loss and is increasingly prescribed before obesitysurgery to minimize risk and difficulty by reducing liver size andabdominal adiposity. Despite its growing popularity, a VLED in thissetting has received little attention.Objective: The aim of this study was to investigate the efficacy andacceptability of a preoperative VLED.Design: In a prospective observational study, 32 subjects (n 19men and 13 women) with a mean (SD) age of 47.5 8.3 y and abody mass index (in kg/m2) of 47.35.3 consumed a VLED for 12wk. Primary outcomes included changes in liver volume (LV) and invisceral and subcutaneous adipose tissue (VAT/SAT). Changes inbody weight, anthropometric measures, and biochemical variableswere also recorded, and compliance with, acceptability of, and sideeffects of treatment were assessed. Changes in LV and VAT/SATarea were measured by computed tomography and magnetic resonanceimaging at baseline and weeks 2, 4, 8, and 12.Results: Mean (SD) LV, VAT/SAT, and body weight decreasedsignificantly (P 0.001 for all). The degree of LV reduction wasdirectly related to the reduction in relative body weight (r 0.54,P 0.001) and initial LV (r 0.43, P 0.015). Eighty percent ofthe reduction in LV occurred between weeks 0 and 2 (P 0.001).Reductions in body weight and VAT were uniform over the 12-wkperiod. Attrition was 14%. Acceptability was adequate but wanedover time, and mild transitory side effects occurred.Conclusions: Given the observed early reduction in LV and theprogressive reduction in VAT, we suggest that the minimum durationfor a preoperative VLED be 2 wk. Ideally, the duration shouldbe 6 wk to achieve maximal LV reduction and significant reductionsin VAT and body weight without compromising compliance andacceptability.

Published
2006

44. A Core set of patient-reported outcome measures to measure quality of life in obesity treatment research.

Author

Dijkhorst PJ, de Vries CEE, Terwee CB, Janssen IMC, Liem RSL, van Wagensveld BA, Ottosson J, Halpern B, Flint SW, van Rossum EFC, Saadi A, West-Smith L, O'Kane M, Halford JCG, Coulman KD, Al-Sabah S, Dixon JB, Brown WA, Salas XR, Hoogbergen MM, Abbott S, Budin AJ, Holland JF, Poulsen L, Welbourn R, Ruanova BR, Morton JM, Pattou F, Akpinar EO, Sogg S, Himpens JM, Osborne V, Wijling N, Divine L, Isack N, Birney S, Keenan JMB, Nadglowski J, Bowman J, Clare K, Meloni R, de Blaeij S, Kyle TK, Bahlke M, Healing A, Patton I, and Monpellier VM

Abstract

The lack of standardization in patient-reported outcome measures (PROMs) has made measurement and comparison of quality of life (QoL) outcomes in research focused on obesity treatment challenging. This study reports on the results of the second and third global multidisciplinary Standardizing Quality of life measures in Obesity Treatment (S.Q.O.T.) consensus meetings, where a core set of PROMs to measure nine previously selected patient-reported outcomes (PROs) in obesity treatment research was established. The S.Q.O.T. II online and S.Q.O.T. III face-to-face hybrid consensus meetings were held in October 2021 and May 2022. The meetings were led by an independent moderator specializing in PRO measurement. Nominal group techniques, Delphi exercises, and anonymous voting were used to select the most suitable PROMs by consensus. The meetings were attended by 28 and 27 participants, respectively, including a geographically diverse selection of people living with obesity (PLWO) and experts from various disciplines. Out of 24 PROs and 16 PROMs identified in the first S.Q.O.T. consensus meeting, the following nine PROs and three PROMs were selected via consensus: BODY-Q (physical function, physical symptoms, psychological function, social function, eating behavior, and body image), IWQOL-Lite (self-esteem), and QOLOS (excess skin). No PROM was selected to measure stigma as existing PROMs deemed to be inadequate. A core set of PROMs to measure QoL in research focused on obesity treatment has been selected incorporating patients' and experts' opinions. This core set should serve as a minimum to use in obesity research studies and can be combined with clinical parameters., (© 2024 World Obesity Federation.)

Published
2024
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45. Supporting healthcare professionals to reduce weight stigma.

Author

Hill B, de la Piedad Garcia X, Rathbone JA, Malik Z, Holmes-Truscott E, Lawrence BJ, Kite J, Cooper K, Broady TR, and Dixon JB

Subjects
Humans, Social Stigma, Health Personnel psychology, Obesity psychology
Abstract

Background: Reducing weight stigma in healthcare is critical to supporting and improving the health of people living with overweight or obesity and decreasing the risk of adverse patient outcomes. We were invited as stigma researchers to participate in an online workshop alongside community members, healthcare professionals and policymakers to codesign guidance for reducing weight stigma in healthcare. This workshop prompted us to reflect on why and how weight stigma should be addressed in healthcare, and to provide recommendations for healthcare professionals and policymakers to reduce weight stigma in healthcare., Objective: This paper presents our reflections and recommendations for addressing weight stigma in healthcare following the codesign workshop., Discussion: Recommendations include targeting individual healthcare professionals and involving clear, practical guidelines and training that leverage the notions of 'do no harm', improving practice and recognising biases. Importantly, such strategies must be couched in broader structural approaches to weight stigma reduction.

Published
2024
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46. Core Set of Patient-Reported Outcome Measures for Measuring Quality of Life in Clinical Obesity Care.

Author

Dijkhorst PJ, Monpellier VM, Terwee CB, Liem RSL, van Wagensveld BA, Janssen IMC, Ottosson J, Halpern B, Flint SW, van Rossum EFC, Saadi A, West-Smith L, O'Kane M, Halford JCG, Coulman KD, Al-Sabah S, Dixon JB, Brown WA, Ramos Salas X, Abbott S, Budin AJ, Holland JF, Poulsen L, Welbourn R, Wijling N, Divine L, Isack N, Birney S, Keenan JMB, Kyle TK, Bahlke M, Healing A, Patton I, and de Vries CEE

Subjects
Humans, Netherlands, Female, Male, Surveys and Questionnaires, Body Image psychology, Self Concept, Bariatric Surgery, Weight Loss, Adult, Patient Reported Outcome Measures, Quality of Life, Obesity therapy, Obesity psychology
Abstract

Purpose: The focus of measuring success in obesity treatment is shifting from weight loss to patients' health and quality of life. The objective of this study was to select a core set of patient-reported outcomes and patient-reported outcome measures to be used in clinical obesity care., Materials and Methods: The Standardizing Quality of Life in Obesity Treatment III, face-to-face hybrid consensus meeting, including people living with obesity as well as healthcare providers, was held in Maastricht, the Netherlands, in 2022. It was preceded by two prior multinational consensus meetings and a systematic review., Results: The meeting was attended by 27 participants, representing twelve countries from five continents. The participants included healthcare providers, such as surgeons, endocrinologists, dietitians, psychologists, researchers, and people living with obesity, most of whom were involved in patient representative networks. Three patient-reported outcome measures (patient-reported outcomes) were selected: the Impact of Weight on Quality of Life-Lite (self-esteem) measure, the BODY-Q (physical function, physical symptoms, psychological function, social function, eating behavior, and body image), and the Quality of Life for Obesity Surgery questionnaire (excess skin). No patient-reported outcome measure was selected for stigma., Conclusion: A core set of patient-reported outcomes and patient-reported outcome measures for measuring quality of life in clinical obesity care is established incorporating patients' and experts' opinions. This set should be used as a minimum for measuring quality of life in routine clinical practice. It is essential that individual patient-reported outcome measure scores are shared with people living with obesity in order to enhance patient engagement and shared decision-making., (© 2024. The Author(s).)

Published
2024
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47. Lymphatic endothelial cell-targeting lipid nanoparticles delivering VEGFC mRNA improve lymphatic function after injury.

Author

Michalaki E, Chin R, Jeong K, Qi Z, Liebman LN, González-Vargas Y, Echeverri ES, Paunovska K, Muramatsu H, Pardi N, Tamburini BJ, Jakus Z, Dahlman JE, and Dixon JB

Abstract

Dysfunction of the lymphatic system following injury, disease, or cancer treatment can lead to lymphedema, a debilitating condition with no cure. Advances in targeted therapy have shown promise for treating diseases where conventional therapies have been ineffective and lymphatic vessels have recently emerged as a new therapeutic target. Lipid nanoparticles (LNPs) have emerged as a promising strategy for tissue specific delivery of nucleic acids. Currently, there are no approaches to target LNPs to lymphatic endothelial cells, although it is well established that intradermal (ID) injection of nanoparticles will drain to lymphatics with remarkable efficiency. To design an LNP that would effectively deliver mRNA to LEC after ID delivery, we screened a library of 150 LNPs loaded with a reporter mRNA, for both self-assembly and delivery in vivo to lymphatic endothelial cells (LECs). We identified and validated several LNP formulations optimized for high LEC uptake when administered ID and compared their efficacy for delivery of functional mRNA with that of free mRNA and mRNA delivered with a commercially available MC3-based LNP (Onpattro ™ ). The lead LEC-specific LNP was then loaded with VEGFC mRNA to test the therapeutic advantage of the LEC-specific LNP (namely, LNP7) for treating a mouse tail lymphatic injury model. A single dose of VEGFC mRNA delivered via LNP7 resulted in enhanced LEC proliferation at the site of injury, and an increase in lymphatic function up to 14-days post-surgery. Our results suggest a therapeutic potential of VEGFC mRNA lymphatic-specific targeted delivery in alleviating lymphatic dysfunction observed during lymphatic injury and could provide a promising approach for targeted, transient lymphangiogenic therapy., Competing Interests: Competing interests: Dahlman, Dixon, Michalaki, and Tamburini are authors on a patent application associated with this work.

Published
2024
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48. Associations between Preschool Teachers' Food-Based Learning Frequency, Level of Personal Priority and Identified Resources and Challenges: A Needs Assessment.

Author

Resor J, Dixon JB, Wu Q, Hegde AV, Lee TD, Goodell LS, Méndez LI, McMillan VJ, and Stage VC

Subjects
Humans, Female, Male, Child, Preschool, North Carolina, Adult, Surveys and Questionnaires, Early Intervention, Educational, Learning, Middle Aged, Diet, Healthy, School Teachers psychology, School Teachers statistics & numerical data, Needs Assessment
Abstract

Food-based learning (FBL) is the use of food as a teaching tool in the classroom, which can expose children to healthy foods to improve preference and consumption. However, more research is needed on the use and perception of FBL in the Head Start (HS) preschool classroom. In an online survey, we explored associations between North Carolina HS teachers' ( n = 168) experiences (e.g., resources, challenges, needs, and preferences) with FBL, how frequently teachers implemented it, and how much they prioritized it. We used frequencies and chi-square tests of independence to assess associations between study variables. Teachers reported using FBL regularly with access to FBL resources (e.g., books and center play materials) and experiencing challenges (e.g., lack of funding and material resources). Teachers partnered with parents and farmers markets and expressed a need for additional FBL professional development. Our needs assessment findings revealed specific resources, challenges, and perceptions significantly associated with how often teachers used FBL and their priority level. Additional research should investigate how to alleviate FBL challenges and strategies to create policy and environmental changes that facilitate early FBL.

Published
2024
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49. Mild exercise expedites joint clearance and slows joint degradation in a joint instability model of osteoarthritis in male rats.

Author

Kaiser JM, Bernard FC, Pucha K, Raval SK, Eng T, Fulton T, Anderson SE, Allen KD, Dixon JB, and Willett NJ

Subjects
Animals, Male, Rats, Disease Models, Animal, Gait physiology, Knee Joint physiopathology, Glycosaminoglycans metabolism, Osteoarthritis physiopathology, Osteoarthritis metabolism, Osteophyte, Disease Progression, Rats, Inbred Lew, Physical Conditioning, Animal physiology, Joint Instability physiopathology, Osteoarthritis, Knee physiopathology
Abstract

Objective: Exercise remains a hallmark treatment for post-traumatic osteoarthritis (PTOA) and may maintain joint homeostasis in part by clearing inflammatory cytokines, cells, and particles. It remains largely unknown whether exercise-induced joint clearance can provide therapeutic relief of PTOA. In this study, we hypothesized that exercise could slow the progression of preclinical PTOA in part by enhancing knee joint clearance., Design: Surgical medial meniscal transection was used to induce PTOA in 3-month-old male Lewis rats. A sham surgery was used as a control. Mild treadmill walking was introduced 3 weeks post-surgery and maintained to 6 weeks post-surgery. Gait and isometric muscle torque were measured at the study endpoint. Near-infrared imaging tracked how exercise altered lymphatic and venous knee joint clearance during discrete time points of PTOA progression., Results: Exercise mitigated joint degradation associated with PTOA by preserving glycosaminoglycan content and reducing osteophyte volume (effect size (95% Confidence Interval (CI)); 1.74 (0.71-2.26)). PTOA increased hind step widths (0.57 (0.18-0.95) cm), but exercise corrected this gait dysfunction (0.54 (0.16-0.93) cm), potentially indicating pain relief. Venous, but not lymphatic, clearance was quicker 1-, 3-, and 6-weeks post-surgery compared to baseline. The mild treadmill walking protocol expedited lymphatic clearance rate in moderate PTOA (3.39 (0.20-6.59) hrs), suggesting exercise may play a critical role in restoring joint homeostasis., Conclusions: We conclude that mild exercise has the potential to slow disease progression in part by expediting joint clearance in moderate PTOA., (Published by Elsevier Ltd.)

Published
2024
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50. Sentinel lymph node biopsy is unreliable in predicting melanoma mortality for both younger and older patients.

Author

Dixon AJ, Kyrgidis A, Steinman HK, Dixon JB, Sladden M, Garbe C, Lallas A, Zachary CB, Leiter-Stöppke U, Smith H, Nirenberg A, Zouboulis CC, Longo C, Argenziano G, Apalla Z, Popescu C, Tzellos T, Anderson S, Nanz L, Cleaver L, and Thomas JM

Subjects
Humans, Middle Aged, Aged, Young Adult, Adult, Aged, 80 and over, Sentinel Lymph Node Biopsy, Neoplasm Staging, Prognosis, Retrospective Studies, Melanoma pathology, Skin Neoplasms pathology, Sentinel Lymph Node pathology
Abstract

Background: Melanoma disease patterns vary with patient age., Aim: To evaluate sentinel lymph node biopsy (SLNB) in managing melanoma at differing patient ages., Methods: Online prediction tools were applied to compare SLNB positivity (SLNB + ) and survival risk at patient ages 20-80. Tübingen melanoma data were used to determine variations in the hazard ratio of SLNB + for mortality at different patient ages., Results: Regardless of tumour thickness, predicted SLNB + rates were markedly higher than mortality rates for 20-year-old patients. For 80-year-old patients, it is the opposite., Discussion: If 1000 20-year-olds with a 0.4 mm thickness non-ulcerated melanoma underwent SLNB, 100 would likely be positive. If all 100 were to be offered adjuvant drug therapy (ADT), fewer than three more melanoma deaths in those 1000 patients would be avoided. In total, 97 patients would have received medication they may never have needed. If 1000 80-year-olds with a 3 mm thickness non-ulcerated melanoma underwent SLNB, only 40 would likely be positive. In total, 274 patients would be predicted to die of melanoma, 245 being SLNB negative and 29 SLNB + . ADT linked to SLNB + could deny treatment to 89% of these high-risk patients., Limitations: The authors relied on published risk data., Conclusion: SLNB has poor specificity at predicting mortality in young melanoma patients and poor sensitivity in older patients. SLNB is not indicated in managing cutaneous melanoma for patients under 40 or over 60 years of age. Many such patients could be managed with wide local excision alone in their clinician's office-based practice. For all cutaneous melanoma patients at all ages, linking ADT to BAUSSS biomarker, (an algorithm of Breslow thickness, age, ulceration, subtype, sex and Site) rather than SLNB + is likely more appropriate. BAUSSS provides a more accurate melanoma-specific mortality risk assessment for patients without burdening them with added surgery, hospitalization, costs or morbidity risk., (© 2024 European Academy of Dermatology and Venereology.)

Published
2024
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