Effect of Central Sympathoinhibition With Moxonidine on Sympathetic Nervous Activity in Polycystic Ovary Syndrome-A Randomized Controlled Trial

Sympathetic nervous system (SNS) activity is increased in polycystic ovary syndrome (PCOS). Moxonidine is a centrally acting sympatholytic drug with known beneficial effects on hypertension, insulin sensitivity, dyslipidemia and inflammation. In this double-blind placebo controlled randomized clinical trial we examined the effect of moxonidine on modulating sympathetic activity and downstream metabolic abnormalities in 48 pre-menopausal women with PCOS (Rotterdam diagnostic criteria), recruited from the community (January 2013-August 2015). Participants received moxonidine (0.2 mg daily initially, up titrated to 0.4 mg daily in 2 weeks) (n = 23) or placebo (n = 25) for 12 weeks. Multiunit muscle sympathetic activity (by microneurography) and plasma noradrenaline levels were measured (primary outcomes). Fasting lipids, insulin resistance, serum androgens, and inflammatory markers were measured as secondary outcomes. Forty three women completed the trial (19 moxonidine, 24 placebo). Mean change in burst frequency (-3 ± 7 vs. -3 ± 8 per minute) and burst incidence (-3 ± 10 vs. -4 ± 12 per 100 heartbeat) did not differ significantly between moxonidine and placebo groups. Women on moxonidine had a significant reduction in hs-CRP compared to placebo group (-0.92 ± 2.3 vs. -0.04 ± 1.5) which did not persist post Bonferroni correction. There was a significant association between markers of insulin resistance at baseline and reduction in sympathetic activity with moxonidine. Moxonidine was not effective in modulating sympathetic activity in PCOS. Anti-inflammatory effects of moxonidine and a relationship between insulin resistance and sympathetic response to moxonidine are suggested which need to be further explored. Clinical Trial Registration Number: (NCT01504321).

Cardiovascular Risk Factors After Adolescent Bariatric Surgery

BACKGROUND AND OBJECTIVES

Severely obese adolescents harbor numerous cardiovascular disease risk factors (CVD-RFs), which improve after metabolic and bariatric surgery (MBS). However, predictors of change in CVD-RFs among adolescents have not yet been reported.

METHODS

The Teen-Longitudinal Assessment of Bariatric Surgery study (NCT00474318) prospectively collected anthropometric and health status data on 242 adolescents undergoing MBS at 5 centers. Predictors of change in CVD-RFs (blood pressure, lipids, glucose homeostasis, and inflammation) 3 years after Roux-en-Y gastric bypass and vertical sleeve gastrectomy were examined.

RESULTS

The mean (±SD) age of participants at baseline was 17 ± 1.6 years; 76% were girls, and 72% were white, with a median BMI of 51. Participants underwent Roux-en-Y gastric bypass (n = 161), vertical sleeve gastrectomy (n = 67), or adjustable gastric banding (n = 14). Increasing weight loss was an independent predictor of normalization in dyslipidemia, elevated blood pressure (EBP), hyperinsulinemia, diabetes, and elevated high-sensitivity C-reactive protein. Older participants at time of surgery were less likely to resolve dyslipidemia compared with younger participants, whereas girls were more likely than boys to demonstrate improvements in EBP. Even those participants without frank dyslipidemia or EBP at baseline showed significant improvements in lipid and blood pressure values over time.

CONCLUSIONS

Numerous CVD-RFs improve among adolescents undergoing MBS. Increased weight loss, female sex, and younger age predict a higher probability of resolution of specific CVD-RFs. The elucidation of predictors of change in CVD-RFs may lead to refinements in patient selection and optimal timing of adolescent bariatric surgery designed to improve clinical outcomes.

Bad words: why language counts in our work with bariatric patients

Language is powerful. Our words convey our impressions, attitudes, and worldview. Language not only reflects, but also shapes, the way that we think. In the field of bariatric-metabolic surgery, it is critical for clinicians to choose our language thoughtfully. In this paper, we demonstrate the importance of language choices in our clinical work and our professional communications; explore the potential pitfalls of words and phrases commonly used in the field of obesity; and encourage the use of more productive language choices in our communications with patients and professional colleagues, both within and outside of our field.

Health Outcomes and Explant Rates After Laparoscopic Adjustable Gastric Banding: A Phase 4, Multicenter Study over 5 Years

OBJECTIVE

This study aimed to evaluate the real-world safety and effectiveness of the LAP-BAND (Apollo Endosurgery Inc., Austin, Texas) adjustable gastric banding system (LBS) for 5 years following implantation.

METHODS

This prospective, longitudinal, phase 4, multicenter study involved 652 patients who had implantation of the LBS system. The primary outcome was the percentage of subjects who had LBS explant over 5 years. The secondary outcomes included the rate of reoperations, clinical and biochemical measures, and patient-reported outcome measures over 5 years.

RESULTS

The study cohort consisted of 79.3% females with a mean age of 44 years and a mean BMI of 45.4 kg/m² . The primary end point was met with an explant rate of 8.74% (95% CI: 6.6%-10.9%) at 5 years. The rates for completer-only analysis and imputed missing data analysis were 12.81% (95% CI: 9.7%-15.9%) and 12.85% (95% CI: 10.2%-15.5%), respectively. All were significantly lower than the historic rate of 39.4% (P < 0.001). There were 43 patients who required reoperations or revisions excluding explants (6.6%). A mean weight loss of 18.7% was maximally achieved by 2 years, and weight loss was maintained through to 5 years. All patient-reported outcomes showed improvement following LBS treatment throughout 5 years.

CONCLUSIONS

This study validates the long-term safety and effectiveness of LBS for the treatment of patients with obesity and its related conditions.

Commissioning guidance for weight assessment and management in adults and children with severe complex obesity

The challenge of managing the epidemic of patients with severe and complex obesity disease in secondary care is largely unmet. In England, the National Institute of Health and Care Excellence and the National Health Service England have published guidance on the provision of specialist (non-surgical) weight management services. We have undertaken a systematic review of 'what evidence exists for what should happen in/commissioning of: primary or secondary care weight assessment and management clinics in patients needing specialist care for severe and complex obesity?' using an accredited methodology to produce a model for organization of multidisciplinary team clinics that could be developed in every healthcare system, as an update to a previous review. Additions to the previous guidance were multidisciplinary team pathways for children/adolescent patients and their transition to adult care, anaesthetic assessment and recommendations for ongoing shared care with general practitioners, as a chronic disease management pathway.

Food for Thought: Reward Mechanisms and Hedonic Overeating in Obesity

PURPOSE OF REVIEW

This review examines the food addiction model and the role of food hedonic pathways in the pathogenesis and treatment of obesity.

RECENT FINDINGS

The hedonic pathway interacts with the obesogenic environment to override homeostatic mechanisms to cause increase in body weight. Weight gain sustained over time leads to "upward setting" of defended level of body-fat mass. There are neurobiological and phenotypic similarities and differences between hedonic pathways triggered by food compared with other addictive substances, and the entity of food addiction remains controversial. Treatment for obesity including pharmacotherapy and bariatric surgery impacts on neural pathways governing appetite and hedonic control of food intake. The food addiction model may also have significant impact on public health policy, regulation of certain foods, and weight stigma and bias. Recent rapid progress in delineation of food hedonic pathways advances our understanding of obesity and facilitates development of effective treatment measures against the disease.

Endothelial Function in Healthy Young Individuals Is Associated with Dietary Consumption of Saturated Fat

Background: A diet rich in fat, in particular saturated fat (SF), may be linked to cardiovascular disease development, possibly due to a detrimental effect of fat on endothelial function (EF).

Objective: We aimed to determine whether the habitual SF intake [as a ratio to total fat (the sum of saturated, polyunsaturated, and monounsaturated fat)] might influence endothelial function in young, overweight but otherwise healthy adults.

Design: Sixty-nine young adults (49 males, mean age: 23 ± 1 years, mean BMI: 29.1 ± 0.8 kg/m²) were classified into three tertiles according to their habitual SF intake consumption (low SF: <39%, medium SF 39.1–43.7%, and high SF: >43.7% of total fat). Endothelial function was assessed using digital amplitude tonometry.

Results: The three groups of individuals were comparable for total energy intake and calories from: fat, protein, and carbohydrates. There was no difference in anthropometric and hemodynamic variables among the groups. Those in the high SF group presented with impaired endothelial function [reactive hyperemia index (RHI): high SF: 1.60 ± 0.08 compared to 2.23 ± 0.16 in the medium SF and 2.12 ± 0.14 in the low SF group, P < 0.01]. Regression analysis, including gender, age, ethnicity, body mass index indicated that the ratio of SF to total fat was an independent predictor of the RHI (P < 0.05).

Conclusion: The habitual consumption of a diet high in SF in relation to polyunsaturated and monounsaturated fat was strongly associated with impaired endothelial function in young overweight adults, potentially contributing to increased risk of developing cardiovascular disease.

Effects of Moxonidine and Low-Calorie Diet: Cardiometabolic Benefits from Combination of Both Therapies

OBJECTIVE

Because sympathetic nervous system activity plays a detrimental role in metabolic and cardiovascular health, this study compared the effects of a centrally acting sympatholytic agent, the effects of a weight loss (WL) program using a low-calorie diet, and the effects of a combination of both.

METHODS

Young (18-30 years) male subjects with overweight (BMI > 25 kg/m² ) were allocated to a WL program (n = 10), a moxonidine treatment course (M; n = 10, 0.4 mg/d), a combination of both (WL + M; n = 11), or to a control (C) group (n = 6) for 6 months. Muscle sympathetic nerve activity (MSNA), endothelial function, renal function (Cockcroft-Gault formula), and the metabolic profile were assessed before and after intervention.

RESULTS

WL occurred in the WL and WL + M groups (-7.6 ± 1.9 kg, P < 0.001 in both). MSNA and systolic blood pressure decreased similarly in the WL, M, and WL + M groups (by ∼10 bursts/min, P < 0.001, and by ∼9 mm Hg, P < 0.05). All other parameters for the WL, C, and M groups remained unchanged. In the WL + M group, decreased total cholesterol (-0.78 ± 0.23 mmol/L, P < 0.001), decreased low-density lipoprotein cholesterol (-0.49 ± 0.16 mmol/L, P < 0.01), decreased insulin (-6.5 ± 2.8 mmol/L, P < 0.05), and attenuated glomerular hyperfiltration (-19 ± 5 mL/min, P < 0.01) occurred.

CONCLUSIONS

The combination of moxonidine with a WL program has beneficial effects on aspects of the metabolic profile and end organ damage in young males with overweight.

Muscle Sympathetic Nerve Activity Is Associated With Elements of the Plasma Lipidomic Profile in Young Asian Adults

BACKGROUND

Asian subjects are at increased cardio-metabolic risk at comparatively lower body mass index (BMI) compared with white subjects. Sympathetic nervous system activation and dyslipidemia, both characteristics of increased adiposity, appear to be related. We therefore analyzed the association of muscle sympathetic nerve activity (MSNA) with the plasma lipidomic profile in young adult Asian and white subjects.

METHODS

Blood samples were collected from 101 participants of either Asian or white background (age, 18 to 30 years; BMI, 28.1 ± 5.9 kg/m2). Lipids were extracted from plasma and analyzed using electrospray ionization-tandem mass spectrometry. MSNA was quantified using microneurography. The association of MSNA and obesity with lipid species was examined using linear regression analysis.

RESULTS

The plasma concentrations of total dihydroceramide, ceramide, GM3 ganglioside, lysoalkylphosphatidylcholine, alkenylphosphatidylethanolamine, and lysophosphatidylinositol were elevated in the Asian subjects relative to the white subjects. After adjustment for confounders, diacylglycerols and triacylglycerols, cholesterol esters, phosphatidylinositols, phosphatidylethanolamines, and phosphatidylglycerols bore significant associations with MSNA but only in the Asian subjects. These associations remained significant after further adjustment for the participants' degree of insulin resistance and appeared not to be related to differences in diet macronutrient content between groups.

CONCLUSIONS

The lipidomic profile differs between Asian and white subjects. There exists a strong relationship between certain lipid species and MSNA. The association is stronger in Asian subjects, despite their lower BMI. This study demonstrates an association between circulating lipids and central sympathetic outflow. Whether the stronger association between the lipid profile and sympathetic activation underpins the apparent greater risk posed by increased adiposity in Asian individuals merits further attention.

Neck Circumference Is Associated with Muscle Sympathetic Nerve Activity in Overweight and Obese Men but Not Women

Background: Neck circumference (NC) is a predictor of cardiometabolic risk. The objective of this study was to explore the relationship of NC to muscle sympathetic nerve activity (MSNA) within an overweight and obese population.

Methods: The study design was a retrospective cross-sectional analysis. Un-medicated persons (72 men, 53 postmenopausal women) aged 56 ± 1 years (mean ± SEM) with body mass index (BMI) 32.8 ± 0.4 kg/m², were studied. NC was measured together with traditional anthropometric measures, supine blood pressure, fasting blood lipids, insulin, and glucose. Insulin sensitivity was assessed by homeostasis model (HOMA-IR) and Matsuda Insulin Sensitivity Index (ISI) derived from 75-g oral glucose tolerance test. Resting multiunit MSNA was recorded by microneurography in the peroneal nerve and expressed as burst frequency and burst incidence.

Results: Men within the highest tertile of NC had significantly higher fasting and post-glucose plasma insulin levels (insulin AUC₀₋₁₂₀), HOMA-IR, non-esterified fatty acids, MSNA (45 ± 2 vs. 36 ± 2 bursts per min; 69 ± 3 vs. 58 ± 3 bursts per 100 hb) and heart rate, and lower Matsuda ISI compared to men in the lowest tertile (P all <0.05). In stepwise regression analyses, NC alone explained 12%, and together with insulin AUC₀₋₁₂₀ it accounted for 22%, of the variance in MSNA in men. In women, NC was associated with anthropometric measures but not with MSNA or metabolic indices.

Conclusions: Among overweight and obese men, NC was independently associated with elevated MSNA and hyperinsulinemia, and thus may be relevant to cardiometabolic risk prediction. The biological basis of gender differences merits further elucidation.

Long-term outcomes of bariatric surgery in adolescents with severe obesity (FABS-5+): a prospective follow-up analysis

BACKGROUND

Little is known about the long-term outcomes of bariatric surgery for severe adolescent obesity, raising questions about the durability of early responses to surgery. We aimed to analyse long-term (>5 years) outcomes of Roux-en-Y gastric bypass in a cohort of young adults who had undergone the operation during adolescence, in the Follow-up of Adolescent Bariatric Surgery at 5 Plus Years (FABS-5+) extension study.

METHODS

A cohort of young people aged 13-21 years underwent Roux-en-Y gastric bypass for clinically severe obesity at a paediatric academic medical centre in the USA. We did a prospective follow-up analysis of these patients' outcomes 5-12 years after surgery. Outcomes assessed included BMI, comorbidities, micronutrient status, safety, and other risks. The FABS study is registered with ClinicalTrials.gov, number NCT00776776.

FINDINGS

Between May, 2001, and February, 2007, 74 young people underwent Roux-en-Y gastric bypass in the FABS study. Of these, 58 individuals were eligible for the FABS-5+ study, could be located, and agreed to follow-up assessment. At baseline, the mean age of the cohort was 17·1 years (SD 1·7) and mean BMI was 58·5 kg/m² (10·5). At mean follow-up of 8·0 years (SD 1·6; range 5·4-12·5), the mean age of the cohort was 25·1 years (2·4) and mean BMI was 41·7 kg/m² (12·0; mean change in BMI -29·2% [13·7]). From baseline to long-term follow-up, significant declines were recorded in the prevalence of elevated blood pressure (27/57 [47%] vs 9/55 [16%]; p=0·001), dyslipidaemia (48/56 [86%] vs 21/55 [38%]; p<0·0001), and type 2 diabetes (9/56 [16%] vs 1/55 [2%]; p=0·03). At follow-up, 25 (46%) of 58 patients had mild anaemia (ie, not requiring intervention), 22 (45%) had hyperparathyroidism, and eight (16%) had low amounts of vitamin B12 (ie, below the normal cutpoint).

INTERPRETATION

Roux-en-Y gastric bypass surgery resulted in substantial and durable bodyweight reduction and cardiometabolic benefits for young adults. Long-term health maintenance after Roux-en-Y gastric bypass should focus on adherence to dietary supplements and screening and management of micronutrient deficiencies.

FUNDING

Ethicon Endosurgery, National Center for Advancing Translational Sciences (US National Institutes of Health).

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

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 (AUC_0–120, 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.

Comparable Attenuation of Sympathetic Nervous System Activity in Obese Subjects with Normal Glucose Tolerance, Impaired Glucose Tolerance, and Treatment Naïve Type 2 Diabetes following Equivalent Weight Loss

Background and Purpose: Elevated sympathetic nervous system (SNS) activity is a characteristic of obesity and type 2 diabetes (T2D) that contributes to target organ damage and cardiovascular risk. In this study we examined whether baseline metabolic status influences the degree of sympathoinhibition attained following equivalent dietary weight loss.

Methods: Un-medicated obese individuals categorized as normal glucose tolerant (NGT, n = 15), impaired glucose tolerant (IGT, n = 24), and newly-diagnosed T2D (n = 15) consumed a hypocaloric diet (29% fat, 23% protein, 45% carbohydrate) for 4-months. The three groups were matched for baseline age (56 ± 1 years), body mass index (BMI, 32.9 ± 0.7 kg/m²), and gender. Clinical measurements included whole-body norepinephrine kinetics, muscle sympathetic nerve activity (MSNA, by microneurography), spontaneous cardiac baroreflex sensitivity (BRS), and oral glucose tolerance test.

Results: Weight loss averaged −7.5 ± 0.8, −8.1 ± 0.5, and −8.0 ± 0.9% of body weight in NGT, IGT, and T2D groups, respectively. T2D subjects had significantly greater reductions in fasting glucose, 2-h glucose and glucose area under the curve (AUC₀₋₁₂₀) compared to NGT and IGT (group effect, P <0.001). Insulinogenic index decreased in IGT and NGT groups and increased in T2D (group × time, P = 0.04). The magnitude of reduction in MSNA (−7 ± 3, −8 ± 4, −15 ± 4 burst/100 hb, respectively) and whole-body norepinephrine spillover rate (−28 ± 8, −18 ± 6, and −25 ± 7%, respectively), time effect both P <0.001, did not differ between groups. After adjustment for age and change in body weight, Δ insulin AUC₀₋₁₂₀ was independently associated with reduction in arterial norepinephrine concentration, whilst Δ LDL-cholesterol and improvement in BRS were independently associated with decrease in MSNA.

Conclusions: Equivalent weight loss through hypocaloric diet is accompanied by similar sympathoinhibition in matched obese subjects with different baseline glucose tolerance. Attenuation of hyperinsulinemia and hyperlipidemia, rather than glycemic indices, is associated with reduction in SNS activity following weight loss intervention.

Weigh Forward: a clinical audit of weight management in Australian general practice

Weigh Forward was a prospective clinical audit, aimed to assess the use and efficacy of 12-week weight management program in general practice. Twenty-eight practitioners participated in the audit, with a total of 258 patients observed. Of these, 147 (57%) were retained to 24 weeks. Practices were asked to implement a structured 12-week weight loss program, and encouraged to utilize relevant weight management guidelines as necessary. Patients were followed up regularly, and comprehensively assessed at baseline, 12 and 24 weeks. Evaluations were made of patient weight loss, practitioner willingness to utilize available weight loss interventions, practitioner set weight loss goals and the appropriateness of such goals. Overall, the 57% of completing patients lost an average of 6.1% ± 0.5% body weight, with 27.2% losing ≥10% body weight. Practitioners were hesitant to intensify treatment, and those with comorbidities were less likely (odds ratio 1.8; 95% CI 1.4-2.4) to receive intensified treatment than those without. Practitioners also tended to set high weight loss goals, with a mean goal of 17.3% body-weight loss. The clinically significant mean weight loss demonstrates that practitioners are able to generate meaningful weight loss in primary care settings, however, could benefit from increased use of available interventions.

Effects of different metabolic states and surgical models on glucose metabolism and secretion of ileal L-cell peptides: protocol for a cross-sectional study

INTRODUCTION

Obesity and type 2 diabetes mellitus are increasing worldwide, reaching pandemic proportions. The understanding of the role of functional restriction and gut hormones can be a beneficial tool in treating obesity and diabetes. However, the exact hormonal profiles in different metabolic states and surgical models are not known.

METHODS AND ANALYSIS

The HIPER-1 Study is a single-centre cross-sectional study in which 240 patients (in different metabolic states and surgical models) will receive an oral mixed-meal tolerance test (OMTT). At baseline and after 30, 60 and 120 min, peptide YY and glucagon-like peptide 1 levels and glucose and insulin sensitivity will be measured. The primary end point of the study will be the area under the glucagon-like peptide 1 and peptide YY curves after the OMTT. Secondary study end points will include examination of the difference in plasma levels of the distal ileal hormones in subjects with various health statuses and in patients who have been treated with different surgical techniques.

ETHICS AND DISSEMINATION

An independent ethics committee, the Institutional Review Board of Istanbul Sisli Kolan International Hospital, Turkey, has approved the study protocol. Dissemination will occur via publication, national and international conference presentations, and exchanges with regional, provincial and national stakeholders.

TRIAL REGISTRATION NUMBER

NCT02532829; Pre-results.

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

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.m² 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 training to a VLED provides more favourable improvements in body composition, physical function, quality of life, and markers of cardiometabolic risk for women with clinically severe obesity, compared to VLED alone.

Trial registration

Australian New Zealand Clinical Trials Registry (ACTRN12611000694910). Date registered: 4 July 2011

Leg to leg bioelectrical impedance analysis of percentage fat mass in obese patients-Can it tell us more than we already know?

BACKGROUND

Bioelectrical impedance analysis (BIA) is well tolerated, inexpensive, and readily available, but can it be used to detect with clinical precision aberrant changes in the proportion of fat mass to fat-free mass during weight loss?

OBJECTIVES

To assess the variance in percentage body fat mass explained by the readily available inputs and assess residual variance provided by leg-to-leg BIA scales.

METHODS

Using cross-sectional data from a cohort of 665 patients of Indian ethnicity presenting for bariatric surgery, we examine the determinants of percentage body fat as provided by leg-to-leg output from Tanita SC-330 BIA scales.

RESULTS

Four input factors-sex, weight, height, and age-contributed to provide 92% and 95% explanation in output variance for percentage fat mass (%FM) and actual fat mass, respectively, in 665 patients. Body mass index alone explained 89% and 81% of variance in %FM output for women and men, respectively. Neither weight distribution, as indicated by waist and hip circumference or waist to hip ratio, nor plasma lipids or markers of glucose metabolism contributed additional variance in %FM when controlled for the 4 key inputs.

CONCLUSIONS

Simple, known input variables dominate the leg-to-leg BIA output of %FM, and this may compromise the detection of aberrant changes in %FM and fat-free mass with substantial weight loss. For clinical research, validated methods not largely dependent on known inputs should be used for evaluating changes in body composition after substantial weight loss.

Determinants of Diabetes Remission and Glycemic Control After Bariatric Surgery

OBJECTIVE

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.

RESEARCH DESIGN AND METHODS

Seven hundred twenty-seven patients were included in a database merged from the Swedish Obese Subjects (SOS) study and two randomized controlled studies, with 415 surgical and 312 medical patients in total. Bariatric operations were divided into gastric only (GO) and gastric plus diversion (GD).

RESULTS

Sixty-four percent of patients in the surgical arm and 15.0% in the medical arm experienced diabetes remission (P < 0.001). GO yielded 60% remission, and GD yielded 76% remission. The best predictors of diabetes remission were lower baseline glycemia and shorter diabetes duration. However, when operation type was considered, GD predicted a higher likelihood of remission and greater weight loss. Patients in remission (responders) lost more weight (25% vs. 17%) and waist circumference (18% vs. 13%) and experienced better insulin sensitivity than nonresponders.

CONCLUSIONS

Surgery is more effective than medical treatment in achieving diabetes remission and tighter glycemic control. Shorter diabetes duration, lower fasting glycemia before surgery, and GD versus GO procedures independently predict higher rates of remission, whereas baseline HbA1c and waist circumference predict improved glycemic control. The results show the advantage of an early operation together with better controlled glycemia on diabetes remission independently of BMI.

Neuroendocrine adaptations to bariatric surgery

The global epidemic of obesity and its related disease in combination with robust physiological defence of intentional weight loss generates a pressing need for effective weight loss therapies. Bariatric surgery, which works very effectively at delivering substantial sustained weight loss, has been an enigma with respect to mechanism of action. Naive concepts of restriction and malabsorption do not explain the efficacy of the most commonly used bariatric procedures. This century has seen increased interest in unravelling the mystery of the mechanisms underlying surgery associated weight loss with a focus on integrative gastrointestinal (GI) physiology, gut-brain signalling, and beyond weight loss effects on metabolism. GI interventions, some very minor, can alter GI wall stretch and pressure receptors; a range of GI hormones affecting hunger and satiety; bile acid metabolism and signalling; the characteristics of GI microbiome; portal vein nutrient sensing; and circulating concentrations of amino acids. Understanding the mechanisms involved should present targets for less invasive effective therapies.