Morbidity and Effectiveness of Laparoscopic Sleeve Gastrectomy, Adjustable Gastric Band, and Gastric Bypass for Morbid Obesity

Evaluation of Weight Loss Indicators and Laparoscopic One-Anastomosis Gastric Bypass Outcomes

Mini-gastric bypass/One-anastomosis gastric bypass (MGB-OAGB) is an effective bariatric technique for treating overweight and obesity, controlling and improving excess-weight-related comorbidities. Our study evaluated OAGB characteristics and resulting weight evolution, plus surgical success criteria based on various excess weight loss indicators. A prospective observational study of 100 patients undergoing OAGB performed by the same surgical team (two-year follow-up). Surgical characteristics were: surgery duration, associated complications, bowel loop length, hospital stay, and weight loss at 6 postoperative points. 100 patients were treated (71 women, 29 men); mean initial age was 42.61 years and mean BMI, 42.61 ± 6.66 kg/m². Mean surgery duration was 97.84 ± 12.54 minutes; biliopancreatic loop length was 274.95 ± 23.69 cm. Average hospital stay was 24 hours in 98% of patients; no surgical complications arose. Weight decreased significantly during follow-up (P < 0.001). Greatest weight loss was observed at 12 months postsurgery (68.56 ± 13.10 kg). Relative weight loss showed significant positive correlation, with greatest weight loss at 12 months and %excess BMI loss > 50% achieved from the 3-month follow-up in 92.46% of patients. OAGB seems to be effective in treating obesity, with short hospital stays. Relative weight loss correlates optimally with absolute outcomes, but both measures should be used to evaluate surgical results.

Awakening: a qualitative study on maintaining weight loss after bariatric surgery

AIMS AND OBJECTIVES

To describe the experiences of adults who were successful in maintaining weight loss after bariatric surgery.

BACKGROUND

The majority of studies examine a homogenous demographic group of postbariatric surgical patients who have gone through initial weight loss, which occurs within the first 12-24 months post surgery. Maintenance of weight loss begins 24 months after bariatric surgery; however, there is a paucity of research examining experiences during this period. The lack of conclusive research related to interactions between intrapersonal, behavioural and environmental influences suggests a need to develop a better understanding of patients' experiences related to weight loss maintenance post bariatric surgery.

DESIGN

Bandura's Social Cognitive Theory provided the framework for the semi-structured interviews for this qualitative descriptive study.

METHODS

In-person interviews with n = 14 participants who were able to maintain weight loss at least 24 months after a bariatric surgery.

RESULTS

Participants experienced an awakening and gained a new perspective on their life. They identified negative attitudes, influences and behaviours and modified their environment to support their desired healthy behaviour.

CONCLUSIONS

To maintain weight loss, an individual must seek out and be surrounded by positive family and peer support influences. Positive support may provide the opportunity for an individual to place personal health needs as a priority.

RELEVANCE TO CLINICAL PRACTICE

Therapeutic education and counselling for individuals, couples and families should occur during all phases of bariatric surgery. Communication techniques may empower clients to deflect negative comments and influences in a constructive manner. Support groups should accommodate the various phases of bariatric surgery. Clients should be prepared for how to work through emotions associated with weight fluctuations.

Fifth International Consensus Conference: current status of sleeve gastrectomy

BACKGROUND

For the purpose of building best practice guidelines, an international expert panel was surveyed in 2014 and compared with the 2011 Sleeve Gastrectomy Consensus and with survey data culled from a general surgeon audience.

OBJECTIVES

To measure advancement on aspects of laparoscopic sleeve gastrectomy and identify current best practices.

SETTING

International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) 2014, Fifth International Summit for Laparoscopic Sleeve Gastrectomy, Montréal, Canada.

METHODS

In August 2014, expert surgeons (based on having performed>1000 cases) completed an online anonymous survey. Identical survey questions were then administered to general surgeon attendees.

RESULTS

One hundred twenty bariatric surgeons completed the expert survey, along with 103 bariatric surgeons from IFSO 2014 general surgeon audience. The following indications were endorsed: as a stand-alone procedure (97.5%); in high-risk patients (92.4%); in kidney and liver transplant candidates (91.6%); in patients with metabolic syndrome (83.8%); body mass index 30-35 with associated co-morbidities (79.8%); in patients with inflammatory bowel disease (87.4%); and in the elderly (89.1%). Significant differences existed between the expert and general surgeons groups in endorsing several contraindications: Barrett's esophagus (80.0% versus 31.3% [P<.001]), gastroesophageal reflux disease (23.3% versus 52.5% [P<.001]), hiatal hernias (11.7% versus 54.0% [P<.001]), and body mass index>60 kg/m(2) (5.0% versus 28.0% [P<.001]). Average reported weight loss outcomes 5 years postoperative were significantly higher for the expert surgeons group (P = .005), as were reported stricture (P = .001) and leakage (P = .005) rates. The following significant differences exist between 2014 and 2011 expert surgeons: Patients with gastroesophageal reflux disease should have pH and manometry study pre-laparoscopic sleeve gastrectomy (32.8% versus 50.0%; P = .033); it is important to take down the vessels before resection (88.1% versus 81.8%; P = .025); it is acceptable to buttress (81.4% versus 77.3%; P<.001); the smaller the bougie size and tighter the sleeve, the higher the incidence of leaks (78.8% versus 65.2%; P = .006).

CONCLUSION

This study highlights areas of new and improved best practices on various aspects of laparoscopic sleeve gastrectomy performance among experts from 2011 and 2014 and among the current general surgeon population.

Sleeve gastrectomy surgery in obese patients post-organ transplantation

BACKGROUND

Among organ transplant recipients, a common side effect of immunosuppressive therapy is the development of obesity, which affects a third of the patients within 3 years after transplantation. Bariatric surgery represents a possible surgical option for weight loss among posttransplant patients.

OBJECTIVES

The aim of this study was to examine percent excess weight loss (%EWL), and percent weight loss (%WL) and perioperative and postoperative complications in posttransplant obese patients after sleeve gastrectomy (SG) compared with nontransplant patients. We hypothesize that transplant patients who undergo SG will not significantly differ in their perioperative or postoperative complications or in their %EWL and %WL compared with nontransplant patients who undergo SG. The second aim was to evaluate the impact of SG on graft function and immunosuppressive therapy in transplant patients.

SETTING

University hospital.

METHODS

Among 500 consecutive patients who underwent SG from January 2008 to June 2014, 10 patients were organ transplant recipients. The following variables were compared between groups: patient demographic characteristics and co-morbidities, type of transplant surgery, date of transplant surgery, pretransplant body mass index (BMI), date of bariatric surgery, prebariatric surgery BMI, operative time, length of hospitalization, postoperative complications, and change in BMI, %EWL, and %WL. Data were also collected on renal, liver, and pancreas graft function parameters and changes in immunosuppressive medications.

RESULTS

Six patients had a kidney transplant, 2 patients had a liver transplant, and 2 had a pancreas transplant. No significant differences were observed in %EWL or %WL at 6 and 12 months follow-up between transplant and nontransplant patients. No transplant patients were lost to follow-up at 6 and 12 months. Among nontransplant patients, 36.7% and 35.7% were lost to follow-up at 6 and 12 months, respectively. No postoperative complications were registered in the transplant group. SG did not negatively affect the graft function.

CONCLUSION

Initials results found that there were no significant differences in %EWL or %WL at 6 and 12 months follow-up between transplant and nontransplant patients. There were also no perioperative and postoperative complications among transplant patients after SG.

Weight loss outcomes and complications from bariatric surgery in the super super obese

BACKGROUND

Bariatric surgery has been established as the most effective long-term treatment for morbid obesity.

METHODS

We performed a retrospective review of SSO patients treated at our institute between 2008 and 2013 who underwent a laparoscopic gastric bypass (LGBP) or sleeve gastrectomy (LSG). The primary end point for this study was excess weight loss (EWL) at 1, 3, 6, and 12 months. Secondary end points included procedure length (PL), length of stay (LOS), diabetes management and postoperative complications.

RESULTS

We identified 135 SSO patients who underwent bariatric surgery (93 LGBP, 42 LSG) at our institute from 2008 to 2013 with a median follow-up of 49 months. The incidence of EWL > 30 % for patients in the LGBP group was 3.9, 29.0, 72.2 and 94.6 % at 1, 3, 6 and 12 months, respectively, while the incidence of EWL > 30 % in patients in the LSG group was 4.2, 25.0, 59.1 and 100 % at 1, 3, 6 and 12 months, respectively. PL was 124 ± 49 min for the LGBP group and 98 + 51 min for the LSG group (p < 0.005). LOS was on average 3.0 days (range 1-21) for the LGBP group and 3.4 days (range 1-13) for the LSG group (p = 0.41). Patients experienced a decrease in their hemoglobin A1C level by 10 % for the LGBP group and 9 % for the LSG group at 1 year (p = 0.89). Postoperative complications were seen in 15.1 % of LGBP patients and 4.8 % of LSG patients.

CONCLUSIONS

Bariatric surgery is feasible in the SSO patients with comparable EWL outcomes and postoperative complications to historical non-SSO patients.

Psychopathological similarities and differences between obese patients seeking surgical and non-surgical overweight treatments

PURPOSE

To compare the psychopathological characteristics of obese patients seeking bariatric surgery with those seeking a medical approach.

METHODS

A total of 394 consecutive outpatients seeking bariatric surgery were compared with 683 outpatients seeking a medical treatment. All patients were referred to the same institution.

RESULTS

Obesity surgery patients reported higher body mass index (BMI), objective/subjective binging and more severe general psychopathology, while obesity medical patients showed more eating and body shape concerns. Depression was associated with higher BMI among obesity surgery clinic patients, whereas eating-specific psychopathology was associated with higher BMI and objective binge-eating frequency among obesity medical clinic patients.

CONCLUSIONS

Patients seeking bariatric surgery showed different psychopathological features compared with those seeking a non-surgical approach. This suggests the importance for clinicians to consider that patients could seek bariatric surgery on the basis of the severity of the psychological distress associated with their morbid obesity, rather than criteria only based on clinical indication.

Identifying Patients at Risk for High Medical Costs and Good Candidates for Obesity Intervention

Purpose.

To develop a risk-scoring tool to identify in a base year patients likely to have high medical spending in the subsequent year and to understand the role obesity and obesity reduction may play in mitigating this risk.

Design.

Cross-sectional analysis, using commercial claims and health risk assessment data.

Setting.

United States, 2004–2009.

Subjects.

Panel of 192,750 person-year observations from 116,868 unique working-age employees of large companies.

Measures.

Probability of high medical expenses (80th percentile or above) in the following year; adjusted body mass index (BMI).

Analysis.

Generate risk scores by modeling the likelihood of high next-year expenses as a function of base-year age, sex, medical utilization, comorbidities, and BMI. Estimate the effect of simulated bariatric intervention on patient risk scores.

Results.

Individuals with higher BMI were more likely to be categorized in the very high risk group, in which the average annual medical expense was $8621. A weight-loss intervention transitioning a patient to the next lower obesity class was predicted to reduce this risk by 1.5% to 27.4%—comparable to hypothetically curing a patient of depression or type 2 diabetes.

Conclusion.

A logistic model was used to capture the effect of BMI on the risk of high future medical spending. Weight-loss interventions for obese patients may generate significant savings by reducing this risk.

Short-term morbidity associated with removal and revision of the laparoscopic adjustable gastric band

BACKGROUND

Laparoscopic adjustable gastric band (LAGB) insertion is a commonly performed bariatric procedure with low associated short-term risk. Given that a significant number of patients will require additional revision/removal procedures, overall morbidity may be underestimated. The objective of this study was to define the 30-day morbidity associated with LAGB removal and revision procedures.

METHODS

Patients undergoing revision or removal of LAGB were identified within The American College of Surgeons National Surgery Quality Improvement Program (ACS-NSQIP) participant use file using current procedural terminology and ICD-9 coding. Patients having concurrent procedures were excluded. Primary outcomes included 30-day morbidity. The rate of complications in the removal/revision patients versus primary LAGB insertion was compared. We also analyzed trends over time.

RESULTS

A total of 3,236 patients underwent LAGB removal (n = 1,580), revision (n = 1,111) or port site revision (n = 545) from 2006-2011. The overall 30-day complication rate was 5.6% (95% confidence interval [CI]: 4.8%, 6.4%) and was higher in patients undergoing LAGB removal with a 6.8% (95% CI: 5.6%, 8.1%) adverse event rate (2.5% infectious, 2.3% wound, 2.4% reoperation). A total of 24,438 patients underwent primary LAGB insertion within the data set with a 30-day complication rate of 2.6% (95% CI: 2.4%, 2.8%). Patients undergoing LABG removal had a significantly higher complication rate than those having primary LAGB insertion with an odds ratio of 2.72 (95% CI: 2.18, 3.37). The proportion of LAGB revision/removal compared to primary placement increased annually over the study period (P for trend<.001).

CONCLUSION

The 30-day morbidity associated with LAGB revision is significant and higher than that associated with primary LAGB insertions. The potential need for future procedures and the associated additional morbidity should be considered when evaluating LAGB as a treatment option for morbid obesity.

Efficacy and safety of laparoscopic mini gastric bypass. A systematic review

BACKGROUND

Laparoscopic mini-gastric bypass (LMGB) is a relatively new bariatric procedure; published studies are accumulating in various settings. The objective of this study was to summarize the available evidence about the efficacy and safety of LMGB.

METHODS

A systematic search in the literature was performed , and PubMed and reference lists were scrutinized (end-of-search date: July 15, 2013). For the assessment of the eligible articles, the Newcastle-Ottawa quality assessment scale was used.

RESULTS

Ten eligible studies were included in this study, reporting data on 4,899 patients. According to all included studies, LMGB induced substantial weight and body mass index reduction, as well as substantial excess weight loss. Moreover, resolution or improvement in all major associated medical illnesses and improvement in overall Gastrointestinal Quality of Life Index score were recorded. Major bleeding and anastomotic ulcer were the most commonly reported complications. Readmission rate ranged from 0%- 11%, whereas the rate of revision operations ranged from .3%- 6%. The latter were conducted due to a variety of medical reasons such as inadequate or excessive weight loss, malnutrition, and upper gastrointestinal bleeding. Finally, the mortality rate ranged between 0% and .5% among primary LMGB procedures.

CONCLUSION

LMGB represents an effective bariatric procedure; its safety and minimal postoperative morbidity seem remarkable. Randomized comparative studies seem mandatory for the further evaluation of LMGB.

Prevalence of comorbidities and baseline characteristics of LAP-BAND AP® subjects in the Helping Evaluate Reduction in Obesity (HERO) study

OBJECTIVE

To describe the baseline characteristics in patients who chose placement of a LAP-BAND AP® System (LBAP) and participated in the Helping Evaluate Reduction in Obesity (HERO) Study across regions.

PATIENTS AND METHODS

HERO is a five-year, prospective, multicenter, international study of patients with LBAP placement between July 22, 2009 and January 31, 2011. In addition to baseline and peri-surgery clinical data, seven follow up visits are scheduled at 3, 6 and 12 months, and annually through year five. Data collection included family and medical history, clinical outcomes, laboratory data, health-related quality of life (HRQoL), productivity, healthcare resource utilization, and adverse events.

RESULTS

LBAP were placed in 1106 enrolled patients; 56.6% from the US, 26.3% from Europe, 7.1% from Canada, and 10.0% from Australia. The majority were female (n = 877 (79.3%)) with a mean age of 43 years (s.d. = 11.4) and mean body mass index of 45.1 kg/m(2) (s.d. = 6.9). The most common comorbidities were hypertension (HTN) (overall  = 42.9%) and diabetes (overall 22.2%, with 27% from the US and 14% from Europe). Overall, less than 5% had a history of cardiovascular disease. The prevalence rates of HTN, diabetes and cardiovascular disease were significantly (p<0.001) higher in men than in women across all regions. Overall HRQoL also worsened with increasing BMI.

CONCLUSIONS

The HERO study is the first large, multinational and long-term registry with the LBAP. This study will provide real-world outcomes data on LAGB that will help inform patient choice, clinician treatment strategies, and payer reimbursement decisions.

Bariatric surgery: a safe and effective conduit to cardiac transplantation

BACKGROUND

Obesity and obesity-related co-morbidities, including advanced heart failure, are epidemic. Some of these patients will progress to require cardiac allografts as the only means of long-term survival. Unfortunately, without adequate weight loss, they may never be deemed acceptable transplant candidates. Often surgical weight loss may be the only effective and durable option for these complex patients. The objective of this study was to assess whether bariatric surgery is feasible and safe in patients with severe heart failure, which in turn, after adequate weight loss, would allow these patients to be listed for a heart transplant.

METHODS

Four patients who underwent bariatric procedures, such as laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (SG), for the purpose of attaining adequate weight loss with the goal to improve their eligibility for orthotopic heart transplants are presented.

RESULTS

All patients did well around the time of surgery, and 3 of the 4 progressed to receiving a heart transplant. The fourth patient will be listed pending attaining adequate weight loss.

CONCLUSION

Bariatric surgery may be an important bridge to transplantation for morbidly obese patients with severe heart failure. With the appropriate infrastructure, bariatric surgery is a feasible and effective weight loss method in this population.

Psychiatric aspects of bariatric surgery

While most conventional treatments for individuals with severe obesity have a modest and short lived impact bariatric surgery has been consistently shown to result in long-term marked weight loss and significant improvement in medical comorbidities. Empirical data suggest a high prevalence of mental disorders among bariatric surgery candidates. This article reviews specific areas of psychopathology, problems in using psychopharmacological medications post-surgery, body contouring, and recommendations for pre and post-surgery care. Available research indicates a decrease in psychiatric symptoms post-surgery. However, in some patients the improvement appears to erode over time. Therefore, bariatric surgery patients should be monitored not only before surgery but also following surgery and referred for mental health treatment if problems develop.

Location and number of sutures placed for hiatal hernia repair during laparoscopic adjustable gastric banding: does it matter?

BACKGROUND

It has been demonstrated that hiatal hernia repair (HHR) during laparoscopic adjustable gastric banding (LAGB) decreases the rate of reoperation. However, the technical aspects (location and number of sutures) are not standardized. It is unknown whether such technical details are associated with differing rates of reoperation for band-related problems.

METHODS

A retrospective analysis was performed from a single institution, including 2,301 patients undergoing LAGB with HHR from July 1, 2007 to December 31, 2011. Independent variables were number and location of sutures. Data collected included demographics, operating room (OR) time, length of stay (LOS), follow-up time, postoperative BMI/%EWL, and rates of readmission/reoperation. Statistical analyses included ANOVA and Chi squared tests. Kaplan-Meier, log-rank, and Cox regression tests were used for follow-up data and reoperation rates, in order to account for differential length of follow-up and confounding variables.

RESULTS

There was no difference in length of follow-up among all groups. The majority of patients had one suture (range 1-6; 55 %). Patients with fewer sutures had shorter OR time (1 suture 45 min vs. 4+ sutures 56 min, p < 0.0001). LOS, 30-day readmission, band-related reoperation, and postop BMI/%EWL were not statistically significant. Anterior suture placement (vs. posterior vs. both) was most common (61 %). OR time was shorter in those with anterior suture (41 min vs. posterior 56 min vs. both 59 min, p < 0.0001). Patients with posterior suture had a longer LOS (84 % 1 day vs. anterior 74 % 1 day vs. both 74 % 1 day, p < 0.0001). There was no difference in 30-day readmission, band-related reoperation, and postoperative BMI/%EWL.

CONCLUSIONS

Patients with fewer or anterior sutures have shorter OR times. However, 30-day readmission, band-related reoperation, and postoperative weight loss were unaffected by number or location of suture. The technical aspects of HHR did not appear to be associated with readmission or reoperation, and therefore a standardized approach may not be necessary.

Laparoscopic sleeve gastrectomy compared with other bariatric surgical procedures: a systematic review of randomized trials

BACKGROUND

The evidence regarding the effectiveness and safety of laparoscopic sleeve gastrectomy (LSG) has been mostly based on the data derived from nonrandomized studies. The objective of this study was to evaluate the outcomes of LSG and to present an up-to-date review of the available evidence based on the recent publications of new randomized, controlled trials (RCTs).

METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched until November 2012 for RCTs on LSG.

RESULTS

Fifteen RCTs, comprising a total of 1191 patients, of whom 795 had undergone LSG, were included. No patient required conversion to open surgery for LSG, laparoscopic gastric bypass (LGB), or laparoscopic adjustable gastric banding (LAGB) procedures. There were no deaths, and the complication rate was 12.1% (range 10%-13.2%) in the LSG group versus 20.9% (range 10%-26.4%) in the LGB group, and 0% in the LAGB group (only 1 RCT). The complications included leakage, bleeding, stricture, and reoperation that occurred with rates of .9%, 3.3%, 0%, and 2.1%, respectively, in the LSG group and rates of 0%, 5%, 0%, and 4%, respectively, in the LGB group. The average operating time in the LSG group was 106.5 minutes versus 132.3 minutes in the LGB group. The percentage of excess weight loss (%EWL) ranged from 49% to 81% in the LSG group, from 62.1% to 94.4% in the LGB group, and from 28.7% to 48% in the LAGB group, with a follow-up ranging from 6 months to 3 years. The type 2 diabetes mellitus (T2DM) remission rate ranged from 26.5% to 75% in the LSG group and from 42% to 93% in the LGB group.

CONCLUSIONS

LSG is a well-tolerated, feasible procedure with a relatively short operating time. Its effectiveness in terms of weight loss is confirmed for short-term follow-up (≤ 3 years). The role of LSG in the treatment of T2DM requires further investigation.

Improvements in hippocampal-dependent memory and microglial infiltration with calorie restriction and gastric bypass surgery, but not with vertical sleeve gastrectomy

BACKGROUND

Much recent evidence suggest that obesity and related comorbidities contribute to cognitive decline, including the development of non age-related dementia and Alzheimer's disease. Obesity is a serious threat to public health, and few treatments offer proven long-term weight loss. In fact, bariatric surgery remains the most effective long-term therapy to reduce weight and alleviate other aspects of the metabolic syndrome (MetS). Unlike the demonstrated benefits of caloric restriction to prevent weight gain, few if any studies have compared various means of weight loss on central nervous system function and hippocampal-dependent cognitive processes.

DESIGN AND RESULTS

Our studies comprise the first direct comparisons of caloric restriction to two bariatric surgeries (Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG)) on cognitive function. Weight loss following caloric restriction, RYGB and VSG was associated with generalized improvements in metabolic health and hippocampal-dependent learning, as measured in the radial arm maze and spontaneous alternation tests. However, VSG-treated rats exhibited deficits on spatial learning tasks in the Morris water maze. In addition, whereas VSG animals had elevated hippocampal inflammation, comparable to that of obese controls, RYGB and calorie-restricted (pair-fed, PF) controls exhibited an amelioration of inflammation, as measured by the microglial protein ionized calcium binding adaptor molecule 1 (IBA1). We also assessed whether GHR (ghrelin) replacement would attenuate hippocampal inflammation in VSG, as post-surgical GHR levels are significantly reduced in VSG relative to RYGB and PF rats. However, GHR treatment did not attenuate the hippocampal inflammation.

CONCLUSION

Although VSG was comparably effective at reducing body weight and improving glucose regulation as RYGB, VSG did not appear to confer an equal benefit on cognitive function and markers of inflammation.

Prolonged diet induced obesity has minimal effects towards brain pathology in mouse model of cerebral amyloid angiopathy: implications for studying obesity-brain interactions in mice

Cerebral amyloid angiopathy (CAA) occurs in nearly every individual with Alzheimer's disease (AD) and Down's syndrome, and is the second largest cause of intracerebral hemorrhage. Mouse models of CAA have demonstrated evidence for increased gliosis contributing to CAA pathology. Nearly two thirds of Americans are overweight or obese, with little known about the effects of obesity on the brain, although increasingly the vasculature appears to be a principle target of obesity effects on the brain. In the current study we describe for the first time whether diet induced obesity (DIO) modulates glial reactivity, amyloid levels, and inflammatory signaling in a mouse model of CAA. In these studies we identify surprisingly that DIO does not significantly increase Aβ levels, astrocyte (GFAP) or microglial (IBA-1) gliosis in the CAA mice. However, within the hippocampal gyri a localized increase in reactive microglia were increased in the CA1 and stratum oriens relative to CAA mice on a control diet. DIO was observed to selectively increase IL-6 in CAA mice, with IL-1β and TNF-α not increased in CAA mice in response to DIO. Taken together, these data show that prolonged DIO has only modest effects towards Aβ in a mouse model of CAA, but appears to elevate some localized microglial reactivity within the hippocampal gyri and selective markers of inflammatory signaling. These data are consistent with the majority of the existing literature in other models of Aβ pathology, which surprisingly show a mixed profile of DIO effects towards pathological processes in mouse models of neurodegenerative disease. The importance for considering the potential impact of ceiling effects in pathology within mouse models of Aβ pathogenesis, and the current experimental limitations for DIO in mice to fully replicate metabolic dysfunction present in human obesity, are discussed. This article is part of a Special Issue entitled: Animal Models of Disease.