Association of changes in mental health with weight loss during intensive lifestyle intervention: does the timing matter?

Effect of very low-carbohydrate high-fat diet and high-intensity interval training on mental health-related indicators in individuals with excessive weight or obesity

Very low carbohydrate high fat (VLCHF) diet and high-intensity interval training (HIIT) are widely utilized for weight reduction and cardiorespiratory fitness improvement, respectively. To assess the acceptability of these approaches, it is essential to examine mental health-related indicators. This secondary analysis of a randomized controlled trial investigated the isolated and synergistic effects of VLCHF and HIIT on mental health-related indicators in individuals with excessive weight or obesity. Sixty-eight participants (age = 42 ± 10.2; 20-60 years; BMI = 29.8 ± 3.7) were analysed across four groups: HIIT (n = 15, 4 males, 11 females), VLCHF (n = 19, 4 males, 15 females), VLCHF + HIIT (n = 19, 4 males, 15 females), and control (n = 15, 4 males, 11 females). The 12-week intervention, involved VLCHF diet or HIIT sessions, depending on group affiliation and completing online questionnaires via Qualtrics software before and after the intervention. The questionnaires included the 12-item Short Form Survey (SF-12) for mental (MHS) and physical health scores (PHS), the Satisfaction with Life Scale (SWLS), and the Perceived Stress Scale (PSS). Using the Kruskal-Wallis test, we found no significant differences in mental health-related indicators between groups after 12 weeks, except for SWLS (p = 0.031; ES = 0.133; medium), which improved significantly in the VLCHF + HIIT group compared to the HIIT group. Our findings indicate that HIIT and VLCHF, alone or combined, do not significantly affect mental health-related indicators.

A predictive model for medium-term weight loss response in people with type 2 diabetes engaging in behavioural weight management interventions

AIMS

To develop and evaluate prediction models for medium-term weight loss response in behavioural weight management programmes.

MATERIALS AND METHODS

We conducted three longitudinal analyses using the Action for HEalth in Diabetes (LookAHEAD) trial, Weight loss Referrals for Adults in Primary care (WRAP) trial, and routine data from the National Health Service Greater Glasgow and Clyde Weight Management Service (NHS-GGCWMS). We investigated predictors of medium-term weight loss (>5% body weight) over 3 years in NHS-GGCWMS and, separately, predictors of weight loss response in LookAHEAD over 4 years. We validated predictors in both studies using WRAP over 5 years. Predictors of interest included demographic and clinical variables, early weight change in-programme (first 4 weeks) and overall in-programme weight change.

RESULTS

In LookAHEAD and WRAP the only baseline variables consistently associated with weight loss response were female sex and older age. Of 1152 participants in NHS-GGCWMS (mean age 57.8 years, 60% female, type 2 diabetes diagnosed for a median of 5.3 years), 139 lost weight over 3 years (12%). The strongest predictor of weight loss response was early weight change (odds ratio 2.22, 95% confidence interval 1.92-2.56) per 1% weight loss. Losing 0.5% weight in the first 4 weeks predicted medium-term weight loss (sensitivity 89.9%, specificity 49.5%, negative predictive value 97.3%). Overall in-programme weight change was also associated with weight loss response over 3 years in NHS-GGCWMS and over 5 years in WRAP.

CONCLUSIONS

Not attaining a weight loss threshold of 0.5% early in weight management programmes may identify participants who would benefit from alternative interventions.

Hybrid Evaluation of a Lifestyle Change Program to Prevent the Development of Type 2 Diabetes Among Individuals With Prediabetes: Intended and Observed Changes in Intervening Mechanisms

BACKGROUND

Lifestyle interventions can prevent type 2 diabetes (T2D) by successfully inducing behavioral changes (eg, avoiding physical inactivity and sedentariness, increasing physical activity and/or healthy eating) that reduce body weight and normalize metabolic levels (eg, HbA1c). For interventions to be successful, it is important to influence "behavioral mechanisms" such as self-efficacy, which motivate behavioral changes. Theory-based expectations of how self-efficacy, chronic stress, and mood changed over time were investigated through a group-based behavior change intervention (PREMIT). At 8 intervention sites, PREMIT was offered by trained primary care providers in 18 group-sessions over a period of 36 months, divided into 4 intervention phases. Adherence to the intervention protocol was assessed.

METHOD

Participants (n = 962) with overweight and prediabetes who had achieved ≥8% weight loss during a diet reduction period and completed the intervention were categorized into 3 groups: infrequent, frequent, or very frequent group sessions attendance. The interactions between participation in the group sessions and changes in self-efficacy, stress, and mood were multivariate tested. Intervention sites were regularly asked where and how they deviated from the intervention protocol.

RESULTS

There was no increase in the participants' self-efficacy in any group. However, the level of self-efficacy was maintained among those who attended the group sessions frequently, while it decreased in the other groups. For all participants, chronic stress and the frequency of attending group sessions were inversely related. Significant differences in mood were found for all groups. All intervention centers reported specific activities, additional to intervention protocol, to promote participation in the group sessions.

CONCLUSIONS

The results suggest that the behavioral changes sought by trained primary care providers are related to attendance frequency and follow complex trajectories. The findings also suggest that group-based interventions in naturalistic primary care settings aimed at preventing T2D require formats and strategies that encourage participants to attend group sessions regularly.

Health-Related Social Control and Perceived Stress Among High-Risk Latina Mothers with Type 2 Diabetes and Their At-Risk Adult Daughters

BACKGROUND

Diabetes-related multi-morbidity and cultural factors place Latinas with diabetes at increased risk for stress, which can threaten illness management. Families provide an ideal focus for interventions that seek to strengthen interpersonal resources for illness management and, in the process, to reduce stress. The current study sought to examine whether participating in a dyadic intervention was associated with reduced perceived stress and, furthermore, whether this association was mediated by persuasion and pressure, two forms of health-related social control.

METHOD

Latina mothers with diabetes and their at-risk adult daughters participated in either (1) a dyadic intervention that encouraged constructive collaboration to improve health behaviors and reduce stress, or (2) a usual-care minimal control condition. Actor-partner interdependence model analysis was used to estimate the effect of the intervention on dyads' perceived stress, and mother-daughter ratings of health-related social control as potential mediators.

RESULTS

Results revealed that participating in the intervention was associated with significantly reduced perceived stress for daughters, but not for mothers (β =  - 3.00, p = 0.02; β =  - 0.57, p = 0.67, respectively). Analyses also indicated that the association between the intervention and perceived stress was mediated by persuasion, such that mothers' who experienced more health-related persuasion exhibited significantly less post-intervention perceived stress (indirect effect =  - 1.52, 95% CI = [- 3.12, - 0.39]). Pressure exerted by others, however, did not evidence a mediating mechanism for either mothers or daughters.

CONCLUSION

These findings buttress existing research suggesting that persuasion, or others' attempts to increase participants' healthy behaviors in an uncritical way, may be a driving force in reducing perceived stress levels.

Mental health diagnosis attenuates weight loss among older adults in a digital diabetes prevention program

Objective

Diabetes Prevention Programs (DPP) are effective at reducing diabetes incidence via clinically significant weight loss. Co-morbid mental health condition(s) may reduce the effect of DPP administered in-person and telephonically but this has not been assessed for digital DPP. This report examines the moderating effect of mental health diagnosis on weight change among individuals who enrolled in digital DPP (enrollees) at 12 and 24 months.

Methods

Secondary analysis of prospective, electronic health record data from a study of digital DPP among adults (N = 3904) aged 65-75 with prediabetes (HbA1c 5.7%-6.4%) and obesity (BMI ≥30 kg/m2).

Results

Mental health diagnosis only moderated the effect of digital DPP on weight change during the first 7 months (p = 0.003) and the effect attenuated at 12 and 24 months. Results were unchanged after adjusting for psychotropic medication use. Among those without a mental health diagnosis, digital DPP enrollees lost more weight than non-enrollees: -4.17 kg (95% CI, -5.22 to -3.13) at 12 months and -1.88 kg (95% CI, -3.00 to -0.76) at 24 months, whereas among individuals with a mental health diagnosis, there was no difference in weight loss between enrollees and non-enrollees at 12 and 24 months (-1.25 kg [95% CI, -2.77 to 0.26] and 0.02 kg [95% CI, -1.69-1.73], respectively).

Conclusions

Digital DPP appears less effective for weight loss among individuals with a mental health condition, similar to prior findings for in-person and telephonic modalities. Findings suggest a need for tailoring DPP to address mental health conditions.

Long-term impact of a behavioral weight management program on depression and anxiety symptoms: 5-year follow-up of the WRAP trial

OBJECTIVE

Behavioral weight management programs may support short-term mental health; however, limited evidence reports the long-term impacts. This study investigated the impact of behavioral weight management programs on depression and anxiety symptoms at 5 years from baseline.

METHODS

The Weight loss Referrals for Adults in Primary care (WRAP) trial randomized 1267 adults with BMI ≥ 28 kg/m² to a brief intervention (BI) or commercial behavioral weight management program (WW; formerly Weight Watchers) for 12 or 52 weeks (CP12 and CP52, respectively). Linear regression was used to separately compare 5-year changes in depression and anxiety symptoms (by Hospital Anxiety and Depression Scale) between randomized groups, adjusting for baseline depression/anxiety symptoms, gender, and research center.

RESULTS

A total of 643 (51%) participants attended the 5-year study follow-up visit. There was no evidence of a difference between the randomized groups for 5-year changes in depression (BI: -0.08 ± 3.29; CP12: 0.02 ± 3.01; CP52: -0.09 ± 3.41) or anxiety (BI: 0.16 ± 3.50; CP12: -0.05 ± 3.55; CP52: -0.66 ± 3.59) symptoms.

CONCLUSIONS

This study found no evidence that commercial weight management programs differed in 5-year changes in depression and anxiety symptoms, compared with BI. These are average effects; some individuals experienced increases or decreases in symptoms. Future research should investigate who is at most risk of mental health declines and investigate how to support them. Future trials should transparently report long-term mental health outcomes to strengthen understanding.

Changes in Health-Promoting Behaviors and Their Association with Weight Loss, Retention, and Engagement on a Digital Program: Prospective Study

Health-promoting lifestyle behaviors (e.g., as measured by the HPLP-II) are associated with reductions in lifestyle disease mortality, as well as improved well-being, mental health, and quality of life. However, it is unclear how a weight-management program relates to a broad range of these behaviors (i.e., health responsibility, physical activity, nutrition, spiritual growth, interpersonal relations, and stress management), especially a fully digital program on which individuals have to self-manage their own behaviors in their daily lives (with assistance from a virtual human coach). In the context of a digital setting, this study examined the changes in health-promoting behaviors over 12 months, as well as the associations between health-promoting behaviors and weight loss, retention, and engagement, among participants who self-enrolled in a mobile CBT-based nutritionally focused behavior change weight management program (n = 242). Participants lost a statistically significant amount of weight (M = 6.7 kg; SD = 12.7 kg; t(80) = 9.26, p < 0.001) and reported significantly improved overall health-promoting lifestyle behaviors (i.e., HPLP-II summary scores), as well as, specifically, health responsibility, physical activity, nutrition, spiritual growth, stress management, and interpersonal relations behaviors from baseline to 6 months and from 6 months to 12 months (all ps < 0.008). Health-promoting behaviors at 6 months (i.e., learned health-promoting behaviors) compared to baseline were better predictors of retention and program engagement. A fully digital, mobile weight management intervention can improve HPLP-II scores, which, in turn, has implications for improved retention, program engagement, and better understanding the comprehensive effects of weight management programs, particularly in a digital setting.

A narrative review of biopsychosocial factors which impact overweight and obesity for individuals with acquired brain injury

Primary Objective: To discuss the biopsychosocial factors that affect being overweight or obese after acquired brain injury (ABI)Research Design: Narrative reviewMethods and Procedures: Based on the biopsychosocial model, we discuss the unique injury-specific factors that can affect bring overweight or obese among individuals with ABI including: (1) biological, (2) psychological and (3) social/ecological factors.Main Outcomes and Results: Injury-specific factors that impact being overweight or obese following ABI include endocrine dysfunction, pain, bowel and bladder incontinence, balance problems and motor impairment, medications, sleep quality and fatigue, alcohol and tobacco use, psychological disorders and symptoms, cognitive changes, social support, isolation, participation, transportation, independence, and knowledge. These factors may also compound general factors impacting weight management, making it difficult for individuals with ABI to maintain a healthy lifestyle.Conclusions: It is important to recognize the biopsychosocial factors that impact weight-loss and lifestyle change after ABI so that interventions can be tailored to meet individuals' unique needs. Empirical research is needed to better understand how biopsychosocial factors interact and impact overweight/ obesity after ABI.

The effectiveness of an online interdisciplinary intervention for mental health promotion: a randomized controlled trial

BACKGROUND

There is an urgent need for efficacious interventions to combat the global mental health crisis, and mental health promotion and primary prevention approaches are paramount. The aim of this study is to examine whether an online interdisciplinary intervention that incorporates evidence-based strategies from the disciplines of Lifestyle Medicine and Positive Psychology improves measures of mental health and emotional wellness.

METHODS

A randomized controlled trial with a wait-list control (N = 425, aged 46.97 ± 14.5, 69.9% females) was conducted in Australia and New Zealand. The intervention group participated in a 10-week online interdisciplinary intervention. Primary outcome measures of mental health and emotional wellness were taken at baseline (Week 1), post-intervention (Week 12), and 12 weeks post-intervention (Week 24). The wait-list control completed the same assessments.

RESULTS

General Linear Modelling analyses indicated that the intervention group experienced significantly greater improvements than the wait-list control group over time in all outcome measures: mental health (F(319) = 7.326, p = 0.007) and vitality (F(319) = 9.445, p = 0.002) subscales of the Short Form Survey (SF-36); depression (F(319) = 7.841, p = 0.005), anxiety (F(319) = 4.440, p = 0.36) and stress (F(319) = 12.494, p < 0.001) scales of the Depression, Anxiety and Stress Scale (DASS-21); and life satisfaction (F(319) = 8.731, p = 0.003) as measured by the Satisfaction With Life Scale. Within the intervention group, significant improvements were observed from Week 1 to 12 in all outcome measures: mental health (10%, t(167) = - 6.423), p < 0.001, dz = 0.50), vitality (22%, t(167) = - 7.043, p < 0.001, dz = 0.54), depression (- 41%, t(167) = 6.189, p < 0.001, dz = 0.48), anxiety (- 38%, t(167) = 5.030, p < 0.001, dz = 0.39), stress (- 31%, t(167) = 6.702, p < 0.001, dz = 0.52) and life satisfaction (8%, t(167) = - 6.199, p < 0.001, dz = 0.48). Improvements in the outcome measures remained significant in the intervention group at 12 weeks post-intervention.

CONCLUSION

The online interdisciplinary intervention improved measures of mental health and emotional wellness suggesting that such interventions may be useful for mental health promotion and prevention. Trial registration The Australian New Zealand Clinical Trials Registry. ACTRN12619000993190. Registered on 12 July 2019 (Retrospectively registered). The ANZCTRN is part of the WHO Primary Registries.

The impact of adult behavioural weight management interventions on mental health: A systematic review and meta-analysis

There is good evidence that behavioural weight management interventions improve physical health; however, the impact on mental health remains unclear. We evaluated the impact of behavioural weight management interventions on mental health-related outcomes in adults with overweight or obesity at intervention-end and 12 months from baseline. Eligible studies were randomized controlled trials (RCTs) or cluster RCTs of adult behavioural weight loss interventions reporting affect, anxiety, binge eating, body image, depression, emotional eating, quality of life, self-esteem and stress. We searched seven databases from inception to 7 May 2019 and included 43 articles reporting 42 RCTs. Eighteen studies were deemed to be at high risk of bias. We conducted random-effects meta-analyses, stratified analyses and meta-regression using Stata. Interventions generated greater improvements than comparators for depression, mental health-related quality of life and self-efficacy at intervention-end and 12 months from baseline. There was no difference between groups for anxiety, overall quality of life, self-esteem or stress at intervention-end. There was insufficient evidence to assess the impact on anxiety, binge eating, body image, emotional eating, affect, life satisfaction, self-esteem or stress at intervention-end and/or 12 months from baseline. Although evidence suggests that interventions benefit some aspects of mental health, high-quality, transparently reported RCTs measuring a range of mental health outcomes over longer durations are required to strengthen the evidence base.

Diabesity and Perinatal Mental Health: Evidence-based Recommendations for Screening and Intervention

Perinatal mental illness, obesity, and diabetes mellitus are common complications of the perinatal period that are becoming ever more prevalent and frequently co-occur. This review seeks to examine the prevalence of comorbid obesity/diabetes (termed "diabesity") and mental illness in the perinatal period and current understandings of the psychosocial and pathophysiological relationships between these diseases. We will present current guidelines for screening and make recommendations for adaptations of mental health treatment in patients with this comorbidity. Finally, we present future directions for research and clinical intervention.

Changes in body mass index and risk of adolescent psychopathology: a longitudinal cohort study

BACKGROUND.

Abnormal body mass index (BMI) has been associated with development of psychopathology. This association in children is well documented, for both overweight and underweight children. However, the association between change in BMI and the development of psychopathology has been less investigated.

AIM.

To investigate the association between change in BMI between childhood and adolescence and psychopathology in adolescence.

METHODS.

Data from the Growing Up in Ireland cohort were used. We investigated the '98 cohort (also known as the child cohort) at age 9/13. BMI, defined using internationally recognised definitions as underweight, healthy or overweight, was used as the exposure, and abnormal Strength and Difficulties Questionnaire scores were used as the outcome. Logistic regression was undertaken for the analysis. All analyses were adjusted for confounders.

RESULTS.

A change to overweight from healthy BMI was significantly associated with increased risk of psychopathology (adjusted OR 1.66; 95% CI 1.19-2.32). Both change from underweight to healthy (adjusted OR 0.12; 95% CI 0.03-0.43) or from overweight to healthy (adjusted OR 0.47; 95% CI 0.79-0.8) was associated with a significantly reduced risk of developing psychopathology.

DISCUSSION.

As a child's BMI returns to within the healthy range, their risk of adolescent psychopathology is reduced. Interventions to restore healthy BMI, in both underweight and overweight, children may reduce their risk of adolescent psychopathology.

Impact of adult weight management interventions on mental health: a systematic review and meta-analysis protocol

INTRODUCTION

The effects of interventions targeting weight loss on physical health are well described, yet the evidence for mental health is less clear. It is essential to better understand the impact of weight management interventions on mental health to optimise care and minimise risk of harm. We will assess the effect of behavioural weight management interventions on mental health in adults with overweight and obesity.

METHODS AND ANALYSIS

The systematic review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. We will include behavioural weight management interventions with a diet and/or physical activity component focusing on weight loss for adults with a body mass index ≥25 kg/m2. Randomised controlled trials (RCTs) and cluster RCTs will be the only eligible study designs. Outcomes of interest will be related to mental health. The following databases were searched from inception to 07 May 2019: MEDLINE, Embase, Cochrane database (CENTRAL), PsycINFO, ASSIA, AMED and CINAHL. The search strategy was based on four concepts: (1) adults, defined as ≥18 years, with overweight/obesity, defined as BMI ≥25kg/m², (2) weight management interventions, (3) mental health outcomes and (4) study design. The search was restricted to English-language published papers, with no other restrictions applied. Two stage screening for eligibility will be completed by two independent reviewers, with two independent reviewers completing data extraction and risk of bias assessment. Data permitting, a random-effects meta-analysis of outcomes, subgroup analyses and meta-regression will be conducted. If not appropriate, narrative synthesis and 'levels of evidence' assessment will be completed.

ETHICS AND DISSEMINATION

Ethical approval is not required as primary data will not be collected. The completed systematic review will be disseminated in a peer-reviewed journal, at conferences and contribute towards the lead author's PhD thesis.

PROSPERO REGISTRATION NUMBER

CRD42019131659.

Metformin for prevention or delay of type 2 diabetes mellitus and its associated complications in persons at increased risk for the development of type 2 diabetes mellitus

BACKGROUND

The projected rise in the incidence of type 2 diabetes mellitus (T2DM) could develop into a substantial health problem worldwide. Whether metformin can prevent or delay T2DM and its complications in people with increased risk of developing T2DM is unknown.

OBJECTIVES

To assess the effects of metformin for the prevention or delay of T2DM and its associated complications in persons at increased risk for the T2DM.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Scopus, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform and the reference lists of systematic reviews, articles and health technology assessment reports. We asked investigators of the included trials for information about additional trials. The date of the last search of all databases was March 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with a duration of one year or more comparing metformin with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or standard care in people with impaired glucose tolerance, impaired fasting glucose, moderately elevated glycosylated haemoglobin A1c (HbA1c) or combinations of these.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles and records, assessed risk of bias and extracted outcome data independently. We used a random-effects model to perform meta-analysis and calculated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 20 RCTs randomising 6774 participants. One trial contributed 48% of all participants. The duration of intervention in the trials varied from one to five years. We judged none of the trials to be at low risk of bias in all 'Risk of bias' domains. Our main outcome measures were all-cause mortality, incidence of T2DM, serious adverse events (SAEs), cardiovascular mortality, non-fatal myocardial infarction or stroke, health-related quality of life and socioeconomic effects.The following comparisons mostly reported only a fraction of our main outcome set. Fifteen RCTs compared metformin with diet and exercise with or without placebo: all-cause mortality was 7/1353 versus 7/1480 (RR 1.11, 95% CI 0.41 to 3.01; P = 0.83; 2833 participants, 5 trials; very low-quality evidence); incidence of T2DM was 324/1751 versus 529/1881 participants (RR 0.50, 95% CI 0.38 to 0.65; P < 0.001; 3632 participants, 12 trials; moderate-quality evidence); the reporting of SAEs was insufficient and diverse and meta-analysis could not be performed (reported numbers were 4/118 versus 2/191; 309 participants; 4 trials; very low-quality evidence); cardiovascular mortality was 1/1073 versus 4/1082 (2416 participants; 2 trials; very low-quality evidence). One trial reported no clear difference in health-related quality of life after 3.2 years of follow-up (very low-quality evidence). Two trials estimated the direct medical costs (DMC) per participant for metformin varying from $220 to $1177 versus $61 to $184 in the comparator group (2416 participants; 2 trials; low-quality evidence). Eight RCTs compared metformin with intensive diet and exercise: all-cause mortality was 7/1278 versus 4/1272 (RR 1.61, 95% CI 0.50 to 5.23; P = 0.43; 2550 participants, 4 trials; very low-quality evidence); incidence of T2DM was 304/1455 versus 251/1505 (RR 0.80, 95% CI 0.47 to 1.37; P = 0.42; 2960 participants, 7 trials; moderate-quality evidence); the reporting of SAEs was sparse and meta-analysis could not be performed (one trial reported 1/44 in the metformin group versus 0/36 in the intensive exercise and diet group with SAEs). One trial reported that 1/1073 participants in the metformin group compared with 2/1079 participants in the comparator group died from cardiovascular causes. One trial reported that no participant died due to cardiovascular causes (very low-quality evidence). Two trials estimated the DMC per participant for metformin varying from $220 to $1177 versus $225 to $3628 in the comparator group (2400 participants; 2 trials; very low-quality evidence). Three RCTs compared metformin with acarbose: all-cause mortality was 1/44 versus 0/45 (89 participants; 1 trial; very low-quality evidence); incidence of T2DM was 12/147 versus 7/148 (RR 1.72, 95% CI 0.72 to 4.14; P = 0.22; 295 participants; 3 trials; low-quality evidence); SAEs were 1/51 versus 2/50 (101 participants; 1 trial; very low-quality evidence). Three RCTs compared metformin with thiazolidinediones: incidence of T2DM was 9/161 versus 9/159 (RR 0.99, 95% CI 0.41 to 2.40; P = 0.98; 320 participants; 3 trials; low-quality evidence). SAEs were 3/45 versus 0/41 (86 participants; 1 trial; very low-quality evidence). Three RCTs compared metformin plus intensive diet and exercise with identical intensive diet and exercise: all-cause mortality was 1/121 versus 1/120 participants (450 participants; 2 trials; very low-quality evidence); incidence of T2DM was 48/166 versus 53/166 (RR 0.55, 95% CI 0.10 to 2.92; P = 0.49; 332 participants; 2 trials; very low-quality evidence). One trial estimated the DMC of metformin plus intensive diet and exercise to be $270 per participant compared with $225 in the comparator group (94 participants; 1 trial; very-low quality evidence). One trial in 45 participants compared metformin with a sulphonylurea. The trial reported no patient-important outcomes. For all comparisons there were no data on non-fatal myocardial infarction, non-fatal stroke or microvascular complications. We identified 11 ongoing trials which potentially could provide data of interest for this review. These trials will add a total of 17,853 participants in future updates of this review.

AUTHORS' CONCLUSIONS

Metformin compared with placebo or diet and exercise reduced or delayed the risk of T2DM in people at increased risk for the development of T2DM (moderate-quality evidence). However, metformin compared to intensive diet and exercise did not reduce or delay the risk of T2DM (moderate-quality evidence). Likewise, the combination of metformin and intensive diet and exercise compared to intensive diet and exercise only neither showed an advantage or disadvantage regarding the development of T2DM (very low-quality evidence). Data on patient-important outcomes such as mortality, macrovascular and microvascular diabetic complications and health-related quality of life were sparse or missing.

Predictors of weight regain after sleeve gastrectomy: an integrative review

BACKGROUND

Sleeve gastrectomy (SG) is one of the most effective treatments for severe obesity, but weight regain after surgery is a challenging issue. The mechanism of postoperative weight relapse is barely understood because of the lack of long-term data.

OBJECTIVES

To review and synthesize current evidence related to factors that contribute to weight regain after SG.

METHODS

Whittemore and Knafl's integrative method guided the research. The databases PubMed, EMBASE, and CINAHL, as well as 2 selected journals, were searched through October 2018 to gather English-language journal articles on the potential predictors of post-SG weight regain among adult populations. Only articles with sample size ≥10 were included. A narrative synthesis was used to analyze the 17 studies included in the review.

RESULTS

In recent years there has been an upward trend in the published reports of SG on longer-term outcomes. After a review of 6863 records, 17 eligible studies were identified, reporting various definitions of weight regain and 3 main categories of predictors: surgical/anatomic factors, hormonal/metabolic imbalance, and behavioral/mood factors. The 17 studies used quantitative (n = 16) and qualitative methods (n = 1).

CONCLUSION

There is a dearth of available literature addressing predictors of weight regain after SG, and the inconsistency in the definition of regain limited the comparability between studies. Besides the surgical/anatomic factors that have been reported as significant predictors, other modifiable factors such as behavioral and psychosocial determinants need to be further investigated.