Effectiveness of lifestyle-based weight loss interventions for adults with type 2 diabetes: a systematic review and meta-analysis

Structured lifestyle intervention based on a trans-cultural diabetes-specific nutrition algorithm (tDNA) in individuals with type 2 diabetes: a randomized controlled trial

OBJECTIVE

Trans-cultural diabetes nutrition algorithm (tDNA) was created by international task force and culturally customized for Malaysian population. This study was designed to evaluate its effectiveness versus usual diabetes care in primary care settings.

RESEARCH DESIGN AND METHODS

We randomized 230 patients with overweight/obesity, type 2 diabetes, and glycated hemoglobin (A1c) 7%-11% to receive usual care (UC) or UC with tDNA for 6 months. The tDNA intervention consisted of structured low-calorie meal plan, diabetes-specific meal replacements, and increased physical activity. Participants were counseled either through motivational interviewing (tDNA-MI) or conventional counseling (tDNA-CC). The UC group received standard dietary and exercise advice through conventional counseling. All patients were followed for another 6 months after intervention.

RESULTS

At 6 months, A1c decreased significantly in tDNA-MI (-1.1±0.1%, p<0.001) and tDNA-CC (-0.5±0.1%, p=0.001) but not in UC (-0.2±0.1%, p=NS). Body weight decreased significantly in tDNA-MI (-6.9±1.3 kg, p<0.001) and tDNA-CC (-5.3±1.2 kg, p<0.001) but not in UC (-0.8±0.5 kg, p=NS). tDNA-MI patients had significantly lower fasting plasma glucose (tDNA-MI: -1.1±0.3 mmol/L, p<0.001; tDNA-CC: -0.6±0.3 mmol/L, p=NS; UC: 0.1±0.3 mmol/L, p=NS) and systolic blood pressure (tDNA-MI: -9±2 mm Hg, p<0.001; tDNA-CC: -9±2 mm Hg, p=0.001; UC: -1±2 mm Hg, p=NS). At 1 year, tDNA-MI patients maintained significant reduction in A1c (tDNA-MI: -0.5±0.2%, p=0.006 vs tDNA-CC: 0.1±0.2%, p=NS and UC: 0.02±0.01%, p=NS) and significant weight loss (tDNA-MI: -5.8±1.3 kg, p<0.001 vs tDNA-CC: -3.3±1.2 kg, p=NS and UC: 0.5±0.6 kg, p=NS).

CONCLUSIONS

Structured lifestyle intervention through culturally adapted nutrition algorithm and motivational interviewing significantly improved diabetes control and body weight in primary care setting.

Effect of weight reduction on glycated haemoglobin in weight loss trials in patients with type 2 diabetes

AIM

To quantify the effect of weight loss on glycated haemoglobin (HbA1c) at group level, based on data from published weight loss trials in overweight and obese patients with type 2 diabetes (T2D).

METHODS

A systematic literature search in MEDLINE, EMBASE and Cochrane CENTRAL (January 1990 through December 2012) was conducted to identify prospective trials of energy-reduced diets, obesity drugs or bariatric surgery in adult, overweight and obese patients with T2D. Based on clinical data with follow-up from 3 to 24 months, a linear model was developed to describe the effect of weight reduction on HbA1c.

RESULTS

The literature search identified 58 eligible articles consisting of 124 treatment groups and 17 204 subjects, yielding a total of 250 data points with concurrent mean changes from baseline in weight and HbA1c. The model-based analyses indicated a linear relationship between weight loss and HbA1c reduction, with an estimated mean HbA1c reduction of 0.1 percentage points for each 1 kg of reduced body weight for the overall population. Baseline HbA1c was a significant covariate for the relationship between weight loss and HbA1c: high HbA1c at baseline was associated with a greater reduction in HbA1c for the same degree of weight loss. The collected trial data also indicated weight-loss-dependent reductions in antidiabetic medication.

CONCLUSIONS

At group level, weight loss in obese and overweight patients with T2D was consistently accompanied by HbA1c reduction in a dose-dependent manner. The model developed in the present study estimates that for each kg of mean weight loss, there is a mean HbA1c reduction of 0.1 percentage points. HbA1c-lowering is greater in populations with poor glycaemic control than in well controlled populations with the same degree of weight loss. This summary of data from previous trials regarding the effect of weight reduction on HbA1c may be used to support the design and interpretation of future studies that aim to demonstrate the efficacy of weight loss interventions for T2D treatment.

Decision-making and goal-setting in chronic disease management: Baseline findings of a randomized controlled trial

OBJECTIVE

Growing interest in collaborative goal-setting has raised questions. First, are patients making the 'right choices' from a biomedical perspective? Second, are patients and providers setting goals of appropriate difficulty? Finally, what types of support will patients need to accomplish their goals? We analyzed goals and action plans from a trial of collaborative goal-setting among 302 residents of a high-poverty urban region who had multiple chronic conditions.

METHODS

Patients used a low-literacy aid to prioritize one of their chronic conditions and then set a goal for that condition with their primary care provider. Patients created patient-driven action plans for reaching these goals.

RESULTS

Patients chose to focus on conditions that were in poor control and set ambitious chronic disease management goals. The mean goal weight loss -16.8lbs (SD 19.5), goal HbA1C reduction was -1.3% (SD 1.7%) and goal blood pressure reduction was -9.8mmHg (SD 19.2mmHg). Patient-driven action plans spanned domains including health behavior (58.9%) and psychosocial (23.5%).

CONCLUSIONS

High-risk, low-SES patients identified high priority conditions, set ambitious goals and generate individualized action plans for chronic disease management.

PRACTICE IMPLICATIONS

Practices may require flexible personnel who can support patients using a blend of coaching, social support and navigation.

Medical Management of Diabesity: Do We Have Realistic Targets?

PURPOSE OF REVIEW

The global prevalence of "diabesity"-diabetes related to obesity-is increasing steadily over the past few decades because of the obesity epidemic. Although bariatric surgery is an effective treatment option for patients with diabesity, its limited availability, invasiveness, relatively high costs and the potential for surgical and postsurgical complications restrict its widespread use. Therefore, medical management is the only option for a majority of patients with diabesity. Diabetes control with several anti-diabetic agents, including insulin, causes weight gain with probability of worsening diabesity. Rational use of anti-diabetic medications with weight loss potential in varying combinations may help to address this key issue for long-term management of diabesity. There is no consensus on such an approach from different professional bodies like American Diabetes Association, European Association for Study of Diabetes, or International Diabetes Federation. We attempt to discuss the key issues and realistic targets for diabesity management in this paper.

RECENT FINDINGS

Rational use of anti-diabetic combinations can mitigate worsening of diabesity to some extent while managing patients. Retrospective studies showed that combination therapy with glucagon-like peptide-1 (GLP-1) receptor agonists and sodium glucose co-transporter 2 (SGLT-2) inhibitors, when administered along with other anti-diabetic medications, offer the best therapeutic benefit in the medical management of diabesity. Different combinations of other anti-diabetic drugs with minimum weight gain potential were also found useful. Because of insufficient evidence based on prospective randomised controlled trials (RCTs), future research should focus on evolving the appropriate rational drug combinations for the medical management of diabesity.

Theory-based self-management educational interventions on patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

AIM

To synthesize the effects of theory-based self-management educational interventions on patients with type 2 diabetes (T2DM) in randomized controlled trials.

BACKGROUND

Type 2 diabetes is a common chronic disease causing complications that put a heavy burden on society and reduce the quality of life of patients. Good self-management of diabetes can prevent complications and improve the quality of life of T2DM patients.

DESIGN

Systematic review with meta-analysis of randomized controlled trials following Cochrane methods.

DATA RESOURCES

A literature search was carried out in the MEDLINE, EMBASE, CINAHL, PSYCINFO, and Web of Science databases (1980-April 2015).

REVIEW METHODS

The risk of bias of these eligible studies was assessed independently by two authors using the Cochrane Collaboration's tool. The Publication bias of the main outcomes was examined. Statistical heterogeneity and random-effects model were used for meta-analysis.

RESULTS

Twenty studies with 5802 participants met the inclusion criteria. The interventions in the studies were based on one or more theories which mostly belong to mid-range theories. The pooled main outcomes by random-effects model showed significant improvements in HbA1c, self-efficacy, and diabetes knowledge, but not in BMI. As for quality of life, no conclusions can be drawn as the pooled outcome became the opposite with reduced heterogeneity after one study was excluded. No significant publication bias was found in the main outcomes.

CONCLUSION

To get theory-based interventions to produce more effects, the role of patients should be more involved and stronger and the education team should be trained beyond the primary preparation for the self-management education program.

Deconstructing interventions: approaches to studying behavior change techniques across obesity interventions

Deconstructing interventions into the specific techniques that are used to change behavior represents a new frontier in behavioral intervention research. This paper considers opportunities and challenges in employing the Behavior Change Techniques Taxonomy (BCTTv1) developed by Michie and colleagues, to code the behavior change techniques (BCTs) across multiple interventions addressing obesity and capture dose received at the technique level. Numerous advantages were recognized for using a shared framework for intervention description. Coding interventions at levels of the social ecological framework beyond the individual level, separate coding for behavior change initiation vs. maintenance, fidelity of BCT delivery, accounting for BCTs mode of delivery, and tailoring BCTs, present both challenges and opportunities. Deconstructing interventions and identifying the dose required to positively impact health-related outcomes could enable important gains in intervention science.

Postpartum Lifestyle Interventions to Prevent Type 2 Diabetes Among Women with History of Gestational Diabetes: A Systematic Review of Randomized Clinical Trials

Women with a history of gestational diabetes mellitus (GDM) are at a higher risk of developing type 2 diabetes. Several postpartum lifestyle intervention studies have been conducted for this high-risk group; however, the randomized clinical trials have not been evaluated systematically. Thus, the aim of this article is to evaluate the outcomes of clinical trials that focus on diabetes prevention among women with DGM. This systematic review utilized Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Chinese and US databases were searched. Randomized controlled trials of postpartum lifestyle interventions to prevent type 2 diabetes in women with prior GDM were reviewed. Outcomes included in this review are type 2 diabetes incidences, insulin insistence, and weight-related measures. The effect size of these outcomes in each study was computed. Data on intervention components were extracted, including type (in-person vs. technology-based), content (diet or physical activity or both), form (individual session vs. group session), duration, intensity, evaluation time point, and program delivery. A total of 12 studies met the inclusion criteria. The mean annual type 2 diabetes mellitus (T2DM) incidence of the intervention group was lower than that of the comparison group (6.0% vs. 9.3%), although there was no statistical difference between the two groups. About 50% of these studies and two-thirds of studies, respectively, reported a significant decrease in insulin resistance-related measures and weight-related measures in the intervention group compared with the comparison group. The median intervention duration and study length were 6 months. Postpartum lifestyle interventions can be effective in reducing T2DM development and insulin resistance, and decrease weight in women with GDM history, regardless of the intervention types (technology-based or in-person). Effective interventions typically include dietary changes while some physical activity changes can also improve outcomes. However, more interventions with long-term efficacy evaluation are warranted.

A systematic review of real-world diabetes prevention programs: learnings from the last 15 years

Background

The evidence base for the prevention of type 2 diabetes mellitus (T2DM) has progressed rapidly from efficacy trials to real-world translational studies and practical implementation trials over the last 15 years. However, evidence for the effective implementation and translation of diabetes programs and their population impact needs to be established in ways that are different from measuring program effectiveness. We report the findings of a systematic review that focuses on identifying the critical success factors for implementing diabetes prevention programs in real-world settings.

Methods

A systematic review of programs aimed at diabetes prevention was undertaken in order to evaluate their outcomes using the penetration, implementation, participation, and effectiveness (PIPE) impact metric. A search for relevant articles was carried out using PubMed (March 2015) and Web of Science, MEDLINE, CENTRAL, and EMBASE. A quality coding system was developed and included studies were rated independently by three researchers.

Results

Thirty eight studies were included in the review. Almost all (92 %) provided details on participation; however, only 18 % reported the coverage of their target population (penetration). Program intensity or implementation—as measured by frequency of contacts during first year and intervention duration—was identified in all of the reported studies, and 84 % of the studies also reported implementation fidelity; however, only 18 % of studies employed quality assurance measures to assess the extent to which the program was delivered as planned. Sixteen and 26 % of studies reported ‘highly’ or ‘moderately’ positive changes (effectiveness) respectively, based on weight loss. Six (16 %) studies reported ‘high’ diabetes risk reduction but ‘low’ to ‘moderate’ weight loss only.

Conclusion

Our findings identify that program intensity plays a major role in weight loss outcomes. However, programs that have high uptake—both in terms of good coverage of invitees and their willingness to accept the invitation—can still have considerable impact in lowering diabetes risk in a population, even with a low intensity intervention that only leads to low or moderate weight loss. From a public health perspective, this is an important finding, especially for resource constrained settings. More use of the PIPE framework components will facilitate increased uptake of T2DM prevention programs around the world.

Electronic supplementary material

The online version of this article (doi:10.1186/s13012-015-0354-6) contains supplementary material, which is available to authorized users.

Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial

BACKGROUND

Few well-controlled studies have comprehensively examined the effects of very-low-carbohydrate diets on type 2 diabetes (T2D).

OBJECTIVE

We compared the effects of a very-low-carbohydrate, high-unsaturated fat, low-saturated fat (LC) diet with a high-carbohydrate, low-fat (HC) diet on glycemic control and cardiovascular disease risk factors in T2D after 52 wk.

DESIGN

In this randomized controlled trial that was conducted in an outpatient research clinic, 115 obese adults with T2D [mean ± SD age: 58 ± 7 y; body mass index (in kg/m(2)): 34.6 ± 4.3; glycated hemoglobin (HbA1c): 7.3 ± 1.1%; duration of diabetes: 8 ± 6 y] were randomly assigned to consume either a hypocaloric LC diet [14% of energy as carbohydrate (carbohydrate <50 g/d), 28% of energy as protein, and 58% of energy as fat (<10% saturated fat)] or an energy-matched HC diet [53% of energy as carbohydrate, 17% of energy as protein, and 30% of energy as fat (<10% saturated fat)] combined with supervised aerobic and resistance exercise (60 min; 3 d/wk). Outcomes were glycemic control assessed with use of measurements of HbA1c, fasting blood glucose, glycemic variability assessed with use of 48-h continuous glucose monitoring, diabetes medication, weight, blood pressure, and lipids assessed at baseline, 24, and 52 wk.

RESULTS

Both groups achieved similar completion rates (LC diet: 71%; HC diet: 65%) and mean (95% CI) reductions in weight [LC diet: -9.8 kg (-11.7, -7.9 kg); HC diet: -10.1 kg (-12.0, -8.2 kg)], blood pressure [LC diet: -7.1 (-10.6, -3.7)/-6.2 (-8.2, -4.1) mm Hg; HC diet: -5.8 (-9.4, -2.2)/-6.4 (-8.4, -4.3) mm Hg], HbA1c [LC diet: -1.0% (-1.2%, -0.7%); HC diet: -1.0% (-1.3%, -0.8%)], fasting glucose [LC diet: -0.7 mmol/L (-1.3, -0.1 mmol/L); HC diet: -1.5 mmol/L (-2.1, -0.8 mmol/L)], and LDL cholesterol [LC diet: -0.1 mmol/L (-0.3, 0.1 mmol/L); HC diet: -0.2 mmol/L (-0.4, 0.03 mmol/L)] (P-diet effect ≥ 0.10). Compared with the HC-diet group, the LC-diet group achieved greater mean (95% CI) reductions in the diabetes medication score [LC diet: -0.5 arbitrary units (-0.7, -0.4 arbitrary units); HC diet: -0.2 arbitrary units (-0.4, -0.06 arbitrary units); P = 0.02], glycemic variability assessed by measuring the continuous overall net glycemic action-1 [LC diet: -0.5 mmol/L (-0.6, -0.3 mmol/L); HC diet: -0.05 mmol/L (-0.2, -0.1 mmol/L); P = 0.003], and triglycerides [LC diet: -0.4 mmol/L (-0.5, -0.2 mmol/L); HC diet: -0.01 mmol/L (-0.2, 0.2 mmol/L); P = 0.001] and greater mean (95% CI) increases in HDL cholesterol [LC diet: 0.1 mmol/L (0.1, 0.2 mmol/L); HC diet: 0.06 mmol/L (-0.01, 0.1 mmol/L); P = 0.002].

CONCLUSIONS

Both diets achieved substantial weight loss and reduced HbA1c and fasting glucose. The LC diet, which was high in unsaturated fat and low in saturated fat, achieved greater improvements in the lipid profile, blood glucose stability, and reductions in diabetes medication requirements, suggesting an effective strategy for the optimization of T2D management. This trial was registered at www.anzctr.org.au as ACTRN12612000369820.