Prevention of type 2 diabetes in a primary healthcare setting: three-year results of lifestyle intervention in Japanese subjects with impaired glucose tolerance

Reframing prediabetes: A call for better risk stratification and intervention

Prediabetes is an intermediate state of glucose homeostasis whereby plasma glucose concentrations are above normal but below the threshold of diagnosis for diabetes. Over the last several decades, criteria for prediabetes have changed as the cut points for normal glucose concentration and diagnosis of diabetes have shifted. Global consensus does not exist for prediabetes criteria; as a result, the clinical course and risk for type 2 diabetes vary. At present, we can identify individuals with prediabetes based on three glycemic tests (hemoglobin A1c, fasting plasma glucose, and 2-h plasma glucose during an oral glucose tolerance test). The majority of individuals diagnosed with prediabetes meet only one of these criteria. Meeting one, two, or all glycemic criteria changes risk for type 2 diabetes, but this information is not widely known and does not currently guide intervention strategies for individuals with prediabetes. This review summarizes current epidemiology, prognosis, and intervention strategies for individuals diagnosed with prediabetes and suggests a call for more precise risk stratification of individuals with prediabetes as elevated (one prediabetes criterion), high risk (two prediabetes criteria), and very high risk (three prediabetes criteria). In addition, the roles of oral glucose tolerance testing and continuous glucose monitoring in the diagnostic criteria for prediabetes need reassessment. Finally, we must reframe our goals for prediabetes and prioritize intensive interventions for those at high and very high risk for type 2 diabetes.

Long-term lifestyle intervention can reduce the development of type 2 diabetes mellitus in subjects with prediabetes: A systematic review and meta-analysis

AIMS

To evaluate the effectiveness of intensive lifestyle intervention (ILI) on the risk of type 2 diabetes (T2D) in prediabetes (PD).

METHODS

We searched the Cochrane Central, Embase, MEDLINE, and Web of Science (until February 2024) to include RCTs of adults with PD, comparing ILI vs. general advice on the incidence of T2D. Two authors extracted the data, applied the Cochrane Risk of Bias (RoB) 2.0 tool and the GRADE framework. Meta-analysis was performed using random effects models, estimating relative risk (RR) and the 95%CI.

RESULTS

Fifteen studies (n = 8,563, 46.7 % female, 53.3 ± 8.7 years, BMI 26.7 ± 5.4 Kg/m2) were included. ILI reduced T2D risk by 22 % when compared with general advice (RR 0.78; 95 %CI 0.72-0.85; I2 = 40 %; low certainty of evidence). Most studies had high risk of bias or raised some concerns. Sensitivity analysis showed that studies with mostly female populations and those using the WHO 1985 criteria for T2D had lower risk of the disease and that the longer the follow-up, the lower the protection.

CONCLUSION

ILI can prevent T2D in subjects with PD. Healthcare teams should aim for structured ILI to maintain long-term lifestyle improvements.

Lifestyle behaviour patterns in the prevention of type 2 diabetes mellitus: the Fukushima Health Database 2015-2020

OBJECTIVES

Lifestyle behaviours associated with the incidence of type 2 diabetes mellitus (T2DM) need further clarification using health insurance data.

STUDY DESIGN

This is a cohort study.

METHODS

In 2015, 193,246 participants aged 40-74 years attended the specific health checkups and were observed up to 2020 in Fukushima, Japan. Using the principal component analysis, we identified two patterns from ten lifestyle behaviour questions, namely, the "diet-smoking" pattern (including smoking, alcohol drinking, skipping breakfast, eating fast, late dinner, and snacking) and the "physical activity-sleep" pattern (including physical exercise, walking equivalent activity, walking fast, and sufficient sleep). Then, individual pattern scores were calculated; the higher the scores, the healthier the behaviours.

RESULTS

The accumulative incidence rate of T2DM was 630.5 in men and 391.9 in women per 100,000 person-years in an average of 4 years of follow-up. Adjusted for the demographic and cardiometabolic factors at the baseline, the hazard ratio (95% confidence interval) of the highest versus lowest quartile scores of the "diet-smoking" pattern for T2DM risk was 0.82 (0.72, 0.92; P for trend = 0.002) in men and 0.87 (0.76, 1·00; P for trend = 0.034) in women; that of the "physical activity-sleep" pattern was 0.92 (0.82, 1·04; P for trend = 0.0996) in men and 0.92 (0.80, 1·06; P for trend = 0.372) in women. The "physical activity-sleep" pattern showed a significant inverse association in non-overweight men.

CONCLUSIONS

Lifestyle behaviour associated with a healthy diet and lack of smoking may significantly lower the risk of T2DM in middle-aged Japanese adults.

Impact of individual and environmental factors on dietary or lifestyle interventions to prevent type 2 diabetes development: a systematic review

BACKGROUND

The variability in the effectiveness of type 2 diabetes (T2D) preventive interventions highlights the potential to identify the factors that determine treatment responses and those that would benefit the most from a given intervention. We conducted a systematic review to synthesize the evidence to support whether sociodemographic, clinical, behavioral, and molecular factors modify the efficacy of dietary or lifestyle interventions to prevent T2D.

METHODS

We searched MEDLINE, Embase, and Cochrane databases for studies reporting on the effect of a lifestyle, dietary pattern, or dietary supplement interventions on the incidence of T2D and reporting the results stratified by any effect modifier. We extracted relevant statistical findings and qualitatively synthesized the evidence for each modifier based on the direction of findings reported in available studies. We used the Diabetes Canada Clinical Practice Scale to assess the certainty of the evidence for a given effect modifier.

RESULTS

The 81 publications that met our criteria for inclusion are from 33 unique trials. The evidence is low to very low to attribute variability in intervention effectiveness to individual characteristics such as age, sex, BMI, race/ethnicity, socioeconomic status, baseline behavioral factors, or genetic predisposition.

CONCLUSIONS

We report evidence, albeit low certainty, that those with poorer health status, particularly those with prediabetes at baseline, tend to benefit more from T2D prevention strategies compared to healthier counterparts. Our synthesis highlights the need for purposefully designed clinical trials to inform whether individual factors influence the success of T2D prevention strategies.

Comprehensive Molecular Evaluation of HNF-1 Alpha, miR-27a, and miR-146 Gene Variants and Their Link with Predisposition and Progression in Type 2 Diabetes Patients

BACKGROUND

Type 2 diabetes (T2D) is a metabolic condition induced by insulin resistance and pancreatic beta cell dysfunction. MicroRNAs (miRNAs) have biological significance because they regulate processes such as the molecular signaling pathways involved in the pathophysiology of diabetes mellitus. The hepatocyte nuclear factor-1 alpha (HNF-1 alpha) is a transcription factor found in hepatocytes and the pancreas. Mutations in the HNF-1 alpha gene were reportedly associated with maturity-onset diabetes of the young (MODY). The objective of the present study was to examine the associations between MiR-27a, MiR-146, and HNF-1 alpha single-nucleotide variations (SNVs) with T2D risk in the Saudi population.

METHODOLOGY

We evaluated the association of SNVs of miR-27a rs895819 A>G, 146a-rs2910164 C>G, and HNF-1 alpha rs1169288 G>T (I27L) with the risk of T2D in Saudi patients with the Amplification Refractory Mutation System PCR (ARMS-PCR). For the miR-27a SNVs, we used 115 cases (82 males, 33 females) and 117 matched healthy controls (HCs); for the Mir-146 SNVs, we used 103 cases (70 males, 33 females) and 108 matched HCs; and for the HNF-1 alpha, we employed 110 patients (80 males, 30 females) and 110 HCs. The blood biochemistry of the participants was essayed using commercial kits, and the methods of statistical analysis used were the Chi-square test, the Fisher exact test, and a multivariate analysis based on logistic regression, like the odds ratio (OD) and risk ratio (RR), with 95% confidence intervals (CIs).

RESULTS

The MiR-27a rs895819 AG genotype was linked to increased T2D susceptibility, with OR = 2.01 and p-value = 0.011, and the miR-146 rs2910164 CG genotype and C allele were linked to an elevated risk of T2D, with OR = 2.75, p-value < 0.0016, OR = 1.77, and p-value = 0.004. The results also showed that the GT genotype and T allele of the HNF-1 alpha (rs1169288) G>T is linked to T2D, with OR = 2.18, p-value = 0.0061, and 1.77, p-value = 0.0059.

CONCLUSIONS

The SNVs in miR-27a, miR-146, and HNF-1 alpha can be potential loci for T2D risk. The limitations of this study include the relatively small sample size and the fact that it was a cross-sectional study. To our knowledge, this is the first study to highlight the association between miR-27a, miR-146, and HNF-1 alpha SNVs and the risk of T2D in the Saudi population. Future large-scale case-control studies, as well as studies on the functions of the proteins and protein interaction studies for HNF-1 alpha, are required to verify our findings. Furthermore, these findings can be used for the identification and stratification of at-risk populations via genetic testing for T2D-prevention strategies.

Role of sociodemographic, clinical, behavioral, and molecular factors in precision prevention of type 2 diabetes: a systematic review

The variability in the effectiveness of type 2 diabetes (T2D) preventive interventions highlights the potential to identify the factors that determine treatment responses and those that would benefit the most from a given intervention. We conducted a systematic review to synthesize the evidence to support whether sociodemographic, clinical, behavioral, and molecular characteristics modify the efficacy of dietary or lifestyle interventions to prevent T2D. Among the 80 publications that met our criteria for inclusion, the evidence was low to very low to attribute variability in intervention effectiveness to individual characteristics such as age, sex, BMI, race/ethnicity, socioeconomic status, baseline behavioral factors, or genetic predisposition. We found evidence, albeit low certainty, to support conclusions that those with poorer health status, particularly those with prediabetes at baseline, tend to benefit more from T2D prevention strategies compared to healthier counterparts. Our synthesis highlights the need for purposefully designed clinical trials to inform whether individual factors influence the success of T2D prevention strategies.

Lifestyle Intervention Guided by Group and Internet-Based Counseling in the T2D-GENE Trial Supports Its Applicability and Feasibility

Type 2 diabetes (T2D) can be prevented or postponed by lifestyle modifications as shown by previous intervention studies. In most of these studies, participants have received resource-demanding individual counseling. In the 3-year T2D-GENE trial with lifestyle intervention, we investigated whether a less resource-demanding form of group and internet-based counseling is feasible and effective in preventing T2D in people with an increased risk for T2D. Altogether, 628 middle-aged to elderly men either with a high number or low number of T2D risk alleles were recruited. Five to seven group sessions were organized during the intervention, in addition to information and activities delivered via the web portal, and weekly monitoring of body weight and physical activity. Four-day food records with personal feedback were documented five times during the study. Of the 549 participants completing the study, over 90% participated in the group sessions and kept the food records. The four self-feedback tasks delivered during the second and the third years of the study were completed by 80-89% of the participants. In conclusion, a group and web portal-based lifestyle intervention is applicable for middle-aged to elderly men as a lifestyle modification aiming to prevent T2D.

[Diabetes mellitus: definition, classification, diagnosis, screening and prevention (Update 2023)]

Diabetes mellitus comprises of a group of heterogeneous disorders, which have an increase in blood glucose concentrations in common. The current classification for diabetes mellitus is presented and the main features of type 1 and type 2 diabetes are compared. Furthermore, the criteria for the correct biochemical diagnosis during fasting and oral glucose tolerance tests as well as the use of hemoglobin A1c (HbA1c) are summarized. The increasing prevalence of diabetes requires targeted screening for detecting diabetes and prediabetes in risk groups. This forms the basis for the early initiation of measures to prevent the onset of diabetes in these risk groups and to delay the progression of diabetes.

Intervention for Prevention of Type 2 Diabetes Mellitus Among Prediabetes: A Review of the Literature

Introduction

In recent decades, the prevalence and incidence of type 2 diabetes mellitus (T2DM) have increased rapidly and represent a significant public health problem worldwide. Long-term T2DM is associated with microvascular complications such as retinopathy, nephropathy, and neuropathy. Prediabetes is a state of hyperglycemia with blood glucose levels higher than normal but lower than the diabetes threshold. Several studies have demonstrated the effectiveness of lifestyle interventions that resulted in a 40% to 70% reduction in diabetes mellitus in adults with prediabetes. These interventions focused on increased physical activity and dietary changes that were able to prevent or delay the onset of T2DM in prediabetes. However, most review studies focused on interventions to prevent T2DM in high-risk groups such as obesity. There was a limitation of reports related to prediabetes. Nevertheless, it remains a high-risk condition for the development of T2DM with a conversion rate of 5% to 10% per year. Therefore, the aim of this study was to review the current evidence on intervention studies aimed at reducing the incidence of type 2 diabetes in prediabetes.

Method

The researcher conducted a literature search of common online databases such as Medline, Google Scholar, and Cochrane Library between January 2011 and December 2021.

Result

The intervention for the prevention of T2DM in prediabetes consisted of a lifestyle intervention, a nutritional supplementation intervention, and a pharmacological intervention.

Conclusion

Several studies suggest that T2DM in prediabetes can be prevented by lifestyle modification and pharmacological interventions, or a combined intervention. However, further interventions may be needed to confirm this.

The impact of healthcare executive seniority on implementation of innovative methods of diagnosis and prevention

Innovative methods of diagnosis and prevention play a key role in the survival of healthcare systems as well as the wellbeing of patients. Effective healthcare management is a critical factor in implementing hospital innovation. Healthcare executive (HE) personal and job characteristics such as age and seniority have been found to affect innovative decision-making. However, no study has yet investigated age and seniority effects on the propensity to implement innovation in health prevention strategies. This study fills the literature gap by providing evidence for the effect of HE age and seniority on the implementation of innovative methods for diagnosis and prevention. Predicated on 57 in-depth interviews with HEs, we employ mixed methods research, combining qualitative and quantitative analysis. Structural Equation Modeling was used to test the model's goodness-of-fit. Results show that while HE age and number of years in the organization positively affect job tenure, job tenure, in turn, negatively affects willingness to implement innovative methods of diagnosis and prevention in hospitals. This study extends the Upper-Echelon Theory to health workforce management. Practical implications are discussed.

A 12-Month Follow-Up of the Effects of a Digital Diabetes Prevention Program (VP Transform for Prediabetes) on Weight and Physical Activity Among Adults With Prediabetes: Secondary Analysis

Background

The prevalence of diabetes is increasing rapidly. Previous research has demonstrated the efficacy of a diabetes prevention program (DPP) in lifestyle modifications that can prevent or delay the onset of type 2 diabetes among individuals at risk. Digital DPPs have the potential to use technology, in conjunction with behavior change science, to prevent prediabetes on a national and global scale.

Objective

The aim of this study is to investigate the effects of a digital DPP (Virgin Pulse [VP] Transform for Prediabetes) on weight and physical activity among participants who had completed 12 months of the program.

Methods

This study was a secondary analysis of retrospective data of adults with prediabetes who were enrolled in VP Transform for Prediabetes for 12 months of the program. The program incorporates interactive mobile computing, remote monitoring, an evidence-based curriculum, behavior tracking tools, health coaching, and online peer support to prevent or delay the onset of type 2 diabetes.

Results

The sample (N=1095) was comprised of people with prediabetes who completed at least 9 months of the VP Transform for Prediabetes program. Participants were 67.7% (n=741) female, with a mean age of 53.6 (SD 9.75) years. After 12 months, participants decreased their weight by an average of 10.9 lbs (5.5%; P<.001) and increased their physical activity by 91.2 (P<.001) minutes.

Conclusions

These results suggest that VP Transform for Prediabetes is effective at preventing type 2 diabetes through a significant reduction in body weight and increase of physical activity. Furthermore, these results suggest that the DPP remains effective 12 months after beginning the program. A prospective randomized controlled clinical study is warranted to validate these findings.

The Long-Term Effects of Non-Pharmacological Interventions on Diabetes and Chronic Complication Outcomes in Patients With Hyperglycemia: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aimed at examining the long-term effects of non-pharmacological interventions on reducing the diabetes incidence among patients with prediabetes and chronic complications events among patients with hyperglycemia (pre-diabetes and diabetes) by performing a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

PubMed, MEDLINE, EMBASE, the Cochrane Library, and the Web of Science Core Collection were searched for studies published between January 1990 and November 2021, looking for RCTs to evaluate the effects of non-pharmacological interventions on preventing the incidence of diabetes and chronic complications in comparison with medical therapy, placebo, or usual diabetes care. Two independent reviews extracted relevant data and quality assessment. Any discrepancies were resolved by a third reviewer.

RESULTS

In total, 20 articles involved 16 RCTs (follow-up ranged from 2 to 30 years) were included. Pooled analysis of intervention studies demonstrated clearly that non-pharmacological interventions have a significant effect on reducing the diabetes events in patients with prediabetes (RR 0.62; 95% CI 0.54, 0.71). Pooled analysis of extended follow-up studies showed that non-pharmacological interventions could effectively reduce the diabetes incidence in patients with prediabetes (RR 0.78; 95% CI 0.63, 0.96). Meta-regression and subgroup analysis indicates that the diabetes incidence of the long-term group (duration > 3 years) was clearly reduced by 0.05% compared with the relatively short-term group (duration ≤ 3 years). The incidence of microvascular complications in patients with hyperglycemia was effectively lowered by non-pharmacological interventions (RR 0.60; 95% CI 0.43, 0.83).

CONCLUSION

Non-pharmacological interventions have a long-term effect on reducing the diabetes incidence among prediabetic patients and effectively preventing microvascular complications on hyperglycemia.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/.

Ethnic differences in response to lifestyle intervention for the prevention of type 2 diabetes in adults: A systematic review and meta-analysis

The risk of type 2 diabetes mellitus (T2DM) varies by ethnicity, but ethnic differences in response to diabetes prevention interventions remain unclear. This systematic review and meta-analysis assessed ethnic differences in the effects of lifestyle interventions on T2DM incidence, glycemic outcomes (fasting glucose, 2-h glucose, HbA_1c ), anthropometric measures (weight, BMI, waist circumference), and lifestyle behaviors (physical activity, energy intake, energy from fat, fiber intake). MEDLINE, EMBASE, and other databases were searched (to June 15, 2020) for randomized and non-randomized controlled trials on lifestyle interventions (diet and/or physical activity) in adults at risk of T2DM. Ethnicity was categorized into European, South Asian, East and Southeast Asian, Middle Eastern, Latin American, and African groups. Forty-four studies were included in meta-analyses. Overall, lifestyle interventions resulted in significant improvement in T2DM incidence, glycemic outcomes, anthropometric measures, physical activity, and energy intake (all P < 0.01). Significant subgroup differences by ethnicity were found for 2-h glucose, weight, BMI, and waist circumference (all P < 0.05) but not for T2DM incidence, fasting glucose, HbA_1c , and physical activity (all P > 0.05). Few studies in non-European groups reported dietary intake. Lifestyle interventions in different ethnic groups may have similar effects in reducing incidence of T2DM although this needs to be confirmed in further studies.

The Effect of Lifestyle Intervention on Diabetes Prevention by Ethnicity: A Systematic Review of Intervention Characteristics Using the TIDieR Framework

Lifestyle intervention is effective in preventing type 2 diabetes mellitus (T2DM), but the efficacy of intervention components across different ethnic groups is less clear. This systematic review examined the effects of intervention characteristics of lifestyle interventions on diabetes incidence and weight loss by ethnicity using the Template for Intervention Description and Replication (TIDieR) framework. MEDLINE, EMBASE and other databases were searched for randomized and non-randomized controlled trials on lifestyle interventions (diet and/or physical activity) in adults at risk of T2DM. Ethnicity was categorized into European, South Asian, East and Southeast Asian, Middle Eastern, Latin American and African groups. Forty-five studies (18,789 participants) were included in the systematic review and 41 studies in meta-analysis. Meta-analysis showed a high number of intervention sessions was significantly associated with a greater reduction in diabetes incidence (P = 0.043) and weight (P = 0.015), while other intervention characteristics including intervention provider and delivery format did not alter the outcomes (all P > 0.05). Additionally, narrative synthesis showed long-term interventions (≥12 months) were associated with significant diabetes risk reduction for all ethnic groups, while short-term interventions (<12 months) were more effective in weight loss in most ethnic groups. There may be ethnic preferences for the optimal number of intervention sessions.

Sex-specific association of BMI change with stroke in middle-aged and older adults with type 2 diabetes

BACKGROUND AND AIMS

We aimed to evaluate the association between BMI change and stroke in middle-aged and older adults with type 2 diabetes and identify sex differences.

METHODS AND RESULTS

The China Health and Retirement Longitudinal Study is an ongoing national population-based cohort study. Participants aged 45 or above with type 2 diabetes were enrolled and followed for stroke incidence. BMI change was defined as BMI at 2013-BMI at 2011. Of 1774 participants (mean [SD] age in 2011, 60.23 [8.88] years), 795 (44.8 %) were men. A total of 112 incident stroke cases were confirmed up to 2018. The incidence rate of stroke was similar between men and women (6.79 % vs 5.92 %, P = 0.516). BMI increase was independently associated with an increased stroke risk (adjusted odds ratio, 1.15; 95 % CI, 1.05-1.31) in men, while this positive association was not significant in women (adjusted odds ratio, 1.12; 95 % CI, 0.98-1.29). In addition, the positive dose-response relationship between BMI increase and stroke was observed only in men.

CONCLUSION

Among middle-aged and older adults with type 2 diabetes, there is a sex-specific association of BMI change with stroke. An increase in BMI could result in a higher risk of incident stroke in men.

Network Meta-analysis of the Therapeutic Effects of Hypoglycemic Drugs and Intensive Lifestyle Modification on Impaired Glucose Tolerance

PURPOSE

In the Guidelines for the Prevention and Control of Type 2 Diabetes in China (2017 edition), intensive lifestyle interventions are recommended for preventing the progression of impaired glucose tolerance (IGT) to type 2 diabetes mellitus. Acarbose and metformin can also be considered if intensive lifestyle modification has been ineffective for 6 months. But the effects of intensive lifestyle modification and glucose-lowering drug interventions that work best in the population with IGT are unclear. This network meta-analysis assessed the effectiveness of intensive lifestyle modification, acarbose, and metformin in treating populations with IGT.

METHODS

We systematically searched both Chinese- and English-language databases, including China Knowledge, the Cochrane Library, Embase, PubMed, VIP, and Wanfang, for articles published between database inception and September 2019. Randomized, controlled clinical trials in patients with IGT treated with acarbose, metformin, and intensive lifestyle modification were assessed for eligibility. The data from all included studies were evaluated by 2 reviewers independently in accordance with the Cochrane Handbook for Systematic Reviews of Intervention version 6.0. A network meta-analysis was performed by using R software version 3.6.1.

FINDINGS

The data from 53 randomized controlled trials were included in the review, with a sample size of 21,208 patients. Compared with the control group, the use of acarbose, metformin, and/or intensive lifestyle modification was associated with reduced rates of progression to diabetes (relative risks [RRs] [95% credible intervals]: acarbose, 0.37 [0.29-0.47]; metformin, 0.39 [0.30-0.50]; intensive lifestyle modification, 0.61 [0.50-0.73]). The surface under the cumulative ranking (SUCRA) value of acarbose was 88.35%, supporting that acarbose was more effective in reducing the rate of progression to diabetes compared with controls. With acarbose, metformin, and intensive lifestyle modification, the rates of achieving a normal glucose level were increased by RR = 2.1, 1.7, and 1.2, respectively when compared with control group. The SUCRA value of acarbose was 99.69%, supporting the optimal effect of acarbose in achieving a normal blood glucose level.

IMPLICATIONS

In this meta-analysis in patients with IGT, compared with controls, acarbose and metformin were associated with decreased rates of progression to diabetes and increased rates of achieving a normal glucose level. Acarbose use was associated with an increased rate of achieving a normal glucose level, while intensive lifestyle modification was not.

Screening for Prediabetes and Type 2 Diabetes: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Type 2 diabetes is common and is a leading cause of morbidity and disability.

OBJECTIVE

To review the evidence on screening for prediabetes and diabetes to inform the US Preventive Services Task Force (USPSTF).

DATA SOURCES

PubMed/MEDLINE, Cochrane Library, and trial registries through September 2019; references; and experts; literature surveillance through May 21, 2021.

STUDY SELECTION

English-language controlled studies evaluating screening or interventions for prediabetes or diabetes that was screen detected or recently diagnosed.

DATA EXTRACTION AND SYNTHESIS

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings; meta-analyses conducted when at least 3 similar studies were available.

MAIN OUTCOMES AND MEASURES

Mortality, cardiovascular morbidity, diabetes-related morbidity, development of diabetes, quality of life, and harms.

RESULTS

The review included 89 publications (N = 68 882). Two randomized clinical trials (RCTs) (25 120 participants) found no significant difference between screening and control groups for all-cause or cause-specific mortality at 10 years. For harms (eg, anxiety or worry), the trials reported no significant differences between screening and control groups. For recently diagnosed (not screen-detected) diabetes, 5 RCTs (5138 participants) were included. In the UK Prospective Diabetes Study, health outcomes were improved with intensive glucose control with sulfonylureas or insulin. For example, for all-cause mortality the relative risk (RR) was 0.87 (95% CI, 0.79 to 0.96) over 20 years (10-year posttrial assessment). For overweight persons, intensive glucose control with metformin improved health outcomes at the 10-year follow-up (eg, all-cause mortality: RR, 0.64 [95% CI, 0.45 to 0.91]), and benefits were maintained longer term. Lifestyle interventions (most involving >360 minutes) for obese or overweight persons with prediabetes were associated with reductions in the incidence of diabetes (23 RCTs; pooled RR, 0.78 [95% CI, 0.69 to 0.88]). Lifestyle interventions were also associated with improved intermediate outcomes, such as reduced weight, body mass index, systolic blood pressure, and diastolic blood pressure (pooled weighted mean difference, -1.7 mm Hg [95% CI, -2.6 to -0.8] and -1.2 mm Hg [95% CI, -2.0 to -0.4], respectively). Metformin was associated with a significant reduction in diabetes incidence (pooled RR, 0.73 [95% CI, 0.64 to 0.83]) and reduction in weight and body mass index.

CONCLUSIONS AND RELEVANCE

Trials of screening for diabetes found no significant mortality benefit but had insufficient data to assess other health outcomes; evidence on harms of screening was limited. For persons with recently diagnosed (not screen-detected) diabetes, interventions improved health outcomes; for obese or overweight persons with prediabetes, interventions were associated with reduced incidence of diabetes and improvement in other intermediate outcomes.

Prediabetes and deprivation: A couple at high risk of diabetes

AIM

The higher prevalence of diabetes in deprived populations is well documented but little is known about the risk of diabetes associated with deprivation among pre-diabetic subjects. The aim of the study was to evaluate the risk of diabetes in a population of deprived pre-diabetic patients.

METHODS

2743 pre-diabetic subjects identified using the American Diabetes Association (ADA) criteria, 16 to 85 years old, 1656 non-deprived and 1087 deprived, had at least two health check-ups at an interval of 4.95 (2.04) vs 3.20 (1.71) years, P<0.0001, respectively. At the first visit, socioeconomic status was assessed using the EPICES score to differentiate deprived and non-deprived subjects.

RESULTS

At the second visit, the prevalence of overt diabetes was 9.5% among deprived vs 5.1% in the non-deprived group (P<0.001). After adjustment on confounding factors, deprivation was found independently associated with occurrence of diabetes [1.70 (1.15-2.51), P=0.01]. Beyond social deprivation, Fasting Plasma Glucose and waist circumference were the main independent predictors of new-onset diabetes.

CONCLUSION

After 4 years of follow-up, among subjects with prediabetes, prevalence of diabetes was twice as high among deprived compared with non-deprived subjects. Deprived populations with pre-diabetes may require specific public health approaches to avoid the occurrence of overt diabetes.

A randomized trial to decrease risk for diabetes among Cambodian Americans with depression: Intervention development, baseline characteristics and process outcomes

Background:

Depression and antidepressant medications are associated with increased risk for type 2 diabetes. It is not known if diabetes can be prevented in the setting of depression. Cambodian Americans have high rates of both depression and diabetes. This paper reports intervention development, experimental design, baseline characteristics, and process outcomes of diabetes prevention interventions for Cambodian Americans with depression, “Diabetes Risk Reduction through Eat, Walk, Sleep and Medication Therapy Management” (DREAM).

Methods:

Participants were aged 35–75, Khmer speaking, at high risk for developing diabetes, and met criteria for likely depression by either a) antidepressant medication and/or b) elevated depressive symptoms at two time-points during a study eligibility period. Treatment arms were: 1) community health educator (CHE) delivered lifestyle intervention called Eat, Walk, Sleep (EWS), 2) EWS plus pharmacist/CHE-delivered medication therapy management (EWS + MTM), and, 3) social services (SS; control).

Results:

188 participants were randomized. Treatment fidelity was high (98% checklist adherence) and on a scale from 0 to 3, participants reported high EWS treatment satisfaction (M = 2.9, SD = 0.2), group cohesion (M = 2.9, SD = 0.3), and therapeutic alliance to CHEs (M = 2.9, SD = 0.2) and to pharmacists (2.9, SD = 0.3). Attendance was challenging but highly successful; in EWS, 99% attended ≥ one session and 86% completed ≥ 24 sessions, M = 27.3 (SD = 3.7) sessions. Of those randomized to EWS + MTM, 98% attended at least one MTM session and 77%) completed ≥ 4 sessions. Retention was high, 95% at 12-month and 96% at 15-month assessments.

Conclusions:

The interventions were successfully implemented. Lessons learned and suggestions for future trials are offered.

ClinicalTrials.gov identifier: NCT02502929

Association of dietary intake, medication and anthropometric indices with serum levels of advanced glycation end products, caspase-3, and matrix metalloproteinase-9 in diabetic patients

Background and objective

Increased serum levels of advanced glycation end products (AGEs), caspase-3 (Cas-3) and matrix metalloproteinase-9 (MMP-9) have been reported in diabetic patients. This study aimed to evaluate association of anthropometric, dietary, and therapeutic factors with serum levels of methylglyoxal (MGO), carboxymethyl lysine (CML), pentosidine (Pen), Cas-3, and MMP-9 in diabetic patients.

Methods

The current study included 36 diabetic subjects. Dietary intake of the participants was assessed using three-day 24-h recall survey and anthropometric indices were measured. Demographic factors and medication intake of every subject were obtained. Serum levels of CML, MGO, Pen, MMP-9, and Cas-3 were measured using ELISA method.

Results

Gliclazide consumption was positively correlated with MMP-9 and Cas-3, but not AGEs levels. Females had higher MGO level compared with males. Further, CML levels were negatively correlated with BMI and WHR. Dietary protein intake was positively correlated with MMP-9, Cas-3, and MGO levels. As well as dietary energy and fat intake had significant positive relationship with serum Cas-3 concentration.

Conclusion

It is concluded that anthropometric characteristics, dietary intake, and therapeutic medications are possible factors that may determine the circulating levels of AGEs, MMP-9, and Cas-3 in patients with diabetes.

Diabetes Complications in Racial and Ethnic Minority Populations in the USA

PURPOSE OF REVIEW

Racial and ethnic minority populations have a higher burden of diabetes-related complications. There have been many epidemiologic studies to better define these racial/ethnic disparities in diabetes outcomes with additional studies offering interventions to mitigate them. This narrative review highlights the epidemiologic trends in diabetes complications specific to racial and ethnic minorities and underscores differences in microvascular and macrovascular complications of diabetes, health care utilization, and diabetes prevention efforts and also reviews interventions aimed to reduce racial/ethnic disparities and their limitations.

RECENT FINDINGS

While we have seen in general an overall improvement in complication rates for all people with diabetes, the disparities between Black and Hispanic compared to non-Hispanic White people with diabetes seem to persist. There is a continued need to better understand the underlying causes of and strategies to mitigate race/ethnicity disparities in diabetes complications in the USA.

Effect of Eating Glutinous Brown Rice Twice a Day for 6 Weeks on Serum 1,5-Anhydroglucitol in Japanese Subjects without Diabetes

We have previously demonstrated that eating glutinous brown rice (GBR) for 1 day or 8 weeks was well accepted and improved glycemic control in patients with type 2 diabetes. The present study evaluated whether eating GBR could also improve glucose metabolism in subjects without diabetes. A prospective 6-week, single-center, randomized, open-label, parallel-group study was carried out in subjects receiving annual medical checkup at our hospital. A total of 42 subjects were randomly assigned to continue their regular diet (RD group) or to switch GBR twice a day (GBR group). The primary outcome was the change in the serum concentration of 1,5-anhydroglucitol (1,5-AG) from baseline after the 6-week dietary intervention. One subject was excluded from the analysis because of a traffic accident. After 6 weeks, the serum 1,5-AG was significantly increased in the GBR group and the mean treatment difference (GBR group - RD group) was 1.1 µg/mL (95% CI: 0.6 to 1.6, p=0.022). Body mass index decreased significantly in both groups, with no significant difference between them (p=0.210). There were no changes in fasting plasma glucose, fasting insulin, or eating behavior. Intake of GBR for 6 weeks significantly increased serum 1,5-AG in Japanese subjects without diabetes. The increase of 1,5-AG may have been due to the alleviation of postprandial hyperglycemia, which could be effective for the primary prevention of diabetes.

Nutritional Strategies in Prediabetes: A Scoping Review of Recent Evidence

Nutritional therapy has been conventionally recommended for people with prediabetes as a method to delay or halt progression to type 2 diabetes. However, recommended nutritional strategies evolve over time. Hence, we performed a scoping review on recently reported nutritional interventions for individuals with prediabetes. Ovid MEDLINE, PubMed, Embase, Scopus, CINAHL and PsycINFO databases were searched to identify relevant research articles published within the past 10 years. Ninety-five articles involving a total of 11,211 participants were included in this review. Nutritional strategies were broadly classified into four groups: low calorie diet, low glycemic index diet, specific foods, and a combination of diet and exercise. The most frequently assessed outcomes were plasma glucose, serum insulin, serum lipid profile, body mass index and body weight. More than 50% of reported interventions resulted in significant improvements in these parameters. Nutritional interventions have demonstrated feasibility and practicality as an effective option for prediabetes management. However, the intervention variability demonstrates the challenges of a 'one-size-fits-all' approach. Investigations in genetically diverse populations and objective assessment of progression rate to diabetes are necessary to better comprehend the impact of these nutritional strategies in prediabetes.

Development, validation and utilisation of dish-based dietary assessment tools: a scoping review

Objective:

To summarise the existing evidence of development, validation and current status of utilisation of dish-based dietary assessment tools.

Design:

Scoping review.

Setting:

Systematic search using PubMed and Web of Science.

Results:

We identified twelve tools from seventy-four eligible publications. They were developed for Koreans (n 4), Bangladeshis (n 2), Iranians (n 1), Indians/Malays/Chinese (n 1), Japanese (n 3) and Chinese Americans (n 1). Most tools (10/12) were composed of a dish-based FFQ. Although the development process of a dish list varied among the tools, six studies classified mixed dishes based on the similarity of their characteristics such as food ingredients and cooking methods. Tools were validated against self-reported dietary information (n 9) and concentration biomarkers (n 1). In the eight studies assessing the differences between the tool and a reference, the mean (or median) intake of energy significantly differed in five studies, and 26–83 % of nutrients significantly differed in eight studies. Correlation coefficients for energy ranged from 0·15 to 0·87 across the thirteen studies, and the median correlation coefficients for nutrients ranged from 0·12 to 0·77. Dish-based dietary assessment tools were used in fifty-nine studies mainly to assess diet–disease relationships in target populations.

Conclusions:

Dish-based dietary assessment tools have exclusively been developed and used for Asian-origin populations. Further validation studies, particularly biomarker-based studies, are needed to assess the applicability of tools.

A systematic review of recruitment strategies and behaviour change techniques in group-based diabetes prevention programmes focusing on uptake and retention

BACKGROUND

Many countries worldwide have developed diabetes prevention programmes (DPPs) that involve lifestyle modification. Research has shown that uptake and retention of DPPs are important and by exploring recruitment strategies and behaviour change techniques (BCTs) used, factors that are most effective in promoting uptake and retention can be identified.

OBJECTIVES

This review aims to identify recruitment strategies of group-based DPPs that are associated with high uptake and common BCTs associated with high retention.

METHODS

Papers were identified with a systematic literature search. Programmes that were predominantly group-based and involved lifestyle modification and in which uptake and/or retention could be determined, were included. Intervention details were extracted, recruitment strategies and BCTs identified, and response, uptake and retention rates were calculated.

RESULTS

A range of recruitment strategies were used making it difficult to discern associations with uptake rates. For BCTs, all programmes used a credible source, 81% used instruction on how to perform a behaviour and 71% used goal setting (behaviour). BCTs more commonly found in high retention programmes included problem-solving, demonstrating the behaviour, using behavioural practice and reducing negative emotions.

CONCLUSIONS

Recommendations include that DPPs incorporate BCTs like problem-solving and demonstrating the behaviour to maximise retention.

What predicts regression from pre-diabetes to normal glucose regulation following a primary care nurse-delivered dietary intervention? A study protocol for a prospective cohort study

INTRODUCTION

Pre-diabetes is a high-risk state for the development of type 2 diabetes mellitus (T2DM) and cardiovascular disease. Regression to normoglycaemia, even if transient, significantly reduces the risk of developing T2DM. The primary aim of this mixed-methods study is to determine if there are clinically relevant differences among those with pre-diabetes and excess weight who regress to normoglycaemia, those who have persistent pre-diabetes and those who progress to T2DM following participation in a 6-month primary care nurse-delivered pre-diabetes dietary intervention. Incidence of T2DM at 2 years will be examined.

METHODS AND ANALYSIS

Four hundred participants with pre-diabetes (New Zealand definition glycated haemoglobin 41-49 mmol/mol) and a body mass index >25 kg/m² will be recruited through eight primary care practices in Hawke's Bay, New Zealand. Trained primary care nurses will deliver a 6-month structured dietary intervention, followed by quarterly reviews for 18 months post-intervention. Clinical data, data on lifestyle factors and health-related quality of life (HR-QoL) and blood samples will be collected at baseline, 6 months, 12 months and 24 months. Sixty participants purposefully selected will complete a semi-structured interview following the 6-month intervention. Poisson regression with robust standard errors and clustered by practice will be used to identify predictors of regression or progression at 6 months, and risk factors for developing T2DM at 2 years. Qualitative data will be analysed thematically. Changes in HR-QoL will be described and potential cost savings will be estimated from a funder's perspective at 2 years.

ETHICS AND DISSEMINATION

This study was approved by the Northern A Health and Disability Ethics Committee, New Zealand (Ethics Reference: 17/NTA/24). Study results will be presented to participants, published in peer-reviewed journals and presented at relevant conferences.

TRIAL REGISTRATION NUMBER

ACTRN12617000591358; Pre-results.

[Diabetes mellitus-Definition, classification, diagnosis, screening and prevention (Update 2019)]

Diabetes mellitus comprises a group of heterogeneous disorders, which have an increase in blood glucose concentrations in common. The current classification for diabetes mellitus is presented and the main features of type 1 and type 2 diabetes are compared. Furthermore, the criteria for the correct biochemical diagnosis during fasting and oral glucose tolerance tests as well as the use of hemoglobin A1c (HbA1c) are summarized. The increasing prevalence of diabetes requires targeted screening for detecting diabetes and prediabetes in risk groups. This forms the basis for the early initiation of measures to prevent the onset of diabetes in these risk groups and to delay the progression of diabetes.

Comparison of the Effectiveness of Lifestyle Modification with Other Treatments on the Incidence of Type 2 Diabetes in People at High Risk: A Network Meta-Analysis

BACKGROUND

Many clinical trials have been conducted to verify the effects of interventions for prevention of type 2 diabetes (T2D) using different treatments and outcomes. The aim of this study was to compare the effectiveness of lifestyle modifications (LM) with other treatments in persons at high risk of T2D by a network meta-analysis (NMA).

METHODS

Searches were performed of PUBMED up to January 2018 to identify randomized controlled trials. The odds ratio (OR) with onset of T2D at 1 year in the intervention group (LM, dietary, exercise, or medication) versus a control group (standard treatments or placebo) were the effect sizes. Frequentist and Bayesian NMAs were conducted.

RESULTS

Forty-seven interventions and 12 treatments (20,113 participants) were used for the analyses. The OR in the LM was approximately 0.46 (95% CI: 0.33 to 0.61) times lower compared to the standard intervention by the Bayesian approach. The effects of LM compared to other treatments by indirect comparisons were not significant.

CONCLUSIONS

This meta-analysis further strengthened the evidence that LM reduces the onset of T2D compared to standard and placebo interventions and appears to be at least as effective as nine other treatments in preventing T2D.

Weight change and mortality and cardiovascular outcomes in patients with new-onset diabetes mellitus: a nationwide cohort study

BACKGROUND

Because weight control is a cornerstone of diabetes management, it is important to understand the relationship of weight change to risk of cardiovascular disease (CVD) among patients with type 2 diabetes mellitus (DM). We aimed to investigate whether changes in weight early after diagnosis influence the incidence of CVD and all-cause mortality in patients with type 2 DM.

METHODS

Using nationally representative data from the Korean National Health Insurance System, 173,246 subjects with new-onset DM who underwent health examinations during 2007-2012 were included. Weight was measured at the time of diabetes diagnosis and 2 years later. Weight change over 2 years was divided into five categories of 5% weight change, from weight loss ≥ - 10% to weight gain ≥ 10%.

RESULTS

There were 3113 deaths (1.8%), 2060 cases of stroke (1.2%), and 1767 myocardial infarctions (MIs) (1.0%) during a median follow-up of 5.5 years. Subjects with weight gain ≥ 10% had a significantly higher risk of stroke (hazard ratio [HR] 1.51, 95% confidence interval [CI] 1.23-1.84), compared with the group with stable weight. There was no significant association between weight change after diagnosis of DM and incident MI. All-cause mortality showed a U-shaped curve according to weight change. The group with weight loss ≥ - 10% had the highest HR for all-cause mortality (HR 1.86; 95% CI 1.61-2.14) and the HR for weight gain ≥ 10% was 1.61 (95% CI 1.37-1.89).

CONCLUSIONS

Weight changes of more than 10% after diabetes diagnosis were associated with higher mortality and over 10% weight gain was associated with increased risk of stroke.

Social cognitive theory-based intervention to promote physical activity among prediabetic rural people: a cluster randomized controlled trial

Background

The present randomized controlled trial (RCT) evaluated the effectiveness of a theory-based physical activity (PA) intervention for rural patients with prediabetes. It was hypothesized that a PA intervention program based on the social cognitive theory (SCT) will modify fasting blood sugar (FBS) among rural people with prediabetes, which in turn will result in a decrease in diabetes incidence in the rural area.

Methods

A cluster RCT on prediabetic people was conducted in Ahar, East Azerbaijan Province, Iran. A PA intervention in prediabetes was performed over 16 weeks of follow-ups in 12 villages (six per arm). Residents (n = 272; n = 136 per arm) were invited to participate in the study through rural health care centers during screening for eligibility. Participants in the intervention and control groups were informed of their prediabetic conditions and encouraged to make appropriate changes to their lifestyles to modify their prediabetes. The intervention was an educational program delivered over 16 weeks and involved behavioral change techniques. Through the education program, the intervention group received one session per week lasting about 90 min (a total of 16 sessions). The importance of risk control with PA, the duration of hill climbing, as well as exercise and safety tips were explained in a brochure that was given to the participants. Anthropometric measures, glycemic status, and PA were evaluated at the beginning of the program and after 16 weeks of follow-up.

Results

The PA program showed a reduction in FBS mg/dl at 16 weeks (large-effect-size Cohen’s d = −0.63, p = 0.001) compared to the control condition. PA intervention led to a large effect size on diastolic blood pressure (BP, − 1.01) and a medium effect size for systolic BP (− 0.57), body mass index (BMI, − 0.33), and weight (− 0.35). Based on generalized linear mixed model analysis, significant reductions in FBS (mg/dl), BMI, weight, and diastolic BP were found in the intervention group compared to the control group.

Conclusion

Our results support the effectiveness of an SCT-based PA intervention to reduce the risk of prediabetes developing into diabetes among rural patients with prediabetes. Findings suggest that implementation of SCT-based PA intervention for a rural population at risk of diabetes has potential benefits.

Trial registration

Iranian Registry of Clinical Trials, IRCT201607198132N4. Registered on 1 September 2017. Prospectively registered.

Effects of Lifestyle Modification and Anti-diabetic Medicine on Prediabetes Progress: A Systematic Review and Meta-Analysis

Background: Pre-diabetes is a risk factor for full-blown diabetes; it presents opportunities to prevent the actual diseases. It is therefore essential to identify effective preventive strategies, and to clarify the direction of future research. Methods: PubMed, Embase and Cochrane Central Register of Controlled Trials were searched using key terms (Supplementary Table 1). We applied network meta-analysis to multiple comparisons among various diabetic preventive strategies, including lifestyle and pharmacological interventions; traditional meta-analysis for the synthesis of basal metabolic changes after interventions; and trial sequential analysis for determinations as to whether analysis conclusions meet expectations. Results: We included 32 randomized controlled trials comprising 43,669 patients and 14 interventions in the meta-analysis. Both lifestyle modifications and anti-diabetic medications improved physical conditions, including weight loss, blood glucose, and blood pressure. Network meta-analysis suggested that the progression of diabetes could be delayed to varying degrees by lifestyle and pharmacological interventions, except for angiotensin-converting enzyme inhibitors, statins, sulfonylureas and vitamin D. The risk ratios (RR) [95% credible interval (CrI)] compared with control were: GLP-1RAs 0.28 (0.15, 0.50), Orlistat 0.33 (0.18, 0.55), TZM 0.33 (0.16, 0.63), TZD 0.39 (0.27, 0.53), LST 0.54 (0.32, 0.88), lifestyle 0.58 (0.49, 0.67), LSM 0.62 (0.45, 0.80), GI 0.66 (0.46, 0.88), SU 0.67 (0.40, 1.00), Vitamin D 0.91 (0.59, 1.40), ACEI 0.93 (0.62, 1.40), statins 1.20 (0.84, 1.60). Conclusions: In adults with pre-diabetes, firm evidence supports the notion that lifestyle modifications and metformin reduces the incidence of diabetes with an average of 20% relative risk reduction, while statins increase the relative risk 20%. We found that lifestyle modifications, promising long-term strategies involving three factors (nutrition, exercise, and weight loss) contribute to health by reducing BMI, body weight, waist and hip circumference, systolic and diastolic pressure, fasting, and 2-h postprandial blood glucose, total cholesterol and by increasing HDL. We made this determination using TSA, avoiding further waste of experimental resources.

Effects of lifestyle changes on adults with prediabetes: A systematic review and meta-analysis

AIMS

To assess the efficacy, safety, and cost-effectiveness of lifestyle intervention, compared with treatment as usual in people with prediabetes as defined by the American Diabetes Association. For older studies, we used the 1985 World Health Organization definition.

METHODS

We systematically searched multiple electronic databases and referenced lists of pertinent review articles from January 1980 through November 2015. We performed an update search in MEDLINE on April 26, 2017. Based on a priori established eligibility criteria, we dually reviewed the literature, extracted data, and rated the risk of bias of included studies with validated checklists. To assess the efficacy of lifestyle intervention to prevent or delay further progression to type 2 diabetes, we conducted a random-effects meta-analysis. We assessed the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.

RESULT

Pooled results of 16 randomized controlled trials showed that people with prediabetes who received lifestyle intervention had a lower rate of progression to type 2 diabetes after one (4% vs. 10%, RR 0.46 [CI 0.32, 0.66]) and three years of follow-up (14% vs. 23%, RR 0.64 [95% CI 0.53, 0.77]). The majority of the studies also showed a greater weight loss in lifestyle intervention participants, with a great variation between studies. Costs per quality-adjusted life-year were lower when the benefits of lifestyle intervention were analyzed over a lifelong time horizon compared to only the period of lifestyle intervention (three years) or to modeling over a ten-year period.

CONCLUSION

Lifestyle intervention is an efficacious, safe, and cost-effective measure to reduce the risk of progression to type 2 diabetes in people diagnosed with prediabetes. More research is necessary to compare the efficacy of various modes, frequencies, and intensities of lifestyle intervention across studies.

Diabetes Among Non-Overweight Individuals: an Emerging Public Health Challenge

PURPOSE OF REVIEW

Overweight and obesity are well-established risk factors for type 2 diabetes. However, a substantial number of individuals develop the disease at underweight or normal weight. In this review, we discuss the epidemiology of type 2 diabetes in non-overweight adults; pose questions about etiology, pathophysiology, diagnosis, and prognosis; and examine implications for prevention and treatment.

RECENT FINDINGS

In population-based studies, the prevalence of type 2 diabetes ranged from 1.4-10.9%. However, the prevalence of type 2 diabetes in individuals with BMI < 25 kg/m² ranged from 1.4-8.8%. In countries from Asia and Africa, the proportion of individuals with diabetes who were underweight or normal weight ranged from 24 to 66%, which is considerably higher than the US proportion of 10%. Impairments in insulin secretion, in utero undernutrition, and epigenetic alterations to the genome may play a role in diabetes development in this subgroup. A substantial number of individuals with type 2 diabetes, particularly those with recent ancestry from Asia or Africa, are underweight or normal weight. Future research should consist of comprehensive studies of the prevalence of type 2 diabetes in non-overweight individuals; studies aimed at understanding gaps in the mechanisms, etiology, and pathophysiology of diabetes development in underweight or normal weight individuals; and trials assessing the effectiveness of interventions in this population.

Rationale and Descriptive Analysis of Specific Health Guidance: the Nationwide Lifestyle Intervention Program Targeting Metabolic Syndrome in Japan

AIM

All health insurers in Japan are mandated to provide Specific Health Checkups and Specific Health Guidance (SHG) focusing on metabolic syndrome (MetS) in middle-aged adults, beginning in 2008; intensive HG for individuals who have abdominal obesity and two or more additional MetS risk factors, and motivational HG for individuals with one risk factor. The aim of this study is to describe medium-term changes in health indexes for intensive and motivational HG groups using the National Database.

METHODS

We compared changes of risk factors and initiation of pharmacological therapy over 3 yr between participants (n=31,790) and nonparticipants (n=189,726) who were eligible for SHG in 2008.

RESULTS

Body weight reduction in intensive HG was 1.98 kg (participants) vs 0.42 kg (nonparticipants) in men (p＜0.01) and 2.25 vs 0.68 kg in women (p＜0.01) after 1 yr. In motivational HG, the respective reduction was 1.40 vs 0.30 kg in men (p＜0.01) and 1.53 vs 0.42 kg in women (p＜0.01). Waist circumference reduction was also greatest among participants in intensive HG (2.34 cm in men and 2.98 cm in women). These reductions were fairly unchanged over 3 yr and accompanied greater improvements in MetS risk factors in participants. We also detected significantly smaller percentages of SHG participants who initiated pharmacological therapy compared with nonparticipants.

CONCLUSION

Participants in SHG showed greater improvements in MetS profiles with proportionally smaller pharmacological treatment initiations than did nonparticipants for 3 yr. Although selection bias may be present, this study suggests SHG would be a feasible strategy to prevent MetS and its sequelae.

Cultural adaptation of a peer-led lifestyle intervention program for diabetes prevention in India: the Kerala diabetes prevention program (K-DPP)

BACKGROUND

Type 2 diabetes mellitus (T2DM) is now one of the leading causes of disease-related deaths globally. India has the world's second largest number of individuals living with diabetes. Lifestyle change has been proven to be an effective means by which to reduce risk of T2DM and a number of "real world" diabetes prevention trials have been undertaken in high income countries. However, systematic efforts to adapt such interventions for T2DM prevention in low- and middle-income countries have been very limited to date. This research-to-action gap is now widely recognised as a major challenge to the prevention and control of diabetes. Reducing the gap is associated with reductions in morbidity and mortality and reduced health care costs. The aim of this article is to describe the adaptation, development and refinement of diabetes prevention programs from the USA, Finland and Australia to the State of Kerala, India.

METHODS

The Kerala Diabetes Prevention Program (K-DPP) was adapted to Kerala, India from evidence-based lifestyle interventions implemented in high income countries, namely, Finland, United States and Australia. The adaptation process was undertaken in five phases: 1) needs assessment; 2) formulation of program objectives; 3) program adaptation and development; 4) piloting of the program and its delivery; and 5) program refinement and active implementation.

RESULTS

The resulting program, K-DPP, includes four key components: 1) a group-based peer support program for participants; 2) a peer-leader training and support program for lay people to lead the groups; 3) resource materials; and 4) strategies to stimulate broader community engagement. The systematic approach to adaptation was underpinned by evidence-based behavior change techniques.

CONCLUSION

K-DPP is the first well evaluated community-based, peer-led diabetes prevention program in India. Future refinement and utilization of this approach will promote translation of K-DPP to other contexts and population groups within India as well as other low- and middle-income countries. This same approach could also be applied more broadly to enable the translation of effective non-communicable disease prevention programs developed in high-income settings to create context-specific evidence in rapidly developing low- and middle-income countries.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Registry: ACTRN12611000262909 . Registered 10 March 2011.

Self-efficacy and diabetes prevention in overweight South Asians with pre-diabetes

OBJECTIVE

We evaluated the effects of a diabetes prevention itervention on self-efficacy (SE) and the associations between SE and diabetes-related outcomes among overweight Asian Indian adults with pre-diabetes in a randomized controlled translational trial (the Diabetes Community Lifestyle Improvement Program, D-CLIP).

RESEARCH DESIGN AND METHODS

Data were obtained from 550 adults who were randomized to a diabetes prevention program or standard of care. Dietary and exercise-related SEs were measured at baseline, core intervention completion (4  months), and annually until the end of follow-up (3 years or diabetes diagnosis). Mixed-effects regressions described changes in SE over time by treatment group. Among treatment participants, multivariable-adjusted models described associations of SE at baseline and intervention completion with diabetes incidence and other secondary outcomes (weight, waist circumference (WC), exercise, and energy intake).

RESULTS

From baseline to 4  months, dietary (β=10.3, p=0.04) and exercise (β=0.49, p=0.04) SE increased significantly in the treatment arm only; however, this increase from baseline was no longer significant at later time points. Among treatment participants, there was no association of dietary or exercise SE with diabetes incidence, but baseline exercise SE was independently associated with improved weight, WC, and exercise at 4  months (p<0.05). Change in exercise SE from baseline to intervention completion also predicted increased exercise at 4, 12, and 24 months (p<0.05).

CONCLUSIONS

Exposure to D-CLIP resulted in improved SE at treatment completion, but this effect was not sustained over longer follow-up. Several short-term and long-term secondary outcomes, but not diabetes risk, were significantly associated with exercise SE, suggesting this psychosocial trait may facilitate success in achieving certain health goals.

TRIAL REGISTRATION NUMBER

NCT01283308.

Lifestyle and the Prevention of Type 2 Diabetes: A Status Report

Diabetes is a costly disease affecting 387 million individuals globally and 28 million in the United States. Its precursor, prediabetes, affects 316 and 86 million individuals globally and in the United States, respectively. People living with elevated blood glucose levels are at high risk for all-cause mortality and numerous cardiometabolic ailments. Fortunately, diabetes can be prevented or delayed by maintaining a healthy lifestyle and a healthy body weight. In this review, we summarize the literature around lifestyle diabetes prevention programs and provide recommendations for introducing prevention strategies in clinical practice. Overall, evidence supports the efficacy and effectiveness of lifestyle diabetes prevention interventions across clinical and community settings, delivery formats (eg, individual-, group-, or technology-based), and implementers (eg, clinicians, community members). Evidence-based diabetes prevention strategies that can be implemented in clinical practice include brief behavior change counseling, group-based education, community referrals, and health information technologies. These strategies represent opportunities where practitioners, communities, and health care systems can work together to provide individuals with education, support and opportunities to maintain healthy, diabetes-free lifestyles.

Diet, physical activity or both for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk of developing 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 diet, physical activity or both can prevent or delay T2DM and its associated complications in at-risk people is unknown.

OBJECTIVES

To assess the effects of diet, physical activity or both on the prevention or delay of T2DM and its associated complications in people at increased risk of developing T2DM.

SEARCH METHODS

This is an update of the Cochrane Review published in 2008. We searched the CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, ICTRP Search Portal and reference lists of systematic reviews, articles and health technology assessment reports. The date of the last search of all databases was January 2017. We continuously used a MEDLINE email alert service to identify newly published studies using the same search strategy as described for MEDLINE up to September 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with a duration of two years or more.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology for data collection and analysis. We assessed the overall quality of the evidence using GRADE.

MAIN RESULTS

We included 12 RCTs randomising 5238 people. One trial contributed 41% of all participants. The duration of the interventions varied from two to six years. We judged none of the included trials at low risk of bias for all 'Risk of bias' domains.Eleven trials compared diet plus physical activity with standard or no treatment. Nine RCTs included participants with impaired glucose tolerance (IGT), one RCT included participants with IGT, impaired fasting blood glucose (IFG) or both, and one RCT included people with fasting glucose levels between 5.3 to 6.9 mmol/L. A total of 12 deaths occurred in 2049 participants in the diet plus physical activity groups compared with 10 in 2050 participants in the comparator groups (RR 1.12, 95% CI 0.50 to 2.50; 95% prediction interval 0.44 to 2.88; 4099 participants, 10 trials; very low-quality evidence). The definition of T2DM incidence varied among the included trials. Altogether 315 of 2122 diet plus physical activity participants (14.8%) developed T2DM compared with 614 of 2389 comparator participants (25.7%) (RR 0.57, 95% CI 0.50 to 0.64; 95% prediction interval 0.50 to 0.65; 4511 participants, 11 trials; moderate-quality evidence). Two trials reported serious adverse events. In one trial no adverse events occurred. In the other trial one of 51 diet plus physical activity participants compared with none of 51 comparator participants experienced a serious adverse event (low-quality evidence). Cardiovascular mortality was rarely reported (four of 1626 diet plus physical activity participants and four of 1637 comparator participants (the RR ranged between 0.94 and 3.16; 3263 participants, 7 trials; very low-quality evidence). Only one trial reported that no non-fatal myocardial infarction or non-fatal stroke had occurred (low-quality evidence). Two trials reported that none of the participants had experienced hypoglycaemia. One trial investigated health-related quality of life in 2144 participants and noted that a minimal important difference between intervention groups was not reached (very low-quality evidence). Three trials evaluated costs of the interventions in 2755 participants. The largest trial of these reported an analysis of costs from the health system perspective and society perspective reflecting USD 31,500 and USD 51,600 per quality-adjusted life year (QALY) with diet plus physical activity, respectively (low-quality evidence). There were no data on blindness or end-stage renal disease.One trial compared a diet-only intervention with a physical-activity intervention or standard treatment. The participants had IGT. Three of 130 participants in the diet group compared with none of the 141 participants in the physical activity group died (very low-quality evidence). None of the participants died because of cardiovascular disease (very low-quality evidence). Altogether 57 of 130 diet participants (43.8%) compared with 58 of 141 physical activity participants (41.1%) group developed T2DM (very low-quality evidence). No adverse events were recorded (very low-quality evidence). There were no data on non-fatal myocardial infarction, non-fatal stroke, blindness, end-stage renal disease, health-related quality of life or socioeconomic effects.Two trials compared physical activity with standard treatment in 397 participants. One trial included participants with IGT, the other trial included participants with IGT, IFG or both. One trial reported that none of the 141 physical activity participants compared with three of 133 control participants died. The other trial reported that three of 84 physical activity participants and one of 39 control participants died (very low-quality evidence). In one trial T2DM developed in 58 of 141 physical activity participants (41.1%) compared with 90 of 133 control participants (67.7%). In the other trial 10 of 84 physical activity participants (11.9%) compared with seven of 39 control participants (18%) developed T2DM (very low-quality evidence). Serious adverse events were rarely reported (one trial noted no events, one trial described events in three of 66 physical activity participants compared with one of 39 control participants - very low-quality evidence). Only one trial reported on cardiovascular mortality (none of 274 participants died - very low-quality evidence). Non-fatal myocardial infarction or stroke were rarely observed in the one trial randomising 123 participants (very low-quality evidence). One trial reported that none of the participants in the trial experienced hypoglycaemia. One trial investigating health-related quality of life in 123 participants showed no substantial differences between intervention groups (very low-quality evidence). There were no data on blindness or socioeconomic effects.

AUTHORS' CONCLUSIONS

There is no firm evidence that diet alone or physical activity alone compared to standard treatment influences the risk of T2DM and especially its associated complications in people at increased risk of developing T2DM. However, diet plus physical activity reduces or delays the incidence of T2DM in people with IGT. Data are lacking for the effect of diet plus physical activity for people with intermediate hyperglycaemia defined by other glycaemic variables. Most RCTs did not investigate patient-important outcomes.

Long-term Sustainability of Diabetes Prevention Approaches: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Importance

Diabetes prevention is imperative to slow worldwide growth of diabetes-related morbidity and mortality. Yet the long-term efficacy of prevention strategies remains unknown.

Objective

To estimate aggregate long-term effects of different diabetes prevention strategies on diabetes incidence.

Data Sources

Systematic searches of MEDLINE, EMBASE, Cochrane Library, and Web of Science databases. The initial search was conducted on January 14, 2014, and was updated on February 20, 2015. Search terms included prediabetes, primary prevention, and risk reduction.

Study Selection

Eligible randomized clinical trials evaluated lifestyle modification (LSM) and medication interventions (>6 months) for diabetes prevention in adults (age ≥18 years) at risk for diabetes, reporting between-group differences in diabetes incidence, published between January 1, 1990, and January 1, 2015. Studies testing alternative therapies and bariatric surgery, as well as those involving participants with gestational diabetes, type 1 or 2 diabetes, and metabolic syndrome, were excluded.

Data Extraction and Synthesis

Reviewers extracted the number of diabetes cases at the end of active intervention in treatment and control groups. Random-effects meta-analyses were used to obtain pooled relative risks (RRs), and reported incidence rates were used to compute pooled risk differences (RDs).

Main Outcomes and Measures

The main outcome was aggregate RRs of diabetes in treatment vs control participants. Treatment subtypes (ie, LSM components, medication classes) were stratified. To estimate sustainability, post-washout and follow-up RRs for medications and LSM interventions, respectively, were examined.

Results

Forty-three studies were included and pooled in meta-analysis (49 029 participants; mean [SD] age, 57.3 [8.7] years; 48.0% [n = 23 549] men): 19 tested medications; 19 evaluated LSM, and 5 tested combined medications and LSM. At the end of the active intervention (range, 0.5-6.3 years), LSM was associated with an RR reduction of 39% (RR, 0.61; 95% CI, 0.54-0.68), and medications were associated with an RR reduction of 36% (RR, 0.64; 95% CI, 0.54-0.76). The observed RD for LSM and medication studies was 4.0 (95% CI, 1.8-6.3) cases per 100 person-years or a number-needed-to-treat of 25. At the end of the washout or follow-up periods, LSM studies (mean follow-up, 7.2 years; range, 5.7-9.4 years) achieved an RR reduction of 28% (RR, 0.72; 95% CI, 0.60-0.86); medication studies (mean follow-up, 17 weeks; range, 2-52 weeks) showed no sustained RR reduction (RR, 0.95; 95% CI, 0.79-1.14).

Conclusions and Relevance

In adults at risk for diabetes, LSM and medications (weight loss and insulin-sensitizing agents) successfully reduced diabetes incidence. Medication effects were short lived. The LSM interventions were sustained for several years; however, their effects declined with time, suggesting that interventions to preserve effects are needed.

Preventing type 2 diabetes: systematic review of studies of cost-effectiveness of lifestyle programmes and metformin, with and without screening, for pre-diabetes

OBJECTIVE

Explore the cost-effectiveness of lifestyle interventions and metformin in reducing subsequent incidence of type 2 diabetes, both alone and in combination with a screening programme to identify high-risk individuals.

DESIGN

Systematic review of economic evaluations.

DATA SOURCES AND ELIGIBILITY CRITERIA

Database searches (Embase, Medline, PreMedline, NHS EED) and citation tracking identified economic evaluations of lifestyle interventions or metformin alone or in combination with screening programmes in people at high risk of developing diabetes. The International Society for Pharmaco-economics and Outcomes Research's Questionnaire to Assess Relevance and Credibility of Modelling Studies for Informing Healthcare Decision Making was used to assess study quality.

RESULTS

27 studies were included; all had evaluated lifestyle interventions and 12 also evaluated metformin. Primary studies exhibited considerable heterogeneity in definitions of pre-diabetes and intensity and duration of lifestyle programmes. Lifestyle programmes and metformin appeared to be cost effective in preventing diabetes in high-risk individuals (median incremental cost-effectiveness ratios of £7490/quality-adjusted life-year (QALY) and £8428/QALY, respectively) but economic estimates varied widely between studies. Intervention-only programmes were in general more cost effective than programmes that also included a screening component. The longer the period evaluated, the more cost-effective interventions appeared. In the few studies that evaluated other economic considerations, budget impact of prevention programmes was moderate (0.13%-0.2% of total healthcare budget), financial payoffs were delayed (by 9-14 years) and impact on incident cases of diabetes was limited (0.1%-1.6% reduction). There was insufficient evidence to answer the question of (1) whether lifestyle programmes are more cost effective than metformin or (2) whether low-intensity lifestyle interventions are more cost effective than the more intensive lifestyle programmes that were tested in trials.

CONCLUSIONS

The economics of preventing diabetes are complex. There is some evidence that diabetes prevention programmes are cost effective, but the evidence base to date provides few clear answers regarding design of prevention programmes because of differences in denominator populations, definitions, interventions and modelling assumptions.

Effect of antihyperglycemic drug monotherapy to prevent the progression of mild hyperglycemia in early type 2 diabetic patients: the Japan Early Diabetes Intervention Study (JEDIS)

To effectively prevent the worsening of hyperglycemia in type 2 diabetes mellitus, it is of interest to see the clinical efficacy of early introduction of pharmacotherapy in addition to lifestyle intervention which is not always easy to continue throughout life. This is a randomized unblinded comparative clinical study on suppressive effects of lifestyle intervention alone and additional monotherapies for mild hyperglycemia at an early stage of treatment-naïve type 2 diabetic patients, whose fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) are less than 140 mg/dl and 7.4%, respectively. The control group (group N = arm N) received conventional lifestyle intervention assisted by routine facilities, while the pharmacological intervention group (group D composed of 4 arms) was additionally treated by monotherapy with one of four kinds of oral antihyperglycemic agents i.e., sulfonylurea (SU), α-glucosidase inhibitor, biguanide and dipeptidyl peptidase-4 inhibitor. The participants were scheduled to follow up for 3 years to maintain glycemic control below primary endpoint which was defined as the first occurrence of FPG ≥140 mg/dl and HbA1c ≥7.4% simultaneously even by increasing doses of oral drug in group D, if necessary. The outcomes of occurrences of primary endpoint were not different between group N and group D composed of 4 arms during 3 years by Kaplan-Meyer plots (p = 0.405). On the other hand, ΔFPG (Δ: incremental change from baseline) and ΔHbA1c in group D significantly decreased when compared to those of group N during 3 years (p < 0.05 and p < 0.01 respectively). Significant reductions of ΔBMI were seen similarly in both groups throughout the study (p < 0.05), but did not differ between two groups. Among these 5 arms, significant decreases of ΔHbA1c were observed in three monotherapy arms of group D compared to arm N for 3 years (p < 0.05 or p < 0.01), except for arm SU in which ΔBMI and ΔHbA1c tended to increase at the latter half of the study. The final achievement rates of target HbA1c less than 7.4, 7.0 and 6.5% in all the participants tended to be higher in group D than in group N (p < 0.047 for 7.4%, but not significant for others). In conclusion, the early introduction of pharmacological monotherapy in addition to lifestyle intervention seem to suppress mild hyperglycemia with small doses of antihyperglycemic agents for 3 years, except for the use of SU drug. Although a larger scale of trial will be necessary to conclude, the early treatment with suitable monotherapy could be effective to bring and keep "safe level of glycemia".

Diabetes prevention in the real world: Insights from the JDPP and J-DOIT1

Type 2 diabetes (T2D) is associated with increased risks of morbidity and mortality. Diabetes prevention is an urgent issue in Japan. The Finnish Diabetes Prevention Study and US Diabetes Prevention Program revealed that intensive lifestyle intervention can prevent or delay the development of T2D in high-risk populations. Translational research varies in hospitals, primary care, communities, the workplace, and other settings. Translational research is feasible but less effective. There have been no long-term follow-ups. The outcome of the studies was mainly weight changes. The Japan Diabetes Prevention Program (JDPP) is a trial to test the efficacy of a lifestyle intervention program, which carried out in a primary healthcare setting using existing resources. The Japan Diabetes Outcome Trial-1 (J-DOIT1) is a nationwide telephone-delivered lifestyle intervention in a real-world setting. This review will focus on the effectiveness of a diabetes prevention program (recruitment, target population, method of intervention, and evaluation) in the real world and insights from the JDPP and J-DOIT1.

Lack of efficacy of pomegranate supplementation for glucose management, insulin levels and sensitivity: evidence from a systematic review and meta-analysis

Background

The potential glucose-lowering effects of pomegranate have been reported in animal and observational studies, but intervention studies in humans have generated mixed results. In this paper, we aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the precise effects of pomegranate supplementation on measures of glucose control, insulin levels and insulin sensitivity in humans.

Methods

Comprehensive electronic searches were conducted in PubMed, Embase, and the Cochrane Library. Studies included were RCTs that evaluated the changes in diabetes biomarkers among adults (≥18 years) following pomegranate interventions. The predefined outcomes included fasting blood glucose (FBG), fasting blood insulin (FBI), glycated haemoglobin (HbA1c), and homeostatic model assessment of insulin resistance (HOMA-IR). Endpoints were calculated as weighted mean differences (WMDs) with 95% confidence intervals (CIs) by using a random-effects model. Publication bias, subgroup analyses, sensitivity analysis and random-effects meta-regression were also performed to explore the influence of covariates on the net changes in fasting glucose and insulin concentrations.

Results

Sixteen eligible trials with 538 subjects were included. The pooled estimates suggested that pomegranate did not significantly affect the measures of FBG (WMD, −0.6 mg/dL; 95% CI, −2.79 to 1.58; P=0.59), FBI (WMD, 0.29 μIU/mL; 95% CI, −1.16 to 1.75; P=0.70), HOMA-IR (WMD, −0.04; 95% CI, −0.53 to 0.46; P=0.88) or HbA1c (WMD, −0.11%; 95% CI, −0.39 to −0.18; P=0.46). Overall, significant heterogeneity was detected for FBI and HOMA-IR, but subgroup analysis could not identify factors significantly influencing these parameters. These results were robust in sensitivity analysis, and no significant publication bias was found in the current meta-analysis.

Conclusion

Pomegranate intake did not show a notably favourable effect on improvements in glucose and insulin metabolism. The current evidence suggests that daily pomegranate supplementation is not recommended as a potential therapeutic strategy in glycemic management. Further large-scale RCTs with longer duration are required to confirm these results.

Electronic supplementary material

The online version of this article (10.1186/s12937-017-0290-1) contains supplementary material, which is available to authorized users.

Lifestyle precision medicine: the next generation in type 2 diabetes prevention?

The driving force behind the current global type 2 diabetes epidemic is insulin resistance in overweight and obese individuals. Dietary factors, physical inactivity, and sedentary behaviors are the major modifiable risk factors for obesity. Nevertheless, many overweight/obese people do not develop diabetes and lifestyle interventions focused on weight loss and diabetes prevention are often ineffective. Traditionally, chronically elevated blood glucose concentrations have been the hallmark of diabetes; however, many individuals will either remain 'prediabetic' or regress to normoglycemia. Thus, there is a growing need for innovative strategies to tackle diabetes at scale. The emergence of biomarker technologies has allowed more targeted therapeutic strategies for diabetes prevention (precision medicine), though largely confined to pharmacotherapy. Unlike most drugs, lifestyle interventions often have systemic health-enhancing effects. Thus, the pursuance of lifestyle precision medicine in diabetes seems rational. Herein, we review the literature on lifestyle interventions and diabetes prevention, describing the biological systems that can be characterized at scale in human populations, linking them to lifestyle in diabetes, and consider some of the challenges impeding the clinical translation of lifestyle precision medicine.

The Effectiveness and Cost of Lifestyle Interventions Including Nutrition Education for Diabetes Prevention: A Systematic Review and Meta-Analysis

BACKGROUND

Type 2 diabetes is a significant public health concern. With the completion of the Diabetes Prevention Program, there has been a proliferation of studies attempting to translate this evidence base into practice. However, the cost, effectiveness, and cost-effectiveness of these adapted interventions is unknown.

OBJECTIVE

The purpose of this systematic review was to conduct a comprehensive meta-analysis to synthesize the effectiveness, cost, and cost-effectiveness of lifestyle diabetes prevention interventions and compare effects by intervention delivery agent (dietitian vs non-dietitian) and channel (in-person vs technology-delivered).

METHODS

English and full-text research articles published up to July 2015 were identified using the Cochrane Library, PubMed, Education Resources Information Center, CAB Direct, Science Direct, and Google Scholar. Sixty-nine studies met inclusion criteria. Most employed both dietary and physical activity intervention components (four of 69 were diet-only interventions). Changes in weight, fasting and 2-hour blood glucose concentration, and hemoglobin A1c were extracted from each article. Heterogeneity was measured by the I2 index, and study-specific effect sizes or mean differences were pooled using a random effects model when heterogeneity was confirmed.

RESULTS

Participants receiving intervention with nutrition education experienced a reduction of 2.07 kg (95% CI 1.52 to 2.62; P<0.001; I2=90.99%, 95% CI 88.61% to 92.87%) in weight at 12 months with effect sizes over time ranging from small (0.17, 95% CI 0.04 to 0.30; P=0.012; I2= 86.83%, 95% CI 80.42% to 91.14%) to medium (0.65, 95% CI 0.49 to 0.82; P<0.001; I2=98.75%, 95% CI 98.52% to 98.94). Effect sizes for 2-hour blood glucose and hemoglobin A1c level changes ranged from small to medium. The meta-regression analysis revealed a larger relative weight loss in dietitian-delivered interventions than in those delivered by nondietitians (full sample: -1.0 kg; US subsample: -2.4 kg), and did not find statistical evidence that the delivery channel was an important predictor of weight loss. The average cost per kilogram weight loss ranged from $34.06 over 6 months to $1,005.36 over 12 months. The cost of intervention per participant delivered by dietitians was lower than interventions delivered by non-dietitians, although few studies reported costs.

CONCLUSIONS

Lifestyle interventions are effective in reducing body weight and glucose-related outcomes. Dietitian-delivered interventions, compared with those delivered by other personnel, achieved greater weight reduction. No consistent trend was identified across different delivery channels.