Lifestyle Intervention With or Without Lay Volunteers to Prevent Type 2 Diabetes in People With Impaired Fasting Glucose and/or Nondiabetic Hyperglycemia: A Randomized Clinical Trial

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.

Level of attendance at the English National Health Service Diabetes Prevention Programme and risk of progression to type 2 diabetes

BACKGROUND

We evaluated the dose-response relationship between the level of attendance at the English National Health Service Diabetes Prevention Programme (DPP) and risk of progression to type 2 diabetes amongst individuals participating in the programme.

METHODS

We linked data on DPP attendance for 51,803 individuals that were referred to the programme between 1st June 2016 and 31st March 2018 and attended at least one programme session, with primary care records of type 2 diabetes diagnoses from the National Diabetes Audit up to 31st March 2020. Weibull survival regressions were used to estimate the association between the number of programme sessions attended and risk of progression to type 2 diabetes.

RESULTS

Risk of developing type 2 diabetes declined significantly for individuals attending seven of the 13 programme sessions and continued to decline further up to 12 sessions. Attending the full 13 sessions was associated with a 45.5% lower risk (HR: 0.545 95% CI: 0.455 to 0.652). Compared to individuals that only partially attended the programme, attendance at 60% or more of the sessions was associated with a 30.7% lower risk of type 2 diabetes (HR: 0.693 95% CI: 0.645 to 0.745).

CONCLUSIONS

Reducing the risk of progression to type 2 diabetes through diabetes prevention programmes requires a minimum attendance level at seven of the 13 programme sessions (54%). Retaining participants beyond this minimum level yields further benefits in diabetes risk reduction. Commissioners may wish to consider altering provider payment schedules to incentivise higher retention levels beyond 60% of programme sessions.

Quantity and specificity of action-plans as predictors of weight loss: analysis of data from the Norfolk Diabetes Prevention Study (NDPS)

OBJECTIVE

Investigate associations between quantity, content and specificity of action-plans and weight loss in a diabetes prevention study.

DESIGN

Prospective cohort study nested within a randomised controlled trial. Participants completed action-planning worksheets during intervention sessions.

MAIN OUTCOME MEASURES

Action-plans were coded in terms of: number of plans set, their content, and specificity. Multivariate regression analyses assessed associations with weight loss at four-months.

RESULTS

890 planning-worksheets from 106 participants were analysed. Participants wrote a mean of 2.12 (SD = 1.20) action-plans per worksheet, using a mean of 2.20 (SD = 0.68) specificity components per action-plan. Quantity of action-plans per worksheet decreased over time (r = -0.137, p < 0.001) and increased quantity was associated with reduced specificity [r = -.215, p < 0.001]. Walking (34.9% of action-plans) and reducing high fat/sugar snacks (26.1%) were the most commonly planned lifestyle actions. In multivariate modelling, increased quantity of action-plans was associated with greater weight loss (R2 = 0.135, Unstandardised Beta = 0.144, p = 0.002). Specificity was not significantly associated with weight-loss (p = 0.096).

CONCLUSION

Producing more action-plans was associated with greater weight loss. Further research should directly compare more versus less specific action-plans and explore ways to sustain engagement in action-planning. Our findings imply that participants should freely set numerous action-plans, rather than being encouraged to focus on specificity.

Supplemental data for this article is available online at https://doi.org/10.1080/08870446.2022.2055026 .

Association of meal-specific protein intake and cardiometabolic risk factors: a cross-sectional study

We aimed to investigate the association of main meals' specific protein intake with cardiometabolic risk factors, including general and abdominal obesity, serum lipid profile, and blood pressure (BP). This cross-sectional study was conducted on 850 subjects aged 20-59 years. Dietary intakes were assessed by completing three 24-h recalls, and the protein intake of each meal was extracted. Anthropometric measures, lipid profile, fasting blood sugar and BP were measured. Multivariate logistic regression controlling for age, physical activity, sex, marital status, smoking status, BMI and energy intake was applied to obtain OR and CI. The mean age was 42 years, and the mean BMI of the participants was 27·2. The mean protein intake for breakfast, lunch and dinner was 12·5, 22·2 and 18·7 g/d, respectively. After adjustment for confounders, higher protein intake was not associated with any of the cardiometabolic risk factors, including LDL-cholesterol, HDL-cholesterol, total cholesterol (TC), TAG, body weight, BP and fasting plasma glucose, in any of the three main meals consumed within a day. Adherence to a higher protein intake at each meal was not associated with cardiometabolic risk factors in Iranian adults. Further prospective studies are needed to justify our findings.

Addressing the psychology of weight loss and maintenance: A feasibility study of the Skills for weight loss and Maintenance weight management programme

OBJECTIVES

Building on prior theory, we aimed to evaluate the feasibility and acceptability of integrating novel, weight loss maintenance strategies into existing weight management programmes. We also piloted recruitment and data collection procedures for future research.

DESIGN

Two phases of action research nested within a single-arm feasibility study. The intervention was refined between phases using feedback from intervention fidelity analysis and qualitative exploration of patient and provider experiences. Changes in outcomes were assessed up to 18 months post-baseline.

METHODS

One hundred adults with a mean body mass index of 37 kg/m2 were offered the Skills for weight loss and Maintenance (SkiM) intervention. This included existing weight management programme content and additional weight loss maintenance techniques delivered fortnightly for 6 months in local community centres to groups of 11-15 people.

RESULTS

Of the 100 participants, 65%, 58% and 56% provided data at 7, 12 and 18 months. Across both phases, the mean initial weight loss was 4.2 kg (95% CI: 2.4-5.9) and 3.1 kg at 18 months (95% CI: .8-5.5). In Phase 2, we observed better weight loss maintenance (.5 kg [13.2%] regain from 7 to 18 months, vs. 1.7 kg [36.2%] in Phase 1). Variation in outcomes, high early dropout rates and qualitative feedback indicated that, although delivery of the intervention and trial procedures was feasible and acceptable, there was scope to refine the intervention to engage a wider range of participants. Intervention fidelity was acceptable, particularly in Phase 2.

CONCLUSIONS

The SkiM intervention seems promising, but more research is needed to improve recruitment and retention prior to further evaluation.

Evaluating the Short-Term Costs and Benefits of a Nationwide Diabetes Prevention Programme in England: Retrospective Observational Study

BACKGROUND

Prevention programmes typically incur short-term costs and uncertain long-term benefits. We use the National Health Service (NHS) England Diabetes Prevention Programme (NHS-DPP) to investigate whether behaviour change programmes may be cost-effective even within the short-term participation period.

METHODS

We analysed 384,611 referrals between June 2016 and March 2019. We estimated NHS costs using implementation costs and provider payments. We used linear regressions to relate utility changes to the number of sessions attended, based on responses to the five-level EQ-5D (EQ-5D-5L) at baseline and final session for 18,959 participants. We then calculated the corresponding quality-adjusted life year (QALY) change for all 384,611 referrals by combining the estimated regression coefficients with the observed level of attendance, with individuals that did not attend any programme sessions being assumed to experience zero benefit. In secondary analysis, we added weight change, recorded for 18,105 participants to the regression and applied predicted values to all referrals with missing weight change values estimated using multiple imputation with chained equations. We then estimated the cost-per-QALY generated.

RESULTS

Average cost per referral was £119 (standard deviation: £118; 2020 price year, UK £ Sterling). Each session attended was associated with a 0.0042 increase in utility (95% confidence interval (CI): 0.0025-0.0059). This generated 1,773 QALYs across all referrals (95% CI: 889-2,656). Cost-per-QALY was £24,929 (95% CI: £16,635-49,720) when implementation costs were excluded. Secondary analysis showed each session attended and kilogram of weight lost were associated with 0.0034 (95% CI: 0.0016-0.0051) and 0.0025 (95% CI: 0.0020-0.0031) increases in utility, respectively. These generated 1,542 QALYs, at a cost-per-QALY of £28,661 when implementation costs were excluded.

CONCLUSION

Participants experienced small utility gains from session attendance and weight loss during their programme participation. These benefits alone made this low-cost behaviour change programme potentially cost-effective in the short-term.

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.

Effects of treatment with Glucagon-like peptide-1 receptor agonist on prediabetes with overweight/obesity: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the effects of Glucagon-like peptide-1 receptor agonist (GLP-1RA) on prediabetes with overweight/obesity.

METHODS

A search of PubMed, Embase, Cochrane Library, and Web of Science databases was performed to identify randomised controlled trials (up to 4 July 2022) which evaluated the effect of GLP-1RA on prediabetes with overweight/obesity.

RESULTS

Eight hundred and nine articles were retrieved (80 from PubMed, 481 from Embase, 137 from Cochrane library, and 111 from Web of Science) and a total of 5 articles were included in this meta-analysis. More individuals in GLP-1RAs group regressed from prediabetes to normoglycemia than individuals in the placebo group (OR = 4.56, 95% CI:3.58, 5.80, P = 0.004); fewer individuals in GLP-1RAs group were diagnosed with diabetes than those in the placebo group (OR = 0.31, 95% CI:0.12,0.81, P = 0.017). Results from five studies showed that GLP-1RAs significantly reduced fasting glucose (mean difference = -0.41 mmol/L, 95% CI: -0.58, -0.25, P < 0.00001), with an acceptable heterogeneity (I2  = 42%).

CONCLUSIONS

The present meta-analysis suggested that GLP-1RA significantly improves glucose metabolism, reduces systolic blood pressure and body weight in prediabetes with overweight/obesity. It could also prevent the development of diabetes and reverse abnormal glucose metabolism.

Intervention fidelity assessment: A sub-study of the Norfolk Diabetes Prevention Study (NDPS)

BACKGROUND

Previous research has shown that lifestyle modification can delay or prevent the onset of type 2 diabetes in high-risk individuals. The Norfolk Diabetes Prevention Study (NDPS) was a parallel, three-arm, randomized controlled trial with up to 46 months follow-up that tested a group-delivered, theory-based lifestyle intervention to reduce the incidence of type 2 diabetes in high-risk groups. The current study aimed to evaluate if the NDPS intervention was delivered to an acceptable standard and if any part(s) of the delivery required improvement.

METHODS

A sub-sample of 30, 25 for inter-rater reliability and audio-recordings of the NDPS intervention education sessions were assessed independently by two reviewers (CT, TW) using a 12-item checklist. Each item was scored on a 0-5 scale, with a score of 3 being defined as 'adequate delivery'. Inter-rater reliability was assessed. Analysis of covariance (ANCOVA) was used to assess changes in intervention fidelity as the facilitators gained experience.

RESULTS

Inter-rater agreement was acceptable (86%). A mean score of 3.47 (SD = .38) was achieved across all items of the fidelity checklist and across all intervention facilitators (n = 6). There was an apparent trend for intervention fidelity scores to decrease with experience; however, this trend was non-significant (p > .05) across all domains in this small sample.

CONCLUSION

The NDPS was delivered to an acceptable standard by all Diabetes Prevention Facilitators. Further research is needed to better understand how the intervention's delivery characteristics can be optimized and how they might vary over time.

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.

Polygenic Risk Score, Lifestyles, and Type 2 Diabetes Risk: A Prospective Chinese Cohort Study

The aim of this study was to generate a polygenic risk score (PRS) for type 2 diabetes (T2D) and test whether it could be used in identifying high-risk individuals for lifestyle intervention in a Chinese cohort. We genotyped 80 genetic variants among 5024 participants without non-communicable diseases at baseline in the Wuxi Non-Communicable Diseases cohort (Wuxi NCDs cohort). During the follow-up period of 14 years, 440 cases of T2D were newly diagnosed. Using Cox regression, we found that the PRS of 46 SNPs identified by the East Asians was relevant to the future T2D. Participants with a high PRS (top quintile) had a two-fold higher risk of T2D than the bottom quintile (hazard ratio: 2.06, 95% confidence interval: 1.42-2.97). Lifestyle factors were considered, including cigarette smoking, alcohol consumption, physical exercise, diet, body mass index (BMI), and waist circumference (WC). Among high-PRS individuals, the 10-year incidence of T2D slumped from 6.77% to 3.28% for participants having ideal lifestyles (4-6 healthy lifestyle factors) compared with poor lifestyles (0-2 healthy lifestyle factors). When integrating the high PRS, the 10-year T2D risk of low-clinical-risk individuals exceeded that of high-clinical-risk individuals with a low PRS (3.34% vs. 2.91%). These findings suggest that the PRS of 46 SNPs could be used in identifying high-risk individuals and improve the risk stratification defined by traditional clinical risk factors for T2D. Healthy lifestyles can reduce the risk of a high PRS, which indicates the potential utility in early screening and precise prevention.

Construction and Validation of a Model for Predicting Impaired Fasting Glucose Based on More Than 4000 General Population

Purpose

Impaired fasting glucose (IFG) is associated with an increased risk of multiple diseases. Therefore, the early identification and intervention of IFG are particularly significant. Our study aims to construct and validate a clinical and laboratory-based nomogram (CLN) model for predicting IFG risk.

Patients and Methods

This cross-sectional study collected information on health check-up subjects. Risk predictors were screened mainly by the LASSO regression analysis and were applied to construct the CLN model. Furthermore, we showed examples of applications. Then, the accuracy of the CLN model was evaluated by the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC) values, and the calibration curve of the CLN model in the training set and validation set, respectively. The decision curve analysis (DCA) was used to estimate the level of clinical benefit. Furthermore, the performance of the CLN model was evaluated in the independent validation dataset.

Results

In the model development dataset, 2340 subjects were randomly assigned to the training set (N = 1638) and validation set (N = 702). Six predictors significantly associated with IFG were screened and used in the construction of the CLN model, a subject was randomly selected, and the risk of developing IFG was predicted to be 83.6% by using the CLN model. The AUC values of the CLN model were 0.783 in the training set and 0.789 in the validation set. The calibration curve demonstrated good concordance. DCA showed that the CLN model has good clinical application. We further performed independent validation (N = 1875), showed an AUC of 0.801, with the good agreement and clinical diagnostic value.

Conclusion

We developed and validated the CLN model that could predict the risk of IFG in the general population. It not only facilitates the diagnosis and treatment of IFG but also helps to reduce the medical and economic burdens of IFG-related diseases.

Mechanisms of gut microbiota-immune-host interaction on glucose regulation in type 2 diabetes

Intestinal absorption of food is one of the sources of glucose. Insulin resistance and impaired glucose tolerance caused by lifestyle and diet are the precursors of type 2 diabetes. Patients with type 2 diabetes have trouble controlling their blood sugar levels. For long-term health, strict glycemic management is necessary. Although it is thought to be well correlated with metabolic diseases like obesity, insulin resistance, and diabetes, its molecular mechanism is still not completely understood. Disturbed microbiota triggers the gut immune response to reshape the gut homeostasis. This interaction not only maintains the dynamic changes of intestinal flora, but also preserves the integrity of the intestinal barrier. Meanwhile, the microbiota establishes a systemic multiorgan dialog on the gut-brain and gut-liver axes, intestinal absorption of a high-fat diet affects the host's feeding preference and systemic metabolism. Intervention in the gut microbiota can combat the decreased glucose tolerance and insulin sensitivity linked to metabolic diseases both centrally and peripherally. Moreover, the pharmacokinetics of oral hypoglycemic medications are also influenced by gut microbiota. The accumulation of drugs in the gut microbiota not only affects the drug efficacy, but also changes the composition and function of them, thus may help to explain individual therapeutic variances in pharmacological efficacy. Regulating gut microbiota through healthy dietary patterns or supplementing pro/prebiotics can provide guidance for lifestyle interventions in people with poor glycemic control. Traditional Chinese medicine can also be used as complementary medicine to effectively regulate intestinal homeostasis. Intestinal microbiota is becoming a new target against metabolic diseases, so more evidence is needed to elucidate the intricate microbiota-immune-host relationship, and explore the therapeutic potential of targeting intestinal microbiota.

A group-based exercise and behavioural maintenance intervention for adults over 65 years with mobility limitations: the REACT RCT

Background

Mobility limitation in older age reduces quality of life, generates substantial health- and social-care costs, and increases mortality.

Objective

The REtirement in ACTion (REACT) trial aimed to establish whether or not a community-based active ageing intervention could prevent decline in physical functioning in older adults already at increased risk of mobility limitation.

Design

A multicentre, pragmatic, two-arm, parallel-group randomised controlled trial with parallel process and health economic evaluations.

Setting

Urban and semi-rural locations across three sites in England.

Participants

Physically frail or pre-frail older adults (aged ≥ 65 years; Short Physical Performance Battery score of 4–9). Recruitment was primarily via 35 primary care practices.

Interventions

Participants were randomly assigned to receive brief advice (three healthy ageing education sessions) or a 12-month, group-based, multimodal exercise and behavioural maintenance programme delivered in fitness and community centres. Randomisation was stratified by site and used a minimisation algorithm to balance age, sex and Short Physical Performance Battery score. Data collection and analyses were blinded.

Main outcome measures

The primary outcome was change in lower limb physical function (Short Physical Performance Battery score) at 24 months, analysed using an intention-to-treat analysis. The economic evaluation adopted the NHS and Personal Social Services perspective.

Results

Between June 2016 and October 2017, 777 participants (mean age 77.6 years, standard deviation 6.8 years; 66% female; mean Short Physical Performance Battery score 7.37, standard deviation 1.56) were randomised to the intervention arm (n = 410) or the control arm (n = 367). Data collection was completed in October 2019. Primary outcome data at 24 months were provided by 628 (80.8%) participants. At the 24-month follow-up, the Short Physical Performance Battery score was significantly greater in the intervention arm (mean 8.08, standard deviation 2.87) than in the control arm (mean 7.59, standard deviation 2.61), with an adjusted mean difference of 0.49 (95% confidence interval 0.06 to 0.92). The difference in lower limb function between intervention and control participants was clinically meaningful at both 12 and 24 months. Self-reported physical activity significantly increased in the intervention arm compared with the control arm, but this change was not observed in device-based physical activity data collected during the trial. One adverse event was related to the intervention. Attrition rates were low (19% at 24 months) and adherence was high. Engagement with the REACT intervention was associated with positive changes in exercise competence, relatedness and enjoyment and perceived physical, social and mental well-being benefits. The intervention plus usual care was cost-effective compared with care alone over the 2 years of REACT; the price year was 2019. In the base-case scenario, the intervention saved £103 per participant, with a quality-adjusted life-year gain of 0.04 (95% confidence interval 0.006 to 0.074) within the 2-year trial window. Lifetime horizon modelling estimated that further cost savings and quality-adjusted life-year gains were accrued up to 15 years post randomisation.

Conclusion

A relatively low-resource, 1-year multimodal exercise and behavioural maintenance intervention can help older adults to retain physical functioning over a 24-month period. The results indicate that the well-established trajectory of declining physical functioning in older age is modifiable.

Limitations

Participants were not blinded to study arm allocation. However, the primary outcome was independently assessed by blinded data collectors. The secondary outcome analyses were exploratory, with no adjustment for multiple testing, and should be interpreted accordingly.

Future work

Following refinements guided by the process evaluation findings, the REACT intervention is suitable for large-scale implementation. Further research will optimise implementation of REACT at scale.

Trial registration

This trial is registered as ISRCTN45627165.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 10, No. 14. See the NIHR Journals Library website for further project information.

Long-term Effect of Lifestyle Interventions on the Cardiovascular and All-Cause Mortality of Subjects With Prediabetes and Type 2 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

Lifestyle interventions improve the metabolic control of individuals with hyperglycemia.

PURPOSE

We aimed to determine the effect of lifestyle interventions on cardiovascular and all-cause mortality in this population.

DATA SOURCES

Searches were made through MEDLINE, Cochrane CENTRAL, Embase, and Web of Science (no date/language restriction, until 15 May 2022).

STUDY SELECTION

We included randomized clinical trials (RCTs) of subjects with prediabetes and type 2 diabetes, comparing intensive lifestyle interventions with usual care, with a minimum of 2 years of active intervention.

DATA EXTRACTION

Data from the 11 RCTs selected were extracted in duplicate. A frequentist and arm-based meta-analysis was performed with random-effects models to estimate relative risk (RR) for mortality, and heterogeneity was assessed through I2 metrics. A generalized linear mixed model (GLMM) was used to confirm the findings.

DATA SYNTHESIS

Lifestyle interventions were not superior to usual care in reducing cardiovascular (RR 0.99; 95% CI 0.79-1.23) or all-cause (RR 0.93; 95% CI 0.85-1.03) mortality. Subgroup, sensitivity, and meta-regression analyses showed no influence of type of intervention, mean follow-up, age, glycemic status, geographical location, risk of bias, or weight change. All of these results were confirmed with the GLMM. Most studies had a low risk of bias according to the RoB 2.0 tool and the certainty of evidence was moderate for both outcomes.

LIMITATIONS

Most studies had a low risk of bias according to the RoB 2.0 tool, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach resulted in moderate certainty of evidence for both outcomes. Differences in lifestyle programs and in usual care between the studies should be considered in the interpretation of our results.

CONCLUSIONS

Intensive lifestyle interventions implemented so far did not show superiority to usual care in reducing cardiovascular or all-cause mortality for subjects with prediabetes and type 2 diabetes.

The 6-Month Efficacy of an Intensive Lifestyle Modification Program on Type 2 Diabetes Risk Among Rural Women with Prior Gestational Diabetes Mellitus: a Cluster Randomized Controlled Trial

This study aimed to evaluate the efficacy of an intensive lifestyle modification program tailored to rural Chinese women with prior gestational diabetes mellitus compared with usual care. In a cluster randomized controlled trial, 16 towns (clusters) in two distinct rural areas in China were randomly selected (8 towns per district); and 320 women with prior gestational diabetes mellitus were recruited from these towns. With stratification for the two study districts, eight towns (160 women) were randomly assigned to the intervention group of a tailored intensive lifestyle modification program and 8 towns (160 women) to the control group. Process measures were collected on attendance, engagement, fidelity, and satisfaction. Primary efficacy outcomes included glycemic and weight-related outcomes, while secondary efficacy outcomes were behavioral outcomes and type 2 diabetes risk score, which were collected at baseline, 3-month, and 6-month follow-up. Generalized estimation equations were used to analyze the data. High attendance (72% of sessions), engagement (67% of interactive activities and group discussions), fidelity (98%), and satisfaction (92%) with the tailored intensive lifestyle modification program were achieved. There were significant reductions in fasting blood glucose, oral glucose tolerance test 2 h, waist circumference, and type 2 diabetes risk score of participants in the intervention group compared to the control group (p < .05). There was no significant intervention effect on body mass index or behavioral outcomes (p > .05). In this study, we demonstrate the successful efficacy of an Intensive Lifestyle Modification Program in reducing type 2 diabetes risk among younger women with prior gestational diabetes mellitus. This tailored program delivered by local healthcare providers is a promising approach for diabetes prevention in rural China, reducing health disparities in rural communities about diabetes prevention. Registered in the Chinese Clinical Trial Registry (ChiCTR2000037956) on 3rd Jan 2018.

Effect of an Interdisciplinary Weight Loss and Lifestyle Intervention on Obstructive Sleep Apnea Severity: The INTERAPNEA Randomized Clinical Trial

IMPORTANCE

Obesity is the leading cause of obstructive sleep apnea (OSA); however, the effects of weight loss and lifestyle interventions on OSA and comorbidities remain uncertain.

OBJECTIVE

To evaluate the effect of an interdisciplinary weight loss and lifestyle intervention on OSA and comorbidities among adults with moderate to severe OSA and overweight or obesity.

DESIGN, SETTING, AND PARTICIPANTS

The Interdisciplinary Weight Loss and Lifestyle Intervention for OSA (INTERAPNEA) study was a parallel-group open-label randomized clinical trial conducted at a hospital-based referral center in Granada, Spain, from April 1, 2019, to October 23, 2020. The study enrolled 89 Spanish men aged 18 to 65 years with moderate to severe OSA and a body mass index (calculated as weight in kilograms divided by height in meters squared) of 25 or greater who were receiving continuous positive airway pressure (CPAP) therapy. The sole inclusion of men was based on the higher incidence and prevalence of OSA in this population, the differences in OSA phenotypes between men and women, and the known effectiveness of weight loss interventions among men vs women.

INTERVENTIONS

Participants were randomized to receive usual care (CPAP therapy) or an 8-week weight loss and lifestyle intervention involving nutritional behavior change, aerobic exercise, sleep hygiene, and alcohol and tobacco cessation combined with usual care.

MAIN OUTCOMES AND MEASURES

The primary end point was the change in the apnea-hypopnea index (AHI) from baseline to the intervention end point (8 weeks) and 6 months after intervention. Secondary end points comprised changes in other OSA sleep-related outcomes, body weight and composition, cardiometabolic risk, and health-related quality of life.

RESULTS

Among 89 men (mean [SD] age, 54.1 [8.0] years; all of Spanish ethnicity; mean [SD] AHI, 41.3 [22.2] events/h), 49 were randomized to the control group and 40 were randomized to the intervention group. The intervention group had a greater decrease in AHI (51% reduction; change, -21.2 events/h; 95% CI, -25.4 to -16.9 events/h) than the control group (change, 2.5 events/h; 95% CI, -2.0 to 6.9 events/h) at the intervention end point, with a mean between-group difference of -23.6 events/h (95% CI, -28.7 to -18.5 events/h). At 6 months after intervention, the reduction in AHI was 57% in the intervention group, with a mean between-group difference of -23.8 events/h (95% CI, -28.3 to -19.3 events/h). In the intervention group, 18 of 40 participants (45.0%) no longer required CPAP therapy at the intervention end point, and 6 of 40 participants (15.0%) attained complete OSA remission. At 6 months after intervention, 21 of 34 participants (61.8%) no longer required CPAP therapy, and complete remission of OSA was attained by 10 of 34 participants (29.4%). In the intervention vs control group, greater improvements in body weight (change, -7.1 kg [95% CI, -8.6 to -5.5 kg] vs -0.3 kg [95% CI, -1.9 to 1.4 kg]) and composition (eg, change in fat mass, -2.9 kg [95% CI, -4.5 to -1.3 kg] vs 1.4 kg [95% CI, -0.3 to 3.1 kg]), cardiometabolic risk (eg, change in blood pressure, -6.5 mm Hg [95% CI, -10.3 to -2.6 mm Hg] vs 2.2 mm Hg [95% CI, -2.1 to 6.6 mm Hg]), and health-related quality of life (eg, change in Sleep Apnea Quality of Life Index, 0.8 points [95% CI, 0.5-1.1 points] vs 0.1 points [95% CI, -0.3 to 0.4 points]) were also found at the intervention end point.

CONCLUSIONS AND RELEVANCE

In this study, an interdisciplinary weight loss and lifestyle intervention involving Spanish men with moderate to severe OSA and had overweight or obesity and were receiving CPAP therapy resulted in clinically meaningful and sustainable improvements in OSA severity and comorbidities as well as health-related quality of life. This approach may therefore be considered as a central strategy to address the substantial impact of this increasingly common sleep-disordered breathing condition.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03851653.

The year in cardiovascular medicine 2021: diabetes and metabolic disorders

In the current paper, we review recently published studies that are helping us to understand how the treatment landscape for glucagon-like peptiide-1 receptor agonists and sodium glucose cotransporter 2 inhibitors is moving forward. We have also included relevant articles related to cardiovascular disease prevention in the setting of obesity, atherogenic dyslipidaemia and chronic kidney disease.

Fluctuations in waist circumference increase diabetes risk: a 4-year cohort study in 61,587 older adults

PURPOSE

To evaluate the effect of fluctuations in waist circumference (WC), weight, and body mass index (BMI) on the incidence of diabetes in older adults.

PATIENTS AND METHODS

A prospective cohort of 61,587 older adults (age, 60-96 years) who did not have diabetes at study initiation was examined. Data on weight, BMI, and WC were collected, and participants were followed up until 31 December 2018. The main end point was new-onset diabetes. A Cox regression model was used to estimate the risk of diabetes (hazard ratios [HRs] and confidence intervals [CI]) in these participants.

RESULTS

During a mean follow-up of 3.6 years, being overweight (HR [95% CI] 1.87 [1.62-2.17]), obesity (1.41 [1.26-1.59]), abdominal obesity (1.42 [1.28-1.58]), and obesity plus abdominal obesity at baseline (1.93 [1.66-2.25]) increased the risk of diabetes onset. Compared with older adults who "maintained normal WC", those who "remained abdominally obese" (HR = 1.66), "became abdominally obese" (HR = 1.58), or "achieved normal WC" (HR = 1.36) were at a higher risk of diabetes onset, as well as those with an increase in WC > 3 cm or > 5% compared with the baseline level. Weight gain or loss > 6 kg or weight gain > 5%, increase or decrease in BMI > 2 kg/m², or an increase in BMI > 10% were associated with a higher diabetes risk. The diabetes risk was reduced by 19% in overweight older adults who exercised daily.

CONCLUSION

For older adults, WC, BMI, and healthy weight maintenance reduce the diabetes risk. The findings may provide evidence for developing guidelines of proper weight and WC control for older adults.

Trained Volunteers With Type 2 Diabetes Experience Significant Health Benefits When Providing Peer Support

Trained lay volunteers may have value in supporting lifestyle change programs in the prevention of type 2 diabetes, but the potential health benefits (or harms) experienced by these lay volunteers have not been well described. This is important, as this is an appealing model in terms of workforce planning. The aim of the prespecified quantitative study reported here, was to examine the possible health benefits or harms experienced by these trained lay volunteers with type 2 diabetes. In a large type 2 diabetes prevention program, we recruited and trained 104 lay volunteers with type 2 diabetes themselves, to act as diabetes prevention mentors and codeliver the lifestyle intervention. Mentors made motivational telephone calls to 461 participants randomized to one of the trial arms to encourage lifestyle changes. Weight, diet, physical activity, well-being, quality of life, diabetes-specific self-efficacy, and glycaemic control were measured at baseline, 12 and 24 months. Average mentor age was 62.0 years, 57 (54.8%) were male, 92 (88.5%) were overweight or obese (BMI>30 kg/m²). At 12 months, mentor dietary behaviors (fat and fiber intake) improved significantly, sedentary time spent fell significantly, and diabetes specific self-efficacy scores significantly increased. These significant improvements, with no evidence of harms, suggest lay volunteers with type 2 diabetes codelivering a lifestyle intervention, may themselves experience health benefits from volunteering.

Effects of a lifestyle intervention programme after 1 year of follow-up among South Asians at high risk of type 2 diabetes: a cluster randomised controlled trial

INTRODUCTION

South Asians are at high risk of type 2 diabetes (T2D). We assessed whether intensive family-based lifestyle intervention leads to significant weight loss, improved glycaemia and blood pressure in adults at elevated risk for T2D.

METHODS

This cluster randomised controlled trial (iHealth-T2D) was conducted at 120 locations across India, Pakistan, Sri Lanka and the UK. We included 3684 South Asian men and women, aged 40-70 years, without T2D but with raised haemoglobin A1c (HbA1c) and/or waist circumference. Participants were randomly allocated either to the family-based lifestyle intervention or control group by location clusters. Participants in the intervention received 9 visits and 13 telephone contacts by community health workers over 1-year period, and the control group received usual care. Reductions in weight (aim >7% reduction), waist circumference (aim ≥5 cm reduction), blood pressure and HbA1C at 12 months of follow-up were assessed. Our linear mixed-effects regression analysis was based on intention-to-treat principle and adjusted for age, sex and baseline values.

RESULTS

There were 1846 participants in the control and 1838 in the intervention group. Between baseline and 12 months, mean weight of participants in the intervention group reduced by 1.8 kg compared with 0.4 kg in the control group (adjusted mean difference -1.10 kg (95% CI -1.70 to -1.06), p<0.001). The adjusted mean difference for waist circumference was -1.9 cm (95% CI -2.5; to 1.3), p<0.001). No overall difference was observed for blood pressure or HbA1c. People who attended multiple intervention sessions had a dose-dependent effect on waist circumference, blood pressure and HbA1c, but not on weight.

CONCLUSION

An intensive family-based lifestyle intervention adopting low-resource strategies led to effective reduction in weight and waist circumference at 12 months, which has potential long-term benefits for preventing T2D. A higher number of attended sessions increased the effect on waist circumference, blood pressure and HbA1c.

TRIAL REGISTRATION NUMBER

EudraCT: 2016-001350-18; ClinicalTrials.gov: NCT02949739.

Metformin for diabetes prevention: update of the evidence base

We have conducted a narrative review based on a structured search strategy, focusing on the effects of metformin on the progression of non-diabetic hyperglycemia to clinical type 2 diabetes mellitus. The principal trials that demonstrated a significantly lower incidence of diabetes in at-risk populations randomized to metformin (mostly with impaired glucose tolerance [IGT]) were published mainly from 1999 to 2012. Metformin reduced the 3-year risk of diabetes by -31% in the randomized phase of the Diabetes Prevention Program (DPP), vs. -58% for intensive lifestyle intervention (ILI). Metformin was most effective in younger, heavier subjects. Diminishing but still significant reductions in diabetes risk for subjects originally randomized to these groups were present in the trial's epidemiological follow-up, the DPP Outcomes Study (DPPOS) at 10 years (-18 and -34%, respectively), 15 years (-18 and -27%), and 22 years (-18 and -25%). Long-term weight loss was also seen in both groups, with better maintenance under metformin. Subgroup analyses from the DPP/DPPOS have shed important light on the actions of metformin, including a greater effect in women with prior gestational diabetes, and a reduction in coronary artery calcium in men that might suggest a cardioprotective effect. Improvements in long-term clinical outcomes with metformin in people with non-diabetic hyperglycemia ("prediabetes") have yet to be demonstrated, but cardiovascular and microvascular benefits were seen for those in the DPPOS who did not vs. did develop diabetes. Multiple health economic analyses suggest that either metformin or ILI is cost-effective in a community setting. Long-term diabetes prevention with metformin is feasible and is supported in influential guidelines for selected groups of subjects. Future research will demonstrate whether intervention with metformin in people with non-diabetic hyperglycemia will improve long-term clinical outcomes.

Effects of the Norfolk diabetes prevention lifestyle intervention (NDPS) on glycaemic control in screen-detected type 2 diabetes: a randomised controlled trial

BACKGROUND

The purpose of this trial was to test if the Norfolk Diabetes Prevention Study (NDPS) lifestyle intervention, recently shown to reduce the incidence of type 2 diabetes in high-risk groups, also improved glycaemic control in people with newly diagnosed screen-detected type 2 diabetes.

METHODS

We screened 12,778 participants at high risk of type 2 diabetes using a fasting plasma glucose and glycosylated haemoglobin (HbA1c). People with screen-detected type 2 diabetes were randomised in a parallel, three-arm, controlled trial with up to 46 months of follow-up, with a control arm (CON), a group-based lifestyle intervention of 6 core and up to 15 maintenance sessions (INT), or the same intervention with additional support from volunteers with type 2 diabetes trained to co-deliver the lifestyle intervention (INT-DPM). The pre-specified primary end point was mean HbA1c compared between groups at 12 months.

RESULTS

We randomised 432 participants (CON 149; INT 142; INT-DPM 141) with a mean (SD) age of 63.5 (10.0) years, body mass index (BMI) of 32.4 (6.4) kg/m2, and HbA1c of 52.5 (10.2) mmol/mol. The primary outcome of mean HbA1c at 12 months (CON 48.5 (9.1) mmol/mol, INT 46.5 (8.1) mmol/mol, and INT-DPM 45.6 (6.0) mmol/mol) was significantly lower in the INT-DPM arm compared to CON (adjusted difference -2.57 mmol/mol; 95% CI -4.5, -0.6; p = 0.007) but not significantly different between the INT-DPM and INT arms (-0.55 mmol/mol; 95% CI -2.46, 1.35; p = 0.57), or INT vs CON arms (-2.14 mmol/mol; 95% CI -4.33, 0.05; p = 0.07). Subgroup analyses showed the intervention had greater effect in participants < 65 years old (difference in mean HbA1c compared to CON -4.76 mmol/mol; 95% CI -7.75, -1.78 mmol/mol) than in older participants (-0.46 mmol/mol; 95% CI -2.67, 1.75; interaction p = 0.02). This effect was most significant in the INT-DPM arm (-6.01 mmol/mol; 95% CI -9.56, -2.46 age < 65 years old and -0.22 mmol/mol; 95% CI -2.7, 2.25; aged > 65 years old; p = 0.007). The use of oral hypoglycaemic medication was associated with a significantly lower mean HbA1c but only within the INT-DPM arm compared to CON (-7.0 mmol/mol; 95% CI -11.5, -2.5; p = 0.003).

CONCLUSION

The NDPS lifestyle intervention significantly improved glycaemic control after 12 months in people with screen-detected type 2 diabetes when supported by trained peer mentors with type 2 diabetes, particularly those receiving oral hypoglycaemics and those under 65 years old. The effect size was modest, however, and not sustained at 24 months.

TRIAL REGISTRATION

ISRCTN34805606 . Retrospectively registered 14.4.16.

Long-Term Weight Loss Strategies for Obesity

CONTEXT

Obesity is a chronic disease that is difficult to manage without holistic therapy. The therapeutic armamentarium for obesity primarily consists of 4 forms of therapy: lifestyle modification (ie, diet and exercise), cognitive behavioral therapy, pharmacotherapy, and bariatric surgery.

EVIDENCE ACQUISITION

Evidence was consolidated from randomized controlled trials, observational studies, and meta-analyses.

EVIDENCE SYNTHESIS

After 2 years, lifestyle interventions can facilitate weight loss that equates to ~5%. Even though lifestyle interventions are plagued by weight regain, they can have substantial effects on type 2 diabetes and cardiovascular disease risk. Although 10-year percentage excess weight loss can surpass 50% after bariatric surgery, weight regain is likely. To mitigate weight regain, instituting a multifactorial maintenance program is imperative. Such a program can integrate diet, exercise, and pharmacotherapy. Moreover, behavioral therapy can complement a maintenance program well.

CONCLUSIONS

Obesity is best managed by a multidisciplinary clinical team that integrates diet, exercise, and pharmacotherapy. Bariatric surgery is needed to manage type 2 diabetes and obesity in select patients.

A simulation study of the economic and health impact of a diabetes prevention programme in Ireland

AIMS

Type 2 diabetes is a major public health issue that has a large effect on society including its health and social services. The aims of this paper are to generate a projection of the number of cases and explore the potential impact of a preventive intervention targeted at people with pre-diabetes on disease prevalence, complications, mortality and cost.

METHODS

A Markov simulation model of diabetes and pre-diabetes in Ireland, for the period 1991 to 2036, was generated based on international epidemiological data. The simulation was calibrated with the available Irish data on the prevalence of pre-diabetes, diabetes and diabetic complications. The economic and health impact of a hypothetical nationwide preventive intervention programme, which reduces the incidence by a factor consistent with the international literature, was estimated under three scenarios of alternative effectiveness and uptake.

RESULTS

The estimated number of people over 40 years of age with type 2 diabetes in Ireland is projected to increase from 216,000 in 2020 to 414,000 in 2036. A prevention programme, based on the NHS Diabetes Prevention Programme, is estimated to result in a reduction of between 2000 (0.5%) and 19,000 (4.6%) in the number of prevalent cases of diabetes in 2036 resulting in substantial health and quality of life benefits.

CONCLUSIONS

A wide range of initiatives with uncertain outcomes will be required to reduce the impact of obesity and type 2 diabetes. A diabetes prevention programme seems likely to be worth pursuing as one element of this set of initiatives.