Impact of lifestyle intervention in primary prevention of Type 2 diabetes did not differ by baseline age and BMI among Asian-Indian people with impaired glucose tolerance

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.

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.

Comparative Effectiveness of Lifestyle Intervention on Fasting Plasma Glucose in Normal Weight Versus Overweight and Obese Adults With Prediabetes

Background. It is hypothesized that normal weight individuals develop diabetes through different pathophysiological mechanisms and that methods of prevention may differ in the absence of overweight/obesity. In this study, we compared the effect of lifestyle health coaching (LHC) on fasting plasma glucose (FPG) in normal weight, overweight, and obese US adults with prediabetes. Methods. Subjects were 1358 individuals who completed baseline and follow-up evaluations as part of an LHC program (follow-up = ~6 months). Participants were stratified, based on baseline body mass index (BMI), into normal weight (n = 129), overweight (n = 345), and obese (n = 884) cohorts. LHC included counseling, predominantly via telehealth, on exercise and nutrition. Results. BMI decreased ( P < .001) in the overweight and obese participants but was unchanged in the normal weight participants. FPG decreased ( P < .001) in all 3 cohorts, and the magnitude of decrease did not differ significantly among cohorts. FPG decreased to <5.6 mmol/L in 58.1%, 49.3%, and 41.4% of the normal weight, overweight, and obese participants, respectively. Conclusions. To our knowledge, this study is the first outside of Asia to show that LHC is as effective in managing FPG in normal weight adults with prediabetes versus those who are overweight/obese.

Effects of lifestyle interventions on glucose regulation and diabetes risk in adults with impaired glucose tolerance or prediabetes: a meta-analysis

The prevalence of diabetes mellitus is increasing and is related to sedentary lifestyles and obesity. Many studies were published on the effect of lifestyle interventions on glucose regulation and delay the onset of diabetes in adults with impaired glucose tolerance (IGT) or prediabetes. This study aimed to investigate the role of lifestyle interventions in individuals with IGT or prediabetes using a meta-analytic approach. PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases were searched from their inception up to January 2020 to select eligible randomized controlled trials (RCTs). The weighted mean difference (WMD; for fasting plasma glucose (FPG) and 2-hour plasma glucose (2hPPG)) or relative risk (RR; for the risk of diabetes) with 95% confidence interval (CI) were calculated for pooled effect estimates using the random-effects model. Thirteen RCTs involving 3376 individuals with IGT or prediabetes were selected for this meta-analysis. The results showed that lifestyle interventions were associated with lower FPG (WMD: -0.14; 95% CI: -0.24 to -0.05 mmol/L; p=0.004) and 2hPPG (WMD: -0.66; 95% CI: -1.12 to -0.20 mmol/L; p=0.005) in adults with IGT or prediabetes. Moreover, the risk of diabetes was significantly reduced in individuals who received lifestyle interventions (RR: 0.75; 95% CI: 0.60-0.95; p=0.015). Lifestyle interventions could help improve glucose dysregulation and prevent the progression of diabetes in adults with IGT or prediabetes. Further large-scale RCTs should be conducted to assess the effects of long-term lifestyle interventions on diabetic complications in adults with IGT or prediabetes.

Morbidity and mortality after lifestyle intervention for people with impaired glucose tolerance: 30-year results of the Da Qing Diabetes Prevention Outcome Study

BACKGROUND

Lifestyle interventions can delay the onset of type 2 diabetes in people with impaired glucose tolerance, but whether this leads subsequently to fewer complications or to increased longevity is uncertain. We aimed to assess the long-term effects of lifestyle interventions in people with impaired glucose tolerance on the incidence of diabetes, its complications, and mortality.

METHODS

The original study was a cluster randomised trial, started in 1986, in which 33 clinics in Da Qing, China, were randomly assigned to either be a control clinic or provide one of three interventions (diet, exercise, or diet plus exercise) for 6 years for 577 adults with impaired glucose tolerance who usually receive their medical care from the clinics. Subsequently, participants were followed for up to 30 years to assess the effects of intervention on the incidence of diabetes, cardiovascular disease events, composite microvascular complications, cardiovascular disease death, all-cause mortality, and life expectancy.

FINDINGS

Of the 577 participants, 438 were assigned to an intervention group and 138 to the control group (one refused baseline examination). After 30 years of follow-up, 540 (94%) of 576 participants were assessed for outcomes (135 in the control group, 405 in the intervention group). During the 30-year follow-up, compared with control, the combined intervention group had a median delay in diabetes onset of 3·96 years (95% CI 1·25 to 6·67; p=0·0042), fewer cardiovascular disease events (hazard ratio 0·74, 95% CI 0·59-0·92; p=0·0060), a lower incidence of microvascular complications (0·65, 0·45-0·95; p=0·025), fewer cardiovascular disease deaths (0·67, 0·48-0·94; p=0·022), fewer all-cause deaths (0·74, 0·61-0·89; p=0·0015), and an average increase in life expectancy of 1·44 years (95% CI 0·20-2·68; p=0·023).

INTERPRETATION

Lifestyle intervention in people with impaired glucose tolerance delayed the onset of type 2 diabetes and reduced the incidence of cardiovascular events, microvascular complications, and cardiovascular and all-cause mortality, and increased life expectancy. These findings provide strong justification to continue to implement and expand the use of such interventions to curb the global epidemic of type 2 diabetes and its consequences.

FUNDING

US Centers for Disease Control and Prevention, WHO, Chinese Center for Disease Control and Prevention, World Bank, Ministry of Public Health of the People's Republic of China, Da Qing First Hospital, China-Japan Friendship Hospital, and National Center for Cardiovascular Diseases & Fuwai Hospital.

The effect of community-based programs on diabetes prevention in low- and middle-income countries: a systematic review and meta-analysis

BACKGROUND

The increasing prevalence of type 2 diabetes mellitus (T2DM) can have a substantial impact in low- and middle-income countries (LMICs). Community-based programs addressing diet, physical activity, and health behaviors have shown significant benefits on the prevention and management of T2DM, mainly in high-income countries. However, their effects on preventing T2DM in the at-risk population of LMICs have not been thoroughly evaluated.

METHODS

The Cochrane Library (CENTRAL), MEDLINE, EMBASE and two clinical trial registries were searched to identify eligible studies. We applied a 10 years limit (from 01 Jan 2008 to 06 Mar 2018) on English language literature. We included randomized controlled trials (RCTs) with programs focused on lifestyle changes such as weight loss and/or physical activity increase, without pharmacological treatments, which aimed to alter incidence of diabetes or one of the T2DM risk factors, of at least 6 months duration based on follow-up, conducted in LMICs.

RESULTS

Six RCTs randomizing 2574 people were included. The risk of developing diabetes in the intervention groups reduced more than 40%, RR (0.57 [0.30, 1.06]), for 1921 participants (moderate quality evidence), though it was not statistically significant. Significant differences were observed in weight, body mass index, and waist circumference change in favor of community-based programs from baseline, (MD [95% CI]; - 2.30 [- 3.40, - 1.19], p < 0.01, I2 = 87%), (MD [95% CI]; - 1.27 [- 2.10, - 0.44], p < 0.01, I2 = 96%), and (MD [95% CI]; - 1.66 [- 3.17, - 0.15], p = 0.03, I2 = 95%), respectively. The pooled effect showed a significant reduction in fasting blood glucose and HbA1C measurements in favor of the intervention (MD [95% CI]; - 4.94 [- 8.33, - 1.55], p < 0.01, I2 = 62%), (MD [95% CI]; - 1.17 [- 1.51, - 0.82], p < 0.01, I2 = 46%), respectively. No significant difference was observed in 2-h blood glucose values, systolic or diastolic blood pressure change between the two groups.

CONCLUSION

Based on available literature, evidence suggests that community-based interventions may reduce the incidence rate of T2DM and may positively affect anthropometric indices and HbA1C. Due to the heterogeneity observed between trials we recommend more well-designed RCTs with longer follow-up durations be executed, to confirm whether community-based interventions lead to reduced T2DM events in the at-risk population of LMIC settings.

Major Pathophysiology in Prediabetes and Type 2 Diabetes: Decreased Insulin in Lean and Insulin Resistance in Obese

CONTEXT

Lowering of body mass index (BMI) to ≥25 kg/m2 as obesity by ADA suggests insulin resistance as a major mechanism of impaired glucose metabolism (IGM) in Asians. However, glimepiride, an insulin secretagogue, delayed onset of type 2 diabetes (DM2) from prediabetes (PreDM), indicating decreased insulin secretion (IS) as a major factor in lean (L; BMI < 27 kg/m2) subjects with IGM.

OBJECTIVE

Assessment of IS and insulin resistance (IR) in L and obese (Ob; BMI ≥ 27 kg/m2) subjects with euglycemia (N), PreDM, and new onset DM2.

SUBJECTS

Seventy-five men and 45 women ages 36 to 75 years were divided into six groups: LN, LPreDM, LDM2, ObN, ObPreDM, and ObDM2.

METHODS

Determination of IS by insulinogenic indices (I/G) at fasting (FI/FG), first phase (∆I/∆G), and cumulative responses over 2 hours of OGTT (CRI/CRG), and IR by FIXFG, ∆IX∆G, and CRIXCRG. Changes in IS and IR for PreDM and DM2 were calculated as % fall and % rise, respectively, from levels in N.

RESULTS

All indices of IS and IR were lower (P < 0.05) in L than corresponding Ob groups (P < 0.05). Moreover, decline in IS and rise in IR were progressive from N to PreDM (P < 0.05) and DM2 (P < 0.05) in both groups. However, the declines in IS were greater (P < 0.05) than rises in IR in LPreDM and LDM2. Whereas, the rises in IR were higher (P < 0.05) than declines in IS in ObPreDM and ObDM2.

CONCLUSION

In L, major mechanism of IGM is declining IS and not rising IR documented among Ob.

Risk factor control, adherence to medication and follow up visit, five years after coronary artery bypass graft surgery

Introduction: Inadequate adherence to medication and follow up visits were proposed correlated with cardiovascular mortality and complications. This study was planned to evaluate medication and follow up adherence and risk factor control in patients with coronary artery disease 5 years after coronary artery bypass grafting (CABG). Methods: In this retrospective cohort study, adult patients who underwent CABG in 2010 were enrolled. Conventional and probable risk factor control and adherence to medication and follow up visits were assessed. Results: 196 patients were recruited to the study. Uncontrolled blood pressure, blood glucose and low-density lipoprotein (LDL)were reported in 48%, 61% and 32% of patients, respectively. More than 63% of former smokers restarted smoking during 6-12 months after bypass. Poor medication adherence was present in 10.7% in the study population. The last follow up visit time for 30% of patients was later than 12 months after CABG. Conclusion: Poor risk factors control and adherence to follow up visits was common among patients undergoing CABG.

Clinical impact of lifestyle interventions for the prevention of diabetes: an overview of systematic reviews

OBJECTIVES

To review the clinical outcomes of combined diet and physical activity interventions for populations at high risk of type 2 diabetes.

DESIGN

Overview of systematic reviews (search dates April-December 2015).

SETTING

Any level of care; no geographical restriction.

PARTICIPANTS

Adults at high risk of diabetes (as per measures of glycaemia, risk assessment or presence of risk factors).

INTERVENTIONS

Combined diet and physical activity interventions including ≥2 interactions with a healthcare professional, and ≥12 months follow-up.

OUTCOME MEASURES

Primary: glycaemia, diabetes incidence. Secondary: behaviour change, measures of adiposity, vascular disease and mortality.

RESULTS

19 recent reviews were identified for inclusion; 5 with AMSTAR scores <8. Most considered only randomised controlled trials (RCTs), and RCTs were the major data source in the remainder. Five trials were included in most reviews. Almost all analyses reported that interventions were associated with net reductions in diabetes incidence, measures of glycaemia and adiposity, at follow-up durations of up to 23 years (typically <6). Small effect sizes and potentially transient effect were reported in some studies, and some reviewers noted that durability of intervention impact was potentially sensitive to duration of intervention and adherence to behaviour change. Behaviour change, vascular disease and mortality outcome data were infrequently reported, and evidence of the impact of intervention on these outcomes was minimal. Evidence for age effect was mixed, and sex and ethnicity effect were little considered.

CONCLUSIONS

Relatively long-duration lifestyle interventions can limit or delay progression to diabetes under trial conditions. However, outcomes from more time-limited interventions, and those applied in routine clinical settings, appear more variable, in keeping with the findings of recent pragmatic trials. There is little evidence of intervention impact on vascular outcomes or mortality end points in any context. 'Real-world' implementation of lifestyle interventions for diabetes prevention may be expected to lead to modest outcomes.

The Stepwise Approach to Diabetes Prevention: Results From the D-CLIP Randomized Controlled Trial

OBJECTIVE

This study tests the effectiveness of expert guidelines for diabetes prevention: lifestyle intervention with addition of metformin, when required, among people with prediabetes.

RESEARCH DESIGN AND METHODS

The Diabetes Community Lifestyle Improvement Program (D-CLIP) is a randomized, controlled, translation trial of 578 overweight/obese Asian Indian adults with isolated impaired glucose tolerance (iIGT), isolated impaired fasting glucose (iIFG), or IFG+IGT in Chennai, India. Eligible individuals were identified through community-based recruitment and randomized to standard lifestyle advice (control) or a 6-month, culturally tailored, U.S. Diabetes Prevention Program-based lifestyle curriculum plus stepwise addition of metformin (500 mg, twice daily) for participants at highest risk of conversion to diabetes at ≥4 months of follow-up. The primary outcome, diabetes incidence, was assessed biannually and compared across study arms using an intention-to-treat analysis.

RESULTS

During 3 years of follow-up, 34.9% of control and 25.7% of intervention participants developed diabetes (P = 0.014); the relative risk reduction (RRR) was 32% (95% CI 7-50), and the number needed to treat to prevent one case of diabetes was 9.8. The RRR varied by prediabetes type (IFG+IGT, 36%; iIGT, 31%; iIFG, 12%; P = 0.77) and was stronger in participants 50 years or older, male, or obese. Most participants (72.0%) required metformin in addition to lifestyle, although there was variability by prediabetes type (iIFG, 76.5%; IFG+IGT, 83.0%; iIGT, 51.3%).

CONCLUSIONS

Stepwise diabetes prevention in people with prediabetes can effectively reduce diabetes incidence by a third in community settings; however, people with iIFG may require different interventions.