The epidemic of pre-diabetes: the medicine and the politics

The impact of financial incentives on utilization and outcomes of diabetes prevention programs among Medicaid managed care adults in New York state

Diabetes prevalence has risen rapidly and has become a global health challenge. The Diabetes Prevention Program (DPP) has been shown to prevent or delay the development of diabetes among individuals with prediabetes. Yet, diabetes prevention studies within the Medicaid population are limited and results are mixed. This study aimed to evaluate the impact of different financial incentive strategies on the utilization of the DPP for Medicaid managed care adults in New York State. A four-arm randomized controlled trial was conducted among Medicaid managed care adult enrollees diagnosed with prediabetes and/or obesity. Study participants were offered a 16-week DPP with various incentive strategies based on class attendance and weight loss as follows: Attendance-Only, Weight-Loss Only, and both Attendance and Weight-Loss. A control group was offered DPP with no incentives for attendance or weight loss. We evaluated the impact of incentives on achievement of the program completion and weight-loss milestone. Participants who received incentives for the Attendance-Only class were least likely to be lost to follow-up, more likely to complete the program, and had two times higher percentage of meeting the weight-loss milestone compared to the control group. Results for the other incentive cohorts were mixed. A strong positive association was observed for participants who attended 9 or more classes and weight-loss regardless of incentive strategies. Providing monetary incentives for DPP class attendance had a positive impact on program completion and achieving the weight-loss milestone. However, the results from this study indicate that participant enrollment and retention remained challenges despite the incentives.

Comparing different definitions of prediabetes with subsequent risk of diabetes: an individual participant data meta-analysis involving 76 513 individuals and 8208 cases of incident diabetes

Objective

There are currently five widely used definition of prediabetes. We compared the ability of these to predict 5-year conversion to diabetes and investigated whether there were other cut-points identifying risk of progression to diabetes that may be more useful.

Research design and methods

We conducted an individual participant meta-analysis using longitudinal data included in the Obesity, Diabetes and Cardiovascular Disease Collaboration. Cox regression models were used to obtain study-specific HRs for incident diabetes associated with each prediabetes definition. Harrell's C-statistics were used to estimate how well each prediabetes definition discriminated 5-year risk of diabetes. Spline and receiver operating characteristic curve (ROC) analyses were used to identify alternative cut-points.

Results

Sixteen studies, with 76 513 participants and 8208 incident diabetes cases, were available. Compared with normoglycemia, current prediabetes definitions were associated with four to eight times higher diabetes risk (HRs (95% CIs): 3.78 (3.11 to 4.60) to 8.36 (4.88 to 14.33)) and all definitions discriminated 5-year diabetes risk with good accuracy (C-statistics 0.79-0.81). Cut-points identified through spline analysis were fasting plasma glucose (FPG) 5.1 mmol/L and glycated hemoglobin (HbA1c) 5.0% (31 mmol/mol) and cut-points identified through ROC analysis were FPG 5.6 mmol/L, 2-hour postload glucose 7.0 mmol/L and HbA1c 5.6% (38 mmol/mol).

Conclusions

In terms of identifying individuals at greatest risk of developing diabetes within 5 years, using prediabetes definitions that have lower values produced non-significant gain. Therefore, deciding which definition to use will ultimately depend on the goal for identifying individuals at risk of diabetes.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Response to diagnosis of pre-diabetes in socioeconomically deprived areas: a qualitative study

Background

Diabetes prevention is a key priority for the NHS, with a particular focus on populations at highest risk. The NHS Diabetes Prevention Programme (NHS DPP) has been introduced, offering a course of dietary and lifestyle education to individuals with pre-diabetes. However, concerns about the NHS DPP include: (1) the possible unintended consequences of labelling more people with a ‘pre-condition’; (2) the possibility of worsening health inequalities as people in socioeconomically deprived areas tend to access behaviour-change programmes less readily; (3) the appropriateness of an intervention focused on individuals versus population-wide public health policy interventions.

Aim

To explore the experience of diagnosis of pre-diabetes, and understand the barriers and facilitators to uptake of the NHS DPP for people living in socioeconomically deprived areas.

Design & setting

A qualitative study was undertaken. Participants with pre-diabetes were recruited from practices serving socioeconomically deprived areas of Sheffield, UK.

Method

Semi-structured interviews were conducted and continued until data saturation (23 participants). Thematic analysis of data was undertaken.

Results

Both healthcare context and an individual’s personal and community context shaped response to diagnosis and likelihood of engaging with the NHS DPP. Patient activation was a useful concept in understanding response. Whether or not people participated in the NHS DPP, being diagnosed with pre-diabetes tended to provoke some degree of dietary change and did not cause significant anxiety for most. However, there were multiple barriers to engaging with the NHS DPP for this patient group.

Conclusion

Diagnosing pre-diabetes can provoke an individual positive response, but the sociocultural environment often limits an individual’s ability to engage with the NHS DPP or make lifestyle change.

Lorcaserin for prevention and remission of type 2 diabetes mellitus in people with overweight or obesity: protocol for a systematic review and meta-analysis

INTRODUCTION

High body mass index (BMI) is associated with risk of diabetes. Lorcaserin is a selective 5-hydroxytryptamine 2C agonist which exerts robust benefits on long-term weight loss by suppressing appetite among adults with overweight or obesity. The magnitude of efficacy of lorcaserin for preventing and remitting type 2 diabetes mellitus (T2DM) among those people remains undefined. Therefore, we plan to conduct this systematic review and meta-analysis to aggregate data from all published studies with regard to the issue to acquire reliable evidence.

METHODS AND ANALYSIS

We will search various databases for relevant trials published up to June 2019. Randomised controlled trials investigating the efficacy of lorcaserin for preventing and remitting T2DM among overweight and obese population will be included. A standardised data form will be used to complete data search and extraction in duplicate. All discrepancies will be resolved by consensus. The primary outcome will be incidence of T2DM in patients with pre-diabetes. Secondary outcomes will include achievement of normoglycaemia in people with pre-diabetes, remission of hyperglycaemia in patients with diabetes, the proportion of patients with weight loss of at least 5% or 10% and hypoglycaemia incident. Data synthesis and statistical analysis will be performed for each outcome with Stata V.14.0.

ETHICS AND DISSEMINATION

Ethics approval is not required. Results of our study will be submitted to a peer-review journal.

PROSPERO REGISTRATION NUMBER

CRD42019119136.

Lifestyle factors do not explain the difference on diabetes progression according to type of prediabetes: Results from a Spanish prospective cohort of prediabetic patients

AIMS

We studied the role of lifestyle factors associated to type 2 diabetes (T2DM) onset according to type of prediabetes.

METHODS

We used data from the observational prospective cohort study in Primary Health Care on the Evolution of Patients with Prediabetes in Spain (PREDAPS). Participants were classified by American Diabetes Association criteria using either fasting plasma glucose levels (100-125 mg/dL) (group 1), HbA1c (5.7%-6.4%) (group 2) or both impaired parameters (group 3). Relationship between lifestyles and diabetes onset according to prediabetes at third year of follow up were estimated by Hazard Ratios (HRs) using three sequential models.

RESULTS

Incidence rate of diabetes was 2.27 cases per 1000 person-years (95% CI: 1.4-3.6) for group 1, 1.18 (95% CI: 0.65-2.13) for group 2 and 6.68 (95% CI: 5.71-8.23) for group 3. The most important risk factors were: abdominal obesity (HR: 2.29 (95% CI: 1.49-3.52)) and hypertension (HR: 2.16 (95% CI: 1.41-3.30)). Using as reference group 2, group 3 had a HR of 5.82 (3.13-10.82) and 1.83 (95% CI: 0.85-3.93) for group 1, estimates remained constant when adjusting by lifestyle and metabolic factors.

CONCLUSIONS

Lifestyle and metabolic do not seem to explain the differences on T2DM onset by type of prediabetes.

Understanding the diagnosis of pre-diabetes in patients aged over 85 in English primary care: a qualitative study

Background

The benefit of a “diagnosis” of pre-diabetes in very elderly patients is debated. How clinicians manage pre-diabetic blood results in these patients is unknown. This study aims to understand how clinicians are “diagnosing” older patients with pre-diabetic blood parameters.

Methods

Semi-structured interviews and focus groups with health care staff (24 total participants) were conducted in the north of England. Interviews and focus groups were recorded, transcribed and analysed thematically. A grounded theory approach was taken with the theory of candidacy being used as a sensitising concept through which questions were framed and results interpreted.

Results

There is a complex system of competing pressures that influence a clinician in deciding whether, and in what way, to inform a very elderly patient that they have pre-diabetes. The majority of clinicians adjust their management of pre-diabetes to the age and perceived risk/benefit for the patient. Whilst some clinicians choose not to inform certain patients of their blood results, many clinicians maintain, what could be seen as a somewhat paradoxical approach of labeling all older patients with pre-diabetes but downplaying the significance to the patient. The policy, organisational context, workload and professional constraints under which clinicians work, play a significant role in shaping how they deal with pre-diabetic blood results in the very elderly.

Conclusion

There has been recent acknowledgement of how policy and organisational context frames decision-making, but there is a lack of evidence on how this influences uncertainty and dilemmas in decision-making in practice. These findings add further weight for the argument that treatment burden should be included in clinical guidelines.

Ethnic differences in prediabetes incidence among immigrants to Canada: a population-based cohort study

BACKGROUND

Prediabetes appears to be increasing worldwide. This study examined the incidence of prediabetes among immigrants to Canada of different ethnic origins and the age at which ethnic differences emerged.

METHODS

We assembled a cohort of Ontario adults (≥ 20 years) with normoglycemia based on glucose testing performed between 2002 and 2011 through a single commercial laboratory database (N = 1,772,180). Immigration data were used to assign ethnicity based on country of origin, mother tongue, and surname. Individuals were followed until December 2013 for the development of prediabetes, defined using either the World Health Organization/Diabetes Canada (WHO/DC) or American Diabetes Association (ADA) thresholds. Multivariate competing risk regression models were derived to examine the effect of ethnicity and immigration status on prediabetes incidence.

RESULTS

After a median follow-up of 8.0 years, 337,608 individuals developed prediabetes. Using definitions based on WHO/DC, the adjusted cumulative incidence of prediabetes was 40% (HR 1.40, CI 1.38-1.41) higher for immigrants relative to long-term Canadian residents (21.2% vs 16.0%, p < 0.001) and nearly twofold higher among South Asian than Western European immigrants (23.6%; HR 1.95, CI1.87-2.03 vs 13.1%; referent). Cumulative incidence rates based on ADA thresholds were considerably higher (47.1% and 32.3% among South Asians and Western Europeans, respectively). Ethnic differences emerged at young ages. South Asians aged 20-34 years had a similar prediabetes incidence as Europeans who were 15 years older (35-49 years), regardless of which prediabetes definition was used (WHO/DC 14.4% vs 15.7%; ADA 38.0% vs 33.0%).

CONCLUSION

Prediabetes incidence was substantially higher among non-European immigrants to Canada, highlighting the need for early prevention strategies in these populations.

Global epidemiology of prediabetes - present and future perspectives

Prediabetes is defined as an intermediate state of hyperglycaemia with glucose levels above the normal state but below the diagnostic levels of diabetes. It is increasingly recognised as an important metabolic state, as individuals with prediabetes are at high risk of developing overt diabetes and its associated complications. A better understanding of prediabetes could help with earlier identification, thereby allowing earlier intervention, potentially lowering the number of individuals who go on to develop diabetes. The definitions and screening criteria for prediabetes differ between guidelines published by different organisations, resulting in estimations of prevalence that can vary widely from one another. Despite these differences, these estimates suggest that the number of individuals affected by prediabetes is increasing rapidly in all areas of the world. This short review compares and contrasts the diagnostic criteria for screening of prediabetes, the impact of various glycaemic measures on prevalence estimates, and discusses current and future trends in the global prevalence estimates of prediabetes.

Patient and Clinician Perceptions of Prediabetes: A Mixed-Methods Primary Care Study

Purpose

The purpose of the study was to assess patient and clinician perceptions of prediabetes in an academic family medicine practice. Data were collected in preparation for an implementation study to increase utilization of the National Diabetes Prevention Program (N-DPP).

Methods

In this mixed-methods study, discussions from 3 focus groups composed of patients with prediabetes were evaluated using thematic analysis for their understanding of and beliefs about prediabetes, care experiences, and attitudes toward N-DPP. Clinicians completed a Likert-scaled survey assessing attitudes and perceived barriers to providing prediabetes care.

Results

Among the 15 focus group participants, more than half were not aware of their diagnosis. Attitudes toward prediabetes were mixed: while many believed it was serious and elicited more fear than being “at risk,” others thought there were varying degrees of risk within the same diagnosis, making the diagnosis less impactful. Patients repeatedly expressed the perception that clinicians were not forthcoming about necessary behavior changes. Patients agreed on barriers to N-DPP, including scheduling and transportation. Clinicians (N = 31) concurred that patients lack awareness of their prediabetes diagnosis. They reported that time is available to screen all patients and that a prediabetes diagnosis is effective for advising patients of the need for lifestyle modification. There was consensus from both patients and clinicians that prediabetes is curable.

Conclusions

Increased patient awareness and patient-centered education is needed to overcome barriers to prediabetes care. To facilitate implementation of N-DPP referral processes, clinicians should clearly communicate risk, treatment information, and linkage to N-DPP as the suggested treatment plan.

Intermediate hyperglycaemia to predict progression to type 2 diabetes (ELSA-Brasil): an occupational cohort study in Brazil

BACKGROUND

The burden of diabetes is increasing worldwide and diabetes can be prevented with intervention in people with impaired glucose tolerance (IGT). Intermediate hyperglycaemia defined without an oral glucose tolerance test as impaired fasting glucose (IFG) and high HbA_1c are also used to characterise risk. We aimed to assess the prognostic properties of five definitions of intermediate hyperglycaemia (also known as prediabetes) on the basis of their ability to predict who will progress to diabetes.

METHODS

The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is an occupational cohort study of active or retired civil servants, aged 35-74 years, recruited from public universities and research institutes in six state capital cities in Brazil. We excluded participants who provided insufficient information to ascertain diabetes status, those without information on relevant covariates, and those with diabetes. We classified type 2 diabetes on the basis of self-report, medication use, measures of fasting plasma glucose (FPG), 2 h plasma glucose, and HbA_1c. We used five laboratory definitions of intermediate hyperglycaemia: IGT (2 h plasma glucose ≥7·8 mmol/L [≥140 mg/dL]); IFG based on American Diabetes Association (ADA) criteria (FPG ≥5·5 mmol/L [≥100 mg/dL]); IFG based on WHO criteria (FPG ≥6·1 mmol/L [≥110 mg/dL]); HbA_1c based on ADA criteria (HbA_1c ≥39 mmol/mol [5·7%]); and HbA_1c based on International Expert Committee criteria, IEC-HbA_1c, (HbA_1c ≥42 mmol/mol [6·0%]). We estimated risk of each definition using Cox regression and overall predictability (area under the receiver operating characteristic curve [AUC]) using logistic regression.

FINDINGS

We recruited 15 105 participants from Aug 18, 2008, to Dec 20, 2010, and followed up for a mean of 3·7 (SD 0·63) years. Diabetes incidence rate was 2·0 per 100 person-years (95% CI 1·8-2·1). Among the 11 199 eligible participants, 6563 (59%) presented with some form of intermediate hyperglycaemia. ADA-IFG (4870/11 199 [43·5%), IEC-HbA_1c (1005 [9·0%]), and ADA-HbA_1c (2299 [20·5%]) poorly predicted diabetes (3·5-3·6 per 100 person-years). WHO-IFG (1140 [10·2%]) and IGT (2245 [20·0%]) predicted greater conversion (7·5 per 100 person-years and 5·8 per 100 person-years, respectively). All definitions presented either low sensitivity or specificity. Combinations of tests improved prognostic properties, with the combination of IGT or WHO-IFG showing the best, but still insufficient, predictability (sensitivity 67·7%, 95% CI 64·5-70·1; specificity 77·9%, 77·1-78·7). The AUC for the three underlying glycaemic tests was 65·0% (95% CI 63·0-66·9) for HbA_1c, 74·6% (72·7-76·4) for FPG, and 77·1% (75·4-78·8) for 2 h plasma glucose, whereas the AUC for a score composed of clinical information was 71·6% (69·8-73·3). When this score was combined with results of an oral glucose tolerance test, the AUC reached 82·4% (80·9-83·9).

INTERPRETATION

IFG based on WHO criteria and IGT predict diabetes progression better than do the other three definitions of intermediate hyperglycaemia, but their sensitivity is low. IFG based on ADA criteria has better sensitivity than the others, but classifies almost half of adults as having intermediate hyperglycaemia and poorly predicts diabetes. Combining glycaemic results with clinical information improves prognostic properties of those at risk.

FUNDING

The Brazilian Ministry of Health (Science and Technology Department), the Brazilian Ministry of Science, Technology and Innovation (Financiadora de Estudos e Projetos and Conselho Nacional de Desenvolvimento Científico e Tecnológico), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES).

Increased Awareness, Unchanged Behavior: Prediabetes Diagnosis in a Low-Income, Minority Population

Purpose

The purpose of the study was to explore preventive behaviors and attitudes among mostly low-income, young Hispanic women with and without prediabetes.

Methods

In 2017, a convenience sample of women without diabetes aged 18 to 49 years (n = 214, 77.8% Hispanic) was recruited from the waiting room of a community health center to complete a 77-item questionnaire. Attitudes, risk perception, and recent lifestyle change were measured using a validated instrument, the Risk Perceptions Survey: Developing Diabetes. Chi-squared tests and multivariable binary logistic regression were conducted to assess the relationship between prediabetes diagnosis and attitude or lifestyle variables.

Results

Women diagnosed with prediabetes were more likely to report worry about diabetes and to perceive themselves at higher risk for developing diabetes in the next 10 years than women without a prior prediabetes diagnosis. There was no significant association between prediabetes diagnosis and recent adoption of lifestyle changes compared with those without prediabetes. After controlling for demographic characteristics and risk factors for type 2 diabetes, prediabetes diagnosis was significantly associated with elevated risk perception for developing diabetes if no lifestyle change is made but not with worry or risk perception for developing diabetes generally.

Conclusions

Prediabetes diagnosis is associated with heightened perception of diabetes risk but not lifestyle change compared to women without prediabetes in this low-income, predominantly Hispanic population. Prediabetes counseling efforts must emphasize evidence-based approaches for motivating preventive behaviors.

Alpha-glucosidase inhibitors 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

Alpha-glucosidase inhibitors (AGI) reduce blood glucose levels and may thus prevent or delay type 2 diabetes mellitus (T2DM) and its associated complications in people at risk of developing of T2DM.

OBJECTIVES

To assess the effects of AGI in people with impaired glucose tolerance (IGT), impaired fasting blood glucose (IFG), moderately elevated glycosylated haemoglobin A1c (HbA1c) or any combination of these.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and the reference lists of systematic reviews, articles and health technology assessment reports. The date of the last search of all databases was December 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), with a duration of one year or more, comparing AGI with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or no intervention in people with IFG, IGT, moderately elevated HbA1c or combinations of these.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles or records, assessed quality and extracted outcome data independently. One review author extracted data, which were checked by a second review author. We resolved discrepancies by consensus or involvement of a third review author. For meta-analyses we used a random-effects model with assessment of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall quality of the evidence by using the GRADE instrument.

MAIN RESULTS

For this update of the Cochrane Review (first published 2006, Issue 4) we included 10 RCTs (11,814 participants), eight investigating acarbose and two investigating voglibose, that included people with IGT or people "at increased risk for diabetes". The trial duration ranged from one to six years. Most trials compared AGI with placebo (N = 4) or no intervention (N = 4).Acarbose reduced the incidence of T2DM compared to placebo: 670 out of 4014 people (16.7%) in the acarbose groups developed T2DM, compared to 812 out of 3994 people (20.3%) in the placebo groups (RR 0.82, 95% CI 0.75 to 0.89; P < 0.0001; 3 trials; 8008 participants; moderate-certainty evidence). One trial including participants with coronary heart disease and IGT contributed 64% of cases for this outcome. Acarbose reduced the risk of T2DM compared to no intervention: 7 out 75 people (9.3%) in the acarbose groups developed T2DM, compared to 18 out of 65 people (27.7%) in the no-intervention groups (RR 0.31, 95% CI 0.14 to 0.69; P = 0.004; 2 trials; 140 participants; very low-certainty evidence).Acarbose compared to placebo did not reduce or increase the risk of all-cause mortality (RR 0.98, 95% CI 0.82 to 1.18; P = 0.86; 3 trials; 8069 participants; very low-certainty evidence), cardiovascular mortality (RR 0.88; 95% CI 0.71 to 1.10; P = 0.26; 3 trials; 8069 participants; very low-certainty evidence), serious adverse events (RR 1.12, 95% CI 0.97 to 1.29; P = 0.13; 2 trials; 6625 participants; low-certainty evidence), non-fatal stroke (RR 0.50, 95% CI 0.09 to 2.74; P = 0.43; 1 trial; 1368 participants; very low-certainty evidence) or congestive heart failure (RR of 0.87; 95% CI 0.63 to 1.12; P = 0.40; 2 trials; 7890 participants; low-certainty evidence). Acarbose compared to placebo reduced non-fatal myocardial infarction: one out of 742 participants (0.1%) in the acarbose groups had a non-fatal myocardial infarction compared to 15 out of 744 participants (2%) in the placebo groups (RR 0.10, 95% CI 0.02 to 0.53; P = 0.007; 2 trials; 1486 participants; very low-certainty evidence). Acarbose treatment showed an increased risk of non-serious adverse events (mainly gastro-intestinal events), compared to placebo: 751 of 775 people (96.9%) in the acarbose groups experienced an event, compared to 723 of 775 people (93.3%) in the placebo groups (RR 1.04; 95% CI 1.01 to 1.06; P = 0.0008; 2 trials; 1550 participants). Acarbose compared to no intervention showed no advantage or disadvantage for any of these outcome measures (very low-certainty evidence).One trial each compared voglibose with placebo (1780 participants) or diet and exercise (870 participants). Voglibose compared to placebo reduced the incidence of T2DM: 50 out of 897 participants (5.6%) developed T2DM, compared to 106 out of 881 participants (12%) in the placebo group (RR 0.46, 95% CI 0.34 to 0.64; P < 0.0001; 1 trial; 1778 participants; low-certainty evidence). For all other reported outcome measures there were no clear differences between voglibose and comparator groups. One trial with 90 participants compared acarbose with diet and exercise and another trial with 98 participants reported data on acarbose versus metformin. There were no clear differences for any outcome measure between these two acarbose interventions and the associated comparator groups.None of the trials reported amputation of lower extremity, blindness or severe vision loss, end-stage renal disease, health-related quality of life, time to progression to T2DM, or socioeconomic effects.

AUTHORS' CONCLUSIONS

AGI may prevent or delay the development of T2DM in people with IGT. There is no firm evidence that AGI have a beneficial effect on cardiovascular mortality or cardiovascular events.

A Simple Model for Predicting Two-Year Risk of Diabetes Development in Individuals with Prediabetes

CONTEXT

Given the dramatic rise in the incidence of type 2 diabetes mellitus (T2DM) in recent decades, identifying individuals at increased risk of T2DM and validating methods to reduce their risk of disease progression is important. With more than one-third of US adults having prediabetes, a more precise stratification of absolute risk of T2DM incidence would help in prioritizing prevention efforts.

OBJECTIVE

To develop a simple and clinically useful schema to stratify short-term (2-year) absolute risk of T2DM.

DESIGN

Observational study of more than 77,000 adult members (age 18-75 years) from 3 Regions of the Kaiser Foundation Health Plan with prediabetes (hemoglobin A_1C [HbA_1C] = 5.7%-6.4%).

MAIN OUTCOME MEASURES

The 2-year probability for development of diabetes as a function of baseline HbA_1C and body mass index (BMI).

RESULTS

The 2-year risk of diabetes diagnosis varied widely by HbA_1C and BMI. A small subset (5.2%) had a very high risk of T2DM developing within 2 years. Another 13.3% had a moderate 2-year risk of T2DM, whereas most (81.5%) of the population was at much lower risk. Thus, most Kaiser Foundation Health Plan members with prediabetes have only modest risk of progression to T2DM within 2 years.

CONCLUSION

Using HbA_1C and BMI, we created a simple stratification scheme to more precisely estimate risk of T2DM incidence. This will enable more efficient assignment of prevention interventions and clinical and laboratory follow-up to the small subset at highest risk, while minimizing the potentially negative effects of overdiagnosis among the majority with prediabetes who are not at high short-term risk of T2DM.

Not performing an OGTT results in underdiagnosis, inadequate risk assessment and probable cost increases of (pre)diabetes in Han Chinese over 40 years: a population-based prospective cohort study

OBJECTIVE

To explore the influence by not performing an oral glucose tolerance test (OGTT) in Han Chinese over 40 years.

DESIGN

Overall, 6682 participants were included in the prospective cohort study and were followed up for 3 years.

METHODS

Fasting plasma glucose (FPG), 2-h post-load plasma glucose (2h-PG), FPG and 2h-PG (OGTT), and HbA1c testing using World Health Organization (WHO) or American Diabetes Association (ADA) criteria were employed for strategy analysis.

RESULTS

The prevalence of diabetes is 12.4% (95% CI: 11.6-13.3), while the prevalence of prediabetes is 34.1% (95% CI: 32.9-35.3) and 56.5% (95% CI: 55.2-57.8) using WHO and ADA criteria, respectively. 2h-PG determined more diabetes individuals than FPG and HbA1c. The testing cost per true positive case of OGTT is close to FPG and less than 2h-PG or HbA1c. FPG, 2h-PG and HbA1c strategies would increase costs from complications for false-positive (FP) or false-negative (FN) results compared with OGTT. Moreover, the least individuals identified as normal by OGTT at baseline developed (pre)diabetes, and the most prediabetes individuals identified by HbA1c or FPG using ADA criteria developed diabetes.

CONCLUSIONS

The prevalence of isolated impaired glucose tolerance and isolated 2-h post-load diabetes were high, and the majority of individuals with (pre)diabetes were undetected in Chinese Han population. Not performing an OGTT results in underdiagnosis, inadequate developing risk assessment and probable cost increases of (pre)diabetes in Han Chinese over 40 years and great consideration should be given to OGTT in detecting (pre)diabetes in this population. Further population-based prospective cohort study of longer-term effects is necessary to investigate the risk assessment and cost of (pre)diabetes.

Case study of an adaptation and implementation of a Diabetes Prevention Program for individuals with serious mental illness

The Diabetes Prevention Program (DPP) is an evidence-based lifestyle intervention developed to decrease the risk for type 2 diabetes and promote weight loss in individuals at risk for diabetes. Individuals with serious mental illness have a greater risk for developing diabetes compared with the general population. In this article, the authors provide a detailed description of the adaptation process of the DPP for individuals with serious mental illness (DPP-SMI). The adaptation process was based on a cultural adaptation framework for modifying evidence-based interventions. To assess the effectiveness of the DPP-SMI, 11 individuals from a community mental health residential agency completed a 22-session pilot study of the adapted program and provided physiological measures before and after the intervention. As primary outcomes, participants were expected to report decreased body weight and increased physical activity per week. Completers had an average weight loss of 19 lbs (8%) and their physical activity increased from 161 to 405 min per week. These preliminary results together with participants' feedback informed further refinement of the DPP-SMI. This case study supports that individuals with serious mental illness can benefit from the DPP-SMI, which is tailored to meet the unique needs of this population group.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Current and emerging pharmacotherapy for prediabetes: are we moving forward?

INTRODUCTION

Prediabetes is a state wherein blood glucose levels are above normal but below the diagnostic threshold for diabetes. Seventy percent of patients with prediabetes develop type 2 diabetes in their lifetime. Despite this, prediabetes frequently goes undiagnosed.

AREAS COVERED

This review focuses on the pharmacological treatment of prediabetes and the prevention of progression to diabetes. A literature search was carried out on PubMed and Embase to review randomized controlled trials examining treatment of prediabetes. Emerging pharmacological therapies with potential benefit are discussed.

EXPERT OPINION

Lifestyle intervention is the cornerstone for preventing progression to diabetes, but metformin remains the first line pharmacological intervention. There appears to be minimal additive effect of combining metformin with lifestyle changes. It would be interesting to assess whether using combination pharmacological approaches plus or minus lifestyle interventions have any additive benefit. Despite the good level of evidence available, the penetrance of any interventions remains very low in part due to the prodromal categorization of the prediabetic state.

Overdiagnosis in primary care: framing the problem and finding solutions

Overdiagnosis, is defined as the diagnosis of a condition that, if unrecognized, would not cause symptoms or harm a patient during his or her lifetime, and it is increasingly acknowledged as a consequence of screening for cancer and other conditions. Because preventive care is a crucial component of primary care, which is delivered to the broad population, overdiagnosis in primary care is an important problem from a public health perspective and has far reaching implications. The scope of overdiagnosis as a result of services delivered in primary care is unclear, though overdiagnosis of indolent breast, prostate, thyroid, and lung cancers is well described and overdiagnosis of chronic kidney disease, depression, and attention-deficit/hyperactivity disorder is also recognized. However, overdiagnosis is a known consequence of all screening and can be assumed to occur in many more clinical contexts. Overdiagnosis can harm patients by leading to overtreatment (with associated potential toxicities), diagnosis related anxiety or depression, and labeling, or through financial burden. Many entrenched factors facilitate overdiagnosis, including the growing use of advanced diagnostic technology, financial incentives, a medical culture that encourages greater use of tests and treatments, limitations in the evidence that obscure the understanding of diagnostic utility, use of non-beneficial screening tests, and the broadening of disease definitions. Efforts to reduce overdiagnosis are hindered by physicians' and patients' lack of awareness of the problem and by confusion about terminology, with overdiagnosis often conflated with related concepts. Clarity of terminology would facilitate physicians' understanding of the problem and the growth in evidence regarding its prevalence and downstream consequences in primary care. It is hoped that international coordination regarding diagnostic standards for disease definitions will also help minimize overdiagnosis in the future.

Racial-Ethnic Disparities in Late-Stage Colorectal Cancer Among Hispanics and Non-Hispanic Whites of New Mexico

INTRODUCTION

Hispanics in New Mexico are diagnosed with more later-stage colorectal cancer (CRC) than non-Hispanic Whites (NHW). Our study evaluated the interaction of race/ethnicity and risk factors for later-stage III and IV CRC among patients in New Mexico.

METHOD

CRC patients ages 30 to 75 years ( n = 163, 46% Hispanic) completed a survey on key explanatory clinical, lifestyle, preventive health, and demographic variables for CRC risk. Adjusted logistic regression models examined whether these variables differentially contributed to later-stage CRC among NHW versus Hispanics.

RESULTS

Compared with NHW, Hispanics had a higher prevalence of later-stage CRC ( p = .007), diabetes ( p = .006), high alcohol consumption ( p = .002), low education ( p = .003), and CRC diagnosis due to symptoms ( p = .06). Compared with NHW, Hispanics reporting high alcohol consumption (odds ratio [OR] = 7.59; 95% confidence interval [CI] = 1.31-43.92), lower education (OR = 3.5; 95% CI = 1.28-9.65), being nondiabetic (OR = 3.23; 95% CI = 1.46-7.15), or ever smokers (OR = 2.4; 95% CI = 1.03-5.89) were at higher risk for late-stage CRC. Adjusting for CRC screening did not change the direction or intensity of the odds ratios.

CONCLUSION

The ethnicity-risk factor interactions, identified for late-stage CRC, highlight significant factors for targeted intervention strategies aimed at reducing the burden of later-stage CRC among Hispanics in New Mexico with broad applicability to other Hispanic populations.

Public health implications of overscreening for carotid artery stenosis, prediabetes, and thyroid cancer

Background

Overscreening occurs when people without symptoms undergo tests for diseases and the results will not improve their health. In this commentary, we examine three examples of how campaigns to screen and treat specific vascular, metabolic, and oncologic diseases in asymptomatic individuals have produced substantial overdiagnosis and may well have contributed to more harm than good. These conditions were chosen because they may not be as well known as other cases such as screening for breast or prostate cancer.

Main text

Screening for carotid artery stenosis can be a lucrative business using portable equipment and mobile vans. While this fatty buildup of plaque in the arteries of the neck is one risk factor for ischemic stroke, current evidence does not suggest that performing carotid dopplers to screen for CAS reduces the incidence of stroke or provide long-term benefits. After a positive screening, the follow-up procedures can lead to heart attacks, bleeding, strokes, and even death. Similarly, many organizations have launched campaigns for “prediabetes awareness.” Screening for prediabetes with a blood sugar test does not decrease mortality or cardiovascular events. Identifying people with prediabetes could lead to psychological stress and starting medication that may have significant side effects. Finally, palpating people’s necks or examining them with ultrasounds for thyroid cancer is common in many countries but ineffective in reducing mortality. Deadly forms of thyroid cancer are rare, and the overall 5-year survival rate is excellent. Interventions from treatment for more prevalent, less aggressive forms of thyroid cancer can lead to surgical complications, radiation side effects, or require lifelong thyroid replacement therapy.

Conclusions

Screening for carotid artery stenosis, prediabetes, and thyroid cancer in an asymptomatic population can result in unnecessary, harmful, and costly care. Systemic challenges to lowering overscreening include lack of clinician awareness, examination of conflicts of interests, perverse financial incentives, and communication with the general public.

Cardiovascular and renal burdens of prediabetes in the USA: analysis of data from serial cross-sectional surveys, 1988-2014

BACKGROUND

There is controversy over the usefulness of prediabetes as a diagnostic label. Using data from US National Health and Nutrition Examination Surveys (NHANES) between 1988 and 2014, we examined the cardiovascular and renal burdens in adults with prediabetes over time and compared patterns with other glycaemic status groups.

METHODS

We analysed cross-sectional survey data from non-pregnant adults aged 20 years and older from the NHANES survey periods 1988-94, 1999-2004, 2005-10, and 2011-14. We defined diagnosed diabetes as patients' self-report that they had been previously diagnosed by a physician or health professional; among those with no self-reported diabetes, prediabetes was defined as a fasting plasma glucose (FPG) concentration of 100-125 mg/dL (5·6-6·9 mmol/L) or an HbA1c of 5·7-6·4% (39-47 mmol/mol); undiagnosed diabetes as an FPG of 126 mg/dL (7·0 mmol/L) or higher or an HbA1c of 6·5% (48 mmol/mol) or higher; and normal glycaemic status as an FPG of less than 100 mg/dL (5·6 mmol/L) and an HbA1c of less than 5·7% (39 mmol/mol). We repeated the analyses using varying definitions of prediabetes (FPG 110-125 mg/dL [6·1-6·9 mmol/L] or HbA1c 5·7-6·4% [39-47 mmol/mol], FPG 110-125 mg/dL [6·1-6·9 mmol/L] or HbA1c 6·0-6·4% [42-47 mmol/mol], and FPG 100-125 mg/dL [5·6-6·9 mmol/L] and HbA1c 5·7-6·4% [39-47 mmol/mol]). For each group over time, we estimated the prevalences of hypertension and dyslipidaemia; and among individuals with those conditions, we estimated the proportions who had been treated and who were achieving care goals. By glycaemic group, we estimated those who were current, former, and never smokers; mean 10-year risk of cardiovascular disease (using estimators from the Framingham Heart Study, the United Kingdom Prospective Diabetes Study (UKPDS), and the ACC/AHA ASCVD guidelines); albuminuria (median and albumin-to-creatinine ratio ≥30 mg/g), estimated glomerular filtration rate (eGFR; mean and <60 mL/min per 1·73m2); and prevalence of myocardial infarction and stroke. For all estimates, we calculated predicted changes between 1988-94 and 2011-14 using logistic regression models adjusted for age, sex, and race or ethnic group.

FINDINGS

We obtained data for 27 971 eligible individuals. In 2011-14, in the population of adults with prediabetes, 36·6% (95% CI 32·8-40·5) had hypertension, 51·2% (47·0-55·3) had dyslipidaemia, 24·3% (21·7-27·3) smoked; 7·7% (6·8-8·8) had albuminuria; 4·6% (3·7-5·9) had reduced eGFR; and 10-year cardiovascular event risk ranged from 5% to 7%. From 1988-94 to 2011-14, adults with prediabetes showed significant increases in hypertension (+9·7 percentage points [95% CI 5·4-14·0]); no change in dyslipidaemia; decreases in smoking (-6·4 percentage points [-10·7 to -2·1]); increased use of treatment to lower blood pressure (54·2% [49·0-59·3] to 81·4% [76·7-85·3], +27·2 percentage points [20·5-33·8] p<0·0001) and to reduce lipids (6·6% to 40·2%, +33·6 percentage points [30·2-37·0], p<0·0001); and increased goal achievements for blood pressure (25·8% to 62·0%, +36·2 percentage points [30·7-41·8], p<0·0001) and lipids (1·0% to 32·8%, +31·8 percentage points [29·1-34·4, p<0·0001]). People with prediabetes also showed decreases in cardiovascular risk (ASCVD -1·9 percentage points [-2·5 to -1·3] to UKPDS -2·7 [-3·5 to -1·9], p<0·0001); but no change in prevalence of albuminuria, reduced eGFR, myocardial infarction, or stroke. Prevalence and patterns were consistent across all prediabetes definitions examined. Compared with adults with prediabetes, adults with diagnosed diabetes showed much larger improvements in cardiovascular and renal risk treatments, apart from smoking, which did not decline.

INTERPRETATION

Over 25 years, cardiovascular and renal risks and disease have become highly prevalent in adults with prediabetes, irrespective of the definitions used. Identification of people with prediabetes might increase the opportunity for cardiovascular and renal risk reduction.

FUNDING

None.

Association of Prediabetes With Higher Coronary Atherosclerotic Burden Among Patients With First Diagnosed Acute Coronary Syndrome

Diabetes mellitus (DM) is associated with more extensive coronary atherosclerosis and more vulnerable plaque phenotypes. However, DM should not be considered a homogeneous and purely binary entity in terms of risk assessment. We evaluated the impact of prediabetic status on coronary atherosclerosis burden in patients with first-time acute coronary syndrome (ACS) who underwent urgent coronary angiography. The patients were divided into DM, prediabetes, and control groups. The 3-vessel disease (TVD) rates and SYNTAX and Gensini scoring systems for defining atherosclerotic burden were compared. The study was conducted in 469 consecutive patients admitted with a diagnosis of ACS. Of these, 250 patients were admitted at the first occurrence of ACS undergoing diagnostic coronary angiography. SYNTAX and Gensini scores and TVD rates were higher in prediabetic patients than in nondiabetic patients ( P = .004, P = .008, and P = .014, respectively), but similar in prediabetic and diabetic patients ( P = .912, P = .773, and P = 1.000, respectively). Coronary atherosclerosis burden is more advanced in prediabetic patients than in nondiabetic patients and is comparable between prediabetic and diabetic patients at first presentation of ACS. Cardiologists should not miss the opportunity to diagnose prediabetes and DM when patients present with an ACS.

Discordance in glycemic categories and regression to normality at baseline in 10,000 people in a Type 2 diabetes prevention trial

The world diabetes population quadrupled between 1980 and 2014 to 422 million and the enormous impact of Type 2 diabetes is recognised by the recent creation of national Type 2 diabetes prevention programmes. There is uncertainty about how to correctly risk stratify people for entry into prevention programmes, how combinations of multiple 'at high risk' glycemic categories predict outcome, and how the large recently defined 'at risk' population based on an elevated glycosylated haemoglobin (HbA1c) should be managed. We identified all 141,973 people at highest risk of diabetes in our population, and screened 10,000 of these with paired fasting plasma glucose and HbA1c for randomisation into a very large Type 2 diabetes prevention trial. Baseline discordance rate between highest risk categories was 45.6%, and 21.3-37.0% of highest risk glycaemic categories regressed to normality between paired baseline measurements (median 40 days apart). Accurate risk stratification using both fasting plasma glucose and HbA1c data, the use of paired baseline data, and awareness of diagnostic imprecision at diagnostic thresholds would avoid substantial overestimation of the true risk of Type 2 diabetes and the potential benefits (or otherwise) of intervention, in high risk subjects entering prevention trials and programmes.

Duration of Diabetes and Prediabetes During Adulthood and Subclinical Atherosclerosis and Cardiac Dysfunction in Middle Age: The CARDIA Study

OBJECTIVE

To determine whether the duration of diabetes and duration of prediabetes estimated during a 25-year period in early adulthood are each independently associated with coronary artery calcified plaque (CAC) and abnormalities in left ventricular structure and function later in life.

RESEARCH DESIGN AND METHODS

Participants were 3,628 white and black adults aged 18-30 years without diabetes or prediabetes at baseline (1985-1986) in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Durations of diabetes and prediabetes were estimated based on their identification at examinations 7, 10, 15, 20, and 25 years later. CAC was identified by computed tomography at years 15, 20, and 25. Left ventricular structure and function were measured via echocardiogram at year 25.

RESULTS

Of the 3,628 individuals, 12.7% and 53.8% developed diabetes and prediabetes, respectively; average (SD) duration was 10.7 (10.7) years and 9.5 (5.4) years. After adjustment for sociodemographic characteristics and other cardiovascular risk factors, and mutual adjustment for each other, the hazard ratio for the presence of CAC was 1.15 (95% CI 1.06, 1.25) and 1.07 (1.01, 1.13) times higher for each 5-year-longer duration of diabetes and prediabetes, respectively. Diabetes and prediabetes duration were associated with worse subclinical systolic function (longitudinal strain [Ptrend < 0.001 for both]) and early diastolic relaxation (e' [Ptrend 0.004 and 0.002, respectively]). Duration of diabetes was also associated with a higher diastolic filling pressure (E-to-e' ratio [Ptrend 0.001]).

CONCLUSIONS

Durations of diabetes and prediabetes during adulthood are both independently associated with subclinical atherosclerosis and left ventricular systolic and diastolic dysfunction in middle age.

When Should "Pre" Carry as Much Weight in the Diabetes Comorbidity Debate? Insights From a Population-Based Survey

INTRODUCTION

Estimates indicate that 86 million people in the United States fit the clinical definition of prediabetes, which contributes to the epidemic of nearly 2 million new diagnoses of type 2 diabetes mellitus each year. Effort has focused on preventing prediabetes from progressing to clinical diabetes. We investigated the sociodemographic, behavioral, and health factors in people diagnosed with diabetes or prediabetes and associated leading indicators and comorbidities.

METHODS

We used Behavioral Risk Factor Surveillance System data from 2011 through 2015 (N = 1,699,754). All respondents aged 18 years or older with complete covariate data were included, differentiating between self-reported diagnosis of diabetes or prediabetes. Weighted univariate and multivariable logistic regression analyses of 28 variables were developed, with adjusted odds of diagnosis, and standardized coefficients were calculated to rank predictors for diabetes and prediabetes.

RESULTS

Prevalence of prediabetes increased each year between 2011 and 2014. After adjusting for demographic, lifestyle, and health variables, the most significant predictors in magnitude of importance for prediabetes and diabetes were age and body mass index. Although adjusted odds for cardiovascular disease and kidney disease were higher in respondents with diabetes than in those with prediabetes, respondents with prediabetes had higher adjusted odds of arthritis, depressive disorder, cancer, and chronic obstructive pulmonary disease.

CONCLUSIONS

Concurrent chronic diseases occur in people with prediabetes even at normal and overweight classifications. By identifying the conditions that are concomitant with diabetes, people with prediabetes can be provided with more rigorous and individualized treatments that can lead to better population health.

Effect of Health Plan Financial Incentive Offering on Employees with Prediabetes

BACKGROUND

Prediabetes may be improved or reversed with lifestyle interventions. A worksite wellness program offering financial incentives for participation may be effective in improving the health of employees with prediabetes. We studied the effect of employee health plan financial incentives on health outcomes for employees with prediabetes.

METHODS

We conducted a retrospective cohort study using electronic medical record data from January 2008 to December 2012. Our study participants were employees with prediabetes and propensity-matched non-employees with prediabetes and commercial health insurance, all receiving care within one health system. Exposures included fixed annual financial incentives for program participation and later a premium discount divided between program participation and achievement of goals. We used longitudinal linear mixed models to assess yearly changes in glycosylated hemoglobin (HbA1c), weight, and low-density lipoprotein cholesterol in employees versus non-employees. We also compared outcomes of employees by ever- versus never- program participant status.

RESULTS

Our study population included 1005 employees and 1005 matched non-employees. The yearly reduction in HbA1c for employees versus matched non-employees did not differ in 2008-2010 but was greater in 2010-2012, when incentives were tied to program participation as well as achievement of goals (-0.10% vs -0.08 %, respectively; P for difference in change [DIC] = .01 from 2010 to 2012). Analyses from both periods showed that employees lost more weight per year than matched non-employees (-1.85 vs -0.21 lb [1 lb=0.45 kg] from 2008 to 2010; P for DIC < .001 and -2.35 vs -0.65 lb from 2010 to 2012; P for DIC < .001). Employees who participated in disease management lost more weight than those who did not (-2.14 vs 0.79 lb yearly before 2010 and -2.82 vs -0.91 after January 1, 2010, P for DIC < .01 and < .001, respectively).

CONCLUSION

A worksite wellness program offering health plan financial incentives for participation and outcomes was associated with improvements in weight and HbA1c.

Economic evaluation of type 2 diabetes prevention programmes: Markov model of low- and high-intensity lifestyle programmes and metformin in participants with different categories of intermediate hyperglycaemia

BACKGROUND

National guidance on preventing type 2 diabetes mellitus (T2DM) in the UK recommends low-intensity lifestyle interventions for individuals with intermediate categories of hyperglycaemia defined in terms of impaired fasting glucose (IFG) or 'at-risk' levels of HbA1c. In a recent systematic review of economic evaluations of such interventions, most studies had evaluated intensive trial-based lifestyle programmes in participants with impaired glucose tolerance (IGT). This study examines the costs and effects of different intensity lifestyle programmes and metformin in participants with different categories of intermediate hyperglycaemia.

METHODS

We developed a decision tree and Markov model (50-year horizon) to compare four approaches, namely (1) a low-intensity lifestyle programme based on current NICE guidance, (2) a high-intensity lifestyle programme based on the US Diabetes Prevention Program, (3) metformin, and (4) no intervention, modelled for three different types of intermediate hyperglycaemia (IFG, IGT and HbA1c). A health system perspective was adopted and incremental analysis undertaken at an individual and population-wide level, taking England as a case study.

RESULTS

Low-intensity lifestyle programmes were the most cost-effective (£44/QALY, £195/QALY and £186/QALY compared to no intervention in IGT, IFG and HbA1c, respectively). Intensive lifestyle interventions were also cost-effective compared to no intervention (£2775/QALY, £6820/QALY and £7376/QALY, respectively, in IGT, IFG and HbA1c). Metformin was cost-effective relative to no intervention (£5224/QALY, £6842/QALY and £372/QALY in IGT, IFG and HbA1c, respectively), but was only cost-effective relative to other treatments in participants identified with HbA1c. At a willingness-to-pay threshold of £20,000/QALY, low- and high-intensity lifestyle programmes were cost-effective 98%, 99% and 98% and 81%, 81% and 71% of the time in IGT, IFG and HbA1c, respectively. An England-wide programme for 50-59 year olds could reduce T2DM incidence by < 3.5% over 50 years and would cost 0.2-5.2% of the current diabetes budget for 2-9 years.

DISCUSSION

This analysis suggests that current English national policy of low-intensity lifestyle programmes in participants with IFG or HbA1c will be cost-effective and have the most favourable budget impact, but will prevent only a fraction of cases of T2DM. Additional approaches to prevention need to be investigated urgently.

The contribution of family history to the burden of diagnosed diabetes, undiagnosed diabetes, and prediabetes in the United States: analysis of the National Health and Nutrition Examination Survey, 2009-2014

PURPOSE

Given the importance of family history in the early detection and prevention of type 2 diabetes, we quantified the public health impact of reported family health history on diagnosed diabetes (DD), undiagnosed diabetes (UD), and prediabetes (PD) in the United States.

METHODS

We used population data from the National Health and Nutrition Examination Survey 2009-2014 to measure the association of reported family history of diabetes with DD, UD, and PD.

RESULTS

Using polytomous logistic regression and multivariable adjustment, family history prevalence ratios were 4.27 (confidence interval (CI): 3.57, 5.12) for DD, 2.03 (CI: 1.56, 2.63) for UD, and 1.26 (CI: 1.09, 1.44) for PD. In the United States, we estimate that 10.1 million DD cases, 1.4 million UD cases, and 3.9 million PD cases can be attributed to having a family history of diabetes.

CONCLUSION

These findings confirm that family history of diabetes has a major public health impact on diabetes in the United States. In spite of the recent interest and focus on genomics and precision medicine, family health history continues to be an integral component of public health campaigns to identify persons at high risk for developing type 2 diabetes and early detection of diabetes to prevent or delay complications.

Prediction of Type 2 Diabetes by Hemoglobin A1c in Two Community-Based Cohorts

OBJECTIVE

Hemoglobin A_1c (HbA_1c) can be used to assess type 2 diabetes (T2D) risk. We asked whether HbA_1c was associated with T2D risk in four scenarios of clinical information availability: 1) HbA_1c alone, 2) fasting laboratory tests, 3) clinic data, and 4) fasting laboratory tests and clinic data.

RESEARCH DESIGN AND METHODS

We studied a prospective cohort of white (N = 11,244) and black (N = 2,294) middle-aged participants without diabetes in the Framingham Heart Study and Atherosclerosis Risk in Communities study. Association of HbA_1c with incident T2D (defined by medication use or fasting glucose [FG] ≥126 mg/dL) was evaluated in regression models adjusted for 1) age and sex (demographics); 2) demographics, FG, HDL, and triglycerides; 3) demographics, BMI, blood pressure, and T2D family history; or 4) all preceding covariates. We combined results from cohort and race analyses by random-effects meta-analyses. Subsidiary analyses tested the association of HbA_1c with developing T2D within 8 years or only after 8 years.

RESULTS

Over 20 years, 3,315 individuals developed T2D. With adjustment for demographics, the odds of T2D increased fourfold for each percentage-unit increase in HbA_1c. The odds ratio (OR) was 4.00 (95% CI 3.14, 5.10) for blacks and 4.73 (3.10, 7.21) for whites, resulting in a combined OR of 4.50 (3.35, 6.03). After adjustment for fasting laboratory tests and clinic data, the combined OR was 2.68 (2.15, 3.34) over 20 years, 5.79 (2.51, 13.36) within 8 years, and 2.23 (1.94, 2.57) after 8 years.

CONCLUSIONS

HbA_1c predicts T2D in different common scenarios and is useful for identifying individuals with elevated T2D risk in both the short- and long-term.

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.

Impact of Lifestyle and Metformin Interventions on the Risk of Progression to Diabetes and Regression to Normal Glucose Regulation in Overweight or Obese People With Impaired Glucose Regulation

OBJECTIVE

Both lifestyle and metformin interventions can delay or prevent progression to type 2 diabetes mellitus (DM) in people with impaired glucose regulation, but there is considerable interindividual variation in the likelihood of receiving benefit. Understanding an individual's 3-year risk of progressing to DM and regressing to normal glucose regulation (NGR) might facilitate benefit-based tailored treatment.

RESEARCH DESIGN AND METHODS

We used the values of 19 clinical variables measured at the Diabetes Prevention Program (DPP) baseline evaluation and Cox proportional hazards models to assess the 3-year risk of progression to DM and regression to NGR separately for DPP lifestyle, metformin, and placebo participants who were adherent to the interventions. Lifestyle participants who lost ≥5% of their initial body weight at 6 months and metformin and placebo participants who reported taking ≥80% of their prescribed medication at the 6-month follow-up were defined as adherent.

RESULTS

Eleven of 19 clinical variables measured at baseline predicted progression to DM, and 6 of 19 predicted regression to NGR. Compared with adherent placebo participants at lowest risk of developing diabetes, participants at lowest risk of developing diabetes who adhered to a lifestyle intervention had an 8% absolute risk reduction (ARR) of developing diabetes and a 35% greater absolute likelihood of reverting to NGR. Participants at lowest risk of developing diabetes who adhered to a metformin intervention had no reduction in their risk of developing diabetes and a 17% greater absolute likelihood of reverting to NGR. Participants at highest risk of developing DM who adhered to a lifestyle intervention had a 39% ARR of developing diabetes and a 24% greater absolute likelihood of reverting to NGR, whereas those who adhered to the metformin intervention had a 25% ARR of developing diabetes and an 11% greater absolute likelihood of reverting to NGR.

CONCLUSIONS

Unlike our previous analyses that sought to explain population risk, these analyses evaluate individual risk. The models can be used by overweight and obese adults with fasting hyperglycemia and impaired glucose tolerance to facilitate personalized decision-making by allowing them to explicitly weigh the benefits and feasibility of the lifestyle and metformin interventions.

Prevalence and phenotype of diabetes and prediabetes using fasting glucose vs HbA1c in a Caribbean population

BACKGROUND

Both fasting plasma glucose (FPG) and HbA1c are recommended for the diagnosis of diabetes and prediabetes by the American Diabetes Association (ADA), and for diabetes by the World Health Organization. The ADA guidance is influential on clinical practice in many developing countries, including in the Caribbean and Latin America. We aimed to compare the prevalence and characteristics of individuals identified as having diabetes and prediabetes by FPG and HbA1c in a predominantly African ancestry Caribbean population.

METHODS

A representative population-based sample of 1234 adults (≥25 years of age) resident in Barbados was recruited. Standard methods with appropriate quality control were used to collect data on height, weight, blood pressure, fasting lipids and history of diagnosed diabetes, and to measure fasting glucose and HbA1c. Those with previously diagnosed diabetes (n = 192) were excluded from the analyses. Diabetes was defined as: FPG ≥7.0 mmol/L or HbA1c ≥6.5%; prediabetes as: FPG ≥5.6 to <7mmol/L or HbA1c ≥5.7 to <6.5%.

RESULTS

Complete data were available on 939 participants without previously diagnosed diabetes. The prevalence of undiagnosed diabetes was higher, but not significantly so, by HbA1c (4.9%, 95% CI 3.5, 6.8) vs FPG (3.5%, 2.4, 5.1). Overall 79 individuals had diabetes by either measure, but only 21 on both. The prevalence of prediabetes was higher by HbA1c compared to FPG: 41.7% (37.9, 45.6) vs 15.0% (12.8, 17.5). Overall 558 individuals had prediabetes by either measure, but only 107 on both. HbA1c, but not FPG, was significantly higher in women than men; and FPG, but not HbA1c, was significantly associated with raised triglycerides and low HDL cholesterol.

CONCLUSION

The agreement between FPG and HbA1c defined hyperglycaemia is poor. In addition, there are some differences in the phenotype of those identified, and HbA1c gives a much higher prevalence of prediabetes. The routine use of HbA1c for screening and diagnosis in this population would have major implications for clinical and public health policies and resources. Given the lack of robust evidence, particularly for prediabetes, on whether intervention in the individuals identified would improve outcomes, this approach to screening and diagnosis cannot be currently recommended for this population.

Exploring residual risk for diabetes and microvascular disease in the Diabetes Prevention Program Outcomes Study (DPPOS)

AIM

Approximately half of the participants in the Diabetes Prevention Outcomes Study (DPPOS) had diabetes after 15 years of follow-up, whereas nearly all the others remained with pre-diabetes. We examined whether formerly unexplored factors in the DPPOS coexisted with known risk factors that posed additional risk for, or protection from, diabetes as well as microvascular disease.

METHODS

Cox proportional hazard models were used to examine predictors of diabetes. Sequential modelling procedures considered known and formerly unexplored factors. We also constructed models to determine whether the same unexplored factors that associated with progression to diabetes also predicted the prevalence of microvascular disease. Hazard ratios (HR) are per standard deviation change in the variable.

RESULTS

In models adjusted for demographics and known diabetes risk factors, two formerly unknown factors were associated with risk for both diabetes and microvascular disease: number of medications taken (HR = 1.07, 95% confidence intervals (95% CI) 1.03 to 1.12 for diabetes; odds ratio (OR) = 1.10, 95% CI 1.04 to 1.16 for microvascular disease) and variability in HbA_1c (HR = 1.02, 95% CI 1.01 to 1.03 for diabetes; OR = 1.06, 95% CI 1.04 to 1.09 for microvascular disease per sd). Total comorbidities increased risk for diabetes (HR = 1.10, 95% CI 1.04 to 1.16), whereas higher systolic (OR = 1.22, 95% CI 1.13 to 1.31) and diastolic (OR = 1.14, 95% CI 1.05 to 1.22) blood pressure, as well as the use of anti-hypertensives (OR = 1.41, 95% CI 1.23 to 1.62), increased risk of microvascular disease.

CONCLUSIONS

Several formerly unexplored factors in the DPPOS predicted additional risk for diabetes and/or microvascular disease - particularly hypertension and the use of anti-hypertensive medications - helping to explain some of the residual disease risk in participants of the DPPOS.

[Critical view and argumentation on chronic care programs in Primary and Community Care]

El análisis detallado de los planes de atención a la cronicidad desarrollados por los servicios regionales de salud pone de manifiesto un sorprendente nivel de uniformidad en su diseño y despliegue, a pesar de las diferencias existentes entre dichos servicios. La revisión de la literatura sobre los modelos teóricos que lo sustentan y los instrumentos que lo desarrollan no aporta evidencias concluyentes que permitan afirmar que los modelos de atención a pacientes crónicos alcanzan mejores resultados que modelos de atención alternativos. A pesar de que todos los planes de atención a la cronicidad incluyen sistemas de evaluación de los mismos, no se han publicado hasta la fecha estudios rigurosos sobre su efecto.

Dado que, por el contrario, sí existen pruebas sólidas y reiteradas de que modelos con una Atención Primaria fuerte obtienen mejores resultados, cabe preguntarse sobre la necesidad de buscar modelos alternativos, cuando las metas propuestas probablemente podrían alcanzarse de fortalecer realmente la Atención Primaria.

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.

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.

Do Words Matter? Health Care Providers' Use of the Term Prediabetes

Communication of risk is not solely the transfer of information; it is an interaction and exchange of ideas between concerned individuals. Health care provider communication about type 2 diabetes risk status may influence individual participation in behaviours that prevent or delay the disease, which is concerning from a public health perspective. The term prediabetes is used to convey risk status and little is known about how health care providers view or use the term. In this article, we describe health care provider use and perceptions of the term prediabetes drawing on data from a survey conducted between August and November 2011 of 15 health care providers practicing in Southeast Wyoming and Northern Colorado USA. We used a grounded theory research design to guide data collection and analysis and in the interviews invited providers to describe their use and perception of the term prediabetes. We found that providers use of the term 'prediabetes' depended on their view of the term's meaning (such as, whether patients were likely to understand or be confused by it) and impact (in terms of motivating patients to mitigate risk). We found there were differences in providers' perceptions of the negative and positive associations of the term and this influenced whether or not they used it. These findings are not surprising given the lack of consensus over definitions and diagnosis criteria for prediabetes. Given this this lack of agreement, there are difficulties about the use of the term prediabetes and its use should take place within effective risk communication. Health care providers must consider essential aspects of risk communication in order to enable individuals at risk of type 2 diabetes to mitigate the risk and by doing so reduce incidence and prevalence rates of the disease.

An Interrupted Time Series Analysis to Determine the Effect of an Electronic Health Record-Based Intervention on Appropriate Screening for Type 2 Diabetes in Urban Primary Care Clinics in New York City

OBJECTIVE

To determine the impact of a health system-wide primary care diabetes management system, which included targeted guidelines for type 2 diabetes (T2DM) and prediabetes (dysglycemia) screening, on detection of previously undiagnosed dysglycemia cases.

RESEARCH DESIGN AND METHODS

Intervention included electronic health record (EHR)-based decision support and standardized providers and staff training for using the American Diabetes Association guidelines for dysglycemia screening. Using EHR data, we identified 40,456 adults without T2DM or recent screening with a face-to-face visit (March 2011-December 2013) in five urban clinics. Interrupted time series analyses examined the impact of the intervention on trends in three outcomes: 1) monthly proportion of eligible patients receiving dysglycemia testing, 2) two negative comparison conditions (dysglycemia testing among ineligible patients and cholesterol screening), and 3) yield of undiagnosed dysglycemia among those tested.

RESULTS

Baseline monthly proportion of eligible patients receiving testing was 7.4-10.4%. After the intervention, screening doubled (mean increase + 11.0% [95% CI 9.0, 13.0], proportion range 18.6-25.3%). The proportion of ineligible patients tested also increased (+5.0% [95% CI 3.0, 8.0]) with no concurrent change in cholesterol testing (+0% [95% CI -0.02, 0.05]). About 59% of test results in eligible patients showed dysglycemia both before and after the intervention.

CONCLUSIONS

Implementation of a policy for systematic dysglycemia screening including formal training and EHR templates in urban academic primary care clinics resulted in a doubling of appropriate testing and the number of patients who could be targeted for treatment to prevent or delay T2DM.