Researching how to realize the potential of diabetes prevention

DiAlert: a prevention program for overweight first degree relatives of type 2 diabetes patients: results of a pilot study to test feasibility and acceptability

Background

Prevalence of type 2 diabetes mellitus is increasing due to lifestyle changes, particularly affecting those genetically at risk. We developed DiAlert as a targeted group-based intervention aimed to promote intrinsic motivation and action planning for lifestyle changes and weight loss in first degree relatives of patients with type 2 diabetes mellitus.

The main objective of the pilot of the DiAlert intervention was to assess fidelity, feasibility and acceptability prior to starting the randomized controlled trial.

Methods

Individuals with a family history of type 2 diabetes mellitus were self-identified and screened for eligibility. DiAlert consists of two group sessions. Feasibility, fidelity, acceptability and self-reported perceptions and behavioral determinants were evaluated in a pre-post study using questionnaires and observations. Determinants of behavior change were analyzed using paired-samples t tests and Wilcoxon signed rank tests.

Results

DiAlert was delivered to two groups of first degree relatives of patients with type 2 diabetes mellitus (N = 9 and N = 12). Feasibility and fidelity were confirmed. Overall, the DiAlert group sessions were positively evaluated (8.0 on a scale of 1 to 10) by participants. The intervention did not impact perceived susceptibility or worry about personal diabetes risk. Action planning with regard to changing diet and physical activity increased.

Conclusions

DiAlert proved feasible and was well-accepted by participants. Positive trends in action planning indicate increased likelihood of actual behavior change following DiAlert. Testing the effectiveness in a randomized controlled trial is imperative.

Trial registration

Netherlands National Trial Register (NTR): NTR2036

A behavioral intervention in a cohort of Japanese-Brazilians at high cardiometabolic risk

OBJECTIVE

To assess the effect of a health promotion program on cardiometabolic risk profile in Japanese-Brazilians.

METHODS

A total of 466 subjects from a study on diabetes prevalence conducted in the city of Bauru, southeastern Brazil, in 2000 completed a 1-year intervention program (2005-2006) based on healthy diet counseling and physical activity. Changes in blood pressure and metabolic parameters in the 2005-2006 period were compared with annual changes in these same variables in the 2000-2005 period.

RESULTS

During the intervention, there were greater annual reductions in mean (SD) waist circumference [-0.5(3.8) vs. 1.2(1.2) cm per year, p<0.001], systolic blood pressure [-4.6(17.9) vs. 1.8(4.3) mmHg per year, p<0.001], 2-hour plasma glucose [-1.2(2.1) vs. -0.2(0.6) mmol/L per year, p<0.001], LDL-cholesterol [-0.3(0.9) vs. -0.1(0.2) mmol/L per year, p<0.001] and Framingham coronary heart disease risk score [-0.25(3.03) vs. 0.11(0.66) per year, p=0.02] but not in triglycerides [0.2(1.6) vs. 0.1(0.42) mmol/L per year, p<0.001], and fasting insulin level [1.2(5.8) vs. -0.7(2.2) IU/mL per year, p<0.001] compared with the pre-intervention period. Significant reductions in the prevalence of impaired fasting glucose/impaired glucose tolerance and diabetes were seen during the intervention (from 58.4% to 35.4%, p<0.001; and from 30.1% to 21.7%, p= 0.004, respectively).

CONCLUSIONS

A one-year community-based health promotion program brings cardiometabolic benefits in a high-risk population of Japanese-Brazilians.

Incidence of type 2 diabetes using proposed HbA1c diagnostic criteria in the european prospective investigation of cancer-norfolk cohort: implications for preventive strategies

OBJECTIVE

To evaluate the incidence and relative risk of type 2 diabetes defined by the newly proposed HbA(1c) diagnostic criteria in groups categorized by different baseline HbA(1c) levels.

RESEARCH DESIGN AND METHODS

Using data from the European Prospective Investigation of Cancer (EPIC)-Norfolk cohort with repeat HbA(1c) measurements, we estimated the prevalence of known and previously undiagnosed diabetes at baseline (baseline HbA(1c) ≥6.5%) and the incidence of diabetes over 3 years. We also examined the incidence and corresponding odds ratios (ORs) by different levels of baseline HbA(1c). Incident diabetes was defined clinically (self-report at follow-up, prescribed diabetes medication, or inclusion on a diabetes register) or biochemically (HbA(1c) ≥6.5% at the second health assessment), or both.

RESULTS

The overall prevalence of diabetes was 4.7%; 41% of prevalent cases were previously undiagnosed. Among 5,735 participants without diabetes at baseline (identified clinically or using HbA(1c) criteria, or both), 72 developed diabetes over 3 years (1.3% [95% CI 1.0-1.5]), of which 49% were identified using the HbA(1c) criteria. In 6% of the total population, the baseline HbA(1c) was 6.0-6.4%; 36% of incident cases arose in this group. The incidence of diabetes in this group was 15 times higher than in those with a baseline HbA(1c) of <5.0% (OR 15.5 [95% CI 7.2-33.3]).

CONCLUSIONS

The cumulative incidence of diabetes defined using a newly proposed HbA(1c) threshold in this middle-aged British cohort was 1.3% over 3 years. Targeting interventions to individuals with an HbA(1c) of 6.0-6.4% might represent a feasible preventive strategy, although complementary population-based preventive strategies are also needed to reduce the growing burden of diabetes.

Screening for type 2 diabetes: an update of the evidence

A growing body of evidence on diabetes screening has been published during the last 10 years. Type 2 diabetes meets many but not all of the criteria for screening. Concerns about potential harms of screening have largely been resolved. Screening identifies a high-risk population with the potential to gain from widely available interventions. However, in spite of the findings of modelling studies, the size of the benefit of earlier initiation of treatment and the overall cost-effectiveness remains uncertain, in contrast to other screening programmes (such as for abdominal aortic aneurysms) that are yet to be fully implemented. There is also uncertainty about optimal specifications and implementation of a screening programme, and further work to complete concerning development and delivery of individual- and population-level preventive strategies. While there is growing evidence of the net benefit of earlier detection of individuals with prevalent but undiagnosed diabetes, there remains limited justification for a policy of universal population-based screening for type 2 diabetes at the present time. Data from ongoing studies should inform the key assumptions in existing modelling studies and further reduce uncertainty.

Predictive factors of non-deterioration of glucose tolerance following a 2-year behavioral intervention

AIM

To identify predictive factors associated with non-deterioration of glucose metabolism following a 2-year behavioral intervention in Japanese-Brazilians.

METHODS

295 adults (59.7% women) without diabetes completed 2-year intervention program. Characteristics of those who maintained/improved glucose tolerance status (non-progressors) were compared with those who worsened (progressors) after the intervention. In logistic regression analysis, the condition of non-progressor was used as dependent variable.

RESULTS

Baseline characteristics of non-progressors (71.7%) and progressors were similar, except for the former being younger and having higher frequency of disturbed glucose tolerance and lower C-reactive protein (CRP). In logistic regression, non-deterioration of glucose metabolism was associated with disturbed glucose tolerance - impaired fasting glucose or impaired glucose tolerance - (p < 0.001) and CRP levels </= 0.04 mg/dL (p = 0.01), adjusted for age and anthropometric variables. Changes in anthropometry and physical activity and achievement of weight and dietary goals after intervention were similar in subsets that worsened or not the glucose tolerance status.

CONCLUSION

The whole sample presented a homogeneous behavior during the intervention. Lower CRP levels and diagnosis of glucose intolerance at baseline were predictors of non-deterioration of the glucose metabolism after a relatively simple intervention, independent of body adiposity.

International Diabetes Federation: An update of the evidence concerning the prevention of type 2 diabetes

This article aims to provide an updated summary of diabetes prevention efforts by reviewing relevant literature published between 2007 and 2009. These include results from the long-term follow-up of diabetes prevention trials and the roll-out of community-based interventions in "real world" settings. Some countries have begun to implement population-based strategies for chronic disease prevention, but investment in developing and evaluating population-level interventions remains inadequate. By focussing on the "small change" approach and involving a number of different agencies, it may be possible to shift the population distribution of risk factors for diabetes and cardiovascular disease in a favourable direction. The cost-effectiveness of primary prevention strategies for type 2 diabetes has not been universally demonstrated. Some of the uncertainties relating to screening for diabetes have now been resolved but longer-term data on hard cardiovascular outcomes are still needed. In summary, individual countries should aim to develop and evaluate cost-effective, setting-specific diabetes risk identification and prevention strategies based on available resources. These should be linked to initiatives aimed at reducing the burden of cardiovascular disease, and complemented with population-based strategies focusing on the control and reduction of behavioural and cardiovascular risk factors by targeting their key determinants.