Design of a cluster-randomized trial of the effectiveness and cost-effectiveness of metformin on prevention of type 2 diabetes among prediabetic Mexican adults (the PRuDENTE initiative of Mexico City)

Participatory intervention to improve nutrition and physical activity of school-age children in Mexico

Obesity is one of the major public health problems of the 21st century, affecting every country in the world. In Mexico, the prevalence of overweight and obesity in children (5 to 11 years) was 35.5%. Childhood obesity is a chronic disease itself; and is associated with other chronic conditions.

OBJECTIVE

To assess the effect and feasibility of a participatory intervention to improve nutrition and physical activity within the school environment in children in public elementary schools in Mexico.

METHODS

The present study is a cluster trial. The intervention focused on; changes in food offered, training the schools' food service staff, promoting water consumption and physical activity at the community level, implementing healthy spaces inside the school, improving the quality of physical education within schools, among others. The main outcomes will focus on rate of weight gain, time devoted to physical activity, sedentary behaviors, diet quality and response feeding behaviors. We also will assess the time and personnel involved in the intervention development, maintenance, and dissemination.

CONCLUSION

Findings from this trial will generate new translational knowledge in Mexico; if the results are positive, this participatory intervention could serve as a basis for designing multidimensional interventions that could be scaled up at the national level.

Diagnostic performance of questionnaires to identify individuals with impaired fasting glucose in Mexican adult population

AIMS

To evaluate the diagnostic performance of five questionnaires to identify impaired fasting glucose (IFG) in Mexican adult population.

METHODS

The study included 23,311 subjects from five cohorts, three composed of individuals who sought medical advice in their first level clinics or participated in research studies and two representative surveys of the Mexican population. The reference standard was IFG which was defined as a fasting glucose ≥ 100 mg/dL. Diagnostic performance was evaluated with specificity, sensitivity, positive and negative predictive values, area under the curve, and the proportion of correctly classified individuals.

RESULTS

The prevalence of IFG ranged from 14.4 to 48.1 % across the cohorts. Diagnostic performance of the questionnaires varied in each cohort depending on IFG prevalence. The questionnaires designed by Rojas, American Diabetes Association and International Diabetes Federation had the best performance considering the correct classification (>66.0 %) of subjects in all cohorts. However, Rojas' questionnaire had the best balance between sensitivity and specificity across the cohorts.

CONCLUSION

In the Mexican population, considering different scenarios, the Rojas' questionnaire had the best diagnostic performance. The implementation of questionnaires for the identification of prediabetes and undiagnosed diabetes requires further study in specific populations.

Metformin for diabetes prevention: update of the evidence base

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