2.1 Diagnosis
Elevated HbA1c has recently been proposed as an additional or alternative diagnostic method for diabetes (30), but its applicability in all countries and populations is questionable and needs to be evaluated in terms of diagnostic cut-off points, availability and cost. As some haemoglobin traits can interfere with some HbA1c assay methods and conditions that change red cell turnover, such as chronic malaria, can lead to spurious results, the applicability of this method in all countries and populations needs evaluating. Similarly, HbA1c testing is not currently available in all settings, particularly in low- and middle-income countries, but as demand for HbA1c testing increases it may become a cheaper and more accessible method for identifying individuals with undiagnosed diabetes and those at high risk. For gestational diabetes at the moment there are no generally accepted, easily administered diagnostic measures, making surveys and screening for gestational diabetes difficult, particularly in low- resource settings. The feasibility of glucose challenge tests in antenatal clinics of most low- and middle-income countries is uncertain, and there is a need to develop and evaluate more feasible methods.
2.2 Surveillance
Most low- and middle-income countries do not have a mechanism for monitoring diabetes- related morbidity and mortality. The WHO Diabetes Mondiale (DiaMond) Study and the Europe and Diabetes (EURODIAB) Study, which began in the 1980s, have been instrumental in monitoring trends in type 1 diabetes incidence through the establishment of population- based registries using standardized definitions, data collection forms and methods for validation (20, 31). Many of these registries, especially in low-income countries, have unfortunately ceased to function. Surveillance of the burden of diabetes is an essential step in introducing prevention and control interventions and evaluating their impact. Research directed at developing feasible and valid surveillance methods for monitoring diabetes-related morbidity and mortality is therefore particularly relevant for low- and middle-income countries (32).
2.3 Prevention
2.3.1 Tertiary prevention (management)
The largest proportion of robust research into diabetes prevention has been carried out in the tertiary sector, for example treating people with diagnosed type 1 and type 2 diabetes (33, 34). In the past two decades well-conducted clinical trials have answered many long-standing questions regarding the management of diabetes. The control of vascular risk factors (for example glucose, cholesterol, blood pressure, smoking, albuminuria) has major benefits in preventing diabetes complications (35–37). The attainment of even modest targets in HbA1c, blood pressure and high lipids, treating high-risk diabetic feet and providing pre-pregnancy