Diabetes mellitus (diabetes) is a global disease but its prevalence varies greatly. The introduction of standardized diagnostic criteria for glucose tolerance in the 1980s by the National Diabetes Data Group (NDDG)^[1] and the World Health Organization (WHO),^[2,3] allowed for assessment and comparison of current and projected estimates on a global level.^[4–7]

The revised classification of diabetes by the American Diabetes Association^[8] and WHO^[9,10] encompasses three clinical stages of glycaemia (normoglycaemia, impaired glucose regulation (impaired glucose tolerance, impaired fasting glucose) and diabetes) and four aetiological types of diabetes (type 1, type 2, gestational and other specific types).

By far the most common forms of diabetes globally are type 1 and type 2, accounting for 5–10% and 90–95%, respectively (Tables 36.1, 36.2).^[8]Other forms of diabetes encountered in the tropics include malnutrition-modulated diabetes mellitus …