Malnutrition Modulated Diabetes: A Variant of Type-1 Diabetes or Hybrid Diabetes and Not Type-5 Diabetes'

Malnutrition-modulated diabetes (MMDM) has been extensively studied by the various investigators over the last 70 years. It initially emerged as a distinct clinical entity as youth-onset diabetes in the twenties, having severe hyperglycaemia, ketosis resistance, and requiring a high insulin dose. In 1985, World Health Organisation (WHO) placed it under a major type of diabetes along with type 1 and type 2. Subsequently, it was removed from classification when research revealed that patients with MMDM, though had severe hyperglycaemia, were not immune to ketosis, had no insulin resistance on systematic investigation. With the availability of anti-GAD and IA-2 antibody assays, several investigators assessed a large cohort of MMDM. Demonstration of islet cell antibodies, especially anti-GAD65 led to the realisation that MMDM is possibly a variant of type-1 diabetes. However, the spread of autoimmunity was limited to fewer autoantigens and organs due to the prevailing malnutrition. Limited pancreatic beta cell autoimmunity led to better C-peptide reserves than those of type 1 diabetes. This further brings MMDM near Type-1 in pathogenesis. Alternative MMDM can be called a hybrid of Type-1 and severe Type-2. It will be in the fitness to categorise it as a type of 'hybrid diabetes in the WHO, 2019 classification. Recently, the 'International Diabetes Federation' renamed MMDM as type-5 diabetes. Giving a new name to MMDM is like putting old wine in a new bottle. The current review provides details of MMDM, its possible place in the current classification, and independent views on the term 'Type-5 diabetes'.