The International Diabetes Federation (IDF) has formally recognised a fifth type of diabetes, reviving a long-contested condition and calling on global health authorities, including the World Health Organization (WHO), to do the same.
Known as type 5 diabetes, the condition is thought to affect as many as 25 million people worldwide, largely in low- and middle-income countries where malnutrition and limited access to healthcare are widespread. Despite its scale, the condition has remained poorly understood and frequently misdiagnosed for decades.
First identified in Jamaica in 1955, the disease was later described as malnutrition-related diabetes mellitus (MRDM). Although acknowledged by the WHO in the 1980s, the classification was withdrawn in 1999 because of insufficient evidence, fuelling years of scientific dispute over whether the condition existed as a distinct form of diabetes at all.
Unlike type 1 diabetes, which is autoimmune, or type 2 diabetes, which is largely associated with insulin resistance linked to diet and lifestyle, type 5 diabetes appears to stem from chronic nutrient deficiency. Researchers say prolonged undernutrition, particularly in infancy and early childhood, can impair pancreatic development, reducing insulin production later in life.
Studies suggest people with the condition are insulin-deficient but remain sensitive to insulin, setting them apart metabolically from both type 1 and type 2 diabetes. This distinction is critical, experts say, because standard diabetes treatments may be ineffective or even dangerous.
“Inappropriate insulin treatment could induce hypoglycaemia, especially in settings with food insecurity and limited glucose monitoring,” said Meredith Hawkins, an endocrinologist at the Albert Einstein College of Medicine, who has long campaigned for global recognition of the condition.
Hawkins’ research, published in 2022, identified a unique metabolic profile in patients with malnutrition-related diabetes, based on a trial conducted in south India.
She now chairs a newly established IDF working group tasked with developing diagnostic criteria, treatment guidelines, and a global research registry.
Supporters of the move say recognition is long overdue and essential to unlocking research funding and improving care. Critics argue that diagnostic uncertainty remains and warn against premature classification.
The IDF says the goal is clarity. Without formal recognition, researchers say, millions remain at risk of misdiagnosis and harmful treatment. As undernutrition persists in parts of Africa, Asia, Latin America and the Caribbean, health experts warn that the consequences of inaction could be fatal.
“Once you have seen young patients dying from inappropriate treatment of a neglected form of diabetes,” Hawkins said, “there’s no turning back.”
