The diabetes playbook just got a major update.
The International Diabetes Federation (IDF) officially recognized a fifth form of the disease this year, a landmark step that comes more than 70 years after it was first identified.
The move aims to shine a light on a long-overlooked condition that affects millions worldwide — but the challenges are far from over.
“Doctors are still unsure how to treat these patients, who often don’t live for more than a year after diagnosis,” Dr. Meredith Hawkins, an endocrinologist at the Albert Einstein College of Medicine’s Global Diabetes Institute, said earlier this year.
Known as malnutrition-related diabetes mellitus, or MRDM, the condition is estimated to affect up to 25 million people globally. It primarily strikes lean teens and young adults in low- and middle-income countries, especially across Asia and Africa.
“It’s not something that we see very commonly in this country, but it is generally reported in third-world countries and poverty-stricken areas where people don’t get enough calories or protein in their diet,” Dr. David Cutler, a family medicine physician, told Prevention in October.
Type 5 diabetes is unique because insulin resistance doesn’t appear to be the main cause.
With type 1, patients have an autoimmune condition that destroys the pancreas’s ability to produce insulin, the hormone that regulates blood sugar. Type 2 develops over time due to insulin resistance, often linked to diet and lifestyle.
Other forms exist as well, like type 3c diabetes, which is caused by damage to the pancreas, and gestational diabetes, triggered by hormonal changes during pregnancy and usually resolving after delivery.
But type 5 develops differently.
It appears to stem from underdeveloped pancreatic tissue caused by long-term nutritional deficiencies, especially during childhood or adolescence, which impairs the organ’s ability to produce insulin and regulate blood sugar, according to the IDF.
MRDM was first identified in 1955 in Jamaica, and in 1985 the World Health Organization (WHO) officially recognized it as a distinct condition. However, the designation was removed in 1999 due to limited follow-up studies and supporting evidence.
Since then, scientists have debated whether the condition exists at all.
“Malnutrition-related diabetes is more common than tuberculosis and nearly as common as HIV/AIDS, but the lack of an official name has hindered efforts to diagnose patients or find effective therapies,” said Hawkins, who had pushed for the formal recognition of type 5 for years.
The unique nature of MRDM means that while patients with other forms of diabetes typically respond well to insulin injections, those with type 5 may not experience the same benefits.
Some patients may only need minimal supplementary insulin, and too much can make them worse.
“Inappropriate insulin treatment could induce hypoglycaemia [low blood sugar levels], which can be a particular risk in settings with food insecurity and where glucose monitoring might not be affordable,” Hawkins and her colleagues wrote in a review published earlier this year.
Researchers are currently exploring oral diabetes medications to stimulate insulin secretion as an alternative to high-dose injections for MRDM patients. Addressing the underlying nutritional deficiencies that caused the disease is also considered essential.
Without proper treatment, MRDM patients face an increased risk for complications such as nerve damage, kidney disease and vision problems.
“Life expectancy may be significantly reduced if the condition is not diagnosed and treated accurately,” the IDF said in a statement.
To address the challenges surrounding MRDM, the IDF formed a type 5 diabetes working group in April and appointed Hawkins as chair. The team will develop formal diagnostic criteria, treatment guidelines and training programs for healthcare professionals managing the condition.
“I’m hopeful that this formal recognition as type 5 diabetes will lead to progress against this long-neglected disease that severely debilitates people and is often fatal,” Hawkins said.
