Type 5 diabetes, which primarily affects lean and undernourished young adults in low- and middle-income countries, has now been officially recognized as a distinct form of diabetes by the International Diabetes Federation (IDF). This recognition marks a significant milestone as the condition has been long neglected in research and often misdiagnosed.
According to Dr Nihal Thomas, a professor of endocrinology at Christian Medical College in Vellore and a member of the Type 5 Diabetes Working Group, this form of diabetes leads to abnormal functioning of pancreatic beta cells, resulting in reduced insulin production. This is a fundamental difference from Type 2 diabetes, where the issue primarily revolves around insulin resistance.
A Historical Perspective
The term ‘Type 5 diabetes’ was introduced by Prof Peter Schwarz, the IDF president, this January, and received official recognition on April 7 during the 75th World Congress for Diabetes held in Bangkok. Interestingly, this condition was first reported in Jamaica in 1955 and was referred to as J-type diabetes. In 1985, WHO categorized it as “malnutrition-related diabetes mellitus,” but this classification was removed in 1999 due to insufficient evidence linking it to malnutrition, which is now understood to be a definitive feature of Type 5 diabetes.
Prevalence and Impact
Type 5 diabetes has been documented in several countries including India, Sri Lanka, Bangladesh, Uganda, Ethiopia, Rwanda, and Korea, predominantly affecting populations in the Global South. Current estimates suggest that around 25 million people are living with this condition worldwide. Its recent recognition has been bolstered by renewed research focusing on how malnutrition affects pancreatic development and insulin function.
Identification and Markers
Dr Thomas emphasizes that Type 5 diabetes, particularly seen in young Asian Indians, lacks evidence of autoimmune or genetic causes. Patients typically present with a significantly lower body-mass index (BMI) less than 18.5 kg/m², and insulin secretion levels are severely diminished—lower than those with Type 2 diabetes and just above those seen in Type 1 diabetes.
Causes of Type 5 Diabetes
The primary cause of Type 5 diabetes is malnutrition, which often starts during fetal development. Dr C S Yajnik, director of the Diabetes Unit at KEM Hospital in Pune, explains that insufficient nutrition during pregnancy can predispose individuals to diabetes later in life. Historical factors such as hard labor, colonization, and famine have contributed to widespread undernourishment in India. In recent decades, rapid urbanization has also led to overnutrition, creating a paradox where individuals may remain at risk for malnutrition-related diabetes.
Potential Treatments
Since Type 5 diabetes has only recently been officially recognized, specific diagnostic criteria and treatment protocols are still being developed. The Type 5 Diabetes Working Group aims to create guidelines over the next two years while investigating diverse populations, particularly in resource-limited settings. Dr Thomas suggests that a high-protein diet, tailored to an individual’s BMI and activity levels, is essential. In some cases, anti-diabetic medications or insulin may be administered based on glucose levels and therapeutic response.
This recognition of Type 5 diabetes is a crucial step in addressing the unique challenges faced by affected populations, paving the way for better diagnosis, treatment, and understanding of this condition.
