Type 5 Diabetes: What All You Should Know About This Overlooked Subtype Of Diabetes
Although it is lesser known, Type Diabetes is associated with mitochondrial disease, which is a critical condition that affects cellular energy.
Published : April 22, 2025 at 5:27 PM IST
In the last few years, diabetes has become a common topic of health concern for many. While most people know about Type 1 and Type 2 diabetes, which are conditions tied to insulin production or resistance, many are unaware of Type 5 diabetes.
Dr G. Krishna Mohan Reddy, Senior Consultant Physician and Diabetologist at Yashoda Hospitals in Hyderabad explains that Type 5 diabetes is a rare and often misunderstood subtype of diabetes which is linked to mitochondria dysfunction, where cellular energy impacts the body's ability to regulate blood sugar levels.
What is Type 5 Diabetes
Type 5 Diabetes, also referred to as malnutrition-related diabetes, is a distinct form of diabetes recently classified as a standalone type. "Unlike Type 1 (autoimmune) or Type 2 (insulin resistance), this form is rooted in chronic undernutrition—particularly during early childhood or adolescence— which impairs the pancreas' ability to produce insulin,: says Dr Reddy.
He further explains that it primarily affects lean young adults, especially males in low- and middle-income countries. "These individuals are often underweight (BMI < 18.5) and have very low body fat levels, around 10–12%, compared to 20–25% in healthy adults. They are insulin-deficient but not insulin-resistant, which makes their condition unique," explains the diabetologist.
Symptoms to Watch For
Symptoms of Type 5 Diabetes are mostly similar to other diabetes type. However, Dr Reddy says they can be accompanied by other signs of mitochondrial dysfunction, such as:
- Muscle weakness or fatigue
- Neurological issues like seizures or developmental delays
- Heart problems
- Gastrointestinal disturbances
- Hearing or vision loss
Some of the common symptoms may resemble other types of diabetes such as:
- Excessive thirst and urination
- Fatigue
- Weight loss
- Delayed growth in children
- Recurrent infections
"What sets Type 5 apart is the context: these symptoms appear in undernourished individuals with little or no fat stores, often in resource-limited settings," says Dr Reddy.
How to Detect Type 5 Diabetes
Dr Reddy says Diagnosis of Type 5 Diabetes, or Severe Insulin-Deficient Diabetes (SIDD), involves both clinical evaluation and blood tests.
- Blood tests may show:
- High HbA1c (indicating chronic high blood sugar)
- Severely low insulin levels
- Minimal or absent insulin resistance
- Absence of autoantibodies (seen in Type 1)
"Body scans often reveal severely low-fat reserves. Nutritional assessments show deficiencies in essential nutrients like protein, zinc, and vitamin A, which are important for pancreatic development," says the physician.
What is the Treatment Approach
As of now, there is no cure for Type 5 Diabetes or mitochondrial disease, so treatment focuses on symptom management and maintaining stable blood sugar levels.
Nutritional rehabilitation is the cornerstone. High-protein diets with adequate calories are crucial, using affordable sources like legumes, milk, and fish.
Medical management may include oral drugs like metformin or low-dose insulin, depending on severity. Since patients are not insulin-resistant, small amounts of insulin or even oral drugs may suffice—making management more feasible in low-resource settings.
"Earlier misdiagnosis often led to unnecessary high insulin doses, which sometimes caused dangerous drops in blood sugar," says Dr Reddy.
How Does One Develop Type 5 Diabetes?
Though rare, those with mitochondrial disease or unexplained diabetes symptoms are prone to develop Type 5 Diabetes.
This form of diabetes develops due to:
- Chronic undernutrition during early development (childhood or adolescence)
- Maternal malnutrition during pregnancy, affects fetal pancreatic development
- Impaired insulin production, due to reduced pancreatic beta cell function Unlike other types, it is not driven by autoimmunity or obesity. A genetic component may exist but is not the primary cause.
- What are the Blood Sugar Levels in Type 5 Diabetes?
- Type 5 Diabetes is defined more by insulin deficiency than specific blood sugar thresholds. However, patients may experience:
- Significantly elevated glucose levels, often over 200 mg/dL
"In severe cases, glucose can exceed 350 mg/dL. "That said, high blood sugar alone does not define this type—the lack of insulin and background of malnutrition are key," concludes Dr Reddy.
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