Discussion Paper – Understanding Diabetes Beyond the Labels
Introduction
Diabetes is often described as though it represents a single condition divided into numbered “types”. While most people recognise type 1 and type 2 diabetes, the underlying biology is considerably more complex.
At its most fundamental level, diabetes is defined by persistent elevations in blood glucose. This raises an important consideration: is diabetes itself a single disease, or a shared metabolic outcome arising from multiple biological pathways?
This question has gained renewed relevance following proposals to classify malnutrition-related diabetes as “Type 5 diabetes” within international classification discussions. This development highlights both the progress of scientific understanding and the limitations of current naming conventions, which can clarify in some contexts but confuse in others.
High Blood Glucose as a Shared Clinical Signal
Blood glucose is regulated by a complex and dynamic system involving:
- insulin production and beta-cell function
- tissue responsiveness to insulin
- counter-regulatory hormones and stress responses
- nutrition, growth, pregnancy, and ageing
- genetic, developmental, and early-life influences
When this system is disrupted, hyper– or dysglycaemia occurs.
Elevated glucose is therefore not a cause in itself, but a clinical signal indicating impairment somewhere within the glucose-regulation system. Different individuals may arrive at the same glycaemic outcome through very different pathways.
What We Mean by “Types” of Diabetes
Current “types” of diabetes are best understood as groupings based on dominant biological pathways, rather than discrete disease entities. They function as clinical shorthand — useful in practice, but not definitive.
Examples include:
- Autoimmune-mediated diabetes (commonly termed Type 1 diabetes)
Characterised by immune-driven beta-cell destruction and insulin deficiency. - Insulin resistance–dominant diabetes (commonly termed Type 2 diabetes)
Involves impaired insulin sensitivity, often combined with progressive beta-cell decline. - Gestational diabetes
Arises from pregnancy-related hormonal changes affecting glucose regulation. - Monogenic diabetes
Results from single-gene variants affecting insulin secretion or action and is frequently misclassified. - Secondary diabetes
Occurs due to other medical conditions, medications, or pancreatic injury. - Cystic fibrosis–related diabetes
Associated with progressive pancreatic damage in people with cystic fibrosis. - Malnutrition-related diabetes (proposed as “Type 5 diabetes”)
Linked to severe undernutrition affecting pancreatic development and insulin production. - Stress- or illness-related hyperglycaemia
Occurs during critical illness and may be transient.
Despite different mechanisms, the shared clinical manifestation is dysglycaemia in the absence of treatment.
Why Classification both Helps – and Hinders – Understanding
Classification plays an essential role in:
- guiding treatment decisions
- structuring research
- enabling surveillance and service planning
However, numbered types may unintentionally imply:
- that diabetes represents a single condition with tidy subcategories
- that labels reflect disease severity or progression
- that all people with the same label share the same biology or experience
For people and whānau living with diabetes, misalignment between label and lived reality can contribute to misunderstanding, stigma, and inequity in care.
Is Diabetes a Disease, a Category, or a Shared Concept?
If diabetes is defined by elevated glucose, it may be more accurate to conceptualise it as:
- a family of related conditions, or
- a shared glycaemic signal arising from different biological disruptions,
rather than a single disease divided into fixed types.
This reframing does not diminish the seriousness of diabetes. Instead, it improves clinical precision and strengthens person-centred care.
Why This Matters for Clinical Practice and Policy
Recognising diabetes as a set of heterogeneous pathways leading to dysglycaemia can:
- reduce stigma and moral attribution
- improve diagnostic accuracy and reduce misclassification
- support more tailored and cost-effective care
- recognise genetic, developmental, social, and environmental influences
- improve system design and resource allocation
A more informative clinical question becomes:
What mechanisms are contributing to dysglycaemia in this person, and what does their care require now?
Precision Medicine — From “Type” to Biological Drivers
As diabetes classification evolves, increasing attention is being given to precision medicine — approaches that match diagnosis and treatment to the specific biological mechanisms driving dysglycaemia in an individual.
Monogenic diabetes as a key example
Single-gene variants affecting insulin secretion or production are often misclassified as type 1 or type 2 diabetes. Correct diagnosis through genetic testing and specialist assessment can:
- support optimal therapy selection (including transition from insulin to oral agents where appropriate)
- clarify prognosis
- reduce unnecessary treatment burden
- enable cascade testing for family members
Beyond genetics
Precision medicine also considers:
- variation in immune-mediated beta-cell decline
- differences in insulin resistance and beta-cell reserve
- developmental impacts on pancreatic function
- comorbid conditions and medication effects
- social and environmental determinants influencing risk and treatment outcomes
This supports a shift from “Which type?” to “Which mechanisms are most relevant?”
Benefits — and responsibilities
Potential system-level benefits include:
- earlier and more accurate diagnosis
- more targeted, equitable, and cost-effective care
- improved patient experience and outcomes
- enhanced data quality for planning and research
However, precision medicine requires intentional policy design to avoid widening inequities. Key considerations include:
- equitable access to testing and specialist services
- culturally safe engagement and consent processes
- clear referral pathways and workforce capability
- privacy and data governance
- sustainable funding models
Without these safeguards, innovation risks benefitting only those already advantaged within the health system.
Reframing Diabetes for the Future
Positioning diabetes as a shared metabolic outcome with multiple pathways aligns with both scientific evidence and person-centred care.
Rather than replacing current classifications, this perspective enhances them by acknowledging complexity, variation across the life course, and the influence of wider determinants of health.
Language shapes understanding — and understanding shapes care.
By recognising that diabetes does not represent a single entity but multiple biological pathways leading to a shared signal, health systems can deliver care that is more precise, equitable, and responsive to people’s real-world experiences.
Published: December 2025
